Childhood Schizotypy and Adolescent Mental Disorder

BACKGROUND AND HYPOTHESIS

Schizotypy provides a framework for understanding the developmental nature of psychotic disorders and a means of identifying "at-risk" individuals early in the lifespan. However, there is a lack of prospective longitudinal research examining the relationship between schizotypy in childhood and later psychotic and other mental disorders. We hypothesized that distinct profiles of schizotypy in childhood would be differentially associated with psychotic and other mental disorders emerging later in adolescence.

STUDY DESIGN

In a large population cohort of Australian young people (n = 26 837), we prospectively examined the relationship between person-centered profiles of schizotypy identified in middle childhood (age ~11 years) and adolescent diagnoses (age ~13-18 years) across 7 types of mental disorders using multinomial logistic regression.

RESULTS

Membership in any of 3 childhood schizotypy profiles (true schizotypy, affective schizotypy, or introverted schizotypy) was associated with an increased likelihood of being diagnosed with any type of mental disorder in adolescence; effects were strongest for the true schizotypy group (aOR = 3.07, 95% CI = 2.64, 3.57), followed by the introverted (aOR = 1.94, 95% CI = 1.75, 2.15) and affective (aOR = 1.29, 95% CI = 1.13, 1.47) schizotypy groups. Six of the 7 types of mental disorders measured (including psychotic disorders) were associated with at least 1 schizotypy group.

CONCLUSIONS

Schizotypy in middle childhood is an important correlate of mental disorders in adolescence; however, it does not appear to be specifically associated with psychotic disorders in this age group.

Expression of the wheat multipathogen resistance hexose transporter Lr67res is associated with anion fluxes

Many disease resistance genes in wheat (Triticum aestivum L.) confer strong resistance to specific pathogen races or strains, and only a small number of genes confer multipathogen resistance. The Leaf rust resistance 67 (Lr67) gene fits into the latter category as it confers partial resistance to multiple biotrophic fungal pathogens in wheat and encodes a Sugar Transport Protein 13 (STP13) family hexose-proton symporter variant. Two mutations (G144R, V387L) in the resistant variant, Lr67res, differentiate it from the susceptible Lr67sus variant. The molecular function of the Lr67res protein is not understood, and this study aimed to broaden our knowledge on this topic. Biophysical analysis of the wheat Lr67sus and Lr67res protein variants was performed using Xenopus laevis oocytes as a heterologous expression system. Oocytes injected with Lr67sus displayed properties typically associated with proton-coupled sugar transport proteins-glucose-dependent inward currents, a Km of 110 ± 10 µM glucose, and a substrate selectivity permitting the transport of pentoses and hexoses. By contrast, Lr67res induced much larger sugar-independent inward currents in oocytes, implicating an alternative function. Since Lr67res is a mutated hexose-proton symporter, the possibility of protons underlying these currents was investigated but rejected. Instead, currents in Lr67res oocytes appeared to be dominated by anions. This conclusion was supported by electrophysiology and 36Cl- uptake studies and the similarities with oocytes expressing the known chloride channel from Torpedo marmorata, TmClC-0. This study provides insights into the function of an important disease resistance gene in wheat, which can be used to determine how this gene variant underpins disease resistance in planta.

Cumulative Environmental Risk in Early Life: Associations With Schizotypy in Childhood

BACKGROUND AND HYPOTHESIS

Psychotic disorders are associated with a growing number of recognized environmental exposures. Cumulative exposure to multiple environmental risk factors in childhood may contribute to the development of different patterns of schizotypy evident in early life. Hypotheses were that distinct profiles of schizotypy would have differential associations with a cumulative score of environmental risk factors.

STUDY DESIGN

We prospectively examined the relationship between 19 environmental exposures (which had demonstrated replicated associations with psychosis) measured from the prenatal period through to age 11 years, and 3 profiles of schizotypy in children (mean age = 11.9 years, n = 20 599) that have been established in population data from the New South Wales-Child Development Study. Multinomial logistic regression was used to examine associations between membership in each of 3 schizotypy profiles (true schizotypy, introverted schizotypy, and affective schizotypy) and exposure to a range of 19 environmental risk factors for psychosis (both individually and summed as a cumulative environmental risk score [ERS]), relative to children showing no risk.

RESULTS

Almost all environmental factors were associated with at least 1 schizotypy profile. The cumulative ERS was most strongly associated with the true schizotypy profile (OR = 1.61, 95% CI = 1.52-1.70), followed by the affective (OR = 1.33, 95% CI = 1.28-1.38), and introverted (OR = 1.32, 95% CI = 1.28-1.37) schizotypy profiles.

CONCLUSIONS

Consistent with the cumulative risk hypothesis, results indicate that an increased number of risk exposures is associated with an increased likelihood of membership in the 3 schizotypy profiles identified in middle childhood, relative to children with no schizotypy profile.

In situ amplification of spin echoes within a kinetic inductance parametric amplifier

The use of superconducting microresonators together with quantum-limited Josephson parametric amplifiers has enhanced the sensitivity of pulsed electron spin resonance (ESR) measurements by more than four orders of magnitude. So far, the microwave resonators and amplifiers have been designed as separate components due to the incompatibility of Josephson junction-based devices with magnetic fields. This has produced complex spectrometers and raised technical barriers toward adoption of the technique. Here, we circumvent this issue by coupling an ensemble of spins directly to a weakly nonlinear and magnetic field-resilient superconducting microwave resonator. We perform pulsed ESR measurements with a 1-pL mode volume containing 6 × 10⁷ spins and amplify the resulting signals within the device. When considering only those spins that contribute to the detected signals, we find a sensitivity of [Formula: see text] for a Hahn echo sequence at a temperature of 400 mK. In situ amplification is demonstrated at fields up to 254 mT, highlighting the technique's potential for application under conventional ESR operating conditions.

Pathways from developmental vulnerabilities in early childhood to schizotypy in middle childhood

OBJECTIVES

Childhood disturbances in social, emotional, language, motor and cognitive functioning, and schizotypy have each been implicated as precursors of schizophrenia-spectrum disorders. We investigated whether relationships between early childhood developmental vulnerabilities and childhood schizotypy are mediated by educational underachievement in middle childhood.

METHODS

Participants were members of a large Australian (n = 19,216) population cohort followed longitudinally. Path analyses were used to model relationships between developmental vulnerabilities at age ~5 years, educational underachievement from ages ~8 to 10 years and three distinct profiles of schizotypy at age ~11 years (true, introverted and affective schizotypy).

RESULTS

Early childhood developmental vulnerabilities on five broad domains (related to physical, emotional, social, cognitive and communication development) were associated with schizotypy profiles in middle childhood. Educational underachievement in middle childhood was associated with all schizotypy profiles, but most strongly with the true schizotypy profile (OR = 3.92, 95% CI = 3.12, 4.91). The relationships between schizotypy profiles and early childhood developmental vulnerabilities in 'language and cognitive skills (school-based)' and 'communication skills and general knowledge' domains were fully mediated by educational underachievement in middle childhood, and the relationships with early childhood 'physical health and well-being' and 'emotional maturity' domains were partially mediated.

CONCLUSION

Developmental continuity from early childhood developmental vulnerabilities to schizotypy in middle childhood is mediated by educational underachievement in middle childhood. While some domains of early developmental functioning showed differential relationships with distinct schizotypy profiles, these findings support a developmental pathway to schizotypy in which cognitive vulnerability operates from early childhood through to middle childhood.

OUP accepted manuscript

The molecular biology and genetics of the Ni–Cd–Zn hyperaccumulator Noccaea caerulescens has been extensively studied, but no information is yet available on Ni and Zn redistribution and mobilization during seed germination. Due to the different physiological functions of these elements, and their associated transporter pathways, we expected differential tissue distribution and different modes of translocation of Ni and Zn during germination. This study used synchrotron X-ray fluorescence tomography techniques as well as planar elemental X-ray imaging to elucidate elemental (re)distribution at various stages of the germination process in contrasting accessions of N. caerulescens. The results show that Ni and Zn are both located primarily in the cotyledons of the emerging seedlings and Ni is highest in the ultramafic accessions (up to 0.15 wt%), whereas Zn is highest in the calamine accession (up to 600 μg g^–1). The distribution of Ni and Zn in seeds was very similar, and neither element was translocated during germination. The Fe maps were especially useful to obtain spatial reference within the seeds, as it clearly marked the vasculature. This study shows how a multimodal combination of synchrotron techniques can be used to obtain powerful insights about the metal distribution in physically intact seeds and seedlings.

Vincristine-induced peripheral neuropathy is driven by canonical NLRP3 activation and IL-1β release

Vincristine is an important component of many regimens used for pediatric and adult malignancies, but it causes a dose-limiting sensorimotor neuropathy for which there is no effective treatment. This study aimed to delineate the neuro-inflammatory mechanisms contributing to the development of mechanical allodynia and gait disturbances in a murine model of vincristine-induced neuropathy, as well as to identify novel treatment approaches. Here, we show that vincristine-induced peripheral neuropathy is driven by activation of the NLRP3 inflammasome and subsequent release of interleukin-1β from macrophages, with mechanical allodynia and gait disturbances significantly reduced in knockout mice lacking NLRP3 signaling pathway components, or after treatment with the NLRP3 inhibitor MCC950. Moreover, treatment with the IL-1 receptor antagonist anakinra prevented the development of vincristine-induced neuropathy without adversely affecting chemotherapy efficacy or tumor progression in patient-derived medulloblastoma xenograph models. These results detail the neuro-inflammatory mechanisms leading to vincristine-induced peripheral neuropathy and suggest that repurposing anakinra may be an effective co-treatment strategy to prevent vincristine-induced peripheral neuropathy.

Individual and temporal variation in pathogen load predicts long-term impacts of an emerging infectious disease

Emerging infectious diseases increasingly threaten wildlife populations. Most studies focus on managing short-term epidemic properties, such as controlling early outbreaks. Predicting long-term endemic characteristics with limited retrospective data is more challenging. We used individual-based modeling informed by individual variation in pathogen load and transmissibility to predict long-term impacts of a lethal, transmissible cancer on Tasmanian devil (Sarcophilus harrisii) populations. For this, we employed approximate Bayesian computation to identify model scenarios that best matched known epidemiological and demographic system properties derived from 10 yr of data after disease emergence, enabling us to forecast future system dynamics. We show that the dramatic devil population declines observed thus far are likely attributable to transient dynamics (initial dynamics after disease emergence). Only 21% of matching scenarios led to devil extinction within 100 yr following devil facial tumor disease (DFTD) introduction, whereas DFTD faded out in 57% of simulations. In the remaining 22% of simulations, disease and host coexisted for at least 100 yr, usually with long-period oscillations. Our findings show that pathogen extirpation or host-pathogen coexistence are much more likely than the DFTD-induced devil extinction, with crucial management ramifications. Accounting for individual-level disease progression and the long-term outcome of devil-DFTD interactions at the population-level, our findings suggest that immediate management interventions are unlikely to be necessary to ensure the persistence of Tasmanian devil populations. This is because strong population declines of devils after disease emergence do not necessarily translate into long-term population declines at equilibria. Our modeling approach is widely applicable to other host-pathogen systems to predict disease impact beyond transient dynamics.