In situ generation of cold atmospheric plasma-activated mist and its biocidal activity against surrogate viruses for COVID-19

AIMS

To provide an alternative to ultra violet light and vapourized hydrogen peroxide to enhance decontamination of surfaces as part of the response to the COVID-19 pandemic.

METHODS AND RESULTS

We developed an indirect method for in situ delivery of cold plasma and evaluated the anti-viral activity of plasma-activated mist (PAM) using bacteriophages phi6, MS2, and phiX174, surrogates for SARS-CoV-2. Exposure to ambient air atmospheric pressure derived PAM caused a 1.71 log10 PFU ml-1 reduction in phi6 titer within 5 min and a 7.4 log10 PFU ml-1 reduction after 10 min when the the PAM source was at 5 and 10 cm. With MS2 and phiX174, a 3.1 and 1.26 log10 PFU ml-1 reduction was achieved, respectively, after 30 min. The rate of killing was increased with longer exposure times but decreased when the PAM source was further away. Trace amounts of reactive species, hydrogen peroxide and nitrite were produced in the PAM, and the anti-viral activity was probably attributable to these and their secondary reactive species.

CONCLUSIONS

PAM exhibits virucidal activity against surrogate viruses for COVID-19, which is time and distance from the plasma source dependent.

Novel Antibacterial Properties of the Human Dental Pulp Multipotent Mesenchymal Stromal Cell Secretome

It is well recognized that clearance of bacterial infection within the dental pulp precedes pulpal regeneration. However, although the regenerative potential of the human dental pulp has been investigated extensively, its antimicrobial potential remains to be examined in detail. In the current study bactericidal assays were used to demonstrate that the secretome of dental pulp multipotent mesenchymal stromal cells (MSCs) has direct antibacterial activity against the archetypal Gram-positive and Gram-negative bacteria, Staphylococcus aureus and Escherichia coli, respectively, as well as the oral pathogens Streptococcus mutans, Lactobacillus acidophilus, and Fusobacterium nucleatum. Furthermore, a cytokine/growth factor array, enzyme-linked immunosorbent assays, and antibody blocking were used to show that cytokines and growth factors present in the dental pulp MSC secretome, including hepatocyte growth factor, angiopoietin-1, IL-6, and IL-8, contribute to this novel antibacterial activity. This study elucidated a novel and diverse antimicrobial secretome from human dental pulp MSCs, suggesting that these cells contribute to the antibacterial properties of the dental pulp. With this improved understanding of the secretome of dental pulp MSCs and its novel antibacterial activity, new evidence for the ability of the dental pulp to fight infection and restore functional competence is emerging, providing further support for the biological basis of pulpal repair and regeneration.

Evaluation of a formative peer assessment in research methods teaching using an online platform: A mixed methods pre-post study

BACKGROUND

In higher education settings, there are increasing calls to shift away from traditional summative assessment practices, such end of term written tests, to explore methods of assessing learning in alternative ways. Peer assessment has been advocated as a means of formative assessment to enhance student engagement, empowering students to take responsibility for their own learning. While there is accumulating evidence for the value of peer assessment in higher education, one cannot assume peer feedback will translate appropriately to all settings and educational contexts.

OBJECTIVES

This study evaluated the implementation of formative online peer assessment in a nursing and midwifery research methods module. We explored students' expectations, experiences, and ultimately the acceptability of this approach.

DESIGN

A quantitative descriptive study.

SETTING

Ireland.

METHODS

An online survey to collate expectations and experiences of engagement in peer assessment. Scales were drawn from previous research and non-parametric tests explored changes in perceptions over time. Qualitative content analysis explored patterns evident in open-text responses.

RESULTS

The response rate was 28% (n = 74) at baseline and 31% at follow-up (n = 81). Peer assessment was a new experience for 95% of respondents. Students initially expressed apprehension, perceiving the task as daunting, and doubting their ability to provide feedback to peers. However, through providing instruction and tools to support students in the activity, high levels of satisfaction with the process and the experience were reported. Significant differences in perceptions of peer assessment were evident over time, including an enhanced belief that respondents had the requisite skills to appraise the work of their peers.

CONCLUSIONS

In sum, nursing and midwifery students agreed that peer assessment was a valuable learning experience as part of research methods training and critical skills development.

Non-invasive, 3D printed, colourimetric, early wound-infection indicator

A simple, non-invasive, colour-based carbon dioxide (CO₂) indicator is described. The indicator provides an indirect response to the rapid, aerobic microbial colonisation of an underlying wound when used in conjunction with an occlusive (i.e. sealed) dressing. The indicator has potential as an early warning indicator of infection in chronic wounds.

The prognostic value of neutrophil-to-lymphocyte ratio in patients with epidermal growth factor receptor mutated advanced non-small cell lung cancer (NSCLC)

e21675

Background: An elevated neutrophil-to-lymphocyte ratio (NLR) indicates a poor prognosis across multiple cancers, including non-small cell lung cancer (NSCLC). Our study aims to validate these findings in EGFR-mutated NSCLC patients receiving tyrosine kinase inhibitor (TKI) therapy, and to evaluate other factors that may impact NLR. Methods: We retrospectively analyzed 95 patients with advanced EGFR-mutated NSCLC treated with TKIs at Rush University Medical Center and The University of Chicago Medical Center from August 2011 to August 2018. The prognostic value of NLR was assessed at the start of therapy, and after 6 and 12 weeks of treatment. The median progression free survival (mPFS) and median overall survival (mOS) were calculated by the Kaplan-Meier method and compared with the log rank test. Spearman rank correlation was used to correlate number of disease sites with NLR at diagnosis. T test analysis compared mean NLR between patients with high grade (≥ 3) toxicity versus low or no (grades 0-2) toxicity. The relationship between NLR and body mass index (BMI) changes were analyzed using Pearson correlation. Results: At therapy start, patients with NLR < 5 (n = 57) had a mPFS of 15.3 months and a mOS of 56.7 months, while those with NLR ≥ 5 (n = 35) had a mPFS of 13.8 months ( p= 0.024) and mOS of 40.0 months ( p= 0.0056). After 6 weeks of treatment, patients with NLR < 5 (n = 69) had a mPFS of 14.6 months and mOS of 56.2 months, while those with NLR ≥ 5 (n = 23) had a mPFS of 10.0 months ( p= 0.052) and a mOS of 37.74 months ( p= 0.049). After 12 weeks of treatment, patients with NLR < 5 (n = 66) had a mPFS of 14.2 months and mOS of 54.8 months, while those with NLR ≥ 5 (n = 17) had a mPFS of 3.0 months ( p= 0.0016) and a mOS of 22.4 months ( p= 0.0012). Patients who had a decrease in NLR did not have significantly better mPFS or mOS compared to patients whose NLR increased at either 6 or 12 weeks. Baseline number of disease sites and BMI did not correlate with NLR at diagnosis. Changes in BMI did not correlate with a change in NLR at 6 weeks or at 12 weeks. There was no significant difference in NLR between patients with high grade (≥ 3) versus no or low grade (0-2) drug toxicities. Conclusions: NLR can be used as a prognostic factor to predict which EGFR mutated NSCLC patients on TKI therapy may have worse PFS or OS outcomes. Closer monitoring and potential therapeutic escalation may be beneficial in patients with elevated NLR ≥ 5. Further work studying NLR in patients being treated with a larger osimertinib cohort is ongoing.

High voltage atmospheric cold air plasma control of bacterial biofilms on fresh produce

Atmospheric cold plasma (ACP) offers great potential for decontamination of food borne pathogens. This study examined the antimicrobial efficacy of ACP against a range of pathogens of concern to fresh produce comparing planktonic cultures, monoculture biofilms (Escherichia coli, Salmonella enterica, Listeria monocytogenes, Pseudomonas fluorescens) and mixed culture biofilms (Listeria monocytogenes and Pseudomonas fluorescens). Biotic and abiotic surfaces commonly occurring in the fresh food industry were investigated. Microorganisms showed varying susceptibility to ACP treatment depending on target and process factors. Bacterial biofilm populations treated with high voltage (80 kV) ACP were reduced significantly (p < 0.05) in both mono- and mixed species biofilms after 60 s of treatment and yielded non-detectable levels after extending treatment time to 120 s. However, an extended time was required to reduce the challenge mixed culture biofilm of L. monocytogenes and P. fluorescens inoculated on lettuce, which was dependent on biofilm formation conditions and substrate. Contained treatment for 120 s reduced L. monocytogenes and P. fluorescens inoculated as mixed cultures on lettuce (p < 0.05) by 2.2 and 4.2 Log10 CFU/ml respectively. When biofilms were grown at 4 °C on lettuce, there was an increased resistance to ACP treatment by comparison with biofilm grown at temperature abuse conditions of 15 °C. Similarly, L. monocytogenes and P. fluorescens exposed to cold stress (4 °C) for 1 h demonstrated increased tolerance to ACP treatment compared to non-stressed cells. These finding demonstrates that bacterial form, mono versus mixed challenges as well as environmental stress conditions play an important role in ACP inactivation efficacy.

ICD-11 PTSD and complex PTSD amongst Syrian refugees in Lebanon: the factor structure and the clinical utility of the International Trauma Questionnaire

OBJECTIVE

Support for ICD-11 post-traumatic stress disorder (PTSD) and complex PTSD (CPTSD) is growing; however, few studies include refugees or examine the clinical utility of PTSD/CPTSD classifications. This study sought to provide the first evaluations of (i) the factor structure of ICD-11 PTSD/CPTSD amongst refugees in the Middle East; and (ii) the clinical utility of the International Trauma Questionnaire (ITQ) to identify PTSD/CPTSD in a humanitarian context.

METHOD

Participants were 112 treatment-seeking Syrian refugees living in Lebanon. Factorial validity was assessed using confirmatory factor analysis (CFA) based on responses to the ITQ. Clinical utility of the ITQ was assessed through semi-structured interviews with six Lebanese psychotherapists.

RESULTS

Complex PTSD (36.1%) was more common than PTSD (25.2%), and no sex or age differences were observed at the prevalence or symptomatic levels. CFA results supported a two-factor higher-order model consistent with ICD-11 PTSD/CPTSD. Qualitative findings indicated that the ITQ is generally positively regarded, with some limitations and suggested modifications noted.

CONCLUSION

This is the first study to support the ICD-11 PTSD/CPTSD amongst refugees in the Middle East and the clinical utility of the ITQ in a humanitarian context. Findings support the growing evidence for the cross-cultural applicability of ICD-11 PTSD/CPTSD.

Recurrent Biatrial Myxoma in a 41-Year-Old Woman after Left Atrial Myxoma Resection

Bilateral recurrence of atrial myxoma has been reported only a few times. We describe the case of a 41-year-old woman who had undergone left atrial myxoma resection and presented 9 years later with myxomas in both atria. The patient underwent successful resection of both masses with resolution of symptoms. We discuss the phenomenon of recurrent biatrial myxoma.

Serial bedside emergency ultrasound in a case of pediatric blunt abdominal trauma with severe abdominal pain

We present a case of a teenager with isolated left renal laceration with perirenal hematoma. The patient had presented with severe left upper quadrant (LUQ) pain following blunt abdominal trauma (BAT) sustained during a sledding accident. A screening bedside focused abdominal sonogram for trauma (FAST) rapidly excluded free fluid on two serial examinations, 30 minutes apart. It provided the pediatric emergency physician with a measure of diagnostic confidence that the patient could be safely transported to the CT suite for detailed delineation of his injury. Moreover, narcotic analgesia was liberally administered early in his illness course, without the fear of unmasking potential hypovolemia when it was known that he did not have gross intra-abdominal bleeding on his bedside ultrasound (US). It also provided a working diagnosis of the primary organ of injury. Our hospital, like many pediatric hospitals around the nation, does not have in-house 24-hour radiology support. We suggest that the use of the bedside US be extended to the stable pediatric patient in severe abdominal pain following BAT. It can serve as a valuable, rapid, noninvasive, bedside, easily repeated, fairly accurate triage tool to evaluate pediatric BAT with severe pain.

Determination of systolic blood pressure via pulse oximeter in transported pediatric patients

OBJECTIVE

To compare pulse oximetry waveform systolic blood pressure measurements (POWSBP) to measurements obtained by noninvasive blood pressure measurement (NIBPM) during the transport of children.

DESIGN

A prospective, convenience sample.

SETTING AND PARTICIPANTS

All patients transported by a dedicated Pediatric Critical Care Transport Team were eligible for inclusion. Senior transport nurses with over 3 years of transport experience who had been instructed by the principal investigator (PI) in the technique, obtained the measurements and recorded the results. A convenience sample was obtained based on the presence or absence of one of the senior nurses on the transport team.

METHODS

Measurements of blood pressure were obtained by POWSBP and NIBPM (PROPAQ@; Protocol Systems, Beaverton, OR) on pediatric patients during transport in moving ambulances or fixed wing aircraft. Measurement of systolic blood pressure by pulse oximetry (POWSBP) was obtained on all patients by observing the return of the plethysmographic waveform of the pulse oximeter as the blood pressure cuff deflated. The patients were divided into two groups; in group A POWSBP measurements were obtained by using the automated BP cuff from the PROPAQ@ and in group B by a manual BP cuff. These measurements were compared to NIBPM readings obtained at the same time. Between 3 and 13 paired readings were obtained for each patient. The actual transport time determined the number of measurements obtained.

RESULTS

A total of 24 patients were enrolled in the study. Multiple matched pair readings (both POWSBP and NIBPM) were obtained from each patient for a total of 180 data points. A two variable linear regression model was run which identified a significant correlation between POWSBP and NIBPM. Group A, r = 0.7592 and r = 0.9477 for group B significant at P< 0.000001. Further, a corrective equation was developed for use with an automated BP cuff.

CONCLUSIONS

The use of pulse oximetry waveform systolic blood pressure measurement is a quick and easy method with which to obtain systolic blood pressure in children during transport and shows a close correlation to the standard noninvasive blood pressure measurement. If an automated blood pressure cuff is used, then a corrective equation [NIBP-S = 41.686 + 0.7377(POBPS)] is required. Further validation in a larger group of patients is recommended.

Proficiency test performance and experience with College of American Pathologists' programs

We examined rates of unacceptable results in a large interlaboratory proficiency test program, which is designed for small hospitals, clinics, and physician offices. The objective was to see whether rates of unacceptable results decrease as laboratories gain experience in interlaboratory comparison programs. We examined data from the College of American Pathologists' Excel Surveys, 1987 through 1993, in the areas of chemistry, hematology, immunology, and blood bank. The data for laboratories with consistent participation show consistent and statistically significant improvement in performance for the first 3 to 4 years of proficiency testing. The data for all participants also suggest that laboratories with more experience with proficiency testing have lower rates of unacceptable results, and that these rates tend to decrease with each year of experience. These conclusions support the findings of other researchers who have documented the benefits of interlaboratory comparison programs and proficiency testing.

An investigation of the magnitude and causes of count loss artifacts in SPECT imaging

A quantitative evaluation and an investigation of the mechanism of the count losses that can occur in SPECT imaging is described. The most common clinical example of the artifacts which result from this is encountered when sections are taken through the femoral heads in skeletal studies of the pelvis. From some simple phantom studies, it was identified that the count losses were associated with the presence of a high dynamic range in the projection data. Further information was obtained from simulation studies. It was found that the count loss phenomenon is caused by the combined effects of the presence of a high count density area and a structure with a relatively high attenuation level. An appreciation of the presence, magnitude, and mechanism of this effect is important if erroneous clinical findings are to be avoided. This is particularly relevant because of the existence of a variety of techniques that can be used to remove the resulting artifacts.

College of American Pathologists-Centers for Disease Control collaborative study for evaluating reference materials for total serum cholesterol measurements

Several recent studies to evaluate the performance of laboratory instruments have shown that with some instrument systems processed (lyophilized, frozen, and stabilized) materials exhibit matrix effects that cause the assay for cholesterol to respond differently for them than for patient specimens. To understand this phenomenon better the College of American Pathologists, Northfield, III, and the Centers for Disease Control, Atlanta, Ga, have conducted a collaborative study with 44 laboratories where 16 instruments manufactured by nine companies are evaluated. The purposes were to assess measurement variation on several reference materials used for standardizing total cholesterol measurements and to evaluate a new stabilized liquid serum as a potential reference material. Lypophilized, frozen, fresh-frozen, and stabilized materials at three concentrations were measured for total cholesterol. The results show that the average coefficient of variation of measured total cholesterol for all instruments, laboratories, vials, and replicates is 3.6% to 4.1% for each of the materials measured (excluding the results for one instrument). For one instrument, however, significant bias was found on the stabilized liquid serum material. Results from the fresh-frozen materials indicate that the instrument systems evaluated allow laboratories to attain the National Cholesterol Education Program analytical performance goals.

Supraglottitis in young adults

Supraglottitis is a disorder with the potential for significant morbidity and mortality in adults. Of the 25 patients we reviewed, 18 were black, representing the largest series of black adults with this condition reported in the medical literature. The mean age for black men was 14 years younger than previously described adults with supraglottitis. The index of suspicion for supraglottitis should be high in young adults with odynophagia out of proportion to findings on oropharyngeal examination. Indirect laryngoscopy will confirm the diagnosis and allow prompt initiation of treatment. Early recognition and treatment will avoid complications.

Quality control of agar diffusion susceptibility tests: data from the Quality Assurance Service Microbiology program of the College of American Pathologists

Over a 12-month period, between July 1981 and June 1982, 115 active participants in the Microbiology program of the College of American Pathologists Quality Assurance Service (QAS) submitted a total of 555,619 individual determinations on three quality control reference strains using the NCCLS standardized disc diffusion procedure. Data is presented for those antimicrobic agent/reference strain combinations for which NCCLS control limits have been changed since the last report of QAS microbiology data or that continue to show discrepancies with current NCCLS individual daily test control guidelines. Data for Escherichia coli versus cefoxitin, doxycycline, and nalidixic acid and for Staphylococcus aureus versus cefoxitin, nafcillin, and oxacillin show good compliance with the new NCCLS guidelines and distributions that are all approximately Gaussian. Significant discrepancies were noted for six combinations; cefamandole, cephalothin, neomycin, and nitrofurantoin versus E. coli and amikacin and clindamycin versus S. aureus. Of these discrepancies, only neomycin/E. coli and amikacin/S. aureus can be accounted for by a subpopulation of laboratories, which, when removed, corrects the data.