Toxicological Investigation of a Case Series Involving the Synthetic Cathinone α-Pyrrolidinohexiophenone (α-PHP) and Identification of Phase I and II Metabolites in Human Urine

α-Pyrrolidinohexiophenone (α-PHP) is a derivative of the class of α-pyrrolidinophenones, a subgroup of synthetic cathinones. These substances are the second most abused drugs of new psychoactive substances. Here, we report the toxicological investigation of a series of 29 authentic forensic and clinical cases with analytically confirmed intake of α-PHP including two cases of drug testing in newborns using meconium. The age range of subjects where serum samples were available was 23-51 years (median 39.5), and 90% were male. Serum α-PHP concentrations, determined by a validated LC-MS-MS method, showed a high variability ranging from 1 to 83 ng/mL (mean, 40 ng/mL; median, 36 ng/mL). Comprehensive toxicological analysis revealed co-consumption of other psychotropic drugs in almost all cases with frequent occurrence of opiates (60%), benzodiazepines (35%), cannabinoids (30%), and cocaine (20%). Hence, forensic and clinical symptoms like aggressive behavior, sweating, delayed physical response, and impaired balance could not be explained by the abuse of α-PHP alone but rather by poly-intoxications. Liquid chromatography-quadrupole time-of-flight mass spectrometry and gas chromatography-mass spectrometry were used to investigate the metabolism of α-PHP in vivo using authentic human urine samples. Altogether, 11 phase I metabolites and 5 phase II glucuronides could be identified by this approach. Apart from the parent drug, most abundant findings in urine were the metabolites dihydroxy-pyrrolidinyl-α-PHP and dihydro-α-PHP and, to a lesser extent, 2'-oxo-dihydro-α-PHP and 2'-oxo-α-PHP. Monitoring of these metabolites along with the parent drug in forensic and clinical toxicology could unambiguously prove the abuse of the novel designer drug α-PHP.

Intoxication cases associated with the novel designer drug 3',4'-methylenedioxy-α-pyrrolidinohexanophenone and studies on its human metabolism using high-resolution mass spectrometry

Among the increasing number of new psychoactive substances, 3',4'-methylenedioxy-α-pyrrolidinohexanophenone (MDPHP) belongs to the group of synthetic cathinones, which are the derivatives of the naturally occurring compound cathinone, the main psychoactive ingredient in the khat plant. Currently, only limited data are available for MDPHP, and no information is available on its human metabolism. We describe the toxicological investigation of nine cases associated with the use of MDPHP during the period February-June 2019. Serum MDPHP concentrations showed a high variability ranging from 3.3 to 140 ng/mL (mean 30.3 ng/mL and median 16 ng/mL). Intoxication symptoms of the described cases could not be explained by the abuse of MDPHP alone because in all cases the co-consumption of other psychotropic drugs with frequent occurrence of opiates and benzodiazepines could be verified. Therefore, the patients showed different clinical symptoms, including aggressive behaviour, delayed physical response, loss of consciousness and coma. Liquid chromatography-high-resolution mass spectrometry was successfully used to investigate the human in vivo metabolism of MDPHP using authentic human urine samples. The metabolism data for MDPHP were further substantiated by the analysis of human urine using gas chromatography-mass spectrometry (GC-MS, a widely used systematic toxicological analysis method appropriate for the toxicological detection of MDPHP intake), which revealed the presence of seven phase I metabolites and three phase II metabolites as glucuronides. GC-MS spectral data for MDPHP and metabolites are provided. The identified metabolite pattern corroborates the principal metabolic pathways of α-pyrrolidinophenones in humans.

Toxicological investigation of forensic cases related to the designer drug 3,4-methylenedioxypyrovalerone (MDPV): Detection, quantification and studies on human metabolism by GC-MS

3,4-methylenedioxypyrovalerone (MDPV) is a synthetic cathinone belonging to the class of α-pyrrolidinophenones that become increasingly popular as a designer psychostimulant. Here, we report a comprehensive collection of MDPV exposure with quantitative serum level confirmation in Germany. During the years 2014-2016, we could proof consumption of MDPV in 23 cases where urine and blood samples were submitted to our laboratory by the police of Lower Saxony. Most of the samples underwent systematic toxicological analysis by gas chromatography-mass spectrometry (GC-MS), where MDPV could be detected in urine and/or serum samples. The determined concentrations of MDPV in serum showed a high variability, ranging from traces (<10ng/mL) up to 576ng/mL with a mean concentration of 118ng/mL and median of 47ng/mL. The majority of MDPV users were men (87%) and the age ranged from 23 to 49 years (mean 35.9, median 37 years). For most of the analytically confirmed MDPV cases we could prove co-consumption of other psychotropic drugs with frequent occurrence of opiates and cannabinoids in 22% of the cases, followed by benzodiazepines and cocaine in 17%. Analysis of urine samples by GC-MS disclosed the presence of MDPV and its metabolites 2'-oxo-MDPV, demethylenyl-MDPV, demethylenyl-methyl-MDPV, demethylenyl-oxo-MDPV, demethylenyl-methyl-oxo-MDPV and demethylenyl-methyl-N,N-bisdealkyl-MDPV. The metabolite pattern substantiates previous suggestions for principle metabolic pathways of MDPV in humans.

Music therapy as specific and complementary training for adults after cochlear implantation: A pilot study

OBJECTIVES

Although cochlear implant (CI) users achieve good speech comprehension, they experience difficulty perceiving music and prosody in speech. As the provision of music training in rehabilitation is limited, a novel concept of music therapy for rehabilitation of adult CI users was developed and evaluated in this pilot study.

METHODS

Twelve unilaterally implanted, postlingually deafened CI users attended ten sessions of individualized and standardized training. The training started about 6 weeks after the initial activation of the speech processor. Before and after therapy, psychological and musical tests were applied in order to evaluate the effects of music therapy. CI users completed the musical tests in two conditions: bilateral (CI + contralateral, unimplanted ear) and unilateral (CI only).

RESULTS

After therapy, improvements were observed in the subjective sound quality (Hearing Implant Sound Quality Index) and the global score on the self-concept questionnaire (Multidimensional Self-Concept Scales) as well as in the musical subtests for melody recognition and for timbre identification in the unilateral condition. Discussion Preliminary results suggest improvements in subjective hearing and music perception, with an additional increase in global self-concept and enhanced daily listening capacities.

CONCLUSIONS

The novel concept of individualized music therapy seems to provide an effective treatment option in the rehabilitation of adult CI users. Further investigations are necessary to evaluate effects in the area of prosody perception and to separate therapy effects from general learning effects in CI rehabilitation.

Structure and activity of the only human RNase T2

Mutations in the gene of human RNase T2 are associated with white matter disease of the human brain. Although brain abnormalities (bilateral temporal lobe cysts and multifocal white matter lesions) and clinical symptoms (psychomotor impairments, spasticity and epilepsy) are well characterized, the pathomechanism of RNase T2 deficiency remains unclear. RNase T2 is the only member of the Rh/T2/S family of acidic hydrolases in humans. In recent years, new functions such as tumor suppressing properties of RNase T2 have been reported that are independent of its catalytic activity. We determined the X-ray structure of human RNase T2 at 1.6 Å resolution. The α+β core fold shows high similarity to those of known T2 RNase structures from plants, while, in contrast, the external loop regions show distinct structural differences. The catalytic features of RNase T2 in presence of bivalent cations were analyzed and the structural consequences of known clinical mutations were investigated. Our data provide further insight into the function of human RNase T2 and may prove useful in understanding its mode of action independent of its enzymatic activity.

Molecular characterization of folate receptor 1 mutations delineates cerebral folate transport deficiency

Cerebral folate transport deficiency is an inherited brain-specific folate transport defect that is caused by mutations in the folate receptor 1 gene coding for folate receptor alpha (FRα). This genetic defect gives rise to a progressive neurological disorder with late infantile onset. We screened 72 children with low 5-methyltetrahydrofolate concentrations in the cerebrospinal fluid and neurological symptoms that developed after infancy. We identified nucleotide alterations in the folate receptor 1 gene in 10 individuals who shared developmental regression, ataxia, profound cerebral hypomyelination and cerebellar atrophy. We found four novel pathogenic alleles, one splice mutation and three missense mutations. Heterologous expression of the missense mutations, including previously described mutants, revealed minor decrease in protein expression but loss of cell surface localization, mistargeting to intracellular compartments and thus absence of cellular binding of folic acid. These results explain the functional loss of folate receptor alpha for all detected folate receptor 1 mutations. Three individuals presenting a milder clinical phenotype revealed very similar biochemical and brain imaging data but partially shared pathogenic alleles with more severely affected patients. Thus, our studies suggest that different clinical severities do not necessarily correlate with residual function of folate receptor alpha mutants and indicate that additional factors contribute to the clinical phenotype in cerebral folate transport deficiency.

Function of Ech hydrogenase in ferredoxin-dependent, membrane-bound electron transport in Methanosarcina mazei

Reduced ferredoxin is an intermediate in the methylotrophic and aceticlastic pathway of methanogenesis and donates electrons to membrane-integral proteins, which transfer electrons to the heterodisulfide reductase. A ferredoxin interaction has been observed previously for the Ech hydrogenase. Here we present a detailed analysis of a Methanosarcina mazei Delta ech mutant which shows decreased ferredoxin-dependent membrane-bound electron transport activity, a lower growth rate, and faster substrate consumption. Evidence is presented that a second protein whose identity is unknown oxidizes reduced ferredoxin, indicating an involvement in methanogenesis from methylated C(1) compounds.

Novel CLN8 mutations confirm the clinical and ethnic diversity of late infantile neuronal ceroid lipofuscinosis

The neuronal ceroid lipofuscinoses (NCLs) are a group of inherited lysosomal storage diseases and the prototype of childhood onset neurodegenerative disorders. To date, 10 NCL entities (CLN1-CLN10) are known and characterized by accumulation of autofluorescent storage material, age of onset and clinical symptoms. CLN8 was first identified as the causative gene for a late-onset form with progressive epilepsy and mental retardation in Finnish patients. In addition, CLN8 phenotypes were described in Turkish, Israeli and Italian patients with a more rapid progression of visual loss, epilepsy, ataxia and mental decline. Here, we report the first mutations in German (c.611G>T) and Pakistani (c.709G>A) patients. Our findings confirm previous assumptions that the CLN8 variant can occur in many ethnic groups. So far, large CLN gene deletions are only known for the CLN3 gene. Here, we also describe a novel, large CLN8 gene deletion c.544-2566_590del2613 in a Turkish family with a slightly more severe phenotype. Our data indicate that patients with clinical signs of late infantile NCL and characteristic ultrastructural inclusions should also be screened for CLN8 mutations independent of their ethnic origin.

Folate receptor alpha defect causes cerebral folate transport deficiency: a treatable neurodegenerative disorder associated with disturbed myelin metabolism

Sufficient folate supplementation is essential for a multitude of biological processes and diverse organ systems. At least five distinct inherited disorders of folate transport and metabolism are presently known, all of which cause systemic folate deficiency. We identified an inherited brain-specific folate transport defect that is caused by mutations in the folate receptor 1 (FOLR1) gene coding for folate receptor alpha (FRalpha). Three patients carrying FOLR1 mutations developed progressive movement disturbance, psychomotor decline, and epilepsy and showed severely reduced folate concentrations in the cerebrospinal fluid (CSF). Brain magnetic resonance imaging (MRI) demonstrated profound hypomyelination, and MR-based in vivo metabolite analysis indicated a combined depletion of white-matter choline and inositol. Retroviral transfection of patient cells with either FRalpha or FRbeta could rescue folate binding. Furthermore, CSF folate concentrations, as well as glial choline and inositol depletion, were restored by folinic acid therapy and preceded clinical improvements. Our studies not only characterize a previously unknown and treatable disorder of early childhood, but also provide new insights into the folate metabolic pathways involved in postnatal myelination and brain development.