Accelerating Medicines Partnership® Schizophrenia (AMP® SCZ): Rationale and Study Design of the Largest Global Prospective Cohort Study of Clinical High Risk for Psychosis

This article describes the rationale, aims, and methodology of the Accelerating Medicines Partnership® Schizophrenia (AMP® SCZ). This is the largest international collaboration to date that will develop algorithms to predict trajectories and outcomes of individuals at clinical high risk (CHR) for psychosis and to advance the development and use of novel pharmacological interventions for CHR individuals. We present a description of the participating research networks and the data processing analysis and coordination center, their processes for data harmonization across 43 sites from 13 participating countries (recruitment across North America, Australia, Europe, Asia, and South America), data flow and quality assessment processes, data analyses, and the transfer of data to the National Institute of Mental Health (NIMH) Data Archive (NDA) for use by the research community. In an expected sample of approximately 2000 CHR individuals and 640 matched healthy controls, AMP SCZ will collect clinical, environmental, and cognitive data along with multimodal biomarkers, including neuroimaging, electrophysiology, fluid biospecimens, speech and facial expression samples, novel measures derived from digital health technologies including smartphone-based daily surveys, and passive sensing as well as actigraphy. The study will investigate a range of clinical outcomes over a 2-year period, including transition to psychosis, remission or persistence of CHR status, attenuated positive symptoms, persistent negative symptoms, mood and anxiety symptoms, and psychosocial functioning. The global reach of AMP SCZ and its harmonized innovative methods promise to catalyze the development of new treatments to address critical unmet clinical and public health needs in CHR individuals.

Proteomic Biomarkers for the Prediction of Transition to Psychosis in Individuals at Clinical High Risk: A Multi-cohort Model Development Study

Psychosis risk prediction is one of the leading challenges in psychiatry. Previous investigations have suggested that plasma proteomic data may be useful in accurately predicting transition to psychosis in individuals at clinical high risk (CHR). We hypothesized that an a priori-specified proteomic prediction model would have strong predictive accuracy for psychosis risk and aimed to replicate longitudinal associations between plasma proteins and transition to psychosis. This study used plasma samples from participants in 3 CHR cohorts: the North American Prodrome Longitudinal Studies 2 and 3, and the NEURAPRO randomized control trial (total n = 754). Plasma proteomic data were quantified using mass spectrometry. The primary outcome was transition to psychosis over the study follow-up period. Logistic regression models were internally validated, and optimism-corrected performance metrics derived with a bootstrap procedure. In the overall sample of CHR participants (age: 18.5, SD: 3.9; 51.9% male), 20.4% (n = 154) developed psychosis within 4.4 years. The a priori-specified model showed poor risk-prediction accuracy for the development of psychosis (C-statistic: 0.51 [95% CI: 0.50, 0.59], calibration slope: 0.45). At a group level, Complement C8B, C4B, C5, and leucine-rich α-2 glycoprotein 1 (LRG1) were associated with transition to psychosis but did not surpass correction for multiple comparisons. This study did not confirm the findings from a previous proteomic prediction model of transition from CHR to psychosis. Certain complement proteins may be weakly associated with transition at a group level. Previous findings, derived from small samples, should be interpreted with caution.

Plasma complement and coagulation proteins as prognostic factors of negative symptoms: An analysis of the NAPLS 2 and 3 studies

INTRODUCTION

Negative symptoms impact the quality of life of individuals with psychosis and current treatment options for negative symptoms have limited effectiveness. Previous studies have demonstrated that complement and coagulation pathway protein levels are related to later psychotic experiences, psychotic disorder, and functioning. However, the prognostic relationship between complement and coagulation proteins and negative symptoms is poorly characterised.

METHODS

In the North American Prodrome Longitudinal Studies 2 and 3, negative symptoms in 431 individuals at clinical high-risk for psychosis (mean age: 18.2, SD 3.6; 42.5 % female) were measured at multiple visits over 2 years using the Scale of Psychosis-Risk Symptoms. Plasma proteins were quantified at baseline using mass spectrometry. Four factors were derived to represent levels of proteins involved in the activation or regulation of the complement or coagulation systems. The relationships between standardised protein group factors and serial measurements of negative symptoms over time were modelled using generalised least squares regression. Analyses were adjusted for baseline candidate prognostic factors: negative symptoms, positive symptoms, functioning, depressive symptoms, suicidal ideation, cannabis use, tobacco use, antipsychotic use, antidepressant use, age, and sex.

RESULTS

Clinical and demographic prognostic factors of follow-up negative symptoms included negative, positive, and depressive symptoms, functioning, and age. Adjusting for all candidate prognostic factors, the complement regulators group and the coagulation regulators group were identified as prognostic factors of follow-up negative symptoms (β: 0.501, 95 % CI: 0.160, 0.842; β: 0.430, 95 % CI: 0.080, 0.780 respectively. The relationship between complement regulator levels and negative symptoms was also observed in NAPLS2 alone (β: 0.501, 95 % CI: -0.037, 1.039) and NAPLS3 alone, additionally adjusting for BMI (β: 0.442, 95 % CI: 0.127, 0.757).

CONCLUSION

The results indicate that plasma complement and coagulation regulator levels are prognostic factors of negative symptoms, independent of clinical and demographic prognostic factors. These results suggest complement and coagulation regulator levels could have potential utility in informing treatment decisions for negative symptoms in individuals at risk.

Differential expression of haptoglobin in individuals at clinical high risk of psychosis and its association with global functioning and clinical symptoms

BACKGROUND

Immune dysregulation has been observed in patients with schizophrenia or first-episode psychosis, but few have examined dysregulation in those at clinical high-risk (CHR) for psychosis. The aim of this study was to examine whether the peripheral blood-based proteome was dysregulated in those with CHR. Secondly, we examined whether baseline dysregulation was related to current and future functioning and clinical symptoms.

METHODS

We used data from participants of the North American Prodromal Longitudinal Studies (NAPLS) 2 and 3 (n = 715) who provided blood samples (Unaffected Comparison subjects (UC) n = 223 and CHR n = 483). Baseline proteomic data was quantified from plasma samples using mass spectrometry. Differential expression was examined between CHR and UC using logistic regression. Psychosocial functioning was measured using the Global Assessment of Functioning scale (GAF). Symptoms were measured using the subscale scores from the Scale of Psychosis-risk Symptoms; positive, negative, general, and disorganised. Three measures of each outcome were included: baseline, longest available follow-up (last follow-up) and most severe follow-up (MSF). Associations between the proteomic data, GAF and symptoms were assessed using ordinal regression.

RESULTS

Of the 99 proteins quantified, six were differentially expressed between UC and CHR. However, only haptoglobin (HP) survived FDR-correction (OR:1.45, 95 %CI:1.23-1.69, padj = <0.001). HP was cross-sectionally and longitudinally associated with functioning and symptoms such that higher HP values were associated with poorer functioning and more severe symptoms. Results were evident after stringent adjustment and poorer functioning was observed in both NAPLS cohort separately.

CONCLUSION

We demonstrate that elevated HP is robustly observed in those at CHR for psychosis, irrespective of transition to psychosis. HP is longitudinally associated with poorer functioning and greater symptom severity. These results agree with previous reports of increased HP gene expression in individuals at-risk for psychosis and with the dysfunction of the acute phase inflammatory response seen in psychotic disorders.

Linking enlarged choroid plexus with plasma analyte and structural phenotypes in clinical high risk for psychosis: A multisite neuroimaging study

BACKGROUND

Choroid plexus (ChP) enlargement exists in first-episode and chronic psychosis, but whether enlargement occurs before psychosis onset is unknown. This study investigated whether ChP volume is enlarged in individuals with clinical high-risk (CHR) for psychosis and whether these changes are related to clinical, neuroanatomical, and plasma analytes.

METHODS

Clinical and neuroimaging data from the North American Prodrome Longitudinal Study 2 (NAPLS2) was used for analysis. 509 participants (169 controls, 340 CHR) were recruited. Conversion status was determined after 2-years of follow-up, with 36 psychosis converters. The lateral ventricle ChP was manually segmented from baseline scans. A subsample of 31 controls and 53 CHR had plasma analyte and neuroimaging data.

RESULTS

Compared to controls, CHR (d = 0.23, p = 0.017) and non-converters (d = 0.22, p = 0.03) demonstrated higher ChP volumes, but not in converters. In CHR, greater ChP volume correlated with lower cortical (r = -0.22, p < 0.001), subcortical gray matter (r = -0.21, p < 0.001), and total white matter volume (r = -0.28,p < 0.001), as well as larger lateral ventricle volume (r = 0.63,p < 0.001). Greater ChP volume correlated with makers functionally associated with the lateral ventricle ChP in CHR [CCL1 (r = -0.30, p = 0.035), ICAM1 (r = 0.33, p = 0.02)], converters [IL1β (r = 0.66, p = 0.004)], and non-converters [BMP6 (r = -0.96, p < 0.001), CALB1 (r = -0.98, p < 0.001), ICAM1 (r = 0.80, p = 0.003), SELE (r = 0.59, p = 0.026), SHBG (r = 0.99, p < 0.001), TNFRSF10C (r = 0.78, p = 0.001)].

CONCLUSIONS

CHR and non-converters demonstrated significantly larger ChP volumes compared to controls. Enlarged ChP was associated with neuroanatomical alterations and analyte markers functionally associated with the ChP. These findings suggest that the ChP may be a key an important biomarker in CHR.

Toward a generation free of tuberculosis: TB disease and infection in individuals of college age in the United States

OBJECTIVES

To assess the magnitude of active TB disease and latent TB infection (LTBI) in young adults of college age.

PARTICIPANTS

Individuals who were aged 18-24 years in 2011 were used as a proxy for college students.

METHODS

Active TB cases reported to the 2011 US National TB Surveillance System (NTSS) were included. LTBI prevalence was calculated from the 2011-2012 National Health and Nutrition Examination Survey. The 2011 American Community Survey was used to calculate population denominators. Analyses were stratified by nativity.

RESULTS

Active TB disease incidence among persons aged 18-24 years was 2.82/100,000, 18.8/100,000 among foreign-born individuals and 0.9/100,000 among US-born individuals. In 2011, 878 TB cases were reported; 629 (71.6%) were foreign-born. LTBI prevalence among persons of 18-24 years was 2.5%: 8.7% and 1.3% among foreign-born and US-born, respectively.

CONCLUSION

Active screening and treatment programs for foreign-born young adults could identify TB cases earlier and provide an opportunity for prevention efforts.

Progressive reduction in cortical thickness as psychosis develops: a multisite longitudinal neuroimaging study of youth at elevated clinical risk

BACKGROUND

Individuals at clinical high risk (CHR) who progress to fully psychotic symptoms have been observed to show a steeper rate of cortical gray matter reduction compared with individuals without symptomatic progression and with healthy control subjects. Whether such changes reflect processes associated with the pathophysiology of schizophrenia or exposure to antipsychotic drugs is unknown.

METHODS

In this multisite study, 274 CHR cases, including 35 individuals who converted to psychosis, and 135 healthy comparison subjects were scanned with magnetic resonance imaging at baseline, 12-month follow-up, or the point of conversion for the subjects who developed fully psychotic symptoms.

RESULTS

In a traveling subjects substudy, excellent reliability was observed for measures of cortical thickness and subcortical volumes. Controlling for multiple comparisons throughout the brain, CHR subjects who converted to psychosis showed a steeper rate of gray matter loss in the right superior frontal, middle frontal, and medial orbitofrontal cortical regions as well as a greater rate of expansion of the third ventricle compared with CHR subjects who did not convert to psychosis and healthy control subjects. Differential tissue loss was present in subjects who had not received antipsychotic medications during the interscan interval and was predicted by baseline levels of an aggregate measure of proinflammatory cytokines in plasma.

CONCLUSIONS

These findings demonstrate that the brain changes are not explained by exposure to antipsychotic drugs but likely play a role in psychosis pathophysiology. Given that the cortical changes were more pronounced in subjects with briefer durations of prodromal symptoms, contributing factors may predominantly play a role in acute-onset forms of psychosis.

Differences in mRNA and microRNA microarray expression profiles in human colon adenocarcinoma HT-29 cells treated with either Intensity-modulated Radiation Therapy (IMRT), or Conventional Radiation Therapy (RT)

We carried out this in vitro molecular study to investigate the effect of two clinical X-irradiation modalities (a two-dimensional external beam radiotherapy referred to in this article as conventional RT, and a three dimensional conformal intensity-modulated radiation therapy (IMRT) on a colon adenocarcinoma HT-29 cell line. Cells were synchronized by serum deprivation 48 h before irradiation so that >90% of them were in the G(0)/G(1) phase of the cell cycle. Cells were allowed to recover 3 h after irradiation before total RNA extraction. Two types of arrays, namely Affymetrix Human HG U133A 2.0 oligonucleotide microarrays and Ambion mirVana bioarrays, were employed to study mRNA and microRNA expressions, respectively. Three flasks were used per irradiation dose, and an additional three unirradiated flasks served as control. Microarray data were validated by reverse transcriptase quantitative polymerase chain reaction, and proteins of some expressed genes were determined by Western blots. Results showed the existence of differences in expression profiles between the two irradiation modalities. IMRT appeared to influence expression of some DNA repair genes, whereas in conventional RT, some DNA repair and cell cycle-related genes that initially seemed to be preferentially expressed dwindled to normal levels. Earlier in vitro experiments using cell survival to study sublethal damage repair support our conclusions. Bioinformatic investigation revealed a correlation of gene expression with derepression effects of microRNA molecules. We have presented opinions as to how microRNAs might influence gene expression during radiation-induced stress and have suggested future avenues for research.

Simulating association studies: a data-based resampling method for candidate regions or whole genome scans

MOTIVATION

Reductions in genotyping costs have heightened interest in performing whole genome association scans and in the fine mapping of candidate regions. Improvements in study design and analytic techniques will require the simulation of datasets with realistic patterns of linkage disequilibrium and allele frequencies for typed SNPs.

METHODS

We describe a general approach to simulate genotyped datasets for standard case-control or affected child trio data, by resampling from existing phased datasets. The approach allows for considerable flexibility in disease models, potentially involving a large number of interacting loci. The method is most applicable for diseases caused by common variants that have not been under strong selection, a class specifically targeted by the International HapMap project.

RESULTS

Using the three population Phase I/II HapMap data as a testbed for our approach, we have implemented the approach in HAP-SAMPLE, a web-based simulation tool.

Systematic discovery of the grammar of translational inhibition by RNA hairpins

Recent discovery of gene expression mechanisms has propelled molecular genetics to a state of rapid development, a state likely to persist due to continuing advances in understanding control systems of fundamental cellular processes. An algorithm for that advancement starts in this paper with a gene of interest and a characteristic function of that gene. The set of all genes with counteracting function is identified by pathway searches. Also associated with the first gene is the set of the genes which byproducts of its transcription might downregulate, identified relative to searches involving sequence alignments. Our focus is the intersection of the counteracting gene set and the downregulated gene set. The result is hypothesis generation. Examples of and predictions from this approach are given in the context of apoptosis. Also discussed is application of the algorithm to rational drug design from a new development platform.

Folded RNA from an intron of one gene might inhibit expression of a counteracting gene

Homeostatic maintenance of mRNA levels including prompt availability of mRNAs for translation in response to changing protein demands might be partly enabled by a system of combinatorial controls involving noncoding RNA blocking agents. This article proposes a specific version of that control mechanism, namely, a double-stranded RNA folding from transcription of an intron of one gene might and leading to an agent that inhibits mRNA of a counteracting gene. Thus transcription of the first gene would automatically repress translation of the second. On the basis of a bioinformatics search, we suggest a possible example, namely, that pro-apoptosis gene PAR4 might inhibit anti-apoptosis gene XIAP. Part of an intron from PAR4 folds to form a large, stable hairpin, and reverse complement of the hairpin stem (with approximately 280 nucleotides) matches a sub-sequence of an exon in XIAP. This would be part of an efficient system to drive initiated apoptosis to its conclusion. Figuratively speaking, it replaces two control knobs with one. Since repeats, some with many thousands of copies, occur throughout the genome with complex distributions, care must be taken before asserting that the presence of any repeat in any gene is significant. Our apoptosis example involves repeats, so experimental verification is needed and planned. However, if it is found that the noncoding RNA by-product of one gene folds into a hairpin that is processed into an agent that inhibits a counteracting gene, then the same type of control unit might be found extensively among counteracting families of genes of many types.

Expanding the 'central dogma': the regulatory role of nonprotein coding genes and implications for the genetic liability to schizophrenia

It is now evident that nonprotein coding RNA (ncRNA) plays a critical role in regulating the timing and rate of protein translation. The potential importance of ncRNAs is suggested by the observation that the complexity of an organism is poorly correlated with its number of protein coding genes, yet highly correlated with its number of ncRNA genes, and that in the human genome only a small fraction (2-3%) of genetic transcripts are actually translated into proteins. In this review, we discuss several examples of known RNA mechanisms for the regulation of protein synthesis. We then discuss the possibility that ncRNA regulation of schizophrenia risk genes may underlie the diverse findings of genetic linkage studies including that protein-altering gene polymorphisms are not generally found in schizophrenia. Thus, inadequate or mistimed expression of a functional protein may occur either due to mutation or other dysfunction of the DNA coding base pair sequence, leading to a dysfunctional protein, or due to post-transcriptional events such as abnormal ncRNA regulation of a normal gene. One or more 'schizophrenia disease genes' may turn out to include abnormal transcriptional units that code for RNA regulators of protein coding gene expression or to be proximal to such units, rather than to be abnormalities in the protein coding gene itself. Understanding the genetics of schizophrenia and other complex neuropsychiatric disorders might very well include consideration of RNA and epigenetic regulation of protein expression in addition to polymorphisms of the protein coding gene.

Biochemical mediator demand--a novel rapid alternative for measuring biochemical oxygen demand

The biochemical oxygen demand (BOD) test (BOD5) is a crucial environmental index for monitoring organic pollutants in waste water but is limited by the 5-day requirement for completing the test. We have optimised a rapid microbial technique for measuring the BOD of a standard BOD5 substrate (150 mg glucose/l, 150 mg glutamic acid/l) by quantifying an equivalent biochemical mediator demand in the absence of oxygen. Elevated concentrations of Escherichia coli were incubated with an excess of redox mediator, potassium hexacyanoferrate(III), and a known substrate for 1 h at 37 degrees C without oxygen. The addition of substrate increased the respiratory activity of the microorganisms and the accumulation of reduced mediator; the mediator was subsequently re-oxidised at a working electrode generating a current quantifiable by a coulometric transducer. Catabolic conversion efficiencies exceeding 75% were observed for the oxidation of the standard substrate. The inclusion of a mediator allowed a higher co-substrate concentration compared to oxygen and substantially reduced the incubation time from 5 days to 1 h. The technique replicates the traditional BOD5 method, except that a mediator is substituted for oxygen, and we aim to apply the principle to measure the BOD of real waste streams in future work.

Of barn owls and bankers: a lush variety of alpha/beta hydrolases

alpha/beta Hydrolase fold proteins are an important, diverse, widespread group of enzymes not yet fully exploited by structural biologists. We describe the current state of knowledge of this family, and suggest a smaller definition of the required core and some possible future avenues of exploration.

Characterisation of a thermophilic L-glutamate dehydrogenase biosensor for amperometric determination of L-glutamate by flow injection analysis

Carbon paste wax electrodes incorporating thermophilic L-glutamate dehydrogenase, NADP and a polymeric toluidine blue O (poly-TBO) mediator have been characterised for the amperometric determination of L-glutamate at 313-318 K in a flow injection analysis (FIA) system. The biosensors exhibit good sensitivity, mechanical stability and reproducibilty, unlike carbon paste- or carbon wax-based electrodes under the same conditions. The carbon paste wax electrode responds linearly to L-glutamate up to 40 mM, the detection limit is 0.3 mM and the RSD (n = 10) for 5 mM L-glutamate was 7.6%. The response to some potential interferents has been quantified. Addition of finely ground hexaammineruthenium (III) trichloride ([Ru(NH3)6]Cl3) to the carbon paste wax electrodes decreases the FIA peak width and increases the peak current. The metal complex appears to accelerate the rate of oxidation of NAD(P)H by poly-TBO.

A rapid method to screen for cell-wall mutants using discriminant analysis of Fourier transform infrared spectra

We have developed a rapid method to screen large numbers of mutant plants for a broad range of cell wall phenotypes using Fourier transform infrared (FTIR) microspectroscopy of leaves. We established and validated a model that can discriminate between the leaves of wild-type and a previously defined set of cell-wall mutants of Arabidopsis. Exploratory principal component analysis indicated that mutants deficient in different cell-wall sugars can be distinguished from each other. Discrimination of cell-wall mutants from wild-type was independent of variability in starch content or additional unrelated mutations that might be present in a heavily mutagenised population. We then developed an analysis of FTIR spectra of leaves obtained from over 1000 mutagenised flax plants, and selected 59 plants whose spectral variation from wild-type was significantly out of the range of a wild-type population, determined by Mahalanobis distance. Cell wall sugars from the leaves of selected putative mutants were assayed by gas chromatography-mass spectrometry and 42 showed significant differences in neutral sugar composition. The FTIR spectra indicated that six of the remaining 17 plants have altered ester or protein content. We conclude that linear discriminant analysis of FTIR spectra is a robust method to identify a broad range of structural and architectural alterations in cell walls, appearing as a consequence of developmental regulation, environmental adaptation or genetic modification.

A financial survey of home medical equipment dealers

The Health Industry Distributors Association's ninth annual survey of home medical equipment dealers allows firms to compare their performance to industry averages, enabling managers to identify those specific aspects of company performance that demand their attention.

Potential consequences of a fire in an insecticide storage facility

Assumptions are identified and made in an attempt to model the acute human health risk associated with a hypothetical fire in an insecticide storage facility. The insecticides used in the model are endrin and dimethoate. The model indicates that persons residing a few hundred meters from the facility could suffer a variety of adverse effects, including possible death from contact with smoke from a prolonged, low-temperature fire. Knowledge of the special hazards of cool toxic smoke as well as current atmospheric conditions could be of use to fire fighters. That is, fire fighters might wisely choose to promote a fast, hot fire which would propel toxicants high into the atmosphere rather than risk local fumigation.

The contribution of nitrification in the water column and profundal sediments to the total oxygen deficit of the hypolimnion of a mesotrophic lake (Grasmere, English Lake District)

Estimates ofin situ nitrifying activity have been made in the hypolimnetic water column and surface 1.0 cm of profundal sediments at 2 sites in Grasmere, a mesotrophic lake in the English Lake District. Increases of nitrate concentrations were used to estimate nitrification in the water column whereas a mini-core technique, involving the use of a nitrification inhibitor (allylthiourea), was used to estimate the rate in surface sediments. The pattern of oxygen depletion in the water column was used to estimate the maximum depth to which sediments affect the overlying water. Nitrification in the sediment and in the water column made approximately equal contributions to the total areal oxygen deficit and, as a whole, nitrification accounted for 15-20% of the total oxygen depletion. There was no significant difference in oxygen depletion due to nitrification between the 2 sites. Attempts were made, using the nitrification potential technique, to determine the depth distribution of nitrifying activity in the surface 1.0 cm of sediment.

Effect of medium temperature on recovery of gonococci

The temperature of the isolation medium exerted no significant effect on the rate of positive cultures for Neisseria gonorrhoeae. However, significantly more colonies were obtained on ambient-temperature medium than on cold (4C) medium. A small number of specimens (six) failed to grow on cold medium but grew on ambient-temperature medium. Viable counts showed essentially no effect of medium temperature on the nondiscriminating strain, a 90% reduction on the cold medium for the cold-intolerant strain, and for the strains with warm medium preference, about twice as many colonies on warm as on cold or ambient-temperature medium.

The microbiological flora of penile ulcerations

The penile ulcerations of 100 consecutive men were tested for microorganisms. A polymicrobial flora was identified in the ulcers of 97 men. The microorganisms recovered from these ulcers included combinations of anaerobic and aerobic bacteria (including Mycoplasma), herpes simplex virus, yeasts, and filamentous fungi. Fifty-three study entrants had microorganisms, identified by culture or serologic tests, that were considered primary in ulcer pathogenesis. Herpes simplex virus was the most prevalent and Treponema pallidum was the next most prevalent pathogen identified. Of our patients, 5% had two recognized pathogens confirmed by laboratory tests, and only one of these was suspected at clinical examination. In addition, the study suggests that microorganisms other than Haemophilus ducreyi can produce ulcers with a morphology mimicking chancroid.