Nunziata Barbera

Determination of drugs of abuse in hair: evaluation of external heroin contamination and risk of false positives

One of the most controversial point regarding the validity of hair testing is the risk of false positive due to external contamination. The aim of our experience is to verify if a 5 consecutive days contamination with a small amount of a powdered mixture of heroin hydrochloride and acetylcodeine hydrochloride (10:1 w/w) will last sufficiently long to make a contaminated subject indistinguishable from active users, and if normal washing practices together with the decontamination procedure are sufficient to completely remove the external contamination. Our results suggest that decontamination procedures are not sufficient to remove drugs penetrated into hair from external source. In fact, all contaminated subjects were positive for opiates (heroin, 6-MAM, morphine, acetylcodeine and codeine) for at least 3 months. Significant 6-MAM concentrations (>0.5 ng/mg) were found in each subject until 6th week. Further, 6-MAM/morphine ratio were always above 1.3.

The pathogenetic role of adulterants in 5 cases of drug addicts with a fatal outcome

The purpose of the present study is to determine the role of lidocaine, caffeine and dextromethorphan, used as adulterant substances, in five cases of drug overdose which have come to our attention. Taking into account the pharmacological mechanism, blood concentration and route of administration (intravenous) we evaluated the hypothesis that these substances could act with a synergistic effect - or at least additive - with the illicit drugs on the central nervous system and cardiovascular system.

Post mortem concentrations of endogenous gamma hydroxybutyric acid (GHB) and in vitro formation in stored blood and urine samples

Gamma-hydroxybutyrate (GHB) is a central nervous system depressant, primarily used as a recreational drug of abuse with numerous names. It has also been involved in various instances of drug-facilitated sexual assault due to its potential incapacitating effects. The first aim of this paper is to measure the post-mortem concentration of endogenous GHB in whole blood and urine samples of 30 GHB free-users, who have been divided according to the post-mortem interval (PMI) in three groups (first group: 24-36h; second group: 37-72h; third group: 73-192h), trying to evaluate the role of PMI in affecting post mortem levels. Second, the Authors have evaluated the new formation of GHB in vitro in blood and urine samples of the three groups, which have been stored at -20°C, 4°C and 20°C over a period of one month. The concentrations were measured by GC-MS after liquid-liquid extraction according to the method validated and published by Elliot (For. Sci. Int., 2003). For urine samples, GHB concentrations were creatinine-normalized. In the first group the GHB mean concentration measured after autopsy was: 2.14mg/L (range 0.54-3.21mg/L) in blood and 3.90mg/g (range 0.60-4.81mg/g) in urine; in the second group it was: 5.13mg/L (range 1.11-9.60mg/L) in blood and 3.93mg/g (range 0.91-7.25mg/g) in urine; in the third group it was: 11.8mg/L (range 3.95-24.12mg/L) in blood and 9.83mg/g (range 3.67-21.90mg/g) in urine. The results obtained in blood and urine samples showed a statistically significant difference among groups (p<0.001) in the first analysis performed immediately after autopsy. Throughout the period of investigation up to 4 weeks, the comparison of storage temperatures within each group showed in blood and urine samples a mean difference at 20°C compared to -20°C not statistically significant at the 10% level. These findings allow us to affirm that the PMI strongly affects the post mortem production of GHB in blood and urine samples. Regarding the new formation of GHB in vitro both in blood and urine samples of the three groups, which have been stored at -20°C, 4°C and 20°C over a period of one month, although there was no significant increases of GHB levels throughout the period of investigation, the lowest increases were found both in blood and urine at -20°C, therefore we recommend the latter as optimal storage temperature.

A fatal case of benzene poisoning

Chronic effects following repeated exposure to low doses of benzene have been well assessed, whereas few data are available about acute exposure to benzene. We report a case of fatal acute intoxication which occurred aboard a chemical cargo ship. Autopsy findings included blood clots inside the heart and main vessels, multi-organ congestion, pulmonary edema and the presence of many vibices in the hypostatic areas. Toxicological analysis of blood and urine showed a benzene concentration of 31.67 and 2.26 micrograms/mL, respectively; high concentrations of benzene (microgram/g) were also found in the lungs (22.23), liver (378.60), brain (178.66), heart (182.57) and kidneys (75.15). The above data provide evidence for benzene distribution in various organs.

A suicidal poisoning due to tramadol. A metabolic approach to death investigation

Tramadol is a synthetic opioid, widely used for post-surgical and chronic pain. Lethal overdose due only to tramadol is not common; more often the poisoning is due to tramadol in combination with other substances. Reported is a suicidal case of lethal tramadol poisoning in a 48-year-old woman. Tramadol and its metabolites O-desmethyltramadol (M1), N-desmethyltramadol (M2), N,N-didesmethyltramadol (M3), N,O-didesmethyltramadol (M5) were detected by GC/MS in biological fluids (femoral blood, bile, urine, gastric content) and viscera (brain, lung, liver and kidney). The tramadol concentration in femoral blood was 61.83 mcg/ml which is approximately 30 times higher than that believed to be lethal. According with other Authors, a preferential formation of M1 over M2 (M1/M2 ratio >1) is indicative of acute death, while M1/M2 ratio <1 suggests that death occurred after a longer time lapse from ingestion.

Domino effect: An unusual case of six fatal hydrogen sulfide poisonings in quick succession

Hydrogen sulfide (H2S) is one of the most serious toxic gases encountered in forensic practice. Aside from being a by-product of many industrial processes, this gas is naturally produced during the putrefaction of organic substances. We report six autopsy cases of fatal H2S poisonings from inhalation of H2S gas after an occupational accident. These six men died during the unblocking of a wastewater cistern. The first worker died shortly after clearing the obstruction, the other five died, one by one, as they attempted to help their colleagues. The macroscopic and histological findings are discussed here to provide useful information for future cases. Greenish discoloration of the skin and of internal organs (liver, trachea, esophagus, stomach) was observed, and one case showed signs typical of drowning. We present a very unusual incident, complete with rare photographs and toxicological analysis. In these cases, based on both macroscopic and microscopic findings, the cause of death was most likely an inhibitory effect on cellular cytochrome oxidase causing respiratory failure.

Levamisole-adulterated cocaine: Two fatal case reports and evaluation of possible cocaine toxicity potentiation

Levamisole has been identified as a cocaine adulterant in the United States since 2002. Although there is a variation in the percentage of levamisole in cocaine samples between European countries, measurement of levamisole in human samples of cocaine users has become increasingly important. To our best knowledge, only five deaths are reported (one twice) as a result of complications secondary to levamisole-tainted cocaine and none of these cases reports the post-mortem levamisole concentration. In this article, we present the post-mortem levamisole concentrations in fluids and tissues in two young cocaine users, dead after levamisole-adulterated cocaine intake. With the dearth of levamisole reported concentrations in literature, this particular report is of interest to the forensic toxicological and pathological communities. This article aims to be a supplementary alert to aware the risk that may occur using levamisole-adulterated cocaine and an incentive to publication of toxicity reports and new researches involving the combination of levamisole and cocaine.

Thymic factors influence on behavior in rodents

We studied the effect of thymopentin, a synthetic thymic peptide, on spontaneous behavior and stress models in BALB/c mice in which a WEHI 164 clone 13 murine fibrosarcoma had been implanted, as well as in the intact Sprague-Dawley rat. In untreated animals with tumors, spontaneous behavior was significantly inhibited. Resistance to swimming in cold water was also decreased in untreated animals. Thymopentin (10, 100, 1,000, and 5,000 micrograms/kg body weight, IP, 20 min before the test) enhanced spontaneous behavior in tumor-implanted mice. In addition, thymopentin partially restored floating capability of tumor bearers in either freely moving or animals on which an additional weight had been applied. In the latter test, plasma corticotropin and corticosterone levels were relatedly modified according to treatment. Rats treated with thymopentin showed a decreased sensitivity to painful stimuli. The effect of thymopentin was comparable to acetylsalicylate. Finally, thymic factors appeared capable of restoring the diminished behavioral activity of animals bearing tumors, as well as of increasing resistance to stressful stimuli and pain.

The therapeutic use of cannabinoids: Forensic aspects

UNLABELLED Since 2013 in the Italian market has been introduced the Nabiximols, a drug containing two of the main active cannabinoids: Δ(9)-tetrahydrocannabinol (Δ(9)-THC) and cannabidiol (CBD). This drug has been approved in Italy in the treatment of Multiple Sclerosis (MS). It is an oral spray formulation and each puff of 100μl contains 2.7mg of Δ(9)-THC and 2.5mg of CBD. In the present study we analyzed urine and blood samples collected from a group of 20 patients treated with Nabiximols in order to evaluate: blood Δ(9)-THC concentrations in relation to the dose administered and the duration of treatment and the potentiality of this medication to be used for drug habit. METHODS The study was conducted on a sample group of patients affected by MS, of both sexes, age: 49-61 years, treated with Nabiximols for short (28 days) or long-term. The results of our study allow affirming that it is unlikely to use this medication for drug habit or to sale it in the black market because of the low blood concentrations available and of its high costs. These statements were confirmed by: (a) the low Δ(9)-THC concentrations in the pharmaceutical formulation; (b) the low blood concentrations produced by Nabiximols administration, more than 10 times smaller than the blood concentrations known to produce psychotropic effects; (c) the presence of CBD (Δ(9)-THC natural antagonist); (d) the route of administration (inhaled, not smoked).

A singular case of survival after acute methanol poisoning: toxicological and neuroimaging findings.

AbstractAcute methanol poisoning is a relatively uncommon and dangerous form of intoxication. It generally occurs after suicidal or accidental events and can be potentially fatal if not diagnosed and treated promptly. Here reported is the case of a 52-year-old Romanian man who survived acute methanol intoxication. Therefore, it was possible to monitor the clinical evolution, the arterial blood gas assay and toxicological research of methanol in blood and urine, as well as the brain damage by computed tomography and magnetic resonance imaging during a period of 20 days after the intake.