Determination of opiates in whole blood using microextraction by packed sorbent and gas chromatography-tandem mass spectrometry.

In Portugal, and worldwide, the abuse of psychoactive substances is increasing, with a significant incidence of deaths related to their consumption. Opiates are one of the most prevalent group of substances in that context, and they are responsible for a significant impact of the mentioned harms. Therefore, it becomes necessary to equip labs with faster and effective methods to identify and quantify these substances. This work describes the development and validation of a novel analytical method for the simultaneous determination of morphine, codeine and 6-monoacetylmorphine in blood samples by gas chromatography-tandem mass spectrometry (GC-MS/MS), using microextraction by packed sorbent (MEPS) for sample preparation. Before the MEPS procedure, a precipitation step with acetonitrile was performed. The MEPS parameters were optimized using the fractional factorial planning (2k-1) and surface response methodology. The final optimized conditions were: number of strokes (20), amount of formic acid in the washing solution (3.36%), number of washes of the sorbent (1), amount of ammonium hydroxide in the elution solution (2.36%) and number of elution cycles (11). After the extraction procedure, the analytes were derivatized with MSTFA with 5% TMS. Using a sample volume of 250 µL, the method was validated according to internationally accepted standards. The method proved to be linear in the range of 5-1000 ng/mL with coefficients of determination greater than 0.99 for all analytes. Intra-and inter-day precision and accuracy were in accordance with the above-mentioned criteria, presenting coefficients of variation ≤15% and relative errors within a range of ± 15% of the theoretical concentration. The absolute recoveries ranged from 6 to 23%. The validated method was applied to the analysis of real samples, being an advantageous tool for the detection of those substances in blood. This is the first time that GCMS/MS with MEPS was used for the determination of these compounds in biological fluids.

Determination of methadone and EDDP in oral fluid using the dried saliva spots sampling approach and gas chromatography-tandem mass spectrometry.

The present work describes the development and validation of a novel approach to determine methadone (MTD) and its main metabolite (EDDP) in oral fluid samples, using the dried saliva spots (DSS) sampling approach and gas chromatography-tandem mass spectrometry (GC-MS/MS). Oral fluid samples (50 µL) were applied into Whatman™ 903 protein saver filter paper cards and were allowed to dry overnight. The extraction was carried out by immersion of the spot in 1 mL of isopropyl alcohol with agitation for 1 min. Afterwards, the extract was centrifuged for 15 min at 3500 rpm and the supernatant evaporated to dryness and reconstituted with 50 µL of methanol. The procedure was considered linear in the range of 10 to 250 ng/mL for both compounds, with determination coefficients greater than 0.99. Intra- and inter-day precision and accuracy revealed coefficients of variation (CVs) lower than 15% at the studied concentrations, with mean relative errors within ± 15% of the nominal concentrations. Recoveries ranged from 45 to 74%. The limits of detection and quantification were 5 and 10 ng/mL respectively for both analytes. All studied parameters complied with the defined criteria and the method enabled the successful determination of MTD and EDDP in oral fluid samples from patients undergoing opiate substitution/maintenance therapy.

Hemiballistic movements in a newly HIV patient.

Infections of central nervous system (CNS) include a broad group of conditions and pose a particular challenge to physicians, especially in immunocompromised individuals. This case refers to a 26-year-old male patient with a history of smoked hashish and drug abuse admitted to the infectious disease department with hemiballismus of left hemibody and a positive HIV serologic test. A magnetic resonance imaging (MRI) study showed lesions at lower left and right cerebellar hemisphere, one of them thalamus - mesencephalic suggesting an opportunistic infection or an HIV associated encephalopathy. Lumbar puncture, brain biopsy and successive neuroimaging were not conclusive for one disease and despite the use of directed therapy for cerebral toxoplasmosis, meningeal tuberculosis, anti-retrovirals and sedative medication, after over 6 weeks of hospitalization pallidotomy was performed. After 5 months of oral and surgical treatment the patient showed clinical, immunological and radiological recovery.

Changes in serum RANKL and OPG with sexual development and their associations with bone turnover and bone mineral density in a cohort of girls.

OBJECTIVES: To characterize the variations of serum osteoprotegerin (OPG) and RANK ligand (RANKL) with sexual development in adolescent girls, and to estimate their associations with bone turnover and bone mineral density (BMD). DESIGN AND METHODS: We studied 300 girls evaluated at 13 and 17years of age. Fasting blood samples were collected and the following substances were quantified: RANKL, OPG, C-terminal telopeptide of type I collagen (CTX), and procollagen type I N propeptide (PINP). BMD was measured at the distal forearm. Correlation coefficients were used to quantify associations between those variables at 13 and 17 years of age. Random-effects linear models were used to quantify associations between bone parameters and sexual development (years from menarche). RESULTS: RANKL was positively correlated with bone resorption (CTX) in early and late adolescence (r13=0.15 and r17=0.23) and the OPG/RANKL ratio correlated inversely with CTX at 17 (r17=-0.24). No significant associations were found between RANKL and OPG and bone formation (PINP). In early adolescence, there was an inverse correlation of BMD with CTX (r13=-0.52) but no significant correlations were found between osteoclast regulators and BMD. We observed a linear decrease in serum RANKL with increasing sexual development (-0.09 pmol/L per year, 95% CI: -0.10, -0.07) alongside an increase in OPG (0.02pmol/L, 95% CI: 0.01, 0.04). CONCLUSIONS: Serum RANKL and OPG levels varied markedly with sexual development in adolescence. These cytokines were not predictive of bone turnover or BMD at 13, but serum RANKL bioactivity was associated with bone resorption in late adolescence.

Fructooligosaccharide production by Penicillium expansum.

Fructooligosaccharides (FOS) production by Penicillium expansum was evaluated. In a first stage, the best conditions for P. expansum growth and sporulation were established with potato/dextrose/agar being the most suitable medium at between 22 and 25 degrees C, giving good growth and good sporulation. The inocula from this medium were used for FOS production using shake-flask cultures, and yielded 0.58 g FOS/g sucrose (3.25 g FOS/l.h), demonstrating the potential of this strain for sucrose conversion to FOS.