Determination of relative bioavailability of oral L-carnitine through the use of deuterated L-carnitine

Orientador: Gilberto de NucciDissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Ciências MédicasResumo: A L- carnitina é uma molécula polar essencial para o transporte e posterior oxidação, principalmente de ácidos graxos de cadeia média e longa no interior das mitocôndrias. Devido ao fato dessa molécula ser produzida endogenamente por mamíferos, é necessário o desenvolvimento de um método robusto para a diferenciação da L-carnitina endogenamente produzida daquela administrada exogenamente. Esse estudo piloto, unicêntrico, aberto com 4 períodos, procura avaliar se a deuteração da molécula de L-carnitina, com a posterior utilização de HPLC/MS/MS, é um método adequado para realizar tal diferenciação. Para tal, foram utilizadas três cápsulas, cujo conteúdo total era de 500 mg de L-carnitina, sendo a concentração de L-carnitina deuterada presente nas mesmas de 10, 30 e 100mg, respectivamente. As diferentes formulações foram administradas para seis voluntários, sendo três do sexo masculino e três do sexo feminino, em 4 períodos diferentes, com um intervalo de washout de sete dias entre os períodos. Os pacientes do estudo obedeceram a todos os critérios de inclusão e exclusão, sem nenhuma desistência ou exclusão durante o estudo. Foram colhidas amostras de sangue e dosadas as concentrações plasmáticas de L-carnitina deuterada através do método de HLPC/MS/MS, além disso foram calculados os parâmetros farmacocinéticos pertinentes para um estudo de biodisponibilidade relativa e estabelecidos gráficos de concentração versus tempo para cada indivíduo. O método se mostrou robusto e eficaz, sendo obtido tempo de corrida cromatográfico de 3.2 min, curva de calibração de 10-1000ng/ml e o limite inferior de quantificação de 10 ng/ml. Os parâmetros farmacocinéticos médios obtidos a partir das concentrações de 10, 30 e 100mg de L- carnitina deuterada nos 3 períodos foram: AUCúltimo (72.16, 613.18 e 2450.29 ng*h/ml); Cmax (19.25, 75.59 e 216.79 ng/ml) ; Tmax (3.5, 4,0 e 4,17 h). O coeficiente de variabilidade para a taxa e extensão da absorção foram, respectivamente, 55,37% e 65,10%, levando em consideração o terceiro e quarto período do estudo. Além disso, foi demonstrada através da Correlacão Pearson, linearidade entre os parâmetros farmacocinéticos nas doses estudadas. Não foram observados quaisquer eventos adversos graves durante o estudo. Portanto, pode-se concluir que a cromatografia líquida de alta performance acoplada ao espectrômetro de massa é um método robusto e eficaz que permite diferenciar a L-carnitina exogenamente administrada (deuterada) da L-carnitina endogenamente produzida, sendo que a L-carnitina deuterada (assim como a L-carnitina) apresenta grande coeficiente de variabilidade, farmacocinética linear e é segura nas doses administradasAbstract: L- carnitine is a polar molecule, essential for the transport and subsequent oxidation of long and medium-chain fatty acids inside the mitochondria. Due to the fact that this molecule is produced endogenously by mammals, it is necessary to develop a robust method for the differentiation of endogenously produced L-carnitine from that administered exogenously. This pilot, unicentric, 4-period study seeks to evaluate whether the deuteration of the L-carnitine molecule, with the subsequent use of HPLC/MS/MS, is an appropriate method to perform such differentiation. For this purpose, were used three capsules with total content of 500mg of L-Carnitine. The concentration of deuterated L-carnitine in each capsule was:10, 30 and 100mg respectively. The different formulations were administered to six volunteers, three male and three females, in 4 different periods, with a washout interval of seven days between periods. The volunteers in the study met all inclusion and exclusion criteria, without any dropout or exclusion during the study. Blood samples were taken and plasma concentrations of L-carnitine deuterated were measured using the HLPC/MS/MS method. The method proved to be robust and effective, with chromatographic running time of 3.2 min and calibration curve of 10-1000ng/ml. The limit of quantification was 10 ng/ml. The mean pharmacokinetic parameters obtained from the concentrations of deuterated L- carnitine (10,30 and 100mg) were AUClast: (72.16, 613.18 and 2450.29 ng*h/ml); Cmax (19.25, 75.59 and 216.79 ng/ml) and Tmax (3.5, 4.0 and 4.17 h). The coefficient of variability for the rate and extent of absorption were, respectively, 55.37% and 65.10% taking into account the third and fourth period of the study. In addition, Linearity was demonstrated between the pharmacokinetic parameters at the studied doses by Pearson Correlation. No serious adverse events were observed during the study. Thus, it can be concluded that high performance liquid chromatography coupled to the mass spectrometer is a robust and efficient method that allows to differentiate exogenously administered L-carnitine (deuterated) from endogenously produced L-carnitine. Deuterated L-carnitine (as well as L-carnitine) presents a great coefficient of variability and shows linear pharmacokinetics. The deuterated L-carnitine was safe at the administered dosesMestradoFarmacologiaMestre em Farmacologia134339/2017-7CNPq

Radiopurity control in the NEXT-100 double beta decay experiment: procedures and initial measurements

We have investigated the possibility of calibrating the PMTs of scintillation detectors, using the primary scintillation produced by X-rays to induce single photoelectron response of the PMT. The high-energy tail of this response, can be approximated to an exponential function, under some conditions. In these cases, it is possible to determine the average gain for each PMT biasing voltage from the inverse of the exponent of the exponential fit to the tail, which can be done even if the background and/or noise cover-up most of the distribution. We have compared our results with those obtained by the commonly used single electron response (SER) method, which uses a LED to induce a single photoelectron response of the PMT and determines the peak position of such response, relative to the pedestal peak (the electronic noise peak, which corresponds to 0 photoelectrons). The results of the exponential fit method agree with those obtained by the SER method when the average number of photoelectrons reaching the first dynode per light/scintillation pulse is around 1.0. The SER method has higher precision, while the exponential fit method has the advantage of being useful in situations where the PMT is already in situ, being difficult or even impossible to apply the SER method, e.g. in sealed scintillator/PMT devices

Accurate gamma and MeV-electron track reconstruction with an ultra-low diffusion Xenon/TMA TPC at 10 atm

We report the performance of a 10 atm Xenon/trimethylamine time projection chamber (TPC) for the detection of X-rays (30 keV) and gamma-rays (0.511-1.275 MeV) in conjunction with the accurate tracking of the associated electrons. When operated at such a high pressure and in similar to 1%-admixtures, trimethylamine (TMA) endows Xenon with an extremely low electron diffusion (1.3 +/- 0.13 mm-sigma (longitudinal), 0.95 +/- 0.20 mm-sigma (transverse) along 1 m drift) besides forming a convenient Penning-Fluorescent' mixture. The TPC, that houses 1.1 kg of gas in its fiducial volume, operated continuously for 100 live-days in charge amplification mode. The readout was performed through the recently introduced microbulk Micromegas technology and the AFTER chip, providing a 3D voxelization of 8 mm x 8 mm x 1.2 mm for approximately 10 cm/MeV-long electron tracks. Resolution in energy (epsilon) at full width half maximum (R) inside the fiducial volume ranged from R = 14.6% (30 keV) to R = 4.6% (1.275 MeV). This work was developed as part of the R&D program of the NEXT collaboration for future detector upgrades in the search of the neutrino-less double beta decay (beta beta 0 nu) in Xe-136, specifically those based on novel gas mixtures. Therefore we ultimately focus on the calorimetric and topological properties of the reconstructed MeV-electron tracks. In particular, the obtained energy resolution has been decomposed in its various contributions and improvements towards achieving the R =1.4%root MeV/epsilon levels obtained in small sensors are discussedThe NEXT collaboration acknowledges funding support from the following agencies and institutions: European Research Council under Advanced Grant 339787-NEXT and Starting Grant 240054-TREX, Spanish Ministerio de Economia y Competitividad under grants Consolider-Ingenio 2010 CSD2008-0037 (CUP) and CSD2007-00042 (CPAN), contracts FPA2008-03456 and FPA2009-13697; Portuguese Fundacao para a Ciencia e a Tecnologia; European FEDER under grant PPTDC/FIS/103860/2008; US Department Of Energy under contract DE-AC02-05CH11231.Gonzalez Diaz, D.; Álvarez Puerta, V.; Borges, FIG.; Camargo, M.; Carcel, S.; Cebrian, S.; Cervera, A.... (2015). Accurate gamma and MeV-electron track reconstruction with an ultra-low diffusion Xenon/TMA TPC at 10 atm. Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment. 804:8-24. https://doi.org/10.1016/j.nima.2015.08.033S82480

Clinical indications for image-guided interventional procedures in the musculoskeletal system: a Delphi-based consensus paper from the European Society of Musculoskeletal Radiology (ESSR)-part VII, nerves of the lower limb.

Funder: Università degli Studi di MilanoOBJECTIVES: To perform a Delphi-based consensus on published evidence on image-guided interventional procedures for peripheral nerves of the lower limb (excluding Morton's neuroma) and provide clinical indications. METHODS: We report the results of a Delphi-based consensus of 53 experts from the European Society of Musculoskeletal Radiology who reviewed the published literature for evidence on image-guided interventional procedures offered around peripheral nerves in the lower limb (excluding Morton's neuroma) to derive their clinical indications. Experts drafted a list of statements and graded them according to the Oxford Centre for evidence-based medicine levels of evidence. Consensus was considered strong when > 95% of experts agreed with the statement or broad when > 80% but < 95% agreed. The results of the Delphi-based consensus were used to write the paper. RESULTS: Nine statements on image-guided interventional procedures for peripheral nerves of the lower limb have been drafted. All of them received strong consensus. Image-guided pudendal nerve block is safe, effective, and well tolerated with few complications. US-guided perisciatic injection of anesthetic provides good symptom relief in patients with piriformis syndrome; however, the addition of corticosteroids to local anesthetics still has an unclear role. US-guided lateral femoral cutaneous nerve block can be used to provide effective post-operative regional analgesia. CONCLUSION: Despite the promising results reported by published papers on image-guided interventional procedures for peripheral nerves of the lower limb, there is still a lack of evidence on the efficacy of most procedures. KEY POINTS: • Image-guided pudendal nerve block is safe, effective, and well tolerated with few complications. • US-guided perisciatic injection of anesthetic provides good symptom relief in patients with piriformis syndrome; however, the addition of corticosteroids to local anesthetics still has an unclear role. • US-guided lateral femoral cutaneous nerve block can be used to provide effective post-operative regional analgesia. The volume of local anesthetic affects the size of the blocked sensory area

Shotgun metagenomic sequencing of the first case of monkeypox virus in Brazil, 2022

Monkeypox virus (MPXV), a zoonotic virus endemic to the African continent, has been reported in 33 non-endemic countries since May 2022. We report an almost complete genome of the first confirmed case of MPXV in Brazil. Shotgun metagenomic sequencing was completed in 18 hours, from DNA extraction to consensus sequence generation

Leaf-cutting ants as ecosystem engineers: topsoil and litter perturbations around Atta cephalotes nests reduce nutrient availability

1. Despite considerable research into the effects of leaf-cutting ant nests, the potential occurrence of low-nutrient soils at nest sites has hitherto gone undetected. 2. Leaf litter cover and topsoil conditions (organic carbon, total nitrogen, soil acidity, cation exchange capacity) were assessed along transects running from nests of eight adult Atta cephalotes colonies into the understorey of Atlantic forest to examine the extent of nest effects. 3. Nests were virtually free of leaf litter (c. 150 gm(-2)) and litter cover increased along a saturating curve with nest distance, reaching 1300 gm(-2) in the undisturbed forest. Soil acidity and nutrient concentrations were strongly correlated with leaf litter cover (r = 0.66-0.72) for both soil types occurring in the study region. Total soil nitrogen concentration varied from 0.2 g kg(-1) in sandy nest soil and 0.5 g kg(-1) in clay-rich nest soil to 0.5 and 1.3 g kg(-1), respectively, at a distance of 24m from nests, while soil carbon concentration ranged from 2.1 to 6.1 g kg(-1) (sandy soil) and 4.5 to 15.7 g kg(-1) (clay-rich soil) over the same distance. Nest-associated variations in edaphic parameters suggest that each colony affected an area of up to 0.5 ha. 4. In contrast to the common perception that leaf-cutting ant activities increase nutrient availability, our results suggest that their territories are characterised by reduced levels of leaf litter and, consequently, soil nutrients. 5. The observed nutrient depletion must be taken into account when considering the potential impacts of ant nests for plant regeneration

Shotgun metagenomic sequencing of the first case of monkeypox virus in Brazil, 2022

Monkeypox virus (MPXV), a zoonotic virus endemic to the African continent, has been reported in 33 non-endemic countries since May 2022. We report an almost complete genome of the first confirmed case of MPXV in Brazil. Shotgun metagenomic sequencing was completed in 18 hours, from DNA extraction to consensus sequence generation

Clinical indications for image-guided interventional procedures in the musculoskeletal system: a Delphi-based consensus paper from the European Society of Musculoskeletal Radiology (ESSR)—part VII, nerves of the lower limb

Objectives: To perform a Delphi-based consensus on published evidence on image-guided interventional procedures for peripheral nerves of the lower limb (excluding Morton’s neuroma) and provide clinical indications. Methods: We report the results of a Delphi-based consensus of 53 experts from the European Society of Musculoskeletal Radiology who reviewed the published literature for evidence on image-guided interventional procedures offered around peripheral nerves in the lower limb (excluding Morton’s neuroma) to derive their clinical indications. Experts drafted a list of statements and graded them according to the Oxford Centre for evidence-based medicine levels of evidence. Consensus was considered strong when &gt; 95% of experts agreed with the statement or broad when &gt; 80% but &lt; 95% agreed. The results of the Delphi-based consensus were used to write the paper. Results: Nine statements on image-guided interventional procedures for peripheral nerves of the lower limb have been drafted. All of them received strong consensus. Image-guided pudendal nerve block is safe, effective, and well tolerated with few complications. US-guided perisciatic injection of anesthetic provides good symptom relief in patients with piriformis syndrome; however, the addition of corticosteroids to local anesthetics still has an unclear role. US-guided lateral femoral cutaneous nerve block can be used to provide effective post-operative regional analgesia. Conclusion: Despite the promising results reported by published papers on image-guided interventional procedures for peripheral nerves of the lower limb, there is still a lack of evidence on the efficacy of most procedures. Key Points: • Image-guided pudendal nerve block is safe, effective, and well tolerated with few complications. • US-guided perisciatic injection of anesthetic&nbsp;provides good symptom relief in patients with piriformis syndrome; however, the addition of corticosteroids to local anesthetics still has an unclear role. • US-guided lateral femoral cutaneous nerve block can be used to provide effective post-operative regional analgesia. The volume of local anesthetic&nbsp;affects the size of the blocked sensory area