Association between ADHD and smoking in adolescence: shared genetic,environmental and psychopathological factors

Summary The present study aimed to examine the extent to which the co-occurrence of ADHD and smoking in adolescents could be attributed to common genetic, environmental and psychopathological factors. Data are from an ongoing prospective study of the outcome of early risk factors. At age 15 years, 305 adolescents completed self-report questionnaires measuring tobacco consumption and deviant peer affiliations. Lifetime psychiatric diagnoses were obtained using standardized interviews. DNA was genotyped for the dopamine D4 receptor (DRD4) gene exon III polymorphism. Adolescents with a lifetime diagnosis of ADHD displayed significantly higher smoking activity than non-ADHD controls. A major component of this association could be accounted for by deviant peer affiliations and the comorbidity with oppositional-defiant and conduct disorder, while a minor part was attributable to DRD4 in males but not in females. These findings suggest that the association of ADHD with smoking relies on risk factors shared by the two behaviors.     

Lower P300 amplitude in eight-year-old offspring of alcoholic fathers with a delinquent history

The aim of the present study was to investigate the P300 amplitude as a possible vulnerability marker in children of alcoholic (COA) fathers with and without paternal delinquency. Event-related potentials (ERPs) of 122 children aged 8 years (63 boys, 59 girls) were compared depending on father’s alcoholism subtype: 30 COAs without paternal delinquency, 10 COAs with paternal delinquency, and 82 children of non-alcoholic and non-delinquent fathers. ERPs were recorded from Fz, Cz, and Pz, using an auditory oddball paradigm. Sinus tones of 60 dB HL were presented binaurally at 1,000 Hz (standard stimulus) and 2,000 Hz (target stimulus), at a relative frequency ratio of 80:20. Two trial blocks of 250 stimuli each were collected. Results indicated that only COAs with paternal delinquency displayed significant differences from the control group, characterized by reduced P300 amplitude at frontal site and in the second trial block. Thus, the combination of fathers’ alcoholism and delinquency was more likely to relate to attenuated P300 amplitude in the offspring than paternal alcoholism alone. Our results suggest that both alcoholic and delinquent family history appear to play a role in P300 amplitude reduction in the offspring.     

Triggering sleep slow waves by transcranial magnetic stimulation

During much of sleep, cortical neurons undergo near-synchronous slow oscillation cycles in membrane potential, which give rise to the largest spontaneous waves observed in the normal electroencephalogram (EEG). Slow oscillations underlie characteristic features of the sleep EEG, such as slow waves and spindles. Here we show that, in sleeping subjects, slow waves and spindles can be triggered noninvasively and reliably by transcranial magnetic stimulation (TMS). With appropriate stimulation parameters, each TMS pulse at <1 Hz evokes an individual, high-amplitude slow wave that originates under the coil and spreads over the cortex. TMS triggering of slow waves reveals intrinsic bistability in thalamocortical networks during non-rapid eye movement sleep. Moreover, evoked slow waves lead to a deepening of sleep and to an increase in EEG slow-wave activity (0.5-4.5 Hz), which is thought to play a role in brain restoration and memory consolidation.     

Towards solid tumor treatment by irreversible electroporation: intrinsic redistribution of fields and currents in tissue

Local and drug-free tissue treatment by irreversible electroporation (IRE) involves the creation of aqueous pores in a cell's plasma membrane (PM) and leads to non-thermal cell death by necrosis. To investigate explicit pore-based effects we use two-dimensional system models with different spatial scales. The first is a multicellular system model (spatial scale 100 mum) that has irregularly shaped cells, and quantitatively describes dynamic (creation and destruction, evolution in pore size) pore behavior at the PM. The second is a tissue model (spatial scale 200 mm) that is constructed from a unit cell and uses the asymptotic (fixed pore size) electroporation model. Both system models show that significant redistribution of fields and currents occurs through transient PM pores. Pore histograms for the multicellular model demonstrate the simultaneous presence of small and large pores during IRE pulses. The associated significant increase of PM permeability may prove to be essential to understanding how cell death by necrosis occurs. The averaged tissue conductivity in both models increases during IRE pulses because of electroporation. This leads to greater electrical dissipation (heating) and, thus, to larger temperature increases than suggested by tissue models with passive and static electrical properties.     

Spectacle lenses in sports: optimization of the imaging properties based on physiological aspects

The goal of correction spectacles is to create a sharp image on the retina by the combined optical system of the eye and the spectacle lens for a given ametropia. As a matter of principle, in this optical system an aberration free correction can be achieved in the optical centre of the spectacle lens, but not over the entire range of gaze angles. In spectacle optics large angles play an important role, different from paraxial optics where only rays close to the axis with small angles of incidence are relevant. This generates additional aberrations, the so-called oblique astigmatism, which can only be compensated at the expense of the spherical power. Therefore, every spectacle lens represents apart from the main visual point-, a more or less good compromise. For sports lenses in the currently used curved frames, an additional challenge arises from the fact that their orientation in front of the eye is generally not perpendicular to the principal gaze direction but tilted. In this article the imaging properties of such tilted sports lenses are discussed, and it is described why this results in a minor quality without a specific consideration of the obliqueness. The fact that tilted sports spectacles are also able to possess an improved correction behaviour for all gaze angles is due to individual mathematical optimization methods. The aim of the present article is, based on the underlying physical and physiological effects, to point out the advantages of individually optimized sports spectacle lenses in comparison to tilted lenses generated without applying this sophisticated computational method.     

Bakterielle Kolonisation chronischer Wunden

In this retrospective investigation, we documented the bacterial colonization of 79 patients with chronic wounds, who had been treated between January 2002 and May 2003 in an outpatient wound healing clinic of a university dermatology program. We isolated 106 facultative pathogenic bacterial strains of which 56 were Staphylococcus aureus, 19 Pseudomonas aeruginosa, 11 Escherichia coli, 4 Proteus mirabilis, 4 Enterobacter cloacae, 2 Serratia marcescens, 2 Streptococcus group G und 8 further species. 68 of these bacterial strains were gram-positive and 46 gram-negative. Moreover we identified one patient with Candida parapsilosis. Therefore, 70.8% of all patients showed Staphylococcus aureus in their chronic wounds. Determination of the specific resistances showed 17 patients to be colonized with oxacillin- resistant Staphylococcus aureus (ORSA) strain; this corresponds to 21.5% of all patients. Consequently, 30.4% of all Staphylococcus aureus isolates were ORSA strains. All of the ORSA isolates were sensitive to vancomycin. Sensitivity to tetracycline was documented in 15, to amikacin in 13, to clindamycin in 7, to gentamicin and erythromycin in 6 of the ORSA-positive patients. In the case of trimethoprim/sulfamethoxazole, 10 were sensitive and 3 were intermediate in sensitivity. Beside the obligate resistance to oxacillin, penicillin G, ampicillin, cefuroxime and imipenem, none of the ORSA was sensitive to ofloxacin. The results of our investigations demonstrate the actual spectrum of bacterial colonization in chronic wounds of patients in an university dermatologic wound clinic and underline the growing problem of ORSA.     

Free fatty acids as modulators of the NLRP3 inflammasome in obesity/type 2 diabetes

Free fatty acids (FFAs) are metabolic intermediates that may be obtained through the diet or synthesized endogenously. In addition to serving as an important source of energy, they produce a variety of both beneficial and detrimental effects. They play essential roles as structural components of all cell membranes and as signaling molecules regulating metabolic pathways through binding to nuclear or membrane receptors. However, under conditions of FFAs overload, they become toxic, inducing ROS production, ER stress, apoptosis and inflammation. SFAs (saturated fatty acids), unlike UFAs (unsaturated fatty acids), have recently been proposed as triggers of the NLRP3 inflammasome, a molecular platform mediating the processing of IL-1β in response to infection and stress conditions. Interestingly, UFAs, especially ω-3 FAs, inhibit NLRP3 inflammasome activation in various settings. We focus on emerging models of NLRP3 inflammasome activation with a special emphasis on the molecular mechanisms by which FFAs modulate the activation of this complex. Taking into consideration the current literature and FFA properties, we discuss the putative involvement of mitochondria and the role of cardiolipin, a mitochondrial phospholipid, proposed to be sensed by NLRP3 after release, exposure and/or oxidation. Finally, we review how this SFA-mediated NLRP3 inflammasome activation contributes to the development of both insulin resistance and deficiency associated with obesity/type 2 diabetes. In this context, we highlight the potential clinical use of ω-3 FAs as anti-inflammatory compounds.