NPS-EQA PART II: Four years' experience in external quality assessment program in Italy for classical and new psychoactive substances analysis in hair.

In 2019, the Italian National Institute of Health established an external quality assessment (EQA) program to evaluate the performance of laboratories of collaborative centres participating in the National Early Warning System in hair testing for classical and new psychoactive substances (NPS). The results obtained in the four rounds (2019-2023) and the evolution in hair testing performance for classic drugs of abuse and new psychoactive substances are presented. A total of 11 hair specimens, including 3 blank samples, were prepared by adding different classes of classical and NPS at known concentrations to pre-screened drug-free hair. False negative and false positive results were calculated for the qualitative data evaluation. The quantitative evaluation included the imprecision (as % coefficient of variation, CV%) and the accuracy (as % error, ERR%) of the results with respect to a mean value obtained by reference laboratories and Z-score values were assessed. Over the years, an improvement in false negative results (from 52.4% in the first year to 34.3% in the last one) and false positive results (from 55.0% in the first year to 30.8.% in the last one) was observed. In the first round, the mean ERR% ranged from 6.2% to 112.8% due to NPS determination. However, in the subsequent three rounds, the mean ERR% ranged from 10.4% to 22.4%, The mean CV% in the four rounds was approximately 41.5% (ranging from 44.3% to 53.3%). Between 12.0% and 56.6% of the reported results in all rounds should be considered satisfactory. EQA programs help laboratories to identify and correct problems within their processes by highlighting errors and variations. This ensures that the results produced are accurate and reproducible.

NPS-EQA PART I: Four years' experience in external quality assessment program in Italy for classical and new psychoactive substances analysis in oral fluid.

In 2019, Italian National Institute of Health established an external quality assessment program (EQA) to evaluate the performance of oral fluid testing for classical and new psychoactive substances by laboratories participating in the National Early Warning System collaborative centres. This report presents the results of four rounds between 2019 and 2023. Eleven oral fluid specimens, including 3 blank samples, were prepared by adding different classes of and new psychoactive drugs at known concentrations to pre-screened drug-free oral fluid. False-negative and false-positive results were calculated for the qualitative data evaluation. The quantitative evaluation measured the imprecision and accuracy of the results, in terms of coefficient of variation (CV%) and percent error (ERR%), respectively, with respect to a mean value obtained by reference laboratories. Z-score values were then calculated. Over the years, there has been a significant improvement in false-negative results (from 42.7% in the first year to 19.4% in the last year), but not in false-positive results (from 33.3% in the first year to 22.2% in the last one). In addition to the classic drugs of abuse (e.g. cocaine, amphetamine, methadone), the substances found in false positive samples belonged to the class of synthetic cannabinoids (e.g 5-fluoro CUMYL-PINACA and 5-fluoro-EDMB-PICA), synthetic opioids (e.g butyrylfentanyl) and tryptamines (e.g. 5-methoxy-N-methyl-N-isopropyltryptamine). The four rounds yielded a mean ERR% of approximately 22.1% and a mean CV% of around 41.5%. The participating laboratories demonstrated variable performances in relation to the class of analysed psychoactive substances, as evidenced by the calculated Z-scores. Between 25% and 60% of the reported results in all rounds should be considered satisfactory. EQA is a crucial element of laboratory quality management systems. It promotes continuous improvement and maintains high standards in the field of forensic and clinical drug testing.

Hexahydrocannabinol Pharmacology, Toxicology, and Analysis: The First Evidence for a Recent New Psychoactive Substance.

BACKGROUND: During the last two years, hexahydrocannabinol (HHC), the hydrogenated derivative of tetrahydrocannabinol has been freely sold by internet websites as a "legal" replacement to THC and cannabis in a range of highly attractive branded and unbranded products, some of which are sold as "legal highs". Potentially, there could be a large demand for HHC products by individuals in Europe and internationally. METHODS: Studies reporting HHC pharmacology, toxicology and analysis were identified from Pubmed and Scopus databases, and official international organizations' websites were considered. RESULTS: HHC showed the effects of the typical cannabinoid on the central nervous system, with lower potency than Δ9-THC. A few studies highlighted that 9(R)-HHC is more potent than 9(S)-HHC. This molecule showed an affinity for cannabinoid receptor CB1 both in vitro and in vivo, suggesting a possible therapeutic effect in several pathologies. However, the affinity for the CB1 receptor suggests a possible addiction potential, inducing the users to misuse it. Since actual intoxication cases have not yet been reported, the HHC harmful potential was not described, probably due to the lack of effective analytical methods to detect HHC in biological matrices. Conversely, different analytical assays were developed and validated to separate HHC epimers in natural and non-natural sources. CONCLUSION: Similarly to other NPS, the HHC represents a cheaper alternative to the controlled Δ9-THC. Its monitoring is a crucial challenge for toxicological and forensic purposes. To this concern, it is essential to further investigate HHC to support health providers in the identification of related intoxications.

Ketamine: From Prescription Anaesthetic to a New Psychoactive Substance.

Discovered in the United States of America (USA) in the 1960s, ketamine was introduced as an anaesthetic drug to specifically replace phencyclidine. Briefly, the substance moved from the medical world to recreational users, since it was discovered that intense psychedelic experiences were obtained with dosages lower than those prescribed for anesthesia. At the end of the 90's, it was circulated in London nightclubs as a drug itself and as counterfeit 3,4-methylenedioxymethamphetamine tablets. In 1997, the Drug Enforcement Administration (DEA) alerted the United States (US) government about the increasing diffusion of ketamine in American 'clubs', and in 1999, the substance was added to Schedule III of drugs controlled by federal authorities. In 2002, ketamine epidemics moved to Europe, and the European Monitoring Centre for Drugs and Drug Addiction carried out a risk assessment monitoring of the phenomenon. An estimated ninety-nine percent of all global ketamine seizures occurred in Asia. Its growing popularity is due to the fact that this new psychoactive substance is cheaper than other stimulants, such as MDMA. Moreover, the amount used for recreational purposes does not cause respiratory depression and its legal use as a drug makes it widely available for a diversion towards illicit markets. Nevertheless, acute intoxication and several deaths have been related to exclusive ketamine use both in Europe and internationally. Since 2015, there has been an increasing rise in the illicit ketamine market, and currently, the drug is being used with unprecedented peaks and a consequent significant increase in seizures and clinical cases worldwide.

BDZs, Designer BDZs and Z-drugs: Pharmacology and Misuse Insights.

Benzodiazepines (BZDs) are a widely prescribed class of sedative-hypnotics compounds for the treatment of a broad range of conditions as anxiety and obsessive-compulsive disorders, phobias, sleep-related problems associated with insomnia, and for the management of alcohol and GHB withdrawal. Zolpidem, zopiclone and zaleplon, commonly known as Z-drugs, are non-benzodiazepine hypnotic drugs with pharmacology similar to BDZs. Despite their usefulness, BDZs and Z-drugs present a potential for abuse and dependence. Moreover, the non-medical use of BDZs is a well-known phenomenon and represents an increasingly widespread public health problem since it is associated with an elevated risk of serious health consequences or fatal overdose, especially among specific group of users. The spectrum of BDZs and Z-drugs misuse is extended by new synthetic BDZs, which may pose high risks to users, since the majority have never undergone clinical trials or tests and consequently their pharmacology and toxicology are largely unknown.

The complex and constantly evolving public health threat of new psychoactive substances in Italy: addressing the main functions of a national observatory of drugs.

At the end of the 90s in Europe, the new psychoactive substances (NPS) phenomenon was limited to a small number of molecules created to mimic the actions and psychoactive effects of licensed medicines and existing drugs that are controlled by the United Nations drug conventions and therefore traded as their "legal" replacements. NPS were mostly circulating in rave parties and electronic music festivals. The globalization, the evolution of e-commerce and the growing popularity of NPS, facilitated the development of a wide illegal market in constant expansion. The dynamic nature of this phenomenon has led to an evolution in the prevention and monitoring of NPS trafficking within the European Union. The European legislative system has been amended with the aim of creating a faster and more effective regulatory system to tackle NPS diffusion and ban their sale and circulation. At the end of 2008, in compliance with the European Council Decision 2005/387/JHA, the Anti-Drug Policies Department of the Presidency of the Council of Ministers activated the National Early Warning System to promote a rapid exchange of information on NPS between Italy and the EU.

Turmeric (Curcuma longa L.) food supplements and hepatotoxicity: an integrated evaluation approach.

INTRODUCTION: Turmeric is the common name for the rhizome of Curcuma longa L. In the recent years, food supplements containing turmeric have been marketed and widely used by an increasing number of consumers. Spontaneous reports of suspected adverse reactions to food supplements are collected within the Phytovigilance system. METHODS: An ad hoc multidisciplinary group investigated the suspected cases of hepatotoxicity reported to the Italian Phytovigilance system associated with the assumption of turmeric food supplements with the methodology specific to pharmacovigilance as well as for the evaluation of the quality and safety of food supplements. RESULTS: A cluster of 28 spontaneous reports of acute hepatitis, mostly with cholestasis, associated with turmeric products were sent to the Italian Phytovigilance system in the first six months of 2019. In all cases, except one, the causality assessment was at least possible. The suspected products were collected and analysed for the presence of drugs, heavy metals, aflatoxins, pesticides, synthetic dyes and pyrrolizidine alkaloids. CONCLUSION: On the basis of the results of all the activities performed by multidisciplinary group, regulatory intervention was taken. This study highlights the importance of developing an integrated evaluation approach for the evaluation of the adverse effects associated with the use of food supplements.

Stability and Degradation Pathways of Different Psychoactive Drugs in Neat and in Buffered Oral Fluid.

Sampling and drug stability in oral fluid (OF) are crucial factors when interpreting forensic toxicological analysis, mainly because samples may not be analyzed immediately after collection, potentially altering drug concentrations. Therefore, the stability of some common drugs of abuse (morphine, codeine, 6-monoacetylmorphine, cocaine, benzoylecgonine, Δ9-tetrahydrocannabinol, cannabidiol, amphetamine, 3,4-methylenedioxymethamphetamine, ketamine) and the more commonly consumed new psychoactive substances in our environment (mephedrone, and N-(adamantan-1-yl)-1-(5-fluoropentyl)-1H-indazole-3-carboxamide 5F-AKB48 also known as 5F-APINACA) was investigated in an OF pool for the presence and absence of M3 Reagent Buffer® up to 1 year of storage. Fortified OF samples were stored at three different temperatures (room temperature, 4 and -20°C) to determine the best storage conditions over time. Control fortified OF samples were stored at -80°C for reference purposes. Compounds with concentration changes within ±15% of initial value were considered stable. The drugs were significantly more stable in M3 Reagent Buffer® than in neat OF samples in all storage conditions. All analytes were stable for 1 year at 4°C and -20°C in M3 Reagent Buffer®. Drugs stability in OF varied depending on the analyte, the presence of a stabilizer, the storage duration and temperature. When immediate sample analysis is not possible, we suggest to store OF samples at 4 or -20°C and test them within 2 weeks. Alternatively, OF samples may be stored at 4 or -20°C with M3 Reagent Buffer® to be tested within 1 year.

New Psychoactive Substances: A Matter of Time.

In the last few years, a wide range of new psychoactive substances (NPS) have been produced and marketed to elude the controlled substance lists. These molecules enter the traditional illegal and web market with poor knowledge about their toxicity, mechanism of action, metabolism, abuse potential so that they are directly tested by the consumers. This perspective highlights the main issues connected with NPS: the celerity they enter and leave the market once included in the banning laws to be substituted by new legal analogues; the unavailability of analytical screening tests and certified standards to perform toxicological analyses; the time lag between NPS identification and inclusion in the controlled substances lists. Finally, the authors take a snapshot of the commitment of the Italian Early Warning System in highlighting the recent seizures of NPS as well as the distribution of NPS related intoxication and deaths as an example of what is happening in the European countries and internationally.

Screening methods for rapid determination of new psychoactive substances (NPS) in conventional and non-conventional biological matrices.

In the last years, a global awareness has arisen from the reported harmful effects and public health risks associated with the consumption of new psychoactive substances (NPSs). Improving efforts in the detection and identification of these substances have emerged as a global analytical challenge involving the large range of NPSs' chemical structures and the variety of conventional and non-conventional biological matrices. Indeed, detection capabilities and screening tools impact many fields and settings, including seized products analysis, workplace and roadside drug controls, emergency rooms, drug addiction treatment clinics, post-mortem and criminal caseworks, law enforcement and health interventions. Colorimetric, immunochemical and chromatographic-mass spectrometry techniques have been investigated and developed for the rapid identification of NPSs. Considering the continuous emergence of new substances, this review offers a panoramic view on the current status of analytical approaches for the rapid screening of NPSs, including, when available, data on conventional and non-conventional biological matrices. Although some of the presented methods are sound and promising, their applications are still limited, thus proving the importance of further investigations. New screening and sensitive targeted methods for NPS and their metabolites should be developed in different types of biological matrices, where concentration of substances and matrix effects can be significantly different.

Correlation between Blood and Oral Fluid Psychoactive Drug Concentrations and Cognitive Impairment in Driving under the Influence of Drugs.

BACKGROUND: The effects of drugs on driving performance should be checked with drug concentration in the brain and at the same time with the evaluation of both the behavioural and neurophysiological effects. The best accessible indicator of this information is the concentration of the drug and/or metabolites in blood and, to a certain extent, oral fluid. We sought to review international studies on correlation between blood and oral fluid drug concentrations, neurological correlates and cognitive impairment in driving under the influence of drugs. METHODS: Relevant scientific articles were identified from PubMed, Cochrane Central, Scopus, Web of Science, Science Direct, EMBASE up to April 2017. RESULTS: Up to 2010, no epidemiological studies were available on this matter and International scientists suggested that even minimal amounts of parent drugs in blood and oral fluid could affect driving impairment. More recently, epidemiological data, systematic reviews and meta-analysis on drugged drivers allowed the suggestion of impairment concentration limits for the most common illicit drugs. These values were obtained comparing driving disability induced by psychotropic drugs with that of established blood alcohol limits. Differently from ethyl alcohol where both detection methods and concentration limits have been well established even with inhomogeneity of ranges within different countries, in case of drugs of abuse no official cut-offs have yet been established, nor any standardized analytical protocols. CONCLUSION: Multiple aspects of driving performance can be differently affected by illicit drugs, and even if for few of them some dose/concentration dependent impairment has been reported, a wider knowledge on concentration/impairment relationship is still missing.

Stability of Drugs of Abuse in Urine Samples at Room Temperature by Use of a Salts Mixture.

BACKGROUND: It has long been recognized that ensuring analyte stability is of crucial importance in the use of any quantitative bioanalytical method. As analyses are usually not performed directly after collection of the biological samples, but after these have been processed and stored, it is essential that analyte stability can be maintained at storage conditions to ensure that the obtained concentration results adequately reflect those directly after sampling. The conservation of urine samples in refrigerated/ frozen conditions is strongly recommended; but not always feasible. The aim of this study was to assess the stability of some well-known drugs of abuse methamphetamine (MA), 11-nor-9-carboxy-Δ9- tetrahydrocannabinol (THC-COOH), benzoylecgonine (BE), and morphine (MOR) in urine samples kept at room temperature by adding a salt mixture (sodium citrate, sodium ascorbate, borax). METHODS: Two different urine samples were prepared with and without salt mixture, stored at room temperature and then analyzed by gas chromatography-mass spectrometry at 0, 1, 7, 15, and 30 days after collection/preparation to look for eventual analyte degradation. RESULTS: Methamphetamine showed no significant changes with respect to the time of collection/ preparation (T0) up to 7 days later (T7), with or without salt mixture addiction. Then a significant degradation occurred in both salted and non salted urine. BE decrease was observed starting from day 1 after sample collection in salted and not salted samples, respectively. Salt addition seemed to reduce at least the initial BE degradation, with a significant difference (p<0.001) at 7 and 15 days of storage. However, the degradation was not more prevented in salted samples at 30 days of storage. A 20% decrease of MOR concentration was observed starting from day 1 after collection/preparation, both in salted and not salted samples with no subsequent decrease. With regard to THCCOOH, a significant decrease was observed starting from 7 days after collection/preparation, with of without adding the salt mixture. However, when comparing salted versus non salted samples at each time point, a statistically significant difference was observed at 7 and 30 days of storage. CONCLUSION: The results obtained indicate that the degradation of MA, THC-COOH and BE in urine samples kept at room temperature can be slowed by the addition of the salt mixture, whereas it seems to be ineffective in samples containing MOR. This evidence has to be taken into account, in the eventuality of using salted urine to prevent in a certain extent abuse of above-reported drugs of abuse.

Simple and Fast Gas-chromatography Mass Spectrometry Assay to Assess Delta 9-Tetrahydrocannabinol and Cannabidiol in Dogs Treated with Medical Cannabis for Canine Epilepsy.

BACKGROUND: To date, an increasing number of pet owners, especially in the USA, are using cannabis-derived products containing generally delta 9-tetrahydrocannabinol (THC) and cannabidiol (CBD) to help their animals' health. Unfortunately, studies on the clinical use of cannabinoids in veterinary medicine are still limited, and the application of analytical methodologies for the determination of cannabinoids in animal (especially dog) biological matrices such as plasma, is still missing. METHODS: A reliable, fast, accurate, simple gas chromatography-mass spectrometry (GC-MS) method was developed and validated for the quantification of THC and CBD in plasma samples of eight dogs under therapeutic treatment for epilepsy and receiving oral administration of medical cannabis (Bediol). RESULTS: The method was linear for both the analytes under investigation with coefficients of determination (r2) of at least 0.99. Absolute analytical recovery (mean ± SD) ranged from 80.6 ± 6.2% for THC and 81.7 ± 4.3% for CBD. The matrix effect showed less than 10% analytical suppression due to endogenous substances for both the analytes. The intra-assay and inter-assay precision values ranged from 4.9% to 12.7%, and from 5.2% to 8.7% respectively. The intra-assay and inter-assay accuracy values ranged from 2.3% to 9.6% and from 3.4% to 13.0%, respectively. CONCLUSION: The validated method was successfully applied to real samples; moreover, to assess the potential of the method applicability and robustness in future veterinary clinical studies on cannabinoids therapy, we attempted to follow the kinetic of THC and CBD in the plasma of two dogs under therapy at different times after Bediol administration.

Prion Strain Characterization of a Novel Subtype of Creutzfeldt-Jakob Disease.

In 2007, we reported a patient with an atypical form of Creutzfeldt-Jakob disease (CJD) heterozygous for methionine-valine (MV) at codon 129 who showed a novel pathological prion protein (PrPTSE) conformation with an atypical glycoform (AG) profile and intraneuronal PrP deposition. In the present study, we further characterize the conformational properties of this pathological prion protein (PrPTSE MVAG), showing that PrPTSE MVAG is composed of multiple conformers with biochemical properties distinct from those of PrPTSE type 1 and type 2 of MV sporadic CJD (sCJD). Experimental transmission of CJD-MVAG to bank voles and gene-targeted transgenic mice carrying the human prion protein gene (TgHu mice) showed unique transmission rates, survival times, neuropathological changes, PrPTSE deposition patterns, and PrPTSE glycotypes that are distinct from those of sCJD-MV1 and sCJD-MV2. These biochemical and experimental data suggest the presence of a novel prion strain in CJD-MVAGIMPORTANCE Sporadic Creutzfeldt-Jakob disease is caused by the misfolding of the cellular prion protein, which assumes two different major conformations (type 1 and type 2) and, together with the methionine/valine polymorphic codon 129 of the prion protein gene, contribute to the occurrence of distinct clinical-pathological phenotypes. Inoculation in laboratory rodents of brain tissues from the six possible combinations of pathological prion protein types with codon 129 genotypes results in the identification of 3 or 4 strains of prions. We report on the identification of a novel strain of Creutzfeldt-Jakob disease isolated from a patient who carried an abnormally glycosylated pathological prion protein. This novel strain has unique biochemical characteristics, does not transmit to humanized transgenic mice, and shows exclusive transmission properties in bank voles. The identification of a novel human prion strain improves our understanding of the pathogenesis of the disease and of possible mechanisms of prion transmission.

Monitoring nicotine intake from e-cigarettes: measurement of parent drug and metabolites in oral fluid and plasma.

BACKGROUND: Electronic cigarettes (e-cig) known as electronic nicotine devices recently gained popularity among smokers. Despite many studies investigating their safety and toxicity, few examined the delivery of e-cig-derived nicotine and its metabolites in alternative biological fluids. METHODS: We performed a randomized, crossover, and controlled clinical trial in nine healthy smokers. Nicotine (NIC), cotinine (COT), and trans-3'-hydroxycotinine (3-HCOT) were measured in plasma and oral fluid by liquid chromatography-tandem mass spectrometry after consumption of two consecutive e-cig administrations or two consecutive tobacco cigarettes. RESULTS: NIC and its metabolites were detected both in oral fluid and plasma following both administration conditions. Concentrations in oral fluid resulted various orders of magnitude higher than those observed in plasma. Oral fluid concentration of tobacco cigarette and e-cig-derived NIC peaked at 15 min after each administration and ranged between 1.0 and 1396 µg/L and from 0.3 to 860 µg/L; those of COT between 52.8 and 110 µg/L and from 33.8 to 94.7 µg/L; and those of 3-HCOT between 12.4 and 23.5 µg/L and from 8.5 to 24.4 µg/L. The oral fluid to plasma concentration ratio of both e-cig- and tobacco cigarette-derived NIC peaked at 15 min after both administrations and correlated with oral fluid NIC concentration. CONCLUSIONS: The obtained results support the measurement of NIC and metabolites in oral fluid in the assessment of intake after e-cig use and appear to be a suitable alternative to plasma when monitoring nicotine delivery from e-cig for clinical and toxicological studies.

Herbal Highs: Review on Psychoactive Effects and Neuropharmacology.

BACKGROUND: A new trend among users of new psychoactive substances' the consumption of "herbal highs": plant parts containing psychoactive substances. Most of the substances extracted from herbs, in old centuries were at the centre of religious ceremonies of ancient civilizations. Currently, these herbal products are mainly sold by internet web sites and easily obtained since some of them have no legal restriction. OBJECTIVE: We reviewed psychoactive effects and neuropharmacology of the most used "herbal highs" with characterized active principles, with studies reporting mechanisms of action, pharmacological and subjective effects, eventual secondary effects including intoxications and/or fatalities Method: The PubMed database was searched using the following key.words: herbal highs, Argyreia nervosa, Ipomoea violacea and Rivea corymbosa; Catha edulis; Datura stramonium; Piper methysticum; Mitragyna speciosa. RESULTS: Psychoactive plants here reviewed have been known and used from ancient times, even if for some of them limited information still exist regarding subjective and neuropharmacological effects and consequent eventual toxicity when plants are used alone or in combination with "classical" drugs of abuse. CONCLUSION: Some "herbal highs" should be classified as harmful drugs since chronic administration has been linked with addiction and cognitive impairment; for some others taking into consideration only the recent trends of abuse, studies investigating these aspects are lacking.

Identification and quantification of psychoactive drugs in whole blood using dried blood spot (DBS) by ultra-performance liquid chromatography tandem mass spectrometry.

A procedure based on ultra-high-pressure liquid chromatography tandem mass spectrometry has been developed for the determination of twenty three psychoactive drugs and metabolites in whole blood using dried blood spot (DBS). Chromatographic separation was achieved at ambient temperature using a reverse-phase column and a linear gradient elution with two solvents: 0.1% formic acid in acetonitrile and 5mM ammonium formate at pH 3. The mass spectrometer was operated in positive ion mode, using multiple reaction monitoring via positive electro-spray ionization. The method was linear from the limit of quantification (5ng/ml for all the analytes apart from 15ng/ml for Δ-9-tetrahydrocannabinol and metabolites) to 500ng/ml, and showed good correlation coefficients (r(2)=0.990) for all substances. Analytical recovery of analytes under investigation was always higher than 75% and intra-assay and inter-assay precision and accuracy always better than 15%. Using the validated method, ten DBS samples, collected at the hospital emergency department in cases of acute drug intoxication, were found positive to one or more psychoactive drugs. Our data support the potential of DBS sampling for non invasive monitoring of exposure/intoxication to psychoactive drugs.

Successful Nicotine Intake in Medical Assisted Use of E-Cigarettes: A Pilot Study.

The electronic cigarette (e-cig) has gained popularity as an aid in smoking cessation programs mainly because it maintains the gestures and rituals of tobacco smoking. However, it has been shown in inexperienced e-cig users that ineffective nicotine delivery can cause tobacco craving that could be responsible for unsuccessful smoking reduction/cessation. Moreover, the incorrect use of an e-cig could also led to potential nicotine overdosage and intoxication. Medically assisted training on the proper use of an e-cig plus behavioral support for tobacco dependence could be a pivotal step in avoiding both issues. We performed an eight-month pilot study of adult smokers who started e-cig use after receiving a multi-component medically assisted training program with monitoring of nicotine intake as a biomarker of correct e-cig use. Participants were tested during follow-up for breath carbon monoxide (CO), plasma cotinine and trans-3'-hydroxycotinine, and number of tobacco cigarettes smoked. At the end of the first, fourth, and eighth month of follow-up, 91.1, 73.5, and 76.5% of participants respectively were e-cig users ('only e-cig' and 'dual users'). They showed no significant variation in plasma cotinine and trans-3'-hydroxycotinine with respect to the start of the study when they smoked only tobacco cigarettes, but a significant reduction in breath CO. The proposed medically assisted training program of e-cig use led to a successful nicotine intake, lack of typical cigarette craving and overdosage symptoms and a significant decrease in the biomarker of cigarette combustion products.

Synthetic scrapie infectivity: interaction between recombinant PrP and scrapie brain-derived RNA.

The key molecular event in human cerebral proteinopathies, which include Alzheimer's, Parkinson's and Huntington's diseases, is the structural conversion of a specific host protein into a ß-sheet-rich conformer. With regards to this common mechanism, it appears difficult to explain the outstanding infectious properties attributed to PrP(Sc), the hallmark of another intriguing family of cerebral proteinopathies known as transmissible spongiform encephalopathies (TSE) or prion diseases. The infectious PrP(Sc) or "prion" is thought to be composed solely of a misfolded form of the otherwise harmless cellular prion protein (PrP(c)). To gain insight into this unique situation, we used the 263K scrapie hamster model to search for a putative PrP(Sc)-associated factor that contributes to the infectivity of PrP(Sc) amyloid. In a rigorously controlled set of experiments that included several bioassays, we showed that originally innocuous recombinant prion protein (recPrP) equivalent to PrP(c) is capable of initiating prion disease in hamsters when it is converted to a prion-like conformation (ß-sheet-rich) in the presence of RNA purified from scrapie-associated fibril (SAF) preparations. Analysis of the recPrP-RNA infectious mixture reveals the presence of 2 populations of small RNAs of approximately 27 and 55 nucleotides. These unprecedented findings are discussed in light of the distinct relationship that may exist between this RNA material and the 2 biological properties, infectivity and strain features, attributed to prion amyloid.

Assessment of prion reduction filters in decreasing infectivity of ultracentrifuged 263K scrapie-infected brain homogenates in "spiked" human blood and red blood cells.

BACKGROUND: The safety of red blood cells (RBCs) is of concern because of the occurrence of four transfusion-transmitted variant Creutzfeldt-Jakob disease (vCJD) cases in the United Kingdom. The absence of validated screening tests requires the use of procedures to remove prions from blood to minimize the risk of transmission. These procedures must be validated using infectious prions in a form that is as close as possible to one in blood. STUDY DESIGN AND METHODS: Units of human whole blood (WB) and RBCs were spiked with high-speed supernatants of 263K scrapie-infected hamster brain homogenates. Spiked samples were leukoreduced and then passed through prion-removing filters (Pall Corporation). In another experiment, RBCs from 263K scrapie-infected hamsters were treated as above, and residual infectivity was measured by bioassay. RESULTS: The overall removal of infectivity by the filters from prion-spiked WB and RBCs was approximately two orders of magnitude. No infectivity was detected in filtered hamster RBCs endogenously infected with scrapie. CONCLUSION: The use of prion-removing filters may help to reduce the risk of transfusion-transmitted vCJD. To avoid overestimation of prion removal efficiency in validation studies, it may be more appropriate to use supernates from ultracentrifugation of scrapie-infected hamster brain homogenate rather than the current standard brain homogenates.