Potential of Stem Cell-Based Therapy for Ischemic Stroke

Ischemic stroke is one of the major health problems worldwide. The only FDA approved anti-thrombotic drug for acute ischemic stroke is the tissue plasminogen activator. Several studies have been devoted to assessing the therapeutic potential of different types of stem cells such as neural stem cells (NSCs), mesenchymal stem cells, embryonic stem cells, and human induced pluripotent stem cell-derived NSCs as treatments for ischemic stroke. The results of these studies are intriguing but many of them have presented conflicting results. Additionally, the mechanism(s) by which engrafted stem/progenitor cells exert their actions are to a large extent unknown. In this review, we will provide a synopsis of different preclinical and clinical studies related to the use of stem cell-based stroke therapy, and explore possible beneficial/detrimental outcomes associated with the use of different types of stem cells. Due to limited/short time window implemented in most of the recorded clinical trials about the use of stem cells as potential therapeutic intervention for stroke, further clinical trials evaluating the efficacy of the intervention in a longer time window after cellular engraftments are still needed.

Fully Differential Study of Capture with Vibrational Dissociation in p+H_{2} Collisions

We have measured fully differential cross sections for electron capture in 75 keV p+H_{2} collisions with subsequent dissociation of the intermediate molecular H_{2}^{+} ion by vibrational excitation using different projectile coherence lengths. Data were obtained for two molecular orientations as a function of projectile scattering angle. Two types of interference, single- and molecular two-center interference, were identified. The two-center interference structure is phase shifted by π compared to what we expected. Furthermore, the presence of projectile coherence effects could be reconfirmed.

Polygenic risk has an impact on the structural plasticity of hippocampal subfields during aerobic exercise combined with cognitive remediation in multi-episode schizophrenia

Preliminary studies suggest that, besides improving cognition, aerobic exercise might increase hippocampal volume in schizophrenia patients; however, results are not consistent. Individual mechanisms of volume changes are unknown but might be connected to the load of risk genes. Genome-wide association studies have uncovered the polygenic architecture of schizophrenia. The secondary analysis presented here aimed to determine the modulatory role of schizophrenia polygenic risk scores (PRSs) on volume changes in the total hippocampus and cornu ammonis (CA) 1, CA2/3, CA4/dentate gyrus (DG) and subiculum over time. We studied 20 multi-episode schizophrenia patients and 23 healthy controls who performed aerobic exercise (endurance training) combined with cognitive remediation for 3 months and 21 multi-episode schizophrenia patients allocated to a control intervention (table soccer) combined with cognitive remediation. Magnetic resonance imaging-based assessments were performed at baseline and after 3 months with FreeSurfer. No effects of PRSs were found on total hippocampal volume change. Subfield analyses showed that the volume changes between baseline and 3 months in the left CA4/DG were significantly influenced by PRSs in schizophrenia patients performing aerobic exercise. A larger genetic risk burden was associated with a less pronounced volume increase or a decrease in volume over the course of the exercise intervention. Results of exploratory enrichment analyses reinforced the notion of genetic risk factors modulating biological processes tightly related to synaptic ion channel activity, calcium signaling, glutamate signaling and regulation of cell morphogenesis. We hypothesize that a high polygenic risk may negatively influence neuroplasticity in CA4/DG during aerobic exercise in schizophrenia.

[Healthcare models for traumatized refugees in Germany]

People with a migration background are a risk group for psychiatric disorders. Innovative, transnational and sustainable projects are necessary to ensure adequate care for refugees and asylum seekers. Selected projects of the University of Munich, the Charité Berlin and the University of Konstanz show promising approaches in addition to other initiatives.

Structural brain changes are associated with response of negative symptoms to prefrontal repetitive transcranial magnetic stimulation in patients with schizophrenia

Impaired neural plasticity may be a core pathophysiological process underlying the symptomatology of schizophrenia. Plasticity-enhancing interventions, including repetitive transcranial magnetic stimulation (rTMS), may improve difficult-to-treat symptoms; however, efficacy in large clinical trials appears limited. The high variability of rTMS-related treatment response may be related to a comparably large variation in the ability to generate plastic neural changes. The aim of the present study was to determine whether negative symptom improvement in schizophrenia patients receiving rTMS to the left dorsolateral prefrontal cortex (DLPFC) was related to rTMS-related brain volume changes. A total of 73 schizophrenia patients with predominant negative symptoms were randomized to an active (n=34) or sham (n=39) 10-Hz rTMS intervention applied 5 days per week for 3 weeks to the left DLPFC. Local brain volume changes measured by deformation-based morphometry were correlated with changes in negative symptom severity using a repeated-measures analysis of covariance design. Volume gains in the left hippocampal, parahippocampal and precuneal cortices predicted negative symptom improvement in the active rTMS group (all r⩽-0.441, all P⩽0.009), but not the sham rTMS group (all r⩽0.211, all P⩾0.198). Further analyses comparing negative symptom responders (⩾20% improvement) and non-responders supported the primary analysis, again only in the active rTMS group (F_{(9, 207)}=2.72, P=0.005, partial η ²=0.106). Heterogeneity in clinical response of negative symptoms in schizophrenia to prefrontal high-frequency rTMS may be related to variability in capacity for structural plasticity, particularly in the left hippocampal region and the precuneus.

[Obsessive-Compulsive Symptoms in a Sample of Patients with Chronic Schizophrenia Under Clozapine Treatment]

Background: There is a high prevalence of obsessive-compulsive symptoms (OCS) in patients with schizophrenia. Antipsychotic treatment, especially duration and type of substance, is suspected to increase or even cause OCS. Methods: We examined in a naturalistic cross-sectional study the severity of OCS (Obsessive-Compulsive Inventory - Revised) and the incidence of obsessive-compulsive disorder (OCD) according to ICD-10 criteria in 70 patients with schizophrenia. 26 patients were treated with clozapine and 44 patients were treated with another second-generation antipsychotic (SGA). After group matching, the two groups did not differ significantly in age, gender, duration of illness, treatment duration with the current antipsychotic substance and chlorpromazine-equivalent dosage. Results: Patients treated with Clozapine showed a significantly higher rate of OCD (χ² = 7.304, p = 0.007) and a significantly higher severity of OCS (t = 2.216, p = 0.037) compared to patients treated with another SGA. For the whole sample, duration of treatment with the current antipsychotic medication correlated significantly (p = 0.033, r = 0.323) with the severity of OCS, controlled for duration of illness. However, there was no significant correlation between severity of OCS and duration of illness, controlled for duration of treatment with the current antipsychotic substance. Discussion: Our data suggest an interrelation between the development of OCS or OCD and antipsychotic treatment, especially clozapine. Thereby, duration of treatment is correlated with the severity of OCS, irrespective of the duration of illness.

[Non-invasive brain stimulation for treatment of schizophrenic psychoses]

Despite many different available pharmacological and psychosocial treatment options, an optimal control of symptoms is only partly possible for most schizophrenia patients. Especially, persistent auditory hallucinations, negative symptoms and cognitive impairment are difficult to treat symptoms. Several non-invasive brain stimulation techniques are increasingly being considered as new therapeutic add on options for the management of schizophrenia, targeting these symptom domains. The technique which has been available for the longest time and that is best established in clinical care is electroconvulsive therapy (ECT). New stimulation techniques, such as repetitive transcranial magnetic stimulation (rTMS) and transcranial direct current stimulation (tDCS) allow a more pathophysiological-based approach. This review article introduces various non-invasive brain stimulation techniques and discusses recent treatment studies on schizophrenia. In total, the novel brain stimulation techniques discussed here can be considered relevant add on therapeutic approaches for schizophrenia. In this context, the best evidence is available for the application of rTMS for the treatment of negative symptoms and persistent auditory hallucinations; however, negative studies have also been published for both indications. Studies using other non-invasive brain stimulation techniques showed promising results but further research is needed to establish the clinical efficacy. Based on a growing pathophysiological knowledge, non-invasive brain stimulation techniques provide new treatment perspectives for patients with schizophrenia.

[Psychosis - clinical differential diagnosis]

BACKGROUND

Many patients with psychiatric and organic disorders may present primary or secondary psychotic symptoms. Based on the ICD 10 classification, this article describes the possible underlying diseases and their subdivision. The main focus will be differential-diagnostic evaluations of psychotic syndromes.

RESULTS

In the clinical setting, the differential diagnosis of the paranoid schizophrenia and other psychotic disorders into three main disease groups is important: 1. other psychiatric diseases, 2. primary and secondary organic diseases and 3. autoimmune diseases. The first group contains, for example, drug-induced psychoses, affective disorders, personality disorders. The second group includes forms of dementia, forms of deliria or metabolic diseases. Recently, another focus is set on autoimmune diseases, especially encephalitides.

SUMMARY

A detailed medical history, a physical examination and organic diagnostic can lead to the correct diagnosis and therapy. The differential-diagnostic classification and the detection of organic causes is an important part of psychiatric care, but often a good cooperation with organic specialties is needed.

Evaluation of the 'Jumping to conclusions' bias in different subgroups of the at-risk mental state: from cognitive basic symptoms to UHR criteria

BACKGROUND

Patients with psychosis display the so-called 'Jumping to Conclusions' bias (JTC) - a tendency for hasty decision-making in probabilistic reasoning tasks. So far, only a few studies have evaluated the JTC bias in 'at-risk mental state' (ARMS) patients, specifically in ARMS samples fulfilling 'ultra-high risk' (UHR) criteria, thus not allowing for comparisons between different ARMS subgroups.

METHOD

In the framework of the PREVENT (secondary prevention of schizophrenia) study, a JTC task was applied to 188 patients either fulfilling UHR criteria or presenting with cognitive basic symptoms (BS). Similar data were available for 30 healthy control participants matched for age, gender, education and premorbid verbal intelligence. ARMS patients were identified by the Structured Interview for Prodromal Symptoms (SIPS) and the Schizophrenia Proneness Instrument - Adult Version (SPI-A).

RESULTS

The mean number of draws to decision (DTD) significantly differed between ARM -subgroups: UHR patients made significantly less draws to make a decision than ARMS patients with only cognitive BS. Furthermore, UHR patients tended to fulfil behavioural criteria for JTC more often than BS patients. In a secondary analysis, ARMS patients were much hastier in their decision-making than controls. In patients, DTD was moderately associated with positive and negative symptoms as well as disorganization and excitement.

CONCLUSIONS

Our data indicate an enhanced JTC bias in the UHR group compared to ARMS patients with only cognitive BS. This underscores the importance of reasoning deficits within cognitive theories of the developing psychosis. Interactions with the liability to psychotic transitions and therapeutic interventions should be unravelled in longitudinal studies.

Plasma paraoxonase, oxidative status level, and their relationship with asthma control test in children with asthma

BACKGROUND

Assessment of asthma with a control test has been suggested as a relevant approach in recent years. However, no biomarker of systemic inflammation has been included in the assessment of asthma control.

OBJECTIVE

To evaluate plasma paraoxonase (PON1), total oxidant status (TOS), and total antioxidant status (TAS) levels in children with asthma according to the disease control, and the performance in the identification of uncontrolled patients.

METHODS

Stable asthmatic children (n=85) and healthy controls (n=55) were recruited for this study. Blood samples were collected for plasma PON1, TOS, and TAS measurements. Any contributing factors that may affect plasma PON1, TAS, and TOS levels were excluded from both groups. The diagnostic potential of these measures was evaluated using receiver operating characteristic (ROC) analysis.

RESULTS

Comparing the asthmatic children with the control group, plasma TAS and TOS levels were significantly higher (TAS; 6.9 ± 2.1, 1.05 ± 0.32, P<0.001, and TOS; 12.5 ± 3.4, 5.5 ± 3.8, P<0.001, respectively) and PON1 level was significantly lower (156.5 ± 55, 298.6 ± 87.6, respectively, P<0.001) in the asthmatic group than controls. In ROC analysis, PON1 presented an AUC 0.679 and TOS presented an AUC 0.645 for the identification of uncontrolled asthma, respectively. Asthma Control Test (ACT) presented an AUC of 0.972 for the identification of uncontrolled asthma.

CONCLUSION

PON1 and TOS levels may be systemic markers of uncontrolled asthma in children. Combined use of these two biomarkers with asthma control test may identify patients with uncontrolled asthma in children.

Affinity maturation of T-cell receptor-like antibodies for Wilms tumor 1 peptide greatly enhances therapeutic potential

WT1₁₂₆ (RMFPNAPYL) is a human leukocyte antigen-A2 (HLA-A2)-restricted peptide derived from Wilms tumor protein 1 (WT1), which is widely expressed in a broad spectrum of leukemias, lymphomas and solid tumors. A novel T-cell-receptor (TCR)-like single-chain variable fragment (scFv) antibody specific for the T-cell epitope consisting of the WT1/HLA-A2 complex was isolated from a human scFv phage library. This scFv was affinity-matured by mutagenesis combined with yeast display and structurally analyzed using a homology model. This monovalent scFv showed a 100-fold affinity improvement (dissociation constant (K_D)=3 nm) and exquisite specificity towards its targeted epitope or HLA-A2⁺/WT1⁺ tumor cells. Bivalent scFv-huIgG1-Fc fusion protein demonstrated an even higher avidity (K_D=2 pm) binding to the T-cell epitope and to tumor targets and was capable of mediating antibody-dependent cell-mediated cytotoxicity or tumor lysis by chimeric antigen receptor-expressing human T- or NK-92-MI-transfected cells. This antibody demonstrated specific and potent cytotoxicity in vivo towards WT1-positive leukemia xenograft that was HLA-A2 restricted. In summary, T-cell epitopes can provide novel targets for antibody-based therapeutics. By combining phage and yeast displays and scFv-Fc fusion platforms, a strategy for developing high-affinity TCR-like antibodies could be rapidly explored for potential clinical development.