Therapeutic Drug Monitoring-Based Population Pharmacokinetics of Amikacin in Patients at a Teaching Hospital.

: Amikacin is still an essential antimicrobial to treat life-threatening infections, including multidrug-resistant microorganisms. The effectiveness of treatment has been correlated with the Cmax/MIC ratio, with a ratio of 8 being recommended, which is difficult to reach in some patients. Appropriate antibiotic exposure is important for knowing the disposition of the drug in the population.

Determination of testosterone by liquid Chromatography-Tandem mass spectrometry in dried plasma obtained from capillary blood using the HealthID PSD microsampling device.

Monitoring testosterone (T) levels is essential in various clinical contexts, but traditional venous sampling is invasive and limits access. This study describes the development and validation of a liquid chromatography-tandem mass spectrometry (LC-MS/MS) method to quantify T in dried plasma spot (DPS) samples obtained from capillary blood using the HealthID PSD microsampling device. A chloride-based correction of plasma volume in the DPS and a multiplication factor were applied to estimate venous plasma concentrations.

Quantification of amikacin, gentamicin, and tobramycin in capillary plasma microsamples by LC-MS/MS.

Aminoglycoside antibiotics, including amikacin (AMI), gentamicin (GEN), and tobramycin (TOB), are widely used to treat infections, necessitating plasma concentration monitoring to achieve therapeutic targets and optimize patient treatment. To minimize patient discomfort, less invasive blood collection methods are desirable. Capillary blood microsampling provides an alternative to conventional venous collection, enabling the extraction of small plasma volumes via distal puncture or self-lancing devices.

POU4F2 overexpression promotes the genesis of retinal ganglion cell-like projection neurons from late progenitors.

Retinal ganglion cells (RGCs) are the projection neurons of the retina, and their death promotes an irreversible blindness. Several factors were described to control their genesis during retinal development. These include Atoh7, a major orchestrator of the RGC program, and downstream targets of this transcription factor, including Pou4f factors, that in turn regulate key aspects of terminal differentiation.

Early ultrastructural damage in retina and optic nerve following intraocular pressure elevation.

Elevated intraocular pressure (IOP) is a significant risk factor for glaucoma, causing structural and functional damage to the eye. Increased IOP compromises the metabolic and structural integrity of retinal ganglion cell (RGC) axons, leading to progressive degeneration and influencing the ocular immune response. This study investigated early cellular and molecular changes in the retina and optic nerve (ON) following ocular hypertension (OHT).

Amikacin therapeutic drug monitoring: Evaluation of therapy performance and analytical techniques in a developing country setting.

Introduction: Healthcare systems face several challenges, with microbial infections being one of the main concerns. Therapeutic drug monitoring (TDM) is a strategy that has been encouraged to optimize antimicrobial regimens, particularly those with significant toxicity and narrow therapeutic indices, such as amikacin (AMK). We aimed to evaluate AMK concentrations of patients in a non-routine TDM setting and compare the performance of immunoassay and chromatography methods for routine clinical use.

Determination of drugs of abuse and metabolites in plasma microsamples by LC-MS/MS after microQuEChERS extraction.

Identifying drugs of abuse and their metabolites in plasma is vital in both forensic and clinical toxicology. While the QuEChERS (Quick, Easy, Cheap, Effective, Rugged and Safe) method offers an efficient approach to sample preparation, its application is complex due to the wide-ranging properties of target analytes and the challenges posed by biological matrix interferences. This study aims to develop a microQuEChERS approach for the quantification of 14 drugs of abuse and metabolites utilizing minimal sample and solvent volumes.

Comparison of vancomycin assays in patients undergoing hemodialysis.

Vancomycin is a glycopeptide antibiotic mainly excreted by glomerular filtration. Therefore, patients undergoing hemodialysis tend to accumulate its crystalline degradation product, which has been associated with cross-reaction in commercial immunoassays. The aim of this study was to assess the performance of two commercial immunoassays for measuring vancomycin levels in patients undergoing hemodialysis.

GC-NPD analysis of topiramate in capillary dried plasma: assessing chemical dependency pharmacotherapy.

This study aimed to develop and validate a GC-NPD method for quantifying topiramate (TPM) in capillary dried plasma spots (DPS). Extraction involved three 6 mm DPS with albumin 0.1%, alkaline liquid extraction with tert-Butyl methyl ether and TMAH methylation.

Longitudinal evaluation of morphological, functional and vascular alterations in a rat model of experimental glaucoma.

Glaucoma, the leading cause of irreversible blindness worldwide, is a neurodegenerative disease characterized by chronic axonal damages and progressive loss of retinal ganglion cells, with increased intraocular pressure (IOP) as the primary risk factor. While current treatments focus solely on reducing IOP, understanding glaucoma through experimental models is essential for developing new therapeutic strategies and biomarkers for early diagnosis. Our research group developed an ocular hypertension rat model based on limbal plexus cautery, which provides significant glaucomatous neurodegeneration up to four weeks after injury.

Evaluation of harmful drinking among professional drivers by direct ethanol biomarkers and its relation with psychological distress.

Objective: This study aimed to evaluate the alcohol consumption among professional truck and bus drivers using direct ethanol biomarkers, and to explore its relationship with anxiety, depression, and stress.

Methods: The assessment of potential harmful drinking was conducted through the measurement of direct biomarkers: phosphatidylethanol (PEth), ethyl glucuronide (EtG), and ethyl sulfate (EtS), using dried blood spots (DBS). Additionally, self-reported data from the Alcohol Use Disorders Identification Test (AUDIT-C) were used.

Determination of meropenem in capillary plasma microsamples using LC-MS/MS.

The measurement of meropenem plasma concentrations is employed for dosing regimen individualization. The aim of this study was to develop and validate a LC-MS/MS assay for quantification of meropenem in capillary plasma microsamples. Samples were prepared by protein precipitation with acetonitrile, followed by clean-up with dichloromethane.

Determination of carbamazepine in fingerprints: a feasibility study to evaluate adherence in epilepsy patients.

Fingerprint drug concentrations can be used as a noninvasive and convenient alternative to evaluate adherence to pharmacotherapy. Fingerprints were applied over glass slides, extracted and analyzed by ultra-high performance LC-MS/MS. The assay and drug adherence questionnaires were applied to 30 epilepsy patients.

as a suitable model to evaluate the toxicity of water from Rolante River, southern Brazil.

Urbanization and agricultural activities increased environmental contaminants. Integrated analysis of water parameters and bioassays represents an essential approach to evaluating aquatic resource quality. This study aimed to assess water quality by microbiological and physicochemical parameters as well as the toxicological effects of water samples on the Ames test and model.

rAAV-compatible human mini promoters enhance transgene expression in rat retinal ganglion cells.

Recombinant adeno-associated viral vectors (rAAV) are the safest and most effective gene delivery platform to drive the treatment of many inherited eye disorders in well-characterized animal models. The use in rAAV of ubiquitous promoters derived from viral sequences such as CMV/CBA (chicken β-actin promoter with cytomegalovirus enhancer) can lead to unwanted side effects such as pro-inflammatory immune responses and retinal cytotoxicity, thus reducing therapy efficacy. Thus, an advance in gene therapy is the availability of small promoters, that potentiate and direct gene expression to the cell type of interest, with higher safety and efficacy.

Risk assessment of a Brazilian urban population due to the exposure to pyrethroid insecticides during the COVID-19 pandemic using wastewater-based epidemiology.

Pyrethroids are synthetic insecticides commonly used in agriculture and homes due to their low toxicity to mammals and effectiveness at low doses. However, exposure to pyrethroids can cause various symptoms, depending on the route of exposure. To measure human exposure to pyrethroids, researchers used wastewater-based epidemiology (WBE) with polar organic chemical integrative samplers (POCIS) sampling.

Evaluation of dried blood spots as an alternative sampling strategy for 5-fluorouracil monitoring: From method development to clinical application.

Therapeutic drug monitoring (TDM) of 5-Fluorouracil (5-FU) is strongly recommended because of its large inter-individual pharmacokinetic variability, narrow therapeutic window, and incidence of toxicity. However, there are several factors that limit the application of TDM in clinical settings. Considering the intrinsic advantages of dried microsamples, such as minimally invasive sampling, analyte stability, and cost-effective logistics, this study aimed to develop a method for the determination of 5-FU in dried blood spots (DBS) using ultra-high liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) and to evaluate its clinical application.

Determination of amphetamines, opioids, cocaine metabolites and 11-nor-9-carboxy-Δ9-tetrahydrocannabinol in urine using biocompatible solid-phase microextraction and ultra-performance LC-MS/MS.

Workplace drug testing primarily relies on urine analysis, targeting multiple compounds with varying physicochemical characteristics. Biocompatible solid-phase microextraction (BioSPME) is a miniaturized solid-phase extraction technique that enables the simultaneous extraction and preconcentration of analytes directly from the biological matrix. The BioSPME procedure consisted of the sequential extraction of 50-μl urine samples using LC Tips C18 in basic and acidic pH, followed by desorption with methanol and -hexane, respectively.

Evaluation of the HealthID PSD microsampling device for the simultaneous determination of cholesterol, high-density lipoprotein, triglycerides, creatinine, and HbAc in capillary blood.

Introduction: The use of dried capillary microsamples for clinical chemistry testing is an interesting alternative to conventional phlebotomy. Sampling devices capable to produce plasma from whole blood application are particularly useful. The aim of this study was to validate theHealthID PSDmicrosampling device for the determination of cholesterol (CHOL), high-density lipoprotein (HDL), triglycerides (TRIG), creatinine (CRE), and glycated hemoglobin (HbAc) after collection of capillary blood.

Dried blood spot sampling for therapeutic drug monitoring: challenges and opportunities.

Introduction: The use of dried blood spots (DBS) has gained interest in the field of therapeutic drug monitoring (TDM) due to its potential advantages, such as minimally invasive capillary blood collection, potential stabilization of drugs and metabolites at room or high temperatures, and lower biohazard, allowing for inexpensive storage and transportation. However, there are several drawbacks to the clinical use of DBS in TDM, mostly related to hematocrit (Hct) effects, differences between venous and capillary blood concentrations, among others, that must be evaluated during analytical and clinical method validation.

Area Covered: This review focuses on the most recent publications on the applications of DBS sampling for TDM (2016-2022), with a special focus on the challenges presented by this alternative sampling strategy, as well as the opportunities for clinical applications.