Acute and Chronic Macrophage Differentiation Modulates TREM2 in a Personalized Alzheimer's Patient-Derived Assay.

Neuroinflammation plays a pivotal role in the pathogenesis of Alzheimer`s disease (AD). Brain macrophage populations differentially modulate the immune response to AD pathology according to the disease stage. Triggering receptor expressed on myeloid cells 2 (TREM2) is known to play a protective role in AD and has been postulated as a putative therapeutic target. Whether, and to which extent TREM2 expression can be modulated in the aged macrophage population of the brain is unknown, emphasizing the need for a human, patient-specific model. Using cells from AD patients and matched controls (CO) we designed an assay based on monocyte-derived macrophages to mimic brain-infiltrating macrophages and to assess the individualized TREM2 synthesis in vitro. We systematically assessed the effects of short-term (acute-2 days) and long-term (chronic-10 days) M1- (LPS), M2- (IL-10, IL-4, TGF-ß), and M0- (vehicle) macrophage differentiation on TREM2 synthesis. Moreover, the effects of retinoic acid (RA), a putative TREM2 modulator, on individualized TREM2 synthesis were assessed. We report increased TREM2 synthesis after acute M2- compared to M1-differentiation in CO- but not AD-derived cells. Chronic M2- and M0-differentiation however resulted in an increase of TREM2 synthesis in both AD- and CO-derived cells while chronic M1-differentiation increased TREM2 in AD-derived cells only. Moreover, chronic M2- and M0-differentiation improved the amyloid-ß (Aß) uptake of the CO-derived whereas M1-differentiation of the AD-derived cells. Interestingly, RA-treatment did not modulate TREM2. In the age of personalized medicine, our individualized model could be used to screen for potential drug-mediated treatment responses in vitro. Triggering receptor expressed on myeloid cells 2 (TREM2) has been postulated as a putative therapeutic target in Alzheimer's disease (AD). Using cells from AD patients and matched controls (CO), we designed a monocyte-derived macrophages (Mo-MФs) assay to assess the individualized TREM2 synthesis in vitro. We report increased TREM2 synthesis after acute M2- compared to M1- macrophage differentiation in CO- but not AD-derived cells. Chronic M2- and M0- differentiation however resulted in an increase of TREM2 synthesis in both AD- and CO-derived cells while chronic M1-differentiation increased TREM2 in AD-cells only.

Clozapine modulates retinoid homeostasis in human brain and normalizes serum retinoic acid deficit in patients with schizophrenia.

The atypical antipsychotic clozapine is one of the most potent drugs of its class, yet its precise mechanisms of action remain insufficiently understood. Recent evidence points toward the involvement of endogenous retinoic acid (RA) signaling in the pathophysiology of schizophrenia. Here we investigated whether clozapine may modulate RA-signaling. Effects of clozapine on the catabolism of all-trans RA (at-RA), the biologically most active metabolite of Vitamin A, were assessed in murine and human brain tissue and peripheral blood-derived mononuclear cells (PBMC). In patients with schizophrenia with and without clozapine treatment and matched healthy controls, at-RA serum levels and blood mRNA expression of retinoid-related genes in PBMCs were quantified. Clozapine and its metabolites potently inhibited RA catabolism at clinically relevant concentrations. In PBMC-derived microsomes, we found a large interindividual variability of the sensitivity toward the effects of clozapine. Furthermore, at-RA and retinol serum levels were significantly lower in patients with schizophrenia compared with matched healthy controls. Patients treated with clozapine exhibited significantly higher at-RA serum levels compared with patients treated with other antipsychotics, while retinol levels did not differ between treatment groups. Similarly, in patients without clozapine treatment, mRNA expression of RA-inducible targets CYP26A and STRA6, as well as at-RA/retinol ratio, were significantly reduced. In contrast, clozapine-treated patients did not differ from healthy controls in this regard. Our findings provide the first evidence for altered peripheral retinoid homeostasis in schizophrenia and suggest modulation of RA catabolism as a novel mechanism of action of clozapine, which may be useful in future antipsychotic drug development.

The role of comorbid depressive symptoms on long-range temporal correlations in resting EEG in adults with ADHD.

Attention deficit/hyperactivity disorder (ADHD) is a neurodevelopmental disorder, characterized by core symptoms of inattention, hyperactivity and impulsivity. Comorbid depression is commonly observed in ADHD-patients. Psychostimulants are recommended as first-line treatment for ADHD. Aberrant long-range temporal correlations (LRTCs) of neuronal activities in resting-state are known to be associated with disorganized thinking and concentrating difficulties (typical in ADHD) and with maladaptive thinking (typical in depression). It has yet to be examined whether (1) LRTC occur in ADHD-patients, and if so, (2) whether LRTC might be a competent biomarker in ADHD comorbid with current depression and (3) how depression affects psychostimulant therapy of ADHD symptoms. The present study registered and compared LRTCs in different EEG frequency bands in 85 adults with ADHD between groups with (n = 28) and without (n = 57) additional depressive symptoms at baseline. Treatment-related changes in ADHD, depressive symptoms and LRTC were investigated in the whole population and within each group. Our results revealed significant LRTCs existed in all investigated frequency bands. There were, however, no significant LRTC-differences between ADHD-patients with and without depressive symptoms at baseline and no LRTC-changes following treatment. However, depressed ADHD patients did seem to benefit more from the therapy with psychostimulant based on self-report.

M1/M2 polarization in major depressive disorder: Disentangling state from trait effects in an individualized cell-culture-based approach.

Accumulating evidence indicates the specific involvement of inflammatory processes in major depressive disorder (MDD), particularly affecting innate immunity. Most immune alterations have so far been determined based on plasma or cerebrospinal fluid cytokine levels. To precisely characterize putative innate immune-mediated mechanisms in MDD pathogenesis, we sought to disentangle "state" from "trait" effects in a patient-specific cell model by quantifying the impact of patient-derived autologous sera (AS) on patient-specific monocyte-derived macrophages (Mo-MФs) polarization in vitro. Mo-MФs were generated from 28 patients with moderate to severe MDD and 28 age-, sex-, smoking status- and BMI-matched healthy controls (HC). Cells were treated either with AS or fetal calf serum (FCS) and polarized into M1 (LPS), M2 (IL-10, IL-4, TGF-ß) or M0 (unstimulated) macrophages. Polarization capacity was quantified by means of specific M1 (CCR7, CD86, CXCL10, IL-12p70, TNF-α, IL-6, IL-1ß, IL-12p40, IL-23, IP-10) and M2 (CD206, IL-10, TARC, IL-1RA) markers. Compared to HC, significantly increased M1-polarization was observed for MDD patients in the presence of FCS, however, polarization in AS enriched media determined an increased M2-polarization in patients. Moreover, female MDD patients exhibited increased M1- and decreased M2-polarization in both conditions compared to male MDD patients. Our data suggests that Mo-MФs derived from patients with MDD exhibit facilitated M1-polarization under traditional cell culture conditions and an increased potential for M2-polarization when cultured in AS. Striking inter-individual variation and pronounced gender effects highlight the potential utility of our personalized cell model-based approach to aid diagnostic and therapeutic decisions.

Inhibition of monoamine oxidase activity by repetitive transcranial magnetic stimulation: implications for inter-train interval and frequency.

Repetitive transcranial magnetic stimulation (rTMS) is a neuromodulation technique that stimulates cortical regions via time-varying electromagnetic fields; in several countries this technique has been approved as a treatment for major depressive disorder. One empirically established target in antidepressant pharmacotherapy is the flavin-containing monoamine oxidoreductase (MAO). The function of MAO enzymes is based on oxidation processes that may be sensitive towards strong electromagnetic fields. Therefore, we hypothesized that rTMS-induced electromagnetic fields impact the activity of this enzyme. Using crude synaptosomal cell preparations from human SH-SY5Y neuroblastoma cells and rat cortex as well as viable cells, we assessed the effects of rTMS on MAO-A and -B activity in a well-controlled in vitro set up. In short, samples were stimulated at maximal intensity with an equal number of total stimuli at frequencies of 5, 20, and 100 Hz. Sham stimulation was performed in parallel. Treatment at frequencies of 5 and 20 Hz significantly decreased mainly MAO-B activity in all tissue preparations and species, whereas 100 Hz stimulation remained without effect on any MAO activity. Our results support the hypothesis, that rTMS-induced electromagnetic fields affect MAO activity and provide further evidence for intracellular effects possibly contributing to therapeutic effects of this neuromodulatory method. On a cautionary note, however, our findings are solely based on in vitro evidence.

What happens with schizophrenia patients after their discharge from hospital? Results on outcome and treatment from a "real-world" 2-year follow-up trial.

Aim of the study was to examine the course of schizophrenia patients within 2 years after discharge. Within a multicenter study of the German Competence Network on Schizophrenia, patients suffering from a schizophrenia spectrum disorder were examined regarding their psychopathological improvement, tolerability, and the treatment regime applied during hospitalization and a 2-year follow-up period. Response, remission, the level of everyday functioning, and relapse were furthermore evaluated during the follow-up period using established definitions for these outcome domains. The psychopharmacological treatment was specifically evaluated in terms of a potential association with relapse. 149 patients were available for analysis, with 65% of the patients being in response, 52% in symptomatic remission, and 64% having a satisfiable everyday functioning 2 years after their discharge from hospital. Despite these favorable outcome rates, 63% of the patients suffered from a relapse within the 2-year follow-up period with 86% of these patients being rehospitalized. Discharge non-responder and non-remitter were twice as likely to relapse during follow-up. A significant decrease of side-effects was observed with negligible rates of extrapyramidal side-effects, sedation, and weight gain during follow-up. Patients receiving treatment with atypical antipsychotics were found to have the lowest risk to relapse (p < 0.0001). The results highlight the natural and unsteady course of schizophrenia in most patients underlining the need to develop more specific treatment strategies ensuring ongoing stability and preventing relapse.

Anti-inflammatory effects of minocycline are mediated by retinoid signaling.

BACKGROUND: Minocycline is a lipophilic tetracycline of increasing appeal in neuroscience as it inhibits microglial activation, a mechanism involved in numerous neuropsychiatric disorders. Own data point towards retinoid-mediated effects of minocycline in murine brain and skin, and towards a vicious cycle of neuroinflammation which is driven by microglial activation-induced breakdown of local retinoids such as retinoic acid (RA). We therefore sought to study minocycline's anti-inflammatory effects on human microglial-like monocyte-derived cells in the context of retinoid signaling. RESULTS: As hypothesized, minocycline exposure resulted in a substantial increase of RA levels in the human monocytic cell line THP-1. While pro-inflammatory stimulation with lipopolysaccharides resulted in increased tryptophane-degrading indoleamine-2,3-dioxygenase IDO-expression and TNF-α levels in primary human monocyte-derived microglial-like cells, this effect was attenuated by minocycline only in the presence of retinoids. The anti-inflammatory effects of minocycline on TNF-α expression were completely abolished by a pharmacological blockage of retinoic acid receptors (RARs) using BMS-493 and unaffected by selectively blocking retinoid-X-receptors using UVI-3003. CONCLUSIONS: Our data indicate for the first time a RA-dependent, anti-inflammatory effect for minocycline in human microglial-like cells via inhibition of local RA turnover. The RA-dependent mode of action for minocycline appears to be predominantly mediated through RAR-signaling.

Clozapine-induced agranulocytosis: Evidence for an immune-mediated mechanism from a patient-specific in-vitro approach.

Use of the atypical antipsychotic clozapine (CZP) is compromised by the risk of potentially fatal agranulocytosis/granulocytopenia (CIAG). To address this, we have established a simple, personalized cell culture-based strategy to identify CIAG-susceptible patients, hypothesizing that an immunogenic and possibly haptene-based mechanism underlies CIAG pathophysiology. To detect a putative haptene-induced response to CZP in vitro exposure, a traditional lymphocyte stimulation assay was adapted and applied to patient-specific peripheral blood-derived mononuclear cells (PBMC). 6 patients with a history of CIAG, 6 patients under CZP treatment (without CIAG) and 12 matched healthy controls were studied. In vitro CZP exposure, even at strikingly low levels, resulted in significantly increased proliferation rates only in CIAG patients' PBMC. Other parameters including cell viability and mitogen-induced proliferation were also affected by in vitro CZP exposure, yet there was no significant difference between the groups. This personalized approach is a starting point for further investigations into a putative haptene-based mechanism underlying CIAG development, and may facilitate the future development of predictive testing.

Hypothalamic-Pituitary-Adrenocortical Dysfunction in Elderly, Male Marathon Runners: Feedback Sensitivity, Stress Response, and Effects on Verbal Memory.

Animal studies suggest that repeated episodes of elevated glucocorticoids lead to a dysregulation of the hypothalamic-pituitary-adrenal (HPA) system at a suprapituitary level, and to impaired mnemonic function. We compared cognitive tests, as well as feedback integrity and stress responsivity of the HPA system, between 11 elderly, male marathon runners - a model of repeated HPA system activation - and 10 sedentary controls. The marathon runners had significantly increased baseline, stress, and post-stress ACTH - but not cortisol - concentrations. Also, suppression of ACTH by 3 mg dexamethasone was impaired in the athletes compared to the control subjects, while the ACTH and cortisol response to additional CRH did not differ between the 2 groups. Finally, long-term verbal memory was impaired in the athletes compared to the controls. Regarding the HPA system, these findings are in accordance with an acquired suprapituitary feedback disturbance in marathon runners; however, the similar glucocorticoid concentrations in the 2 groups may be due to reduced adrenal sensitivity to ACTH. Together with impaired verbal memory, these data support the assumption that repeated episodes of HPA system activity may exert negative effects at the level of the hippocampus.

Validity of remission and recovery criteria for schizophrenia and major depression: comparison of the results of two one-year follow-up naturalistic studies.

The objective of the present study was the application and comparison of common remission and recovery criteria between patients with the diagnosis of schizophrenia and major depressive disorder (MDD) under inclusion of other outcome parameters. Patients with schizophrenia and MDD who were treated as inpatients at the beginning of the study were examined within two naturalistic follow-up trials from admission to discharge of an inpatient treatment period and the one-year follow-up assessment. PANSS criteria of the Remission in Schizophrenia Working Group (RSWG) for schizophrenia and HAMD criteria of the ACNP Task Force in MDD for depressive patients as well as the Clinical Global Impression-Severity Scale (CGI-S) were applied as symptomatic outcome measures additionally to functional outcome parameters. Data of 153 schizophrenia patients and 231 patients with a MDD episode have been included in the analysis. More depressive than schizophrenia patients reached a threshold score of ≤3 on the CGI-S, indicating symptomatic remission at discharge and at the one-year follow-up. In contrast similar proportions of patients reaching symptomatic remission at discharge from inpatient treatment and at the one-year follow-up in the schizophrenia and in the MDD group were found when disease-related consensus criteria (RSWG vs. ACNP Task Force) were used. Functional remission and recovery rates were significantly lower in schizophrenia than in depressive patients at the one-year follow-up visit. Common outcome criteria for remission and recovery in schizophrenia and major depression were not directly comparable. However, our results indicated a significantly poorer outcome in schizophrenia than in depressive patients according to terms of remission and recovery.

Add-on Antidepressants in the Naturalistic Treatment of Schizophrenia Spectrum Disorder - When, Who, and How?

The aim of this study was to evaluate antidepressant add-on treatment within the acute treatment of schizophrenia spectrum disorder patients. Antidepressant add-on was evaluated in 365 patients within a naturalistic multicenter study. Patients with/without antidepressant add-on were compared regarding clinical and treatment-related variables, response and remission, and remission of depressive and negative symptoms. The efficacy of antidepressant add-on treatment was furthermore analyzed applying marginal structure models. Twenty-three percent of the patients received antidepressant add-on for a mean duration of 50.28 (33.42) days. Patients with the diagnosis of a schizoaffective disorder, multiple illness episodes, and a longer duration of their illness as well as those with significantly fewer baseline positive symptoms, more negative and depressive symptoms, more side effects, and less subjective well-being were augmented with antidepressants. At discharge no significant effect of antidepressant add-on treatment was observed in terms of a 25% improvement (p=0.2623), a 50% improvement (p=0.3946), remission (p=0.0552), or remission of depressive (p=0.6336) and negative symptoms (p=0.8756). Also, when analyzing marginal structure models considering the diagnostic subgroups, no significant effect was found. Add-on with antidepressants is common. A final recommendation in terms of this strategy's efficacy cannot be given.

Electroconvulsive therapy-induced brain plasticity determines therapeutic outcome in mood disorders.

There remains much scientific, clinical, and ethical controversy concerning the use of electroconvulsive therapy (ECT) for psychiatric disorders stemming from a lack of information and knowledge about how such treatment might work, given its nonspecific and spatially unfocused nature. The mode of action of ECT has even been ascribed to a "barbaric" form of placebo effect. Here we show differential, highly specific, spatially distributed effects of ECT on regional brain structure in two populations: patients with unipolar or bipolar disorder. Unipolar and bipolar disorders respond differentially to ECT and the associated local brain-volume changes, which occur in areas previously associated with these diseases, correlate with symptom severity and the therapeutic effect. Our unique evidence shows that electrophysical therapeutic effects, although applied generally, take on regional significance through interactions with brain pathophysiology.

[Dementia Competence Network. Results and outlook]. / Das Kompetenznetz Demenzen. Erfolge und Ausblicke.

BACKGROUND: The Dementia Competence Network (DCN) is represented by academic memory clinics and has three major aims: (1) To facilitate the development of diagnostic tools including neuropsychology, biomarkers, imaging and genetics. (2) To implement clinical trials in mild cognitive impairment and dementia and (3) to improve standard care for dementia in Germany. AIMS: This article summarizes the achievements of the DCN so far and highlights future perspectives. METHODS: The DCN has built up two multicentre cohorts. Within the first cohort, patients with mild cognitive impairment or mild dementia were examined longitudinally using multiple neuropsychological assessments and numerous different biomarkers. In a subgroup of the first cohort, patients were treated with antidementive drugs in two placebo-controlled clinical trials. The second cohort included cognitively healthy older people and examined repetitively clinical, neuropsychological and psychosocial parameters for ten years. RESULTS AND DISCUSSION: The DCN has generated a large data and biomaterial bank. Numerous publications have helped to develop further diagnostic procedures and treatment of cognitive disorders and dementia. The DCN has contributed to end stigmatisation of dementia.

Inhibition of retinoic acid catabolism by minocycline: evidence for a novel mode of action?

Retinoic acid (RA) represents an essential and highly potent endogenous retinoid with pronounced anti-inflammatory properties and potent anti-acne activity, and has recently been suggested to share a common anti-inflammatory mode of action with tetracycline antibiotics. We hypothesized that tetracyclines may directly interfere with RA homeostasis via inhibition of its local cytochrome P450 (CYP450)-mediated degradation, an essential component of tightly regulated skin RA homeostasis. To test this hypothesis, we performed controlled in vitro RA metabolism assays using rat skin microsomes and measured RA levels in a RA-synthesizing human keratinocyte cell line, both in the presence and in the absence of minocycline, a tetracycline popular in acne treatment. Interestingly, minocycline potently blocked RA degradation in rat skin microsomes, and strikingly enhanced RA levels in RA-synthesizing cell cultures, in a dose-dependent manner. These findings indicate a potential role for CYP-450-mediated RA metabolism in minocycline's pleiotropic mode of action and anti-acne efficacy and could account for the overlap between minocycline and RA-induced effects at the level of their molecular mode of action, but also clinically at the level of the rare side effect of pseudotumor cerebri, which is observed for both, RA and minocycline treatment.

Direct inhibition of retinoic acid catabolism by fluoxetine.

Recent evidence from animal and human studies suggests neuroprotective effects of the SSRI fluoxetine, e.g., in the aftermath of stroke. The underlying molecular mechanisms remain to be fully defined. Because of its effects on the cytochrome P450 system (CYP450), we hypothesized that neuroprotection by fluoxetine is related to altered metabolism of retinoic acid (RA), whose CYP450-mediated degradation in brain tissue constitutes an important step in the regulation of its site-specific auto- and paracrine actions. Using traditional pharmacological in vitro assays, the effects of fluoxetine on RA degradation were probed in crude synaptosomes from rat brain and human-derived SH-SY5Y cells, and in cultures of neuron-like SH-SY5Y cells. Furthermore, retinoid-dependent effects of fluoxetine on neuronal survival following glutamate exposure were investigated in rat primary neurons cells using specific retinoid receptor antagonists. Experiments revealed dose-dependent inhibition of synaptosomal RA degradation by fluoxetine along with dose-dependent increases in RA levels in cell cultures. Furthermore, fluoxetine's neuroprotective effects against glutamate excitotoxicity in rat primary neurons were demonstrated to partially depend on RA signaling. Taken together, these findings demonstrate for the first time that the potent, pleiotropic antidepressant fluoxetine directly interacts with RA homeostasis in brain tissue, thereby exerting its neuroprotective effects.

What are residual symptoms in schizophrenia spectrum disorder? Clinical description and 1-year persistence within a naturalistic trial.

The aim of this study was to evaluate residual symptoms in patients achieving remission according to the consensus criteria and to analyze their potential influence on the patient's outcome one year after discharge. In total, 399 patients suffering from a schizophrenia spectrum disorder were evaluated within a naturalistic study. Remission status was examined using the consensus criteria. Residual symptoms were defined as any symptom present at the time-point of remission following analogous analyses performed in depressed patients. Therefore, a PANSS item with a symptom severity of >1 (= at least borderline mentally ill) was defined to be a residual symptom. Remitters with and without residual symptoms were compared regarding psychopathology, functioning and side effects. In total, 236 patients (59%) were remitters at discharge with 94% of them suffering from at least one residual symptom. The most common residual symptoms were blunted affect (49%), conceptual disorganization (42%) and social withdrawal (40%). A significant association was found between the presence of residual symptoms and the severity of side effects (p < 0.0001) and functioning (p = 0.0003) at discharge as well as between residual symptoms and the risk of relapse and chance of remission one year after discharge. Residual symptoms were highly prevalent in remitted schizophrenia inpatients following the suggested definition. Most residual symptoms were persistent baseline symptoms suggesting an ongoing illness severity. Also, the necessity to re-evaluate the consensus criteria questioning the status of remission in these patients is also pointed out.

Differential effects of early life stress on hippocampus and amygdala volume as a function of emotional abilities.

Early life stress (ELS) is known to have considerable influence on brain development and affective functioning. Previous studies in clinical populations have shown that hippocampus and amygdala, two central structures of limbic emotion processing circuits, are predominantly affected by early stress exposure. Given the inconsistent findings on ELS-related effects in healthy populations and the associations of ELS and affective functioning, the question arises which additional emotion-relevant variables need to be considered to better understand the effects of ELS. We, therefore, investigated the volume of hippocampus and amygdala in 25 high alexithymic (h-ALEX) and 25 low alexithymic (l-ALEX) individuals, which were matched with regard to ELS, but significantly differed in their degree of emotional functioning. Volumetric analyses were performed using FSL-FIRST, a method to automatically segment subcortical structures on T1-weighted magnetic resonance images. Alexithymia was assessed using the Toronto Alexithymia Scale and Bermond-Vorst Alexithymia Questionnaire. ELS was assessed by Childhood Trauma Questionnaire (CTQ) and Early Trauma Inventory. Our data showed that ELS was negatively associated with right hippocampus volume in h-ALEX individuals, while there was no such association in the l-ALEX group. Furthermore, ELS was positively associated with left amygdala volume in l-ALEX individuals, but not in individuals with high levels of alexithymia. The present study emphasizes a substantial relationship between intrapersonal factors, such as alexithymia and neural alterations related to the experience of ELS. Longitudinal study designs are necessary to pursue the question of how emotional abilities interact with individual adaptations to early stress exposure on the neural level.

Do tetracyclines and erythromycin exert anti-acne effects by inhibition of P450-mediated degradation of retinoic acid?

For decades, retinoic acid (RA) is known as the most potent therapeutic option in the therapy of acne and altered homeostasis of endogenous retinoids has been discussed in the context of acne pathogenesis. Besides retinoids, antibiotics such as tetracyclines or erythromycin are well established in acne pharmacotherapy. Accumulating evidence points towards common molecular pathways being targeted by both RA and anti-acne antibiotics; however, a precise 'common denominator' connecting these chemically diverse anti-acne agents has not yet been identified. Interestingly, tetracyclines are associated with the occurrence of pseudotumor cerebri, a rare neurological side effect otherwise associated with retinoid intoxication or RA exposure. This association at the clinical level suggests an interaction between tetracyclines and endogenous RA signalling. As erythromycin does not cross the blood brain barrier, CNS side effects are not to be expected, yet not precluding a possible local interaction of erythromycin with endogenous RA metabolism in the skin. We hypothesize tetracyclines and erythromycin to locally inhibit endogenous RA metabolism in the skin and thus mimic therapeutic action of RA. This readily testable hypothesis suggests inhibition of endogenous RA metabolism and amplification of endogenous RA signalling as a mechanism underlying the biochemical actions of antibiotics in acne therapy. Elucidation of such interactions may ultimately enhance our understanding of acne therapy and pathogenesis and may yield a sound, scientific basis for hypothesis-driven development of novel therapeutic compounds.

Three-Year long-term outcome of 458 naturalistically treated inpatients with major depressive episode: severe relapse rates and risk factors.

In randomized controlled trials, maintenance treatment for relapse prevention has been proven to be efficacious in patients responding in acute treatment, its efficacy in long-term outcome in "real-world patients" has yet to be proven. Three-year long-term data from a large naturalistic multisite follow-up were presented. Severe relapse was defined as suicide, severe suicide attempt, or rehospitalization. Next to relapse rates, possible risk factors including antidepressant medication were identified using univariate generalized log-rank tests and multivariate Cox proportional hazards model for time to severe relapse. Overall data of 458 patients were available for analysis. Of all patients, 155 (33.6%) experienced at least one severe relapse during the 3-year follow-up. The following variables were associated with a shorter time to a severe relapse in univariate and multivariate analyses: multiple hospitalizations, presence of avoidant personality disorder, continuing antipsychotic medication, and no further antidepressant treatment. In comparison with other studies, the observed rate of severe relapse during 3-year period is rather low. This is one of the first reports demonstrating a beneficial effect of long-term antidepressant medication on severe relapse rates in naturalistic patients. Concomitant antipsychotic medication may be a proxy marker for treatment resistant and psychotic depression.

Genetic interaction of PICALM and APOE is associated with brain atrophy and cognitive impairment in Alzheimer's disease.

BACKGROUND: Evidence has emerged indicating that the ε4 allele of APOE and PICALM interact in conferring risk of Alzheimer's disease (AD). The biologic basis of this interaction is unclear, but it is likely to have phenotypic relevance and contribute to the structural and clinical heterogeneity of AD. METHODS: The aim of this study was to investigate interaction effects of the APOE ε4 allele and the alleles at the single-nucleotide polymorphism rs3851179 located in the PICALM locus. We analyzed brain volumes and cognitive phenotypes of 165 patients with early AD dementia. RESULTS: There was a synergistic adverse effect of homozygosity for the PICALM risk allele G in rs3851179 and APOE ε4 on volume in prefrontal and performance on the Trail Making Test A, which is sensitive to processing speed and working memory function. CONCLUSIONS: The data suggest a neural mechanism for APOE-PICALM interactions in patients with manifest AD and indicate that the PICALM genotype modulates both brain atrophy and cognitive performance in APOE ε4 carriers.