Atypicality index as an add-on to combined first-trimester screening for chromosomal aberrations

OBJECTIVES

To compute a set of atypicality indices from combined first-trimester screening (cFTS) markers and second-trimester estimated fetal weight (EFW), and to demonstrate their potential in identifying pregnancies at either reduced or increased risks of chromosomal aberrations following a low-risk cFTS result.

METHODS

The atypicality index quantifies the unusualness of an individual set of measurements relative to a reference distribution and can be computed from any variables or measurements available. A score of 0% on the atypicality index represents the most typical profiles, while a score of 100% indicates the highest level of atypicality. From the Danish Fetal Medicine Database, we retrieved data on all pregnant women seen for cFTS in Central Denmark Region between January 2008 and December 2018. All pregnancies with a cytogenetic or molecular analysis obtained prenatally, postnatally, or following pregnancy loss or termination of pregnancy were identified. A first-trimester atypicality index (AcFTS ) was computed from nuchal translucency (NT) thickness, maternal serum free β-human chorionic gonadotropin (β-hCG) and pregnancy-associated plasma protein-A (PAPP-A). Further, a second trimester index (AcFTS+EFW ) was computed from cFTS markers and estimated fetal weight (EFW) estimated at a routine second-trimester anomaly scan. All pregnancies were stratified into subgroups based on their atypicality levels and their cFTS risk estimates. The risk of chromosomal aberrations in each subgroup was then compared with the overall prevalence, and a graphical presentation of multivariate measurement profiles was introduced.

RESULTS

We retrieved data on 145,955 singleton pregnancies, of which 9824 (6.7%) were genetically examined. Overall, 1 in 122 of all pregnancies seen for cFTS (0.82% [95% CI 0.77-0.87%]) were affected by a fetal chromosomal aberration and in screen-negative pregnancies (cFTS T21 risk <1 in 100 and/or T18/13 risk <1 in 50), 0.41% [95% CI 0.38-0.44%] were affected. In screen-negative pregnancies with a typical first-trimester profile (AcFTS <80% ), the risk of chromosomal aberrations was significantly reduced (0.28%) compared to the overall risk. The risk of chromosomal aberrations increased with higher atypicality index to 0.49% (AcFTS [80-90%) ), 1.52% (AcFTS [90-99%) ), and 4.44% (AcFTS [>99%) ) and was significantly increased in the two most atypical subgroups. The same applied for the second trimester atypicality index (AcFTS+EFW ) with risks of chromosomal aberrations of 0.76% and 4.16% in the two most atypical subgroups (AcFTS+EFW [90-99%) and AcFTS+EFW >99% , respectively).

CONCLUSIONS

As an add-on to cFTS, the atypicality index identifies women with typical measurement profiles which may act as reassurance, whereas atypical profiles may warrant specialist referral and further investigations. In pregnancies at low risk from cFTS but with a highly atypical distribution of NT, PAPP-A, and β-hCG, the risk of a chromosomal aberration is substantially increased. The atypicality index optimizes the interpretation of pre-existing prenatal screening profiles and is not limited to cFTS markers or EFW. This article is protected by copyright. All rights reserved.

Atypicality index: avoiding false reassurance in prenatal screening

OBJECTIVE

To demonstrate the application of the atypicality index as an adjunct to first-trimester risk assessment for major trisomies by the combined test.

METHODS

This was a study of 123 998 Danish women with a singleton pregnancy who underwent routine first-trimester screening, including risk assessment for major trisomies. An atypicality index, which is a measure of the degree to which a profile is atypical, was produced for measurements of fetal nuchal translucency thickness and maternal serum free β-human chorionic gonadotropin and pregnancy-associated plasma protein-A. The incidence of adverse pregnancy outcome, including miscarriage, intrauterine death and termination of pregnancy, was tabulated according to the screening result and atypicality index.

RESULTS

In pregnancies with low risk and those with high risk for major trisomies according to the combined screening test, the incidence of adverse pregnancy outcome increased with increasing atypicality index. In pregnancies with a low risk for trisomies and atypicality index of ≥ 99%, the incidence of adverse outcome was 5.1 (95% CI, 3.4-7.6) times higher compared with that in low-risk pregnancies with a typical measurement profile, reflected by an atypicality index of < 80%. Similarly, in high-risk pregnancies, the incidence of adverse outcome was 7.9 (95% CI, 4.4-14.5) times higher in those with an atypicality index of ≥ 99% compared to those with an atypicality index of < 80%. Using individual profile plots, we were able to demonstrate a transparent and intuitive method for visualization of multiple variables, which can help interpret the individual combination of measurements and level of atypicality.

CONCLUSIONS

In pregnancies undergoing first-trimester combined screening and classified as being at low risk for major trisomies, profiles that are typical of pregnancies with normal outcome provide additional reassurance, whereas those with an atypical profile may warrant further investigation. © 2022 International Society of Ultrasound in Obstetrics and Gynecology.

[The social portrait of child with disability as conceived by population of the Euro-Arctic region of Russia]

The problem of perceiving person with disability as "atypical" individual is one of the most acute in modern society. The stereotypes and fears existing in conceptions of citizens regarding this category are negatively reflected in current intensive inclusive processes. The most negatively negative conceptions about persons with disabilities affect children population, aggravating processes of socialization and inclusion in social practices inherent to their "norm-typical" peers. The survey of population of the Euro-Arctic region, carried out by the author in 2022, to identify characteristics of perception of children with disabilities, established that negative perceptions prevail in assessments of children with disabilities. The results demonstrated that, basically, disabled subjects are perceived through assessments of their personal and behavioral characteristics, and not through the social conditions of their life. The results of the study made it possible to conclude that medical model of disability significantly impact on citizens' perceptions of persons with disabilities. The phenomenon of disability itself can be attributed to factors contributing to negative labeling of its subjects. The conclusions and results of the study can be used to develop positive image of disabled perdsons in the Russian socium in process of further development of inclusive processes.

A Pattern Dictionary Method for Anomaly Detection

In this paper, we propose a compression-based anomaly detection method for time series and sequence data using a pattern dictionary. The proposed method is capable of learning complex patterns in a training data sequence, using these learned patterns to detect potentially anomalous patterns in a test data sequence. The proposed pattern dictionary method uses a measure of complexity of the test sequence as an anomaly score that can be used to perform stand-alone anomaly detection. We also show that when combined with a universal source coder, the proposed pattern dictionary yields a powerful atypicality detector that is equally applicable to anomaly detection. The pattern dictionary-based atypicality detector uses an anomaly score defined as the difference between the complexity of the test sequence data encoded by the trained pattern dictionary (typical) encoder and the universal (atypical) encoder, respectively. We consider two complexity measures: the number of parsed phrases in the sequence, and the length of the encoded sequence (codelength). Specializing to a particular type of universal encoder, the Tree-Structured Lempel-Ziv (LZ78), we obtain a novel non-asymptotic upper bound, in terms of the Lambert W function, on the number of distinct phrases resulting from the LZ78 parser. This non-asymptotic bound determines the range of anomaly score. As a concrete application, we illustrate the pattern dictionary framework for constructing a baseline of health against which anomalous deviations can be detected.

The Emergence of Creative Leaders Within Social Networks: The Case of Andy Warhol in the Art World of New York

The creative leadership literature has identified personality traits, skills, states, and behaviours which are effective within creative contexts and organisations, but it is yet to address how creative leaders emerge from social networks. This conceptual paper delineates the processes of creative leader emergence within the context of contemporary visual arts. Using a relational view of creative leader emergence, this paper incorporates the leader emergence processes of achievement and ascription, and then adjusts them to the context of the art world. We argue that both competence and identity contribute to the status construction of creative leaders by enabling their emergence within social networks. In addition to the processes of leader prototypicality through which leaders emerge within groups, we also identify processes of leader atypicality through which creative leaders emerge within network structures. Finally, our conceptual analysis is illustrated by the case of Pop artist Andy Warhol, focusing on his emergence as a creative leader within the art world of New York and his art studio, the factory.

The blowfish effect: children and adults use atypical exemplars to infer more narrow categories during word learning

Learners preferentially interpret novel nouns at the basic level ('dog') rather than at a more narrow level ('Labrador'). This 'basic-level bias' is mitigated by statistics: children and adults are more likely to interpret a novel noun at a more narrow label if they witness 'a suspicious coincidence' - the word applied to three exemplars of the same narrow category. Independent work has found that exemplar typicality influences learners' inferences and category learning. We bring these lines of work together to investigate whether the content (typicality) of a single exemplar affects the level of interpretation of words and whether an atypicality effect interacts with input statistics. Results demonstrate that both four- to five-year-olds and adults tend to assign a narrower interpretation to a word if it is exemplified by an atypical category member. This atypicality effect is roughly as strong as, and independent of, the suspicious coincidence effect, which is replicated.

Data Discovery and Anomaly Detection Using Atypicality for Real-Valued Data

The aim of using atypicality is to extract small, rare, unusual and interesting pieces out of big data. This complements statistics about typical data to give insight into data. In order to find such “interesting” parts of data, universal approaches are required, since it is not known in advance what we are looking for. We therefore base the atypicality criterion on codelength. In a prior paper we developed the methodology for discrete-valued data, and the current paper extends this to real-valued data. This is done by using minimum description length (MDL). We develop the information-theoretic methodology for a number of “universal” signal processing models, and finally apply them to recorded hydrophone data and heart rate variability (HRV) signal.

Psychopharmacology of atypical antipsychotic drugs: From the receptor binding profile to neuroprotection and neurogenesis

The original definition of atypical antipsychotic drugs (APD) was drugs that are effective against positive symptoms in schizophrenia with no or little extrapyramidal symptoms (EPS). However, atypical APD have been reported to be more effective for cognitive dysfunction and negative symptoms in schizophrenia than typical APD, which expands the definition of 'atypicality'. This article provides a critical review of the pharmacology of atypical APD, especially from the viewpoint of receptor binding profiles and neurotransmitter regulations as well as neuroprotection and neurogenesis. A variety of serotonin (5-HT) receptors, such as 5-HT2A / 2C , 5-HT1A , 5-HT6 and 5-HT7 receptors, may contribute to the mechanisms of action of 'atypicality'. The dopaminergic modulations, including a low affinity for dopamine D2 receptors and a partial D2 receptor agonistic action, and glutamatergic regulations may also be involved in the pharmacological backgrounds of 'atypicality'. Atypical APD, but not typical APD, may facilitate cortical neuroprotection and hippocampal neurogenesis, which might be a part of the action mechanisms of atypical APD. The facilitation of cortical neuroprotection and hippocampal neurogenesis induced by atypical APD might be mediated by an increase in the Ser9 phosphorylation of glycogen synthase kinase-3β (GSK-3β). The stimulation of 5-HT1A receptors and/or the blockade of 5-HT2 receptors, which is characteristic of atypical APD, might increase Ser9 phosphorylation of GSK-3β. Moreover, atypical APD increase brain-derived neurotrophic factor (BDNF) levels. BDNF increases Ser9 phosphorylation of GSK-3β and has neuroprotective and neurogenic effects, as in the case of atypical APD. These findings suggest that GSK-3β might play a role in the action mechanisms of atypical APD, in both the 5-HT-dependent and BDNF-dependent mechanisms.

Adjunctive treatment with mianserin enhances effects of raclopride on cortical dopamine output and, in parallel, its antipsychotic-like effect

Clinical studies indicate that adjunctive treatment with the antidepressant drug mianserin, a 5-hydroxytryptamine (5-HT)(2A/C) receptor antagonist and an alpha(2)- and alpha(1)-adrenoceptor antagonist, may enhance the effect of conventional antipsychotic drugs in schizophrenia, in particular on negative symptoms such as withdrawal retardation, akathisia, and some aspects of cognitive impairment. Here, we have examined the effect of mianserin in combination with the selective dopamine (DA) D(2/3) receptor antagonist raclopride on conditioned avoidance response (CAR), a preclinical test of antipsychotic efficacy with high predictive validity; catalepsy, a preclinical test of extrapyramidal side effect liability; and DA output in the medial prefrontal cortex (mPFC) and the nucleus accumbens (NAC), respectively. Mianserin (5 mg/kg intraperitoneal) significantly enhanced the suppressant effect of a low dose of raclopride (0.1 mg/kg subcutaneous) on CAR without any increase in catalepsy. Administration of raclopride to rats pretreated with mianserin resulted in a large enhancement of DA output in the mPFC and, at the same time, a small but significant reduction in the raclopride-induced DA output in the NAC. These experimental results indicate that adjunctive treatment with mianserin to a typical D(2) antagonist generates an atypical antipsychotic profile.

Adjunctive treatment with mianserin enhances effects of raclopride on cortical dopamine output and, in parallel, its antipsychotic-like effect

Clinical studies indicate that adjunctive treatment with the antidepressant drug mianserin, a 5-hydroxytryptamine (5-HT)(2A/C) receptor antagonist and an alpha(2)- and alpha(1)-adrenoceptor antagonist, may enhance the effect of conventional antipsychotic drugs in schizophrenia, in particular on negative symptoms such as withdrawal retardation, akathisia, and some aspects of cognitive impairment. Here, we have examined the effect of mianserin in combination with the selective dopamine (DA) D(2/3) receptor antagonist raclopride on conditioned avoidance response (CAR), a preclinical test of antipsychotic efficacy with high predictive validity; catalepsy, a preclinical test of extrapyramidal side effect liability; and DA output in the medial prefrontal cortex (mPFC) and the nucleus accumbens (NAC), respectively. Mianserin (5 mg/kg intraperitoneal) significantly enhanced the suppressant effect of a low dose of raclopride (0.1 mg/kg subcutaneous) on CAR without any increase in catalepsy. Administration of raclopride to rats pretreated with mianserin resulted in a large enhancement of DA output in the mPFC and, at the same time, a small but significant reduction in the raclopride-induced DA output in the NAC. These experimental results indicate that adjunctive treatment with mianserin to a typical D(2) antagonist generates an atypical antipsychotic profile.