Low-Cost Polyester-Tipped Three-Dimensionally Printed Nasopharyngeal Swab for the Detection of Severe Acute Respiratory Syndrome-Related Coronavirus 2 (SARS-CoV-2).

Case identification, isolation, and contact tracing are fundamental strategies used to control the spread of coronavirus disease 2019 (COVID-19). This has led to widespread testing that interrupted the supply chain for testing materials around the world. A prospective study was conducted to compare inexpensive and easily sourced 3-dimensionally (3D)-printed polylactic acid and polyester nasopharyngeal swabs to commercially manufactured swabs for the detection of severe acute respiratory syndrome-related coronavirus 2 (SARS-CoV-2). During the study period, 287 laboratory-confirmed hospitalized COVID-19 patients, at multiple stages of their illness, were enrolled. The median age for the study population was 47.6 years (interquartile range [IQR], 34.4 to 56.6 years), and two-thirds (67.6%) of the subjects were male. The median duration of hospitalization, at the time of sampling, was 13 days (IQR, 10 to 16 days). Overall concordance between the prototype and control swabs was 80.8% (Cohen's kappa coefficient, 0.61). Most discrepant results were due to prototype-positive control-negative results. When considering all positive results to be true positives, the prototype swab had a higher sensitivity (90.6% versus 80.8%; 95% confidence interval [CI], 85.7% to 94.0% and 74.7% to 85.7%, respectively; P < 0.015). The cost to produce the prototype swab was estimated to be $0.05 per swab. Polylactic acid 3D-printed polyester-tipped swabs were shown to be effective for nasopharyngeal sample collection. We believe that this design can easily be adopted in countries where commercial swabs are not readily available and can play a vital role in public health efforts for disease control in low-income countries.

Intussusception: A 14-year experience at a UK tertiary referral centre.

AIMS: Intussusception is the most common cause of acute intestinal obstruction in infants. First line management in uncomplicated cases at our centre is fluoroscopy guided air enema reduction. This study reports a 14 year UK single centre experience highlighting management and outcomes of intussusception in children. METHODS: All cases of intussusception (ICD 10-code K56.1) at a single tertiary referral centre from 2004 to 2017 were analyzed. Data evaluated included patient demographics, clinical presentation, treatment modality(s), complications and outcome(s). RESULTS: Two hundred ninety confirmed cases (69% male) of intussusception were identified during the study period. The median age at presentation was 9.5 months (range 4 days-15 years). One hundred eighty-six (64%) cases occurred in children who were transferred to Alder Hey from peripheral district hospitals. One hundred ninety-six cases (68%) proceeded directly to air enema reduction and successful reduction was achieved in 129 cases (66%). A single case (0.5%) of attempted air enema reduction was complicated by perforation. Early recurrence rate following air enema reduction was 9%. Operative management was indicated in 140 (48%) cases of which 66 required bowel resection (47%). There were no deaths. CONCLUSIONS: We highlight one of the largest single centre UK studies defining practice outcomes for intussusception across the British Isles. Our centre has achieved a 66% success rate of non-operative reduction over 14 years in line with the British Society Pediatric Radiology (BSPR) recommendations and within 5% of the national median metric (71%). Moreover these outcomes were achieved with a very low complication rate (0.5%) from air enema reduction and no mortality in the series. TYPE OF STUDY: Retrospective study. LEVEL OF EVIDENCE: III.

Effects of hypoxic preconditioning on neuroblastoma tumour oxygenation and metabolic signature in a chick embryo model.

Hypoxia episodes and areas in tumours have been associated with metastatic dissemination and poor prognosis. Given the link between tumour tissue oxygen levels and cellular metabolic activity, we hypothesised that the metabolic profile between metastatic and non-metastatic tumours would reveal potential new biomarkers and signalling cues. We have used a previously established chick embryo model for neuroblastoma growth and metastasis, where the metastatic phenotype can be controlled by neuroblastoma cell hypoxic preconditioning (3 days at 1% O2). We measured, with fibre-optic oxygen sensors, the effects of the hypoxic preconditioning on the tumour oxygenation, within tumours formed by SK-N-AS cells on the chorioallantoic membrane (CAM) of chick embryos. We found that the difference between the metastatic and non-metastatic intratumoural oxygen levels was small (0.35% O2), with a mean below 1.5% O2 for most tumours. The metabolomic profiling, using NMR spectroscopy, of neuroblastoma cells cultured in normoxia or hypoxia for 3 days, and of the tumours formed by these cells showed that the effects of hypoxia in vitro did not compare with in vivo tumours. One notable difference was the high levels of the glycolytic end-products triggered by hypoxia in vitro, but not by hypoxia preconditioning in tumours, likely due to the very high basal levels of these metabolites in tumours compared with cells. In conclusion, we have identified high levels of ketones (3-hydroxybutyrate), lactate and phosphocholine in hypoxic preconditioned tumours, all known to fuel tumour growth, and we herein point to the poor relevance of in vitro metabolomic experiments for cancer research.