Effect of swab pooling on the Accula point-of-care RT-PCR for SARS-CoV-2 detection

Introduction

Swab pooling may allow for more efficient use of point-of-care assays for SARS-CoV-2 detection in settings where widespread testing is warranted, but the effects of pooling on assay performance are not well described.

Methods

We tested the Thermo-Fisher Accula rapid point-of-care RT-PCR platform with contrived pooled nasal swab specimens.

Results

We observed a higher limit of detection of 3,750 copies/swab in pooled specimens compared to 2,250 copies/swab in individual specimens. Assay performance appeared worse in a specimen with visible nasal mucous and debris, although performance was improved when using a standard laboratory mechanical pipette compared to the transfer pipette included in the assay kit.

Conclusion

Clinicians and public health officials overseeing mass testing efforts must understand limitations and benefits of swab or sample pooling, including reduced assay performance from pooled specimens. We conclude that the Accula RT-PCR platform remains an attractive candidate assay for pooling strategies owing to the superior analytical sensitivity compared to most home use and point-of-care tests despite the inhibitory effects of pooled specimens we characterized.

Psychopathology of schizophrenia in the context of the superior longitudinal fascicle integrity – a DTI study

Introduction

Schizophrenia is a chronic mental illness with unclear etiology. It is characterized by symptoms in various psychopathological domains (e.g. positive, negative). One of the concepts explaining the etiology of schizophrenia is the disconnection hypothesis. It assumes the existence of structural and functional disorders within the connections of brain regions. White matter is largely responsible for the quality of these connections. One of the important structures of white matter is the superior longitudinal fascicle (SLF) which connects many cortical structures.

Objectives

The main aim of our study was to search for a relationship between the integrity of SLF and various psychopathological dimensions among schizophrenia patients.

Methods

42 schizophrenia subjects (SS) and 32 healthy controls (HC) participated in the study. All study participants underwent DTI-MRI analysis. The psychopathology of SS was assessed using the Positive and Negative Syndrome Scale (PANSS). In the study, we used the PANSS dimensions proposed by Shafer. Then, the SLF analysis was performed using fractional anisotropy (FA) and mean diffusivity (MD) parameters.

Results

The differences in FA and MD values in SLF bilaterally between groups were confirmed. A correlation was found between MD values in left SLF and positive symptoms (p = 0.040) and excitement (p = 0.012). A correlation was found between the MD values in the right SLF and the symptoms of disorganization (p <0.000) and excitement (p = 0.004).

Conclusions

SLF seems to play a role in the etiopathogenesis of schizophrenia. Disturbed SLF integrity may be involved in the development of positive, disorganization and excitement symptoms.

Disclosure

No significant relationships.

The relationship between white matter integrity of superior longitudinal fascicle and cognitive functions in chronic schizophrenia

Introduction

Some evidence suggests that disruption of integrity in the superior longitudinal fascicle (SLF) may influence cognitive functions in chronic schizophrenia (CS) but the results are inconclusive.

Objectives

Using diffusion tensor imaging tractography, we investigated the differences in fiber integrity between patients with CS and healthy controls (HC) together with the relationship between fiber integrity and cognitive functions.

Methods

Forty-two patients with CS and 32 HC took part in the study. Assessment of cognitive functions was performed using Measurement and Treatment Research to Improve Cognition in Schizophrenia.

Results

showed group differences, left and right in fractional anisotropy (FA) and mean diffusivity (MD) of the SLF, where patients showed less integrity than controls. Patients performed worse attention/vigilance, working memory, verbal learning, visual learning, reasoning and problem solving, and social cognition tasks than HC. However, when premorbid IQ and level of education were controlled for, the differences were no longer statistically significant in verbal learning and social cognition. In patients with CS, a positive correlation was found between FA of the left SLF and attention/vigilance and working memory. Moreover, in this group there was a negative correlation between MD of the left and right SLF and working memory and social cognition.

Conclusions

These findings provide evidence that SLF disruption appears in patients with CS and might account for impairment of cognitive functioning. This research was funded by the Polish Minister of Science and Higher Education’s program named “Regional Initiative of Excellence” number 002/RID/2018/2019 to the amount of 12 million PLN.

Disclosure

No significant relationships.

A pilot study of the associations between inflammatory markers and the presence of „deficit syndrome” in schizophrenia patients

Introduction

According to current knowledge inflammation seems to be strongly associated with pathogenesis of schizophrenia. Multiple studies and meta-analyses showed increased levels of inflammatory markers in plasma of schizophrenia patients. Individual studies have shown a relationship between the levels of inflammatory markers and the presence of deficit syndrome, but their results are inconsistent.

Objectives

Analysis of associations between inflammatory markers and the presence of deficit syndrome in schizophrenia.

Methods

Studied group consisted of 50 patients with diagnosed schizophrenia (F20) for at least 10 years, including 14 patients with deficit schizophrenia (DS) and 36 patients with non-deficit schizophrenia (NDS). DS and NDS did not differ significantly in age, BMI, duration of schizophrenia, types and doses of antipsychotics (chlorpromazine equivalent), but differed in sex (x2=4.28,p=0.039). Concentrations of inflammatory markers i.e. IL-6,IL-8,IL-10,TNFα,IFNγ,CRP were measured in serum using sensitive ELISA assays.

Results

Initial analysis showed significantly lower concentration of IL-8 in DS compared to NDS (t=-3.18,p=0.002). This association remain significant (F=7.63,p=0.0085) after co-varying for age, sex, BMI, duration of schizophrenia, type of antipsychotic medications and antipsychotics doses. Multiple logistic regression showed that female gender (OR=0.18 [0.04-0.87],p=0.034) and higher IL-8 concentrations (OR=0.03 [0.002-0.39],p=0.007) are independent predictors of lower odds of having DS.

Conclusions

Low IL-8 concentrations seem to be promising predictor of the presence of DS in schizophrenia patients, but results need further investigations. The research was funded by Polish Minister of Science and Higher Education’s program named “Regional Initiative of Excellence” in 2019–2022, grant number 002/RID/2018/2019 to the amount of 12000000PLN and by National Science Centre, Poland (2019/03/X/NZ5/00719)

Disclosure

No significant relationships.

The RADx Tech Test Verification Core and the ACME POCT in the Evaluation of COVID-19 Testing Devices: A Model for Progress and Change

Faced with the COVID-19 pandemic, the US system for developing and testing technologies was challenged in unparalleled ways. This article describes the multi-institutional, transdisciplinary team of the “RADx^SM Tech Test Verification Core” and its role in expediting evaluations of COVID-19 testing devices. Expertise related to aspects of diagnostic testing was coordinated to evaluate testing devices with the goal of significantly expanding the ability to mass screen Americans to preserve lives and facilitate the safe return to work and school. Focal points included: laboratory and clinical device evaluation of the limit of viral detection, sensitivity, and specificity of devices in controlled and community settings; regulatory expertise to provide focused attention to barriers to device approval and distribution; usability testing from the perspective of patients and those using the tests to identify and overcome device limitations, and engineering assessment to evaluate robustness of design including human factors, manufacturability, and scalability.