Brain-derived neurotrophic factor serum levels in cocaine-dependent patients during early abstinence

Preclinical studies indicate that brain-derived neurotrophic factor (BDNF) is involved in neuroplastic changes underlying enduring cocaine-seeking following withdrawal. However, little is known about temporal changes in serum BDNF levels or the involvement of BDNF in craving and abstinence in early-abstinent cocaine-dependent patients. Twenty-three cocaine-dependent individuals (aged 33.65±6.85 years) completed a two-week detoxification program at an inpatient facility. Two serum samples were collected for each patient at baseline and at the end of the protocol. Serum samples were also collected for 46 healthy controls (aged 35.52±9.37 years). Demographic, consumption and clinical data were recorded for all patients. Significantly lower serum BDNF levels (p<.0001) were observed for cocaine-dependent patients at baseline compared to healthy controls. Serum BDNF levels increased significantly across 12 days of early abstinence (p=.030). Baseline BDNF levels correlated with craving (p=.034). Post-detoxification BDNF levels correlated with craving (p=.018), loss of control (p<.000), abstinence measures (p=0.031), depression (p=0.036), and anxiety (p=0.036). Post-detoxification BDNF levels also had predictive value for the loss of control measure of craving. Chronic cocaine use is associated with decreased serum BDNF. A progressive increase in serum BDNF levels during early abstinence correlates with cocaine craving and abstinence symptoms and may reflect increasing BDNF levels in different brain regions. These findings suggest that serum BDNF may be a biomarker for cocaine addiction.     

The Influence of Medical Student Gender and Drug Use on the Detection of Addiction in Patients

Little is known about medical students’ interest in their training on drug addiction, their personal experience of consumption, and whether these aspects influence the detection of addiction in patients. Eighty-eight and one half percent considered that drug dependence issues are important to their professional future. The students report consuming alcohol (69%), cigarettes (19.5%), and illegal drugs (15.8%). Female students consumed fewer illegal drugs than the men (p =.022). Male students consumed more illegal drugs more frequently (p =.005), knew more consumers (p =.023), and those who drink alcohol consumed more illegal drugs than women who drink alcohol (p <.005). Drug and alcohol consumption among medical students may serve to normalize consumption and thus, may prevent the detection of addicts. It is important to educate and raise awareness about drugs and alcohol use, as this may influence detection. The focus should be particularly on the male group.     

Candidatus Rickettsia hoogstraalii in Ethiopian Argas persicus ticks

Ethiopian soft ticks Argas persicus, hard ticks including both Amblyomma variegatum and Rhipicephalus (Boophilus) spp., and fleas were collected from livestock, traditional human dwellings, and cracks and crevices of trees. They were assessed in pools for the presence of Rickettsia using PCR-based methods. The extracted tick DNA was subjected to molecular screening for Rickettsia, which revealed 50.5% of the pooled samples to be positive for Rickettsia spp. These were then subjected to multi-gene analysis using both outer surface proteins and housekeeping genes with proven discriminatory potential. Sequencing of the citrate synthase and outer membrane genes clearly led to the identification of three distinct rickettsial species, Candidatus Rickettsia hoogstraalii in Argas persicus ticks; R. africae in hard tick pools, and R. felis in fleas. Furthermore, we demonstrated the presence of the plasmid-borne small heat-shock protein gene hsp2 in DNA from A. persicus ticks suggesting that Candidatus R. hoogstraalii carried by these ticks possess a plasmid. Unlike chromosomal gene sequences, the hsp2 gene failed to cluster with Candidatus R. hoogstraalii, instead falling into an isolated separate clade, suggesting a different origin for the plasmid.     

Neurophysiological observations on the effects of botulinum toxin treatment in patients with dystonic blepharospasm.

Botulinum toxin treatment improves dystonic blepharospasm by inducing transient paresis of the orbicularis oculi muscle. It is not known if it also reduces the enhanced brainstem neuronal excitability found in this disorder. We have performed conventional electromyography (EMG) and blink reflex excitability studies on fifteen patients with blepharospasm before and after botulinum toxin treatment. Denervation signs were found with needle EMG in all treated muscles. Amplitude of the facial compound muscle action potential (CMAP) and R1 response was reduced after botulinum toxin injections. In blink reflex excitability studies, the recovery of R2 response was enhanced after treatment even when patients were tested at the time of maximal benefit from botulinum toxin injections. The results suggest that there is little influence of botulinum toxin treatment upon the enhanced excitability of brainstem interneurons in patients with blepharospasm.     

Influência da dose de propofol e dos componentes sanguíneos na duração das convulsões elétricas em eletroconvulsoterapia

Background and objectives

Propofol is commonly employed as a hypnotic agent to perform electroconvulsive therapy, but it exhibits also anticonvulsant properties. The main objective was to study the effect of the weight‐adjusted dose of propofol on duration of the electrical seizure. Secondary objectives were to study the effect of absolute dose of propofol on duration of electrical seizure, the effect of both absolute and weight‐adjusted doses on values of bispectral index, and the influence of blood chemistry on anticonvulsant effect.

Novel SLC7A7 large rearrangements in lysinuric protein intolerance patients involving the same AluY repeat

Lysinuric protein intolerance (LPI) is a rare autosomal inherited disease caused by defective cationic aminoacid transport 4F2hc/y(+)LAT-1 at the basolateral membrane of epithelial cells in the intestine and kidney. LPI is a multisystemic disease with a variety of clinical symptoms such as hepatosplenomegaly, osteoporosis, hypotonia, developmental delay, pulmonary insufficiency or end-stage renal disease. The SLC7A7 gene, which encodes the y(+)LAT-1 protein, is mutated in LPI patients. Mutation analysis of the promoter localized in intron 1 and all exons of the SLC7A7 gene was performed in 11 patients from 9 unrelated LPI families. Point mutation screening was performed by exon direct sequencing and a new multiplex ligation probe amplification (MLPA) assay was set up for large rearrangement analysis. Eleven SLC7A7-specific mutations were identified, seven of them were novel: p.L124P, p.C425R, p.R468X, p.Y274fsX21, c.625+1G>C, DelE4-E11 and DelE6-E11. The novel large deletions originated by the recombination of Alu repeats at introns 3 and 5, respectively, with the same AluY sequence localized at the SLC7A7 3' region. The novel MLPA assay is robust and valuable for LPI molecular diagnosis. Our results suggest that genomic rearrangements of SLC7A7 play a more important role in LPI than has been reported, increasing the detection rate from 5.1 to 21.4%. Moreover, the 3' region AluY repeat could be a recombination hot spot as it is involved in 38% of all SLC7A7 rearranged chromosomes described so far.     

Prefrontal cortex volume reduction on MRI in preclinical Huntington's disease relates to visuomotor performance and CAG number

PURPOSE: To investigate grey matter volumes on magnetic resonance imaging (MRI) in preclinical Huntington's disease (HD), and their relationship to neuropsychology and CAG number. MATERIAL AND METHODS: Twenty preclinical HD carriers and 21 healthy controls matched for age, sex, and educational level were included in this study. Clinical (UHDRS), and detailed neuropsychological assessments, and 3D IR SPGR axial MR acquisition. Calculation of global, segmented (SIENAX), and focal (voxel based morphometry, VBM) grey matter volumes was carried out. An analysis of variance (ANOVA) and a general linear model for VBM analysis were used to compare preclinical HD carriers and controls. Small volume correction was used, and clusters at p<0.05 were considered significant. Correlation analysis (VBM) with neuropsychology, and CAG number was also performed. RESULTS: Preclinical HD carriers showed, compared to controls, smaller global volumes of the brain (1279+/-6 vs. 1331+/-46, p=0.003), total (666+/-48 vs. 698+/-34, p=0.020) and cortical grey matter (551+/-44 vs. 577+/-32, p=0.035). When compared to the controls, preclinical carriers showed focal volume losses, which were more prominent in the left prefrontal cortex, cerebellum, and right posterior temporal cortex. Preclinical HD performed slower in a visuomotor integration task, the 15-Objects test, than controls (t (1,25.02)=3.69; p=0.001: pre-HD: 69.55+/-28.86; controls: 45.79+/-8.38). A correlation was found between volume loss in the prefrontal cortex, visuomotor performance, and CAG number. CONCLUSION: Preclinical HD carriers show grey matter volume reduction involving the prefrontal cortex, which relates to the visuomotor performance and CAG number. This suggests that regionally selective neuronal loss/dysfunction occurs prior to the clinical onset of symptoms.