Margarida Coelho

University of Coimbra | UC · Center for Neurosciences and Cell Biology

Water enriched with oxygen‐18 (H2¹⁸O) is a potential tracer for evaluating the sources of glucose and glycogen synthesis since it is incorporated into specific sites of glucose‐6‐phosphate via specific enzyme‐mediated exchange/addition mechanisms. Unlike ²H, ¹⁸O does not experience significant isotope effects for any of these processes. Therefore,...

Thyroid cancer is the most common endocrine system malignancy. However, there is still a lack of reliable and specific markers for the detection and staging of this disease. Fine needle aspiration biopsy is the current gold standard for diagnosis of thyroid cancer, but drawbacks to this technique include indeterminate results or an inability to dis...

Cerebrospinal fluid (CSF) has been considered the key source for the search of biomarkers, in particular for neurological diseases, such as Alzheimer’s and Parkinson’s disease, since it reflects the state of the central nervous system (CNS). Finding biomarkers in the earliest stages of neurodegenerative diseases has become imperative, since, at the...

Caffeine is one of the most widely consumed psycho-stimulants. The study of the beneficial effects of caffeine consumption to decrease the risk of developing several neuropsychiatric pathologies is receiving increasing attention. Thus, accurate and sensitive methods have been developed, mainly by LC-MS/MS, in order to quantify caffeine and its meta...

A liquid chromatography tandem mass spectrometry (LC-MS/MS) using multiple reaction monitoring (MRM) in a triple-quadrupole scan mode was developed and comprehensively validated for the determination of [6,6-(2)H2]glucose and [U-(13)C6]glucose enrichments from dried blood spots (DBS) without prior derivatization. The method is demonstrated with dri...

Mice deficient in adipose triglyceride lipase (ATGL(-/-)) present elevated ectopic lipid levels but are paradoxically glucose-tolerant. Measurement of endogenous glucose production (EGP) and Cori cycle activity provide insights into the maintenance of glycemic control in these animals. These parameters were determined in 7 wild-type (ATGL(+/-)) and...

PurposeEnrichment of glucose position 5 (H5) from deuterated water (2H2O) is widely used for quantifying gluconeogenesis. Exchanges of hexose and triose phosphates mediated by transaldolase have been postulated to enrich H5 independently of gluconeogenesis, but to date this mechanism has not been proven. We determined the enrichment of glucose-6-ph...

A simple method for quantification of citalopram in mice plasma and hair was developed and validated using liquid chromatography tandem mass spectrometry (LC–MS/MS). The procedure involves a protein precipitation extraction of citalopram and desipramine (internal standard) with methanol from mice plasma. On the other hand, hair samples were incubat...