Impact of smoking behavior on clozapine blood levels - a systematic review and meta-analysis

OBJECTIVE

Tobacco smoking significantly impacts clozapine blood levels and has substantial implications on individual efficacy and safety outcomes. By investigating differences in clozapine blood levels in smoking and non-smoking patients on clozapine, we aim to provide guidance for clinicians how to adjust clozapine levels for patients on clozapine who change their smoking habits.

METHODS

We conducted a meta-analysis on clozapine blood levels, norclozapine levels, norclozapine/clozapine ratios, and concentration to dose (C/D) ratios in smokers and non-smokers on clozapine. Data were meta-analyzed using a random-effects model with sensitivity analyses on dose, ethnic origin, and study quality.

RESULTS

Data from 23 studies were included in this meta-analysis with 21 investigating differences between clozapine blood levels of smokers and non-smokers. In total, data from 7125 samples were included for the primary outcome (clozapine blood levels in ng/ml) in this meta-analysis. A meta-analysis of all between-subject studies (N = 16) found that clozapine blood levels were significantly lower in smokers compared with non-smokers (Standard Mean Difference (SMD) -0.39, 95% confidence interval (CI) -0.55 to -0.22, P < 0.001, I²  = 80%). With regard to the secondary outcome, C/D ratios (N = 16 studies) were significantly lower in the smoker group (n = 645) compared with the non-smoker group (n = 813; SMD -0.70, 95%CI -0.84 to -0.56, P < 0.00001, I²  = 17%).

CONCLUSION

Smoking behavior and any change in smoking behavior is associated with a substantial effect on clozapine blood levels. Reductions of clozapine dose of 30% are recommended when a patient on clozapine stops smoking. Reductions should be informed by clozapine steady-state trough levels and a close clinical risk-benefit evaluation.

Marathon running improves mood and negative affect

BACKGROUND

Physical activity has beneficial effects on depression, as well as on other mental and somatic diseases. The amount of recommended exercise is still under discussion. We investigated whether marathon runners (MA) exhibit less or more depressive symptoms and negative affects compared to sedentary controls (SC) and how their mood changes in the context of marathon training and marathon running.

METHODS

We included 100 amateur marathon runners and 46 age- and gender matched sedentary controls in the ReCaP (Running effects on Cognition and Plasticity) study. Questionnaires contained Beck Depression Inventory (BDI), Hamilton Depression Scale (HAMD), Oxford Happiness Questionnaire (OHQ), Visual Analogue Scale (VAS), Positive And Negative Affect Schedule (PANAS), Global Assessment of Functioning (GAF). SC were evaluated one time at baseline, MA six times during the six months study period.

RESULTS

Compared to SC, marathon runners (281.80 ± 131.44 running min/week) exhibited less depressive symptoms, more positive affects (PANAS-PA) and a higher level of functioning (GAF). Within the marathon group, negative affect (PANAS-NA) decreased and general mood states (VAS) further improved throughout the study period with a maximum 24 h after the marathon.

DISCUSSION

MA had less depressive symptoms and a higher level of functioning compared to SC. Higher amounts than the recommended duration of 150 min/week aerobic training (WHO/ACSM) and the participation in a marathon seem to even further improve negative affect. These findings give new insight into the relationship between exercise and mood parameters. They can be implemented in future preventive strategies for depressive symptoms.

Cognitive and emotional empathy in individuals at clinical high risk of psychosis

BACKGROUND

Impairments of social cognition are considered core features of schizophrenia and are established predictors of social functioning. However, affective aspects of social cognition including empathy have far less been studied than its cognitive dimensions. The role of empathy in the development of schizophrenia remains largely elusive.

METHODS

Emotional and cognitive empathy were investigated in large sample of 120 individuals at Clinical High Risk of Psychosis (CHR-P) and compared with 50 patients with schizophrenia and 50 healthy controls. A behavioral empathy assessment, the Multifaceted Empathy Test, was implemented, and associations of empathy with cognition, social functioning, and symptoms were determined.

RESULTS

Our findings demonstrated significant reductions of emotional empathy in individuals at CHR-P, while cognitive empathy appeared intact. Only individuals with schizophrenia showed significantly reduced scores of cognitive empathy compared to healthy controls and individuals at CHR-P. Individuals at CHR-P were characterized by significantly lower scores of emotional empathy and unspecific arousal for both positive and negative affective valences compared to matched healthy controls and patients with schizophrenia. Results also indicated a correlation of lower scores of emotional empathy and arousal with higher scores of prodromal symptoms.

CONCLUSION

Findings suggest that the tendency to 'feel with' an interaction partner is reduced in individuals at CHR-P. Altered emotional reactivity may represent an additional, early vulnerability marker, even if cognitive mentalizing is grossly unimpaired in the prodromal stage. Different mechanisms might contribute to reductions of cognitive and emotional empathy in different stages of non-affective psychotic disorders and should be further explored.

Transport and concentration of wealth: Modeling an amenities-based-theory

We derive a reaction-advection-diffusion equation based framework for analyzing the movement of wealth in urban environments. Gentrification is a core issue that affects many urban areas, and the dynamics of such are not fully understood. To understand the process using a few physically relevant variables, we develop an approach to model the interplay between local amenities and wealth from existing analyses of factors influencing gentrification. We conduct a linear stability analysis on model parameters that results in spatially homogeneous solutions and determine directions for parameter changes to induce instabilities. From these parameters, we determine quantities that lead to the formation of areas of wealth and amenity concentration in the long term on bounded and unbounded domains. We present a global bifurcation result in two dimensions, leading to the existence and stability of non-constant equilibrium solutions, which represents solutions with wealth and amenity hotspots. Finally, we present a theory for discerning the one-dimensional pattern formation in the transition between stability and instability and verify numerically through a weakly nonlinear analysis. The analysis provides a promising framework for further verification using publicly available geospatial data on the relevant variables.

Effect of TiO2 addition on adhesion and biological behavior of BCP-TiO2 composite films deposited by magnetron sputtering

The present investigation focuses on the deposition of biphasic calcium phosphate (BCP) and titania (TiO₂) composite films on Ti-6Al-4V substrates using radio frequency (RF) magnetron sputtering. Three different compositions such as 100% BCP, 25% TiO₂-75% BCP and 50% TiO₂-50% BCP films were fabricated, and the physical, mechanical and biological behaviors of the films were analyzed. Post deposition, the films were annealed at 700 °C for 2 h to induce the crystallinity and to study its effect on different properties. The wettability was found to be 95°(±3°) for 100% BCP, 73°(±2°) for 25% TiO₂-75% BCP and 35°(±1°) for 50% TiO₂-50% BCP films, indicating improvement in wettability with an increase of TiO₂ weight percent in the composite films. The value of critical load (L_c2) for 100 BCP film improved from 8.7 N to 14.8 N (25 TiO₂-BCP) and >19 N (50 TiO₂-BCP film), indicating improvement in bonding strength with TiO₂ addition. The fetal bovine serum (FBS) adsorption decreased from 7.11 ± 0.25 to 4.42 ± 0.17 μg/cm² with TiO₂ weight percent from 0 to 50%. Cell adhesion and proliferation significantly improved in 100% BCP, 25% TiO₂-75% BCP and 50% TiO₂-50% BCP films as compared to uncoated Ti-6Al-4V. The maximum cell proliferation was found on the surface of 50% TiO₂-50% BCP film (210.1 ± 6.5%) after 6 days of incubation. However, after annealing all the films exhibited less cell adhesion and cytocompatibility presumably due to change in composition. Globular apatite structure was observed on all modified surfaces after 7 days immersion in simulated body fluid (SBF); however, the growth rate was higher for 50 TiO₂-BCP films. All these results revealed that the addition of TiO₂ in BCP film (without annealing) is advantageous for improving the bonding strength as well as the bioactivity of implants, which can be used for long-term dental and orthopedic applications.

Zebrafish B cell acute lymphoblastic leukemia: new findings in an old model

Acute lymphoblastic leukemia (ALL) is the most common pediatric, and ninth most common adult, cancer. ALL can develop in either B or T lymphocytes, but B-lineage ALL (B-ALL) exceeds T-ALL clinically. As for other cancers, animal models allow study of the molecular mechanisms driving ALL. Several zebrafish (Danio rerio) T-ALL models have been reported, but until recently, robust D. rerio B-ALL models were not described. Then, D. rerio B-ALL was discovered in two related zebrafish transgenic lines; both were already known to develop T-ALL. Here, we report new B-ALL findings in one of these models, fish expressing transgenic human MYC (hMYC). We describe B-ALL incidence in a large cohort of hMYC fish, and show B-ALL in two new lines where T-ALL does not interfere with B-ALL detection. We also demonstrate B-ALL responses to steroid and radiation treatments, which effect ALL remissions, but are usually followed by prompt relapses. Finally, we report gene expression in zebrafish B lymphocytes and B-ALL, in both bulk samples and single B- and T-ALL cells. Using these gene expression profiles, we compare differences between the two new D. rerio B-ALL models, which are both driven by transgenic mammalian MYC oncoproteins. Collectively, these new data expand the utility of this new vertebrate B-ALL model.

Resistance training in patients with schizophrenia: Concept and proof of principle trial

Resistance training has been shown to contribute to the prevention and management of cardiovascular diseases, which is why it can help reducing morbidity and mortality in schizophrenia patients. Moreover, positive effects on different schizophrenia symptom domains have been proposed. However, a specific resistance training tailored to the needs of schizophrenia patients and its evaluation is still lacking. The objective in this proof of principle trial was to evaluate the feasibility and efficacy of a newly developed 12-week resistance program according to current recommendations of the WHO and the American College of Sports Medicine. We employed a single blind, parallel assignment clinical trial design with participants randomized to attend either a resistance training including three 50min units per week or a balance and tone program as control condition. The primary outcome was the impact on health-related difficulties assessed with the World Health Organization Disability Assessment Schedule (WHO-DAS). Secondary outcome parameters included the level of functioning, schizophrenia symptoms, selected cognitive parameters as well as risk factors for cardiovascular diseases. In our proof of principle trial, we could not find significant time or group effects of resistance training on the WHO-DAS. However, we could observe significant positive effects on the level of functioning assessed with the Global Assessment of Functioning Scale (GAF) over the course of time, which were more pronounced in the intervention group. Our findings indicated that patients with schizophrenia could safely participate in resistance training with relevant improvements in their level of functioning. Well-powered replication trials are needed to provide more efficacy data.

P3440Can pre-operative echocardiography predict RV failure post-LVAD implantation in children?

Background

One of the most frequent complications of left ventricular assist device (LVAD) implantation is the development of right ventricular (RV) failure, which occurs in 10%-40% of patients. It is, therefore, essential to identify which LVAD candidates are at risk for RV failure and will require additional RV mechanical support with a biventricular assist device (BiVAD). However, the echocardiographic assessment of the RV is challenging due to its complex geometry and marked load dependence of its function indices. To our knowledge, there is no published evidence regarding which specific RV echocardiographic parameters should inform this decision in the paediatric population.

Aims

We sought to determine which pre-operative RV echocardiographic parameters best correlate with the need for a BiVAD, as opposed to LVAD alone, in a paediatric population undergoing VAD insertion at a tertiary care institution.

Methods

Retrospective review of the pre-operative echocardiograms of children (<18 years) with dilated cardiomyopathy undergoing elective VAD implantation at our institution, from November 2007 to December 2018. Preoperative quantitative and qualitative RV echocardiographic parameters described in the literature to be associated with RV failure after LVAD implantation in adults were collected. Moreover, qualitative RV function was independently assessed by three echocardiographers, blinded to the outcome of the patients.

Results

89 patients were included, 39 (43.8%) males, median age = 1.7 years (IQR = 6.9), median weight = 11.6 kg (IQR = 13.8). 49 (55.1%) patients had an LVAD implanted, whereas 40 (44.9%) were deemed to need biventricular support. 45 (50.6%) patients received an EXCOR Berlin Heart, 16 (18%) a HeartWare HVAD and 28 (31.4%) a Levitronix Centrimag device. Requirement of BiVAD support was significantly more common in patients with moderate to severe RV impairment, as per expert assessment (OR = 2.864; 95% CI: 1.188–6.903, p=0.018), and tricuspid regurgitation > grade III (OR = 3.154; 95% CI: 1.124–8.850, p=0.025). All the other parameters collected – tricuspid annular plane systolic excursion (TAPSE), tricuspid regurgitant jet velocity, tricuspid regurgitation duration corrected for heart rate, RV tissue Doppler indices, RV fractional area change, and RV/LV diameter ratio– were not significantly different among groups.

Conclusions

In our paediatric population, expert assessment of RV function and degree of tricuspid regurgitation were strong predictors of RV failure among patients undergoing LVAD implantation, allowing for pre-emptive RVAD implantation and improving patient outcomes.

[Autoimmune encephalitis with psychotic symptoms : Diagnostics, warning signs and practical approach]

Despite intensive research, a precise cause of schizophrenic and schizoaffective disorders has not yet been identified. Therefore, psychiatric diagnoses are still made based on clinical ICD-10/DSM‑5 criteria and not on any objective markers; however, various causes or pathophysiological processes may ultimately lead to similar symptoms. An important task for the future of psychiatry is to identify disease subtypes with a distinct pathophysiology to develop more specific and causally acting therapies. A new diagnostic entity has become established in clinical neurology and psychiatry in recent years: autoimmune encephalitis with psychotic symptoms caused by specific antineuronal antibodies has been identified as a rare but potentially treatable cause of psychotic disorders; however, these inflammatory brain diseases are not reliably detected by routine psychiatric diagnostics. Therefore, this qualitative review is intended to provide structured support for clinical practice, which, guided by clinical warning signals, enables a rapid and reliable diagnosis as well as the initiation of immunotherapy. In the case of psychiatric symptoms, the additional onset of focal neurological signs, disturbances of consciousness and orientation, autonomic instability or epileptic seizures and electroencephalograph (EEG) abnormalities should always be followed by a more specific cerebrospinal fluid analysis with determination of antineuronal autoantibodies. Although the scientific evidence indicates that only a small subgroup of patients is affected, the swift and correct diagnosis is of high therapeutic and prognostic relevance for the affected individuals.

[Staging of liver fibrosis in biliary atresia : Comparison of Chevallier and Ishak score as well as automated evaluation]

BACKGROUND

Biliary atresia (BA) is a rare disease of the newborn, resulting in liver cirrhosis due to obliterative cholangiopathy. Liver biopsies are commonly performed in order to confirm the diagnosis and in order to stage fibrosis.

OBJECTIVES

The present study intended to analyze two established scores for evaluating liver fibrosis focusing on the interobserver variability as well as the prognostic reliability towards the time of liver transplantation.

MATERIALS AND METHODS

Liver biopsies of BA patients between 2012 and 2015 were evaluated retrospectively by two pathologists at the Hannover Medical School (MHH) and the RWTH Aachen University Hospital. Fibrosis was measured using Ishak and Chevallier scores. Furthermore, a computerized automatically algorithm-based analyzation (ABAA) was performed. Results were evaluated towards the time point of liver transplantation and hepatoportoenterostomy (HPE).

RESULTS

Overall, 34 liver biopsies were analyzed. The Ishak score showed a remarkable interobserver variability (Κ_W = 0.68) while the Chevallier score was proven to have a poor interobserver variability (Fleiss' Κappa = -0.01). However, both scores were correlated positively, as was the ABAA (p < 0.001). Regarding prognostic reliability, ROC analyses of the Ishak score revealed the best validity towards an early liver transplantation within 12 months (AUC 0.813, p = 0.011). In addition, an increased Ishak score ≥4 reduced the survival time with the native liver (hazard ratio 6.6 [95% CI 1.9-23.3]).

CONCLUSIONS

The Ishak score was revealed to have the best interobserver variability as well as prognostic validity towards an early liver transplantation in BA patients. Due to its easy applicability, the Ishak score was proven superior in comparison to the Chevallier score and ABAA. Therefore, use of the Ishak score is recommended in daily clinical routine for analyzing liver biopsies in BA patients.

Running effects on cognition and plasticity (ReCaP): study protocol of a longitudinal examination of multimodal adaptations of marathon running

Regular moderate physical activity (PA) has been linked to beneficial adaptations in various somatic diseases (e.g. cancer, endocrinological disorders) and a reduction in all-cause mortality from several cardiovascular and neuropsychiatric diseases. This study was designed to investigate acute and prolonged exercise-induced cardio- and neurophysiological responses in endurance runners competing in the Munich Marathon. ReCaP (Running effects on Cognition and Plasticity) is a multimodal and longitudinal experimental study. This study included 100 participants (20-60 years). Six laboratory visits were included during the 3-month period before and the 3-month period after the Munich marathon. The multimodal assessment included laboratory measurements, cardiac and cranial imaging (MRI scans, ultrasound/echocardiography) and neurophysiological methods (EEG and TMS/tDCS), and vessel-analysis (e.g. retinal vessels and wave-reflection analyses) and neurocognitive measurements. The ReCaP study was designed to examine novel exercise-induced cardio- and neurophysiological responses to marathon running at the behavioral, functional and morphological levels. This study will expand our understanding of exercise-induced adaptations and will lead to more individually tailored therapeutic options.

Isolating Malignant and Non-Malignant B Cells from lck:eGFP Zebrafish

Zebrafish (Danio rerio) are a powerful model to study lymphocyte development. Like mammals, D. rerio possess an adaptive immune system that includes B and T lymphocytes. Studies of zebrafish lymphopoiesis are difficult because antibodies recognizing D. rerio cell surface markers are generally not available, complicating isolation and characterization of different lymphocyte populations, including B-lineage cells. Transgenic lines with lineage-specific fluorophore expression are often used to circumvent this challenge. The transgenic lck:eGFP line has been used to study D. rerio T cell development, and has also been utilized to model T cell development and acute lymphoblastic leukemia (T-ALL). Although lck:eGFP fish have been widely used to analyze the T-lineage, they have not been used to study B cells. Recently, we discovered that many zebrafish B cells also express lck, albeit at lower levels. Consequently, lck:eGFP B cells likewise express low levels of GFP. Based on this finding, we developed a protocol to purify B-lineage cells from lck:eGFP zebrafish, which we report here. Our method describes how to utilize a fluorescent-activated cell sorter (FACS) to purify B cells from lck:eGFP fish or related lines, such as double-transgenic rag2:hMYC; lck:eGFP fish. In these lines, B cells, particularly immature B cells, express GFP at low but detectable levels, allowing them to be distinguished from T cells, which express GFP highly. B cells can be isolated from marrow, thymus, spleen, blood, or other tissues. This protocol provides a new method to purify D. rerio B cells, enabling studies focused on topics like B cell development and B lymphocyte malignancies.

Beneficial effects of anodal transcranial direct current stimulation (tDCS) on spatial working memory in patients with schizophrenia

Schizophrenia is a severe and often detrimental psychiatric disorder. The individual patients' level of functioning is essentially determined by cognitive, particularly working memory (WM), deficits that are critically linked to dysfunctional activity of the dorsolateral prefrontal cortex (dlPFC). Transcranial direct current stimulation (tDCS) can transiently modulate activity of the dlPFC and remote areas and has been shown to improve WM functions. It may therefore provide a new, targeted treatment option. For this aim, the present study investigated the effect of anodal tDCS of different intensities on spatial WM in patients with schizophrenia. In two experiments, 32 patients performed a spatial n-back task with increasing WM load (1-, 2-, and 3-back) at baseline and in two sessions with anodal or sham tDCS (EXP I [n = 16]: 1 mA; EXP II [n = 16]: 2 mA) to the right dlPFC (cathode: left m. deltoideus). With 1 mA anodal tDCS, no effect on WM performance could be detected. However, 2 mA anodal tDCS increased accuracy (measured by d') of the task with the highest WM load (3-back). This effect was larger in patients with a lower level of general neurocognitive functioning. These results demonstrate a beneficial effect of 2 mA anodal tDCS on deficient WM accuracy in patients with schizophrenia particularly under challenging conditions and in subjects with higher cognitive impairments. This data will inform future clinical trials on tDCS-enhanced cognitive training to improve treatment of schizophrenia.

Clozapine as a first- or second-line treatment in schizophrenia: a systematic review and meta-analysis

OBJECTIVE

No consensus exists on whether clozapine should be prescribed in early stages of psychosis. This systematic review and meta-analysis therefore focus on the use of clozapine as first-line or second-line treatment in non-treatment-resistant patients.

METHODS

Articles were eligible if they investigated clozapine compared to another antipsychotic as a first- or second-line treatment in non-treatment-resistant schizophrenia spectrum disorders (SCZ) patients and provided data on treatment response. We performed random-effects meta-analyses.

RESULTS

Fifteen articles were eligible for the systematic review (N = 314 subjects on clozapine and N = 800 on other antipsychotics). Our meta-analysis comparing clozapine to a miscellaneous group of antipsychotics revealed a significant benefit of clozapine (Hedges' g = 0.220, P = 0.026, 95% CI = 0.026-0.414), with no evidence of heterogeneity. In addition, a sensitivity analysis revealed a significant benefit of clozapine over risperidone (Hedges' g = 0.274, P = 0.030, 95% CI = 0.027-0.521).

CONCLUSION

The few eligible trials on this topic suggest that clozapine may be more effective than other antipsychotics when used as first- or second-line treatment. Only large clinical trials may comprehensively probe disease stage-dependent superiority of clozapine and investigate overall tolerability.

Simultaneous B and T cell acute lymphoblastic leukemias in zebrafish driven by transgenic MYC: implications for oncogenesis and lymphopoiesis

Precursor-B cell acute lymphoblastic leukemia (pre-B ALL) is the most common pediatric cancer, but there are no useful zebrafish pre-B ALL models. We describe the first highly- penetrant zebrafish pre-B ALL, driven by human MYC. Leukemias express B lymphoblast-specific genes and are distinct from T cell ALL (T-ALL)—which these fish also develop. Zebrafish pre-B ALL shares in vivo features and expression profiles with human pre-B ALL, and these profiles differ from zebrafish T-ALL or normal B and T cells. These animals also exhibit aberrant lymphocyte development. As the only robust zebrafish pre-B ALL model and only example where T-ALL also develops, this model can reveal differences between MYC-driven pre-B vs. T-ALL and be exploited to discover novel pre-B ALL therapies.

Randomised Controlled Clinical Trial Investigating The Impact of Implementation Planning on Behaviour Related to The Diet

There is a perceived gap between dietary advice given by health practitioners and adherence to the advice by patients. We investigated whether a behaviour change technique (implementation-planning) was more effective than standard-of-care diet advice at reducing dietary acid intake using quantitative erosive tooth wear progression as an objective clinical outcome. This study was a randomised controlled, double-blind, single-centre clinical trial in the UK. Participants (n = 60) with high dietary acid intake (≥2 daily), were recruited and randomly assigned (1:1) to receive either implementation-planning or standard-of-care diet advice in a single clinical session. Questionnaires and impressions were taken at baseline and 6 months later. Dental casts were scanned using laser profilometry and superimposed using surface-matching software. Data were analysed per protocol and intention-to-treat using independent t-tests and Mann-Whitney tests. The intervention group reduced their dietary acid intake between meals to 1 intake per day compared to 2 intakes per day for the controls and demonstrated reduced dental hard tissue volume loss (-0.00 mm³ (SD = 0.01)) compared to controls (-0.07 mm³ (SD 0.17)), p = 0.049. This paper supports the use of implementation planning in clinical practice and presents a non-invasive method of intervention assessment in behaviour change. Larger trials are needed to confirm the generalisability of results.