In vitro decontamination efficacy of the RSDL® (Reactive Skin Decontamination Lotion Kit) lotion component against riot control agents: Capsaicin, Mace™ (CN) and CS.

The study examined the degradation of riot control agents (RCAs): 2-chloroacetophenone (CN), 2-chlorobenzalmalononitrile (CS), and capsaicin, using the Reactive Skin Decontamination Lotion Kit (RSDL®) lotion and evaluated the the direct liquid phase reactivity of the RSDL lotion component with each RCA. RSDL lotion was mixed with the selected RCAs at different molar ratios. Reactivity of the active ingredient potassium 2,3-butanedione monoximate (KBDO) with the RCA was observed for one hour. Samples of 10 µL were taken and quenched, analyzed for residual RCA using LC-MS. CN, was degraded at molar ratios of two and above in less than 2 min. At a molar ratio of 1:1 KBDO:CN, ∼90 % of CN was degraded within 2 min, the remaining 10 % residual CN was observed for one hour without any change. CS, degradation of more than 68 % of CS was achieved at 20:1 M ratio of KBDO:CS within 1 h of reaction time. For capsaicin, no degradation was observed regardless of the higher molar ratios of up to 20:1 and longer reaction times of up to one hour. This study provides evaluation of neutralizing action of the RSDL lotion without assessment of the physical removal component by the RSDL Kit.

Rapid and sensitive LC-MS/MS method for simultaneous quantification of capsaicin and dihydrocapsaicin in microdialysis samples following dermal application.

A bioanalytical LC-MS/MS method was developed and validated for the simultaneous quantification of capsaicin (CAPS) and dihydrocapsaicin (D-CAPS) in dermal microdialysis samples from rats. Capsaicinoids were separated by using a C18 column, with a mobile phase of water and acetonitrile, both with 0.1% of formic acid, eluted as a gradient. Compounds were detected by using an electrospray ionization source operating in the positive mode (ESI+) to monitor the m/z transitions of 306.1 > 137.0 for CAPS and 308.1 > 137.0 for D-CAPS. The method showed linearity in the concentration range of 0.5-100 ng/ml for CAPS and 0.25-100 ng/ml for D-CAPS, with coefficients of determination of ≥ 0.99. The inter- and intra-day precision, accuracy, and compound stability in different conditions were in accordance with the limits established by the US Food and Drug Administration guidelines. The recovery of the drugs by microdialysis were dependent on the flow rate, but independent of drug concentration. For CAPS, calibration of the in vitro microdialysis probes by dialysis and retrodialysis resulted in statistically similar drug recovery of 68.5% ± 5.9% and 77.8% ± 6.6%, respectively, at a flow rate of 0.5 µl/min. For D-CAPS, the recovery by dialysis was lower than by retrodialysis, at 51.4% ± 6.6% and 92.6% ± 2.4%, respectively. This difference was attributed to the binding of D-CAPS to the plastic tubing, which was experimentally evaluated and mathematically modeled. In vivo recoveries were 75.7% ± 6.3% for CAPS and 81.9% ± 1.5% for D-CAPS at the same flow rate. The analytical method showed high specificity, accuracy, and sensitivity, and suitability for dermatopharmacokinetic studies. These results will allow the determination of the actual free concentration of these drugs in dermatopharmacokinetic experiments, as shown in a pilot experiment with a commercial cream containing capsaicinoids.

El procesamiento sensorial podría estar organizado en el tiempo por ritmos cerebrales ultradianos / Sensory processing could be temporally organized by ultradian brain rhythms

Introducción. La actividad neuronal de sistemas sensoriales depende de múltiples factores provenientes del ambiente, el cuerpo y el propio cerebro. Varios son los ritmos que afectan al procesamiento sensorial, como el ciclo vigilia-sueño y ritmos ultradianos como el ritmo theta ( θ) del hipocampo, que nos ocupa en el presente trabajo. El hipocampo, estructura reconocidamente involucrada en los procesos de aprendizaje y memoria, posee un ritmo característico, el ritmo θ(4-10 Hz), presente en todos los estados del comportamiento. Este ritmo ha sido relacionado temporalmente con movimientos voluntarios, automáticos y reflejos, tanto durante la vigilia como en el sueño, así como con el control autonómico de la frecuencia cardíaca. Por otra parte, se ha considerado como un detector de novedad, el cual expresa distintos niveles de atención, selecciona las señales de interés y protege de la interferencia. Desarrollo y conclusiones. Nuestra investigación se basa en la hipótesis de que los procesamientos sensoriales necesitan de una organización temporal, una secuenciación de la información que debe procesarse y almacenarse, y que el ritmo θdel hipocampo podría contribuir con dicha función. Hemos demostrado que las descargas unitarias tanto de neuronas auditivas como visuales en cobayas presentan correlación temporal con el ritmo θhipocámpico (phaselocking). Esta relación temporal aparece tanto en las descargas espontáneas como en las provocadas por los estímulos específicos para cada modalidad sensorial. Las descargas neuronales fluctúan entre la situación de correlación y no correlación de fase con el ritmo θ. Este estado cambiante depende de distintas situaciones, conocidas y desconocidas. Podemos provocar, cambiando los estímulos visuales, un aumento en la potencia del ritmo θy la aparición de correlación temporal entre este ritmo y las descargas de más del 50% de las neuronas del núcleo geniculado lateral durante la vigilia. Durante el sueño lento los resultados son diversos: se demuestra que las vías de procesamiento de la información son diferentes

Introduction. Neuronal activity of sensory systems depends on input from the environment, the body and the brain itself. Various rhythms have been shown to affect sensory processing, such as the waking-sleep cycle and hippocampal theta waves, our aim in this revision. The hippocampus, known as a structure involved in learning and memory processing, has the theta ( θ) rhythm (4-10 Hz), present in all behavioural states. This rhythm has been temporally related to automatic, reflex and voluntary movements, both during wakefulness and sleep, and in the autonomic control of the heart rate. On the other hand θ rhythm has been considered as a novelty detector expressing different level of attention, selecting the information and protecting from interference. Development and conclusions. Our research is based on the hypothesis that sensory processing needs a timer to be processed and stored, and hippocampal θrhythm could contribute to the temporal organization of these events. We have demonstrated that auditory and visual unitary discharges in guinea pigs show phase-locking to the hippocampal θrhythm. This temporal correlation appears during both spontaneous and specific sensory stimulation evoked discharges. Neuronal discharges fluctuate between phase-locked and uncorrelated firing modes relative to the θ rhythm. This changing state depends on known and unknown situations. We have provoked, changing the visual stimuli, a power θrhythm increment and the phase-locking between this rhythm and the lateral geniculate neurone discharge during wakefulness. In slow wave sleep results were different demonstrating that the ways of the inputs processing have changed