Volatile molecules for COVID-19: A possible pharmacological strategy?

COVID-19 is a novel coronavirus disease with a higher incidence of bilateral pneumonia and pleural effusion. The high pulmonary tropism and contagiousness of the virus, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), have stimulated new approaches to combat its widespread diffusion. In developing new pharmacological strategies, the chemical characteristic of volatility can add therapeutic value to the hypothetical drug candidate. Volatile molecules are characterized by a high vapor pressure and are consequently easily exhaled by the lungs after ingestion. This feature could be exploited from a pharmacological point of view, reaching the site of action in an uncommon way but allowing for drug delivery. In this way, a hypothetical molecule for COVID-19 should have a balance between its lung exhalation characteristics and both antiviral and anti-inflammatory pharmacological action. Here, the feasibility, advantages, and disadvantages of a therapy based on oral administration of possible volatile drugs for COVID-19 will be discussed. Both aerosolized antiviral therapy and oral intake of volatile molecules are briefly reviewed, and an evaluation of 1,8-cineole is provided in view of a possible clinical use and also for asymptomatic COVID-19.     

Using gas chromatography and mass spectrometry to determine 25-hydroxyvitamin D levels for clinical assessment of vitamin D deficiency

Vitamin D is responsible for multiple metabolic functions in humans. Rickets are the most common disease caused by vitamin D deficiency. It is caused by poor calcium intake resulting in poor serum-ionized calcium. The purpose of this study is to develop a rapid, sensitive, and feasible method to determine the 25-hydroxy-vitamin D3 (25(OH)D3) levels in blood samples for clinical assessment. In this study, gas chromatography coupled mass spectrometry with trimethylsilyl derivatization (TMS-GC-MS) is the most suitable protocol for quantitative analyses of 25(OH)D3. Performance of method was evaluated and compared with liquid chromatography and immunoassay. Method validation has been carried out with plasma specimens. The limit of quantitation of TMS-GC-MS method is 1.5 ppb with good linear correlation. Furthermore, the dietary intake and nutritional status of vegetarian and non-vegetarians in Taiwan were assessed by our validated method. As a result, this vitamin D nutrition survey demonstrates that most Taiwanese people have insufficient vitamin D. Due to dietary habits; the male vegans may have the highest risk of vitamin D deficiency.     

吉非罗齐中有机溶剂残留量的顶空毛细管GC测定

建立了顶空毛细管GC法测定吉非罗齐中甲酸乙酯、THF和甲基环己烷3种有机溶剂的残留量。采用HP-1毛细管柱，溶剂DMA，内标乙酸乙酯。平均同收率分别为99．8％、100．3％、100．0％，RSD分别为0．71％、1．51％和1．76％。     

离体模式下地氟醚、异氟醚和氟烷通过氧合器应用的药代动力学研究

目的研究在离体模式下地氟醚、异氟醚和氟烷通过氧合器应用的药代动力学。方法选择成人型膜式氧合器，预充生理盐水2000ml，连接动静脉端形成环路。将预先配制在钢瓶内的2．4％地氟醚、0．46％异氟醚及0．308％氟烷混合气体输送至氧合器，气体流量3Umin，泵流量4Umin，温度30℃。在摄入及排出的0、1、2、4、8、16、32min采集氧合器入气口、排气口及动脉端样本，测定吸入麻醉药分压。结果在摄入阶段及排出阶段，动脉端溶液中三种吸入麻醉药分压迅速上升或下降，用药后8min时，三种药物的动脉端样本分压与吸入气分压之比(Pa／Pi)均达50％以上，停药后8min动脉端样本分压与动脉端样本分压峰值之比(Pa／Pa0)均降至10％以下。三种药物之间在同一时间点Pa／Pi及Pa／17aO均有显著性差异(P＜0．05)。各吸入麻醉药动脉端样本与氧合器排气口中分压之间呈线性相关关系(r=0．99)。结论(1)Bentley膜式氧合器具有快速转运吸入麻醉药的性能；(2)地氟醚、异氟醚及氟烷通过氧合器应用后摄取和排出速率随着药物的水／气分配系数的增高而减慢；(3)通过监测氧合器排气口中吸入麻醉药分压可以快速、准确地估计液相中吸入麻醉药分压。     

Comparison of trichloroethylene and enflurane as adjuncts to nitrous oxide and relaxant anaesthesia

Forty women who underwent gynaecological surgery were randomly allocated to receive trichloroethylene, enflurane, or enflurane plus fentanyl as adjuncts to nitrous oxide/relaxant anaesthesia with controlled ventilation. No serious cardiac dysrhythmias were seen in any group. Each patient was observed postoperatively for 4 hours by a nurse blind to the technique used, and questioned at 24 hours by a similarly blinded anaesthetist. Recovery after trichloroethylene was not significantly prolonged although postoperative analgesia by visual analogue was better, opiate analgesia was required less frequently and there was less nausea and vomiting than in either of the enflurane groups. We argue for the continued use of trichloroethylene by this technique, because it costs one hundred times less than enflurane and because of the potential morbidity of the postoperative opiate dosage required after enflurane.     

The use of experimental studies to reveal suspected neurotoxic chemicals as occupational hazards: acute and chronic exposures to organic solvents.

The nervous system differs from many other body organs by its central control of vital functions and its low regeneration capacity. Organic solvents have, as a group, been suspected to have neurotoxic effects. Because of their similar physical properties and the fact that in industrial uses, they are often present in various mixtures, organic solvents have also been regarded, unfortunately, to induce common neurotoxic effects. However, it is evident from experimental studies using specified exposure conditions that different organic solvents have very diverse neurotoxic effects and also that the toxic mechanism may differ between acute and chronic exposure. No specific method used to describe a neurotoxic effect or single toxic response can be used for the overall occupational risk assessment of all organic solvents. Each solvent has to be considered as having its own unique toxic effects.     

Sphingolipid metabolites in neural signalling and function

Sphingolipid metabolites, such as ceramide, sphingosine, sphingosine-1-phosphate (S1P) and complex sphingolipids (gangliosides), are recognized as molecules capable of regulating a variety of cellular processes. The role of sphingolipid metabolites has been studied mainly in non-neuronal tissues. These studies have underscored their importance as signals transducers, involved in control of proliferation, survival, differentiation and apoptosis. In this review, we will focus on studies performed over the last years in the nervous system, discussing the recent developments and the current perspectives in sphingolipid metabolism and functions.