Publications by authors named "Maria Jose Nunes Paiva"

Ethnopharmacological Relevance: Lippia lacunosa Mart. & Schauer is an endemic plant from the Serra do Espinhaço mountain range located on the Atlantic plateau, Brazil. It is known as "chá de pedestre" and "rosmaninho" in folk medicine.

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Frontotemporal dementia (FTD) is a neurodegenerative disorder characterized by progressive impairment in behavior, executive function, and language. The behavioral variant (bvFTD) is the most clinical common form and requires differential diagnosis with atypical Alzheimer's disease (AD) cases. This study aimed to investigate the plasma metabolite profile of patients with bvFTD compared to AD patients and cognitively healthy individuals using gas chromatography coupled to mass spectrometry (GCMS).

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In this work a hollow mesoporous structured molecularly imprinted polymer was synthetized and used as adsorbent in pipette-tip solid-phase extraction for the determination of lamivudine (3TC), zidovudine (AZT) and efavirenz (EFZ) from plasma of human immunodeficiency virus (HIV) infected patients by high-performance liquid chromatography (HPLC). All parameters that influence the recovery of the pipette tip based on hollow mesoporous molecularly imprinted polymer solid-phase extraction (PT-HM-MIP-SPE) method were systematically studied and discussed in detail. The adsorbent material was prepared using methacrylic acid and 4-vinylpyridine as functional monomers, ethylene glycol dimethacrylate as crosslinker, acetonitrile as solvent, 4,4'-azobis(4-cyanovaleric acid) as radical initiator, benzalkonium chloride as surfactant, 3TC, and AZT as templates.

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Aim: The increasing use of cocaine (COC) during breastfeeding has led to growing concern about exposure of infants. Therefore, to study this exposure, a new method to analyze COC and benzoylecgonine in breast milk was developed.

Methodology: A new extraction method was used for the first time to analyze COC and its major metabolite, benzoylecgonine, in breast milk using magnetic carbon nanotubes partially doped with nitrogen.

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Bile acids (BAs) are derived from cholesterol and produced in the liver. The most abundant bile acids in humans are usually conjugated with glycine and taurine and are divided into primary BAs such as cholic acid (CA) and chenodeoxycholic acid (CDCA) and secondary BAs like deoxycholic acid (DCA), lithocholic acid (LCA) and ursodeoxycholic acid (UDCA). The differences amongst individual bile acids (BAs) are significant in order to distinguish different pathological processes and exposure to chemical compounds.

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The analysis of amino acid levels is crucial for neuroscience studies because of the roles of these molecules as neurotransmitters and their influence on behavior. The present study describes the distribution and levels of 16 amino acids (alanine, asparagine, aspartic acid, cysteine, glycine, glutamic acid, isoleucine, leucine, lysine, methionine, phenylalanine, proline, sarcosine, serine, valine, and threonine) in brain tissues (prefrontal cortex, striatum, hippocampus and cerebellum) and the serum. Neurochemical analysis was performed on Wistar rats and C57BL/6 mice using an efficient method for extraction, a fast microwave-assisted derivatization and gas chromatography-mass spectrometry analysis.

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The determination of the concentrations of l-amino acids in cerebrospinal fluid (CSF) has been used to gain biochemical insight into central nervous system disorders. This paper describes a microwave-assisted derivatization (MAD) method using N,O-bis-(trimethylsilyl)trifluoroacetamide (BSTFA) as a derivatizing agent for determining the concentrations of l-amino acids in human CSF by gas chromatography with mass spectrometry (GC/MS). The experimental design used to optimize the conditions showed that the optimal derivatization time was 3min with a microwave power of 210W.

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