Next-generation sequencing for minimal residual disease monitoring in acute myeloid leukemia patients with FLT3-ITD or NPM1 mutations

Systematic assessment of minimal residual disease (MRD) in acute myeloid leukemia (AML) patients has been hampered by lack of a reliable, uniform MRD marker applicable to all patients. We evaluated next-generation sequencing (NGS) for MRD assessment in AML patients (n = 80 samples). The ability of NGS technologies to generate thousands of clonal sequences makes it possible to determine the allelic ratio of sequence variants. Using NGS, we were able to determine the allelic ratio of different FLT3-internal tandem duplication (ITD) clones within one patient sample, in addition to resolution of FLT3-ITD insertion site, length, and sequence in a single analysis. Furthermore, NGS allowed us to study emergence of clonal dominance. Parallel assessment of MRD by NGS and quantitative real-time polymerase chain reaction in NPM1 mutated patients was concordant in 95% of analyzed samples (n = 38). The frequency of mutated alleles was linearly quantified by NGS. As NGS sensitivity is scalable depending on sequence coverage, it reflects a highly flexible and reliable tool to assess MRD in leukemia patients.     

Immunogenicity of HIV Virus-Like Particles in Rhesus Macaques by Intranasal Administration

Female rhesus macaques were immunized with HIV virus-like particles (HIV-VLPs) or HIV DNA administered as sequential combinations of mucosal (intranasal) and systemic (intramuscular) routes, according to homologous or heterologous prime-boost schedules. The results show that in rhesus macaques only the sequential intranasal and intramuscular administration of HIV-VLPs, and not the intranasal alone, is able to elicit humoral immune response at the systemic as well as the vaginal level.     

Drugs that inhibit complement

The complement system is an important part of the innate immune system. Complement plays a crucial role in the pathophysiology of many disorders.Despite the pivotal role of the complement system, an approved targeted inhibitor of a complement factor became available only recently. Eculizumab is a humanized monoclonal antibody that inhibits complement factor C5. It is a targeted, disease modifying, treatment of paroxysmal nocturnal hemoglobinuria (PNH). It was approved be the US FDA and the European Commission in 2007. In this review we will update the experience with eculizumab in PNH and discuss potential use of eculizumab in other disorders (e.g. cold agglutinin disease; atypical HUS) and new approaches to complement inhibition with drugs other than eculizumab.     

Agmatine (decarboxylated L-arginine): physiological role and therapeutic potential

Agmatine, a cationic amine formed by decarboxylation of l-arginine by the mitochondrial enzyme arginine decarboxylase (ADC), is widely but unevenly distributed in mammalian tissues. Agmatine in the tissues originates from cellular enzymatic de novo synthesis and from agmatine absorbed from the lumen of the gut. Absorption from the gut and accumulation in the tissues and cells must occur via a specific carrier mechanism because the compound is charged at physiologic pH and, hence, biological membranes are almost completely impermeable to the organic cation in the absence of an uptake system. Agmatine initially attracted attention as an endogenous ligand at imidazoline receptors and α₂-adrenoceptors. However, independent of binding to those receptors, agmatine induces a variety of physiological and pharmacological effects exhibiting a great therapeutic potential of the compound. Although the precise function of endogenous agmatine is presently still unclear, this review summarizes the current knowledge concerning the physiological and pathophysiological function of agmatine.     

An fMRI study on the acute effects of exercise on pain processing in trained athletes

Endurance exercise is known to promote sustained antinociceptive effects, and there is evidence that the reduction of pain perception mediated by exercise is driven by central opioidergic neurotransmission. To directly investigate the involved brain areas and the underlying neural mechanisms in humans, thermal heat-pain challenges were applied to 20 athletes during 4 separate functional magnetic resonance imaging (fMRI) scans, i.e., before and after 2 hours of running (exercise condition) and walking (control condition), respectively. Imaging revealed a reproducible pattern of distributed pain-related activation in all 4 conditions, including the mesial and lateral pain systems, and the periaqueductal gray (PAG) as a key region of the descending antinociceptive pathway. At the behavioral level, running as compared with walking decreased affective pain ratings. The influence of exercise on pain-related activation was reflected in a significant time × treatment interaction in the PAG, along with similar trends in the pregenual anterior cingulate cortex and the middle insular cortex, where pain-induced activation levels were elevated after walking, but decreased or unchanged after running. Our findings indicate that enhanced reactive recruitment of endogenous antinociceptive mechanisms after aversive repeated pain exposure is attenuated by exercise. The fact that running, but not walking, reproducibly elevated β-endorphin levels in plasma indicates involvement of the opioidergic system in exercise. This may argue for an elevated opioidergic tone in the brain of athletes, mediating antinociceptive mechanisms. Our findings provide the first evidence using functional imaging to support the role of endurance exercise in pain modulation.     

Response activation impairments in schizophrenia: evidence from the lateralized readiness potential

Previous research has demonstrated deficits in preresponse motor activity in schizophrenia, as evidenced by a reduced lateralized readiness potential (LRP). The LRP deficit could be due to increased activation of the incorrect response (e.g., failure to suppress competition) or to reduced activation of the correct response (e.g., a low-level impairment in response preparation). To distinguish these possibilities, we asked whether the LRP impairment is increased under conditions of strong response competition. We manipulated the compatibility of stimulus-response mappings (Experiment 1) and the compatibility of the target with flankers (Experiment 2). In both experiments, the patient LRP was reduced as much under conditions of low response competition as under high competition. These results are incompatible with a failure of patients to suppress competition and are instead consistent with a deficit in activating the correct response.     

T-cell trafficking in the central nervous system

To perform their distinct effector functions, pathogen-specific T cells have to migrate to target tissue where they recognize antigens and produce cytokines that elicit appropriate types of protective responses. Similarly, migration of pathogenic self-reactive T cells to target organs is an essential step required for tissue-specific autoimmunity. In this article, we review data from our laboratory as well as other laboratories that have established that effector function and migratory capacity are coordinately regulated in different T-cell subsets. We then describe how pathogenic T cells can enter into intact or inflamed central nervous system (CNS) to cause experimental autoimmune encephalomyelitis or multiple sclerosis. In particular, we elaborate on the role of CCR6/CCL20 axis in migration through the choroid plexus and the involvement of this pathway in immune surveillance of and autoimmunity in the CNS.     

Mimicking normal tissue architecture and perturbation in cancer with engineered micro-epidermis

Correct tissue architecture is essential for normal physiology, yet there have been few attempts to recreate tissues using micro-patterning. We have used polymer brush micro-engineering to generate a stratified micro-epidermis with fewer than 10 human keratinocytes. Epidermal stem cells are captured on 100 μm diameter circular collagen-coated disks. Within 24 h they assemble a stratified micro-tissue, in which differentiated cells have a central suprabasal location. For rings with a non-adhesive centre of up to 40 μm diameter, cell-cell and cell-matrix adhesive interactions together result in correct micro-epidermis assembly. Assembly requires actin polymerization, adherens junctions and desmosomes, but not myosin II-mediated contractility nor coordinated cell movement. Squamous cell carcinoma cells on micro-patterned rings exhibit disturbed architecture that correlates with the characteristics of the original tumours. The micro-epidermis we have generated provides a new platform for screening drugs that modulate tissue assembly, quantifying tissue stratification and investigating the properties of tumour cells.     

Sustainability of interdisciplinary secondary prevention in patients with occupational hand eczema: a 5-year follow-up survey

Background. Occupational hand eczema (OHE) is common in 'wet work' occupations. Thus, effective and sustainable prevention strategies are needed. Objectives. To investigate the long-term effectiveness (sustainability) of an interdisciplinary secondary prevention programme. Methods. One hundred and thirty-four patients with OHE consecutively participated in an outpatient skin protection seminar comprising dermatological and educational interventions. Data were obtained at baseline (T0) and at 9 months (T1) and 5 years (T2) after participation. A cohort of 84 patients was available for analysis of the outcomes 'job continuation', 'skin condition', 'skin protection behaviour', and 'disease management'. Results. At T2, 71.4% of patients remained in their occupation. The prevalence and severity of self-reported OHE were significantly reduced as compared with T0 (p = 0.007, p = 0.002). Of the patients, 13.1% gave up work because of OHE at T2. The intervention was most successful in patients suffering from milder forms of OHE, and there was less success in patients with severe OHE. The results showed a significant reduction in the frequency of 'hand washing' (p = 0.003) but no measurable change in the use of skin care products (p = 1.000). Conclusions. The intervention showed sustainable long-term effects. Early detection and reporting of OHE in the initial stages of the disease is of utmost importance for the effectiveness of secondary prevention. In cases of severe OHE, inpatient programmes may be indicated.