Simultaneous detection and quantification of acidic and basic drugs in serum toxicological screening: use of ion-pairing technique in liquid-liquid extraction

The toxicological screening, using the combination of high performance liquid chromatography with diode array ultraviolet detector and ion-pairing technique in liquid-liquid extraction, is an effective tool in the identification and quantification of the acidic and basic substances in a single run. The use of an ion-pairing technique in the conventional extraction shows the co-extraction of the uncharged and charged form of the analytes present in a serum sample. The stationary phase used is C-18-bonded phase. The mobile phase is acetonitrile--phosphate buffer (pH 3; 25 mM) containing 25 mM triethylammonium as ion-pairing agent. The analytical validation shows reproducible recoveries, good day-to-day repeatability and sensible results compatible with clinical and forensic use

H-1-nmr Study and Conformational Aspects of 20'-deoxy-20'-epivindesine

The 1H NMR spectrum of 20′-deoxy-20′-epivindesine has been unravelled at 500 MHz. COSY and 2D NOESY experiments were used. The conformational features are assigned

The Complexity of Basic Number Processing: A Commentary from a Neurocognitive Perspective.

status: publishe

Cerebral hypoperfusion in multiple sclerosis is reversible and mediated by endothelin-1

<p>Decreased cerebral blood flow (CBF) may contribute to the pathology of multiple sclerosis (MS), but the underlying mechanism is unknown. We investigated whether the potent vasoconstrictor endothelin-1 (ET-1) is involved. We found that, compared with controls, plasma ET-1 levels in patients with MS were significantly elevated in blood drawn from the internal jugular vein and a peripheral vein. The jugular vein/peripheral vein ratio was 1.4 in patients with MS vs. 1.1 in control subjects, suggesting that, in MS, ET-1 is released from the brain to the cerebral circulation. Next, we performed ET-1 immunohistochemistry on postmortem white matter brain samples and found that the likely source of ET-1 release are reactive astrocytes in MS plaques. We then used arterial spin-labeling MRI to noninvasively measure CBF and assess the effect of the administration of the ET-1 antagonist bosentan. CBF was significantly lower in patients with MS than in control subjects and increased to control values after bosentan administration. These data demonstrate that reduced CBF in MS is mediated by ET-1, which is likely released in the cerebral circulation from reactive astrocytes in plaques. Restoring CBF by interfering with the ET-1 system warrants further investigation as a potential new therapeutic target for MS.</p>

Comparison of Culicoides Latreille 1809 populations (Diptera: Ceratopogonidae) present inside a Belgian sheepfold and a nearby sheep meadow

peer reviewedLes moucherons piqueurs du genre Culicoides (Diptera : Ceratopogonidae) sont les vecteurs biologiques de nombreux agents pathogènes, dont les virus de la fièvre catarrhale ovine et de Schmallenberg, récemment décrits en Europe du Nord. Ces maladies ont engendré des pertes économiques considérables dans les cheptels ovin et bovin. Cette étude, entreprise d’août à décembre 2007 au sein d’une exploitation ovine de la province de Namur (Belgique), vise à évaluer, au moyen de pièges lumineux, les populations de Culicoides présentes à l’intérieur d’une bergerie partiellement ouverte et au sein d’une pâture ovine avoisinante. L’analyse comparative des insectes capturés à 18 dates à intervalles réguliers montre que les culicoïdes sont plus abondants à l’intérieur du bâtiment d’élevage (17.450 individus) que dans la prairie voisine (1.121 individus); celle-ci présente toutefois une plus grande diversité spécifique. Les deux espèces C. obsoletus et C. scoticus constituant le complexe Obsoletus sont majoritaires pour l’ensemble des piégeages et les femelles se montrent bien plus nombreuses que les mâles. L’importante capture de femelles gorgées de sang (complexe Obsoletus) à l’intérieur de la bergerie traduit la possibilité d’un comportement endophage opportuniste. Le maintien des ovins préconisé à l’intérieur des bâtiments d’élevage afin de réduire les risques de piqûres de culicoïdes – et de ce fait de transmission de pathogènes – nécessite dès lors de limiter les populations de moucherons piqueurs susceptibles d’y entrer ou de s’y développer. Ainsi la mise en place de mesures d’assainissement et d’hygiène efficaces contre les culicoïdes au sein des exploitations agricoles, ainsi que l’instauration de mesures de protection contre l’intrusion et l’amélioration de l’étanchéité des bâtiments d’élevage sont hautement recommandées.Culicoides biting midges (Diptera: Ceratopogonidae) serve as biological vectors for several pathogens, including the Bluetongue virus and the recently described Schmallenberg virus in northern Europe. These diseases have caused considerable direct and indirect economic losses to the sheep and cattle industries. This study undertaken between August and December 2007 on a sheep farm in the Namur province (Belgium) aims to evaluate Culicoides populations present inside a partially opened sheepfold and in a nearby sheep meadow, using light traps. The comparative analysis of insects trapped at 18 dates at regular intervals showed that Culicoides were most abundant Inside this livestock building (17,450 midges) than in surrounding meadow (1,121 midges); this meadow had however a greater species diversity. The two species C. obsoletus and C. scoticus constituting the Obsoletus complex predominated for all trappings and females were much more numerous than males. Important capture of engorged females of the Obsoletus complex inside the sheepfold seems to reflect the possibility of an opportunistic endophagous behavior. Maintaining sheep inside livestock buildings in order to reduce the risk of Culicoides bites – and thus of pathogens transmission – however requires to limit biting midge populations which are likely to enter or to develop inside these buildings. Implementation of effective sanitation and hygiene measures against midges present inside farms, as well as establishing of measures to protect livestock against intrusion and improvement of “midge-proofing” of animal housing are therefore highly recommended

Diagnostic performance of automated MRI volumetry by icobrain dm for Alzheimer’s disease in a clinical setting: a REMEMBER study

Magnetic resonance imaging (MRI) has become important in the diagnostic work-up of neurodegenerative diseases. icobrain dm, a CE-labeled and FDA-cleared automated brain volumetry software, has shown potential in differentiating cognitively healthy controls (HC) from Alzheimer's disease (AD) dementia (ADD) patients in selected research cohorts. This study examines the diagnostic value of icobrain dm for AD in routine clinical practice, including a comparison to the widely used FreeSurfer software, and investigates if combined brain volumes contribute to establish an AD diagnosis. The study population included HC (n = 90), subjective cognitive decline (SCD, n = 93), mild cognitive impairment (MCI, n = 357), and ADD (n = 280) patients. Through automated volumetric analyses of global, cortical, and subcortical brain structures on clinical brain MRI T1w (n = 820) images from a retrospective, multi-center study (REMEMBER), icobrain dm's (v.4.4.0) ability to differentiate disease stages via ROC analysis was compared to FreeSurfer (v.6.0). Stepwise backward regression models were constructed to investigate if combined brain volumes can differentiate between AD stages. icobrain dm outperformed FreeSurfer in processing time (15-30 min versus 9-32 h), robustness (0 versus 67 failures), and diagnostic performance for whole brain, hippocampal volumes, and lateral ventricles between HC and ADD patients. Stepwise backward regression showed improved diagnostic accuracy for pairwise group differentiations, with highest performance obtained for distinguishing HC from ADD (AUC = 0.914; Specificity 83.0%; Sensitivity 86.3%). Automated volumetry has a diagnostic value for ADD diagnosis in routine clinical practice. Our findings indicate that combined brain volumes improve diagnostic accuracy, using real-world imaging data from a clinical setting

A cross-sectional case–control study on the structural connectome in recovered hospitalized COVID-19 patients

Abstract COVID-19 can induce neurological sequelae, negatively affecting the quality of life. Unravelling this illness's impact on structural brain connectivity, white-matter microstructure (WMM), and cognitive performance may help elucidate its implications. This cross-sectional study aimed to investigate differences in these factors between former hospitalised COVID-19 patients (COV) and healthy controls. Group differences in structural brain connectivity were explored using Welch-two sample t-tests and two-sample Mann–Whitney U tests. Multivariate linear models were constructed (one per region) to examine fixel-based group differences. Differences in cognitive performance between groups were investigated using Wilcoxon Rank Sum tests. Possible effects of bundle-specific FD measures on cognitive performance were explored using a two-group path model. No differences in whole-brain structural organisation were found. Bundle-specific metrics showed reduced fiber density (p = 0.012, Hedges’ g = 0.884) and fiber density cross-section (p = 0.007, Hedges’ g = 0.945) in the motor segment of the corpus callosum in COV compared to healthy controls. Cognitive performance on the motor praxis and digit symbol substitution tests was worse in COV than healthy controls (p < 0.001, r = 0.688; p = 0.013, r = 422, respectively). Associations between the cognitive performance and bundle-specific FD measures differed significantly between groups. WMM and cognitive performance differences were observed between COV and healthy controls