Development and Validation of a GC-MS-EI Method to Determine α-PHP in Blood: Application to Samples Collected during Medico-Legal Autopsies.

New psychoactive substances (NPSs) still represent an issue of great concern worldwide despite efforts made by national and international control systems to limit the spread of these substances. Alpha-pyrrolidinohexanophenone (α-PHP) is a fairly recent synthetic cathinone (the second largest group of monitored substances in Europe) with only a few published studies on the substance. Though there is a low incidence of NPS consumption in Portugal, a recent increase in apprehensions and detections in biological matrices of the substance was verified. An analytical methodology was developed and validated for determining and quantitating α-PHP in blood. Solid-phase extraction was employed for sample preparation (500 µL), which was further analyzed by gas chromatography--mass spectrometry-electron ionization in single-ion monitoring mode with cocaine-d3 as the internal standard. Method validation followed the guidelines of the American National Standards Institute/AAFS Standards Board (ANSI/ASB Standard 036). The procedure was linear between 10 and 1,000 ng/mL, with determination coefficients (r2) higher than 0.999. Carryover was not observed. A limit of detection of 5 ng/mL and a limit of quantitation of 10 ng/mL were achieved. Intraday and intermediate precision and bias assessment showed satisfactory results (coefficient of variation <17.7%; bias <11.6%), and extraction efficiency ranged from 98.5% to 103.3%. The stability of the substance was considered acceptable for at least 6 h at room temperature, 48 h in the autosampler and 21 days after five freeze/thaw cycles. The developed methodology was applied to 15 real samples from the Laboratory of Chemistry and Forensic Toxicology, Centre Branch of the National Institute of Legal Medicine and Forensic Sciences, Portugal, with drug concentrations ranging from 15 to 227 ng/mL. Available information for each case is also detailed in the present article.

Double-Layer Flexible Neural Probe With Closely Spaced Electrodes for High-Density in vivo Brain Recordings.

Flexible polymer neural probes are an attractive emerging approach for invasive brain recordings, given that they can minimize the risks of brain damage or glial scaring. However, densely packed electrode sites, which can facilitate neuronal data analysis, are not widely available in flexible probes. Here, we present a new flexible polyimide neural probe, based on standard and low-cost lithography processes, which has 32 closely spaced 10 µm diameter gold electrode sites at two different depths from the probe surface arranged in a matrix, with inter-site distances of only 5 µm. The double-layer design and fabrication approach implemented also provides additional stiffening just sufficient to prevent probe buckling during brain insertion. This approach avoids typical laborious augmentation strategies used to increase flexible probes' mechanical rigidity while allowing a small brain insertion footprint. Chemical composition analysis and metrology of structural, mechanical, and electrical properties demonstrated the viability of this fabrication approach. Finally, in vivo functional assessment tests in the mouse cortex were performed as well as histological assessment of the insertion footprint, validating the biological applicability of this flexible neural probe for acquiring high quality neuronal recordings with high signal to noise ratio (SNR) and reduced acute trauma.

A versatile and modular tetrode-based device for single-unit recordings in rodent ex vivo and in vivo acute preparations.

BACKGROUND: The demand for affordable tools for recording extracellular activity and successfully isolating single units from different brain preparations has pushed researchers and companies to invest in developing and fabricating new recording devices. However, depending on the brain region of interest, experimental question or type of preparation, different devices are required thus adding substantial financial burden to laboratories. NEW METHOD: We have developed a simple and affordable tetrode-based device that allows interchangeable extracellular recordings of neuronal activity between in vivo and ex vivo preparations and can be easily implemented in all wet-bench laboratories. RESULTS: Spontaneous activity from several putative single neurons could be easily recorded and isolated by lowering the device into ex vivo cerebellum brain slices. The same device was also used in vivo, lowered into primary auditory cortex of adult anesthetized transgenic mice expressing channelrhodopsin in cortical neurons. Acoustic stimulation of the contralateral ear or direct laser optogenetic stimulation successfully evoked cortical activity at the recording site. Several isolated putative single neurons presented time-locked activity response to the different stimuli. COMPARISON WITH EXISTING METHODS: Besides low fabrication cost, our device uses an omnetics connector compatible with the majority of headstages already available at most electrophysiology laboratories. The device allows custom tetrode configuration arrays and extensions for optogenetics and pharmacology, providing experimental flexibility not available in commercial off-the-shelf microelectrode arrays and silicon probes. CONCLUSIONS: We developed an affordable, versatile and modular device to facilitate tetrode extracellular recordings interchangeably between in vivo anaesthetized animals and ex vivo brain slice recordings.

Bioactive Compounds from the Aerial Parts of Evolvulus linarioides.

Three new caryophyllane-type sesquiterpenoids, linariophyllenes A-C (1-3), two new hamamelitol derivatives, linaritols A (4) and B (5), two new chromones, linariosides A (6) and B (7), and three known chromones, cnidimol C (8), monnieriside A (9), and undulatoside A (10), were identified from the aerial parts of Evolvulus linarioides. The structures of these compounds were elucidated by NMR, MS, and IR data. The absolute configurations of compounds 1-5 and 7 were established via electronic circular dichroism data. The anti-inflammatory potential of compounds 1-5 and 7-10 was evaluated by determining their ability to inhibit the production of nitric oxide (NO) and proinflammatory cytokine IL-1ß by stimulated J774 macrophages. Compounds tested at noncytotoxic concentrations inhibited NO production by macrophages, exhibiting IC50 values between 17.8 and 66.2 µM, and inhibited IL-1ß production by stimulated macrophages by 72.7-96.2%.

Influência da sazonalidade na determinação da densidade mineral óssea / Influence of season in the bone mineral densitometry

OBJETIVO: Em locais onde a exposição aos raios do sol durante o inverno é limitada, a densidade mineral óssea (DMO) pode apresentar variações sazonais, elevando-se durante o período do verão e diminuindo durante o inverno. Tem sido sugerido que esta variação pode influenciar a avaliação prospectiva de estudos de DMO. O objetivo deste estudo foi avaliar se a estação do ano está associada a variações nos valores de DMO. MÉTODOS: Estudo transversal, de base clínica, desenvolvido no estado do Rio Grande do Sul (RS). Estudos densitométricos representativos dos períodos do verão/inverno foram selecionados para análise. As densitometrias foram realizadas em aparelho Hologic 4500 através da técnica dual energy X-ray absorptiometry. RESULTADOS/CONCLUSÕES: De 853 exames densitométricos realizados durante um período de 12 meses, 201 foram realizados no verão e 321 no inverno. Os valores de DMO, corrigidos para o peso corporal, não diferiram significamente entre o grupo de indivíduos que realizou o exame no verão ou no inverno (P>0,05). Em conclusão, no RS a estação do ano não afeta os resultados da DMO e não precisa ser levada em conta quando da interpretação dos estudos densitométricos. Este achado, provavelmente, pode ser extrapolado para as demais regiões do Brasil, uma vez que o inverno nestas regiões é menos severo que no RS.

Sesquiterpenes and a phenylpropanoid from Cordia trichotoma.

Two new secondary metabolites, the phenylpropanoid 3-(2',4',5'-trimethoxyphenyl)propanoic acid (1) and the sesquiterpene (+)-1beta,4beta,6alpha-trihydroxyeudesmane (2) were isolated from the heartwood of Cordia trichotoma Vell., along with the known sesquiterpenes (-)-1beta,4beta,7alpha-trihydroxyeudesmane (3) and (+)-1beta,4beta,11-trihydroxyoppositane (4). Their structures were elucidated by means of spectroscopic data interpretation, mainly 1D and 2D NMR and mass spectrometry.

[Influence of season on bone mineral densitometry]. / Influência da sazonalidade na determinação da densidade mineral óssea.

OBJECTIVE: In places where sun exposure during the winter is limited, bone mineral density (BMD) may present seasonal variations, increasing during the summer and decreasing during the winter period. There have been suggestions that this variation could influence prospective evaluations of BMD studies. The aim of this study was to evaluate if the seasons of the year (summer/winter) are associated to variations in BMD values. METHODS: Clinic based cross-sectional study, conducted in the state of Rio Grande do Sul (RS). Densitometric studies representative of the periods of winter/summer were selected. The densitometric studies were realized in a Hologic 4500 unit, using dual energy X-ray absorptiometry. RESULTS/CONCLUSIONS: Of 853 densitometric measurements realized during a 12-month period, 201 were realized in the summer, and 321 in the winter. The BMD measurements, corrected to body weight, did not differ between the group of individuals that were tested in the summer or winter (P>0.05). In conclusion, in RS, the season of the year did not affect the BMD results, and does not need to be taken into account when analyzing densitometry measurements. This finding probably could be extrapolated to other regions of Brazil, since winter in those areas is less severe than in RS.

Avaliação do diagnóstico densitométrico de osteoporose/osteopenia conforme o sítio ósseo / Evaluation of densitometric diagnosis of osteoporosis/osteopenia according to the bone region

O objetivo deste estudo foi avaliar a freqüência de osteoporose de acordo com os sítios ósseos avaliados, utilizando um estudo transversal de base clínica. Foram avaliados 610 exames densitométricos em relação a freqüência de osteoporose/osteopenia e concordância do diagnóstico de acordo com o local avaliado. Apesar de alta correlação da DMO entre os sítios ósseos, a freqüência de osteoporose variou de acordo com o sítio avaliado. Osteoporose esteve presente em 14 e 18 por cento dos pacientes, quando considerado o colo do fêmur e fêmur total, e 42 e 30 por cento quando considerados o triângulo do Ward e coluna (p< 0,05). Um quarto das mulheres consideradas em risco aumentado de fratura pelo exame da coluna lombar foi classificado como normal pelo estudo do colo do fêmur; 16 por cento com risco aumentado pelo estudo do colo do fêmur foi classificado como normal no estudo da coluna. Este estudo demonstra que existe discordância nos resultados densitométricos de acordo com a área estudada, afetando a ocorrência de osteoporose. Para julgamento clínico de risco de fratura, a avaliação combinada de dois sítios ósseos é o procedimento mais adequado.