Development and evaluation of low-volume tests to detect and characterize antibodies to SARS-CoV-2

Low-volume antibody assays can be used to track SARS-CoV-2 infection rates in settings where active testing for virus is limited and remote sampling is optimal. We developed 12 ELISAs detecting total or antibody isotypes to SARS-CoV-2 nucleocapsid, spike protein or its receptor binding domain (RBD), 3 anti-RBD isotype specific luciferase immunoprecipitation system (LIPS) assays and a novel Spike-RBD bridging LIPS total-antibody assay. We utilized pre-pandemic (n=984) and confirmed/suspected recent COVID-19 sera taken pre-vaccination rollout in 2020 (n=269). Assays measuring total antibody discriminated best between pre-pandemic and COVID-19 sera and were selected for diagnostic evaluation. In the blind evaluation, two of these assays (Spike Pan ELISA and Spike-RBD Bridging LIPS assay) demonstrated >97% specificity and >92% sensitivity for samples from COVID-19 patients taken >21 days post symptom onset or PCR test. These assays offered better sensitivity for the detection of COVID-19 cases than a commercial assay which requires 100-fold larger serum volumes. This study demonstrates that low-volume in-house antibody assays can provide good diagnostic performance, and highlights the importance of using well-characterized samples and controls for all stages of assay development and evaluation. These cost-effective assays may be particularly useful for seroprevalence studies in low and middle-income countries.

Contacts and behaviours of university students during the COVID-19 pandemic at the start of the 2020/2021 academic year

University students have unique living, learning and social arrangements which may have implications for infectious disease transmission. To address this data gap, we created CONQUEST (COroNavirus QUESTionnaire), a longitudinal online survey of contacts, behaviour, and COVID-19 symptoms for University of Bristol (UoB) staff/students. Here, we analyse results from 740 students providing 1261 unique records from the start of the 2020/2021 academic year (14/09/2020-01/11/2020), where COVID-19 outbreaks led to the self-isolation of all students in some halls of residences. Although most students reported lower daily contacts than in pre-COVID-19 studies, there was heterogeneity, with some reporting many (median = 2, mean = 6.1, standard deviation = 15.0; 8% had ≥ 20 contacts). Around 40% of students' contacts were with individuals external to the university, indicating potential for transmission to non-students/staff. Only 61% of those reporting cardinal symptoms in the past week self-isolated, although 99% with a positive COVID-19 test during the 2 weeks before survey completion had self-isolated within the last week. Some students who self-isolated had many contacts (mean = 4.3, standard deviation = 10.6). Our results provide context to the COVID-19 outbreaks seen in universities and are available for modelling future outbreaks and informing policy.

Effect of cholesterol re-supplementation and atorvastatin on plaque composition in the thoracic aorta of New Zealand white rabbits

BACKGROUND

Effects of re-supplementation of a cholesterol-enriched diet (CEDrs) on size, cholesterol content and morphology of already existing plaques are not known to date.

METHODS

A group of rabbits received standard chow (SC) for 6 weeks ("negative control"; for plasma lipid measurements only). Group I-IV received 2% CED (induction) for 6 weeks; thereafter, groups II-IV have been fed a SC (= cholesterol withdrawal) for 68 weeks. Afterwards, feeding of groups II-IV was continued as follows: Group II - 10 weeks SC, group III - 4 weeks 0.5% CED (~re-supplementation), afterwards 6 weeks SC (~withdrawal again); group IV - 4 weeks 0.5% CED (re-supplementation) + atorvastatin (2.5 mg/kg body weight/day), afterwards 6 weeks SC (~withdrawal again) + atorvastatin. Plasma lipids, but also plaque size, morphology and cholesterol contents of thoracic aortas were quantified.

RESULTS

After CEDrs, plasma cholesterol levels were increased. However, after withdrawal of CEDrs, plasma cholesterol levels decreased, whereas the cholesterol content of the thoracic aorta was increased in comparison with the group without CEDrs. Plaque size remained unaffected. Atorvastatin application did not change plasma cholesterol level, cholesterol content of the thoracic aorta and plaque size in comparison with the group without drug treatment. However, atorvastatin treatment increased the density of macrophages (MΦ) compared with the group without treatment, with a significant correlation between densities of MΦ (Mac-1⁺) and apoptotic (TUNEL⁺; TP53⁺), antigen-presenting (HLA-DR⁺) or oxidatively stressed (SOD2⁺) cells.

CONCLUSIONS

In rabbits with already existing plaques, CEDrs affects plaque morphology and cellular composition, but not plaque size. Despite missing effects on plasma cholesterol levels, cholesterol content of the thoracic aorta and size of already existing atherosclerotic plaques, atorvastatin treatment transforms the already existing lesions to a more active form, which may accelerate the remodelling to a more stable plaque.

Think about the 'C' (in custard and crackers)

CASE HISTORY

A 9-year-old girl with autistic spectrum disorder (ASD) was admitted for a flare-up of chronic recurrent multi-osteomyelitis (CRMO). She complained of leg pain over 3 months, was unable to weight-bear and had a petechial rash for 10 days. She had bleeding gums and a long history of only eating custard and crackers.CRMO was diagnosed at age 3. She'd had shoulder, knee, and ankle involvement, two courses of pamidronate (2011 and 2015) and was currently taking simple analgesia.On examination, she was afebrile, with a widespread petechial rash, most pronounced over her ankles/shins. Her knees and ankles were tender; her ankles had small medial effusions.

INVESTIGATIONS

Mild hypochromic anaemia, normal platelets, white cell countand coagulation. CRP 16. Figures 1 and 2 show her knee radiograph and MRI, respectively.edpract;103/6/304/F1F1F1Figure 1edpract;103/6/304/F2F2F2Figure 2 QUESTION 1: Give four differential diagnoses of petechial rash, bleeding gums and leg pain in an afebrile child? QUESTION 2: Name three behaviours associated with ASD with health consequences. Answers to the questions are on page 02 ANSWERS TO THE QUESTIONS ON PAGE 02.

Toxicity data for preoperative concurrent chemoradiotherapy with oxaliplatin and continuous infusion 5-fluorouracil for locally advanced esophageal cancer

The purpose of this retrospective analysis was to characterize the feasibility and tolerability of oxaliplatin/5-fluorouracil (5-FU) given concurrently with radiotherapy for patients with locally advanced esophageal cancer. Between July 2005 and March 2009, 15 patients with clinical stage T3/T4 and/or N1/M1a lower esophageal or gastroesophageal junction adenocarcinoma were treated with preoperative chemoradiotherapy using oxaliplatin every 2 weeks and continuous infusion 5-FU. The main treatment-related toxicities were oral mucositis and dysphagia. During the first 2 weeks of treatment, 20% of patients presented with grade 1-2 oral mucositis, and one patient developed grade 1 dysphagia. In weeks 3-4, 53% of the patients experienced grade 1-2 mucositis, and 40% experienced grade 1-2 dysphagia. One patient only experienced grade 3 mucositis in week 4. Three patients (20%) had grade 3-4 dysphagia in weeks 3-4 and were continued on intravenous fluids and pain medications. During the last 2 weeks of chemoradiotherapy, 53% of patients reported grade 1-2 oral mucositis, mostly grade 1 and 73% of patients experienced grade 1-2 dysphagia and 26% patients experienced grade 3-4 dysphagia. Other toxicities included fatigue, nausea, neuropathy, and diarrhea. Only one patient experienced > 10% weight loss. The whole group was treated with aggressive supportive care during radiotherapy. Five (33%) patients achieved a pathological complete response. No patients developed locoregional failure. Sixty percent of the patients developed distant metastases and the 2-year disease-free survival was 53%. The median survival was 3.2 years with the 2-year overall survival of 73%. Preoperative oxaliplatin/5-FU-based chemoradiotherapy for locally advanced esophageal cancer is feasible, but associated with substantial gastrointestinal toxicity. A careful attention to nutrition and hydration throughout the course of therapy is required.

Anti-inflammatory effects of the willow bark extract STW 33-I (Proaktiv(®)) in LPS-activated human monocytes and differentiated macrophages

INTRODUCTION

Willow bark extract is frequently used in the treatment of painful rheumatological diseases, such as arthritis and back pain. Its effect has been attributed to its main component salicin, but pharmacological studies have shown that the clinical efficacy of the willow bark extract cannot be explained by its salicin content alone. Therefore different modes of action have been suggested for the anti-inflammatory effect of willow bark extract. Here, we report in vitro data revelling the effect and mode of action of the aqueous willow bark extract STW 33-I as well as a water-soluble fraction (fraction E [Fr E]) in comparison with well-known non-steroidal anti-inflammatory drugs (NSAIDs) like aspirin (ASA) and diclofenac (Diclo) on pro-inflammatorily activated human monocytes and differentiated macrophages.

RESULTS

STW 33-I and the water-soluble Fr E showed concentration-dependent and significant anti-inflammatory effects in lipopolysaccharide-activated monocytes. Both inhibited the intracellular protein expression of tumour necrosis factor-alpha (TNFα) as well as the mRNA expression of TNFα and cyclooxygenase 2 (COX-2), and the release of nitric oxide (NO). In addition, apoptosis of pro-inflammatorily activated monocytes was induced. Furthermore, treatment of activated macrophages with STW 33-I inhibited the nuclear translocation of the p65 subunit of the nuclear transcription factor-kappa B (NF-κB p65).

CONCLUSIONS

The present in vitro investigations suggest a significant anti-inflammatory activity of willow bark water extract STW 33-1 and of its water-soluble fraction by inhibiting pro-inflammatory cytokines (TNFα), COX-2 and nuclear translocation of the transcription factor NF-κB in pro-inflammatorily activated monocytes. Our results provide further evidence for the therapeutic use of STW 33-I in inflammation-related disorders.

d-wave collapse and explosion of a dipolar bose-einstein condensate

We investigate the collapse dynamics of a dipolar condensate of 52Cr atoms when the s-wave scattering length characterizing the contact interaction is reduced below a critical value. A complex dynamics, involving an anisotropic, d-wave symmetric explosion of the condensate, is observed. The atom number decreases abruptly during the collapse. We find good agreement between our experimental results and those of a numerical simulation of the three-dimensional Gross-Pitaevskii equation, including contact and dipolar interactions as well as three-body losses. The simulation indicates that the collapse induces the formation of two vortex rings with opposite circulations.

[Conclusions and recommendations of a WHO expert consultation meeting on iron supplementation for infants and young children in malaria endemic areas]

This article presents the results of an expert consultation meeting aimed at evaluating the safety and public health implications of administering supplemental iron to infants and young children in malaria-endemic areas. Participants at this meeting that took place in Lyon, France on June 12-14, 2006 reached consensus on several important issues related to iron supplementation for infants and young children in malaria-endemic areas. The conclusions in this report apply specifically to regions where malaria is endemic.

The anaemia of infection

It is a great privilege to contribute to the Festschrift in honour of Professor Hendrik Koornhof. Internationally acclaimed researcher, academic and teacher, he has been the mentor of a whole generation of medical microbiologists. But above all, he has set an example as a humanitarian, rarely equalled by his peers. His numerous acts of kindness and concern for others, especially the underprivileged, are legendary. A man of the highest ethical and moral principles, he has always been intolerant of injustice, and has never hesitated to speak out against it, irrespective of the personal cost. He has enriched the lives of all of us who have been fortunate to know him. Professor Koornhof's major research contributions are in the field of bacterial infectious disease, to which he has made numerous seminal contributions. It seemed fitting then to devote this paper to the anaemia of bacterial infection.

Rabi oscillations at exceptional points in microwave billiards

We experimentally investigated the decay behavior with time t of resonances near and at exceptional points, where two complex eigenvalues and also the associated eigenfunctions coalesce. The measurements were performed with a dissipative microwave billiard, whose shape depends on two parameters. The t2 dependence predicted at the exceptional point on the basis of a two-state matrix model could be verified. Outside the exceptional point the predicted Rabi oscillations, also called quantum echoes in this context, were detected.

Algorithms for network analysis in systems-ADME/Tox using the MetaCore and MetaDrug platforms

The authors have previously applied two integrated platforms, MetaCore and MetaDrug, for the assembly and analysis of human biological networks as a useful method for the integration and functional interpretation of high-throughput experimental data. The present study demonstrates in detail the specific algorithms that are used in both software platforms. Using a standard set of genes as input, namely CYP3A4 (an enzyme), PXR (a nuclear hormone receptor), MDR1 (a transporter) and hERG (an ion channel) related to the absorption, distribution, metabolism, excretion and toxicity (ADME/Tox) of xenobiotics, we have now generated networks with each algorithm. The relative advantages and disadvantages of these algorithms are explained using these examples as well as appropriate instances of utility to illustrate further the particular circumstances for their use. In addition, the benefits of the different network algorithms are identified when compared with algorithms available in other products, where this information is available.

Colorectal cancer patient utilization of an internet based clinical trials matching system

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Background: Colorectal cancer patients are increasingly looking to the Internet for information on clinical trials; however, services offering clinical trials recruitment have not been well defined. This study describes one of the first web-based cancer clinical trials matching resources and the demographics of the colorectal cancer patient user base. Methods: Oncolink ( http://www.oncolink.org ) is the web-based educational resource at the University of Pennsylvania and serves between 1.5–2 million pages per month to over 385,000 unique IP addresses. Oncolink, in conjunction with EmergingMed (New York, NY), launched one of the first clinical trials matching resources on the Internet. Patients input demographic and tumor-specific information via secure Internet-only registration or via the Internet with assistance from a call center, to match to trials. As of 12/2005, there were 112 total colorectal trials in the database. Results: Between 12/2000 and 9/2005 a total of 41,970 individual profiles were created, with 3289 (7.8%) by colorectal cancer patients. Other GI tumors accounted for 15% of profiles. Of the 3289 patients, 54% were male and 46% were female, and the median age was 55 (range 19–96). Most patients reported their disease as having spread to another organ (62%) or to lymph nodes (15.4%). Most patients were previously treated with surgery (81%), radiation (26%), chemotherapy (74%), and/or biological therapies (21%) (bevacizumab, cetuximab, interferon or interleukin). Patients who used the call center with the Internet were more likely to apply for enrollment in a clinical trial after review of the matches (77% vs. 10%, p<0.001). The median number of trial matches in the system was 7 per patient. Of the 3289 colorectal patients, 681 patients (21%) went on to apply for enrollment to trials based on their matches. Conclusions: This report demonstrates that a significant percentage of colorectal cancer patients are willing to use the Internet to match to clinical trials. Contact with a call center greatly increases the likelihood of application to trials. Internet based clinical trials resources should maintain options for personal communication to increase the likelihood of enrollment to clinical trials.

No significant financial relationships to disclose.

Feasibility of a multi-institutional liver cancer registry

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Background: Hepatocellular carcinoma (HCC) is one of major causes of cancer-related death globally, with increasing incidence in the United States. There is still a lack of effective therapy for the disease. Many small phase II studies of systemic therapies for advanced HCC have been performed in the US. Most studies are too small to make definitive conclusions. This registry was developed to pool phase II studies from member institutions of the Liver Cancer Research Group (LCRG) to evaluate the characteristics and outcomes of patients receiving systemic treatments in an attempt to validate known and to identify potentially new prognostic factors in HCC. Methods: An Internet based registry was initiated on the OncoLink website ( https://www.oncolink.org ) and directed by the LCRG. This registry has undergone IRB approval. All data is password protected and maintained on physical and electronically secure servers. The registry contains 37 fields for each patient, which details demographics, tumor parameters, underlying liver disease, and detailed treatment information of chemotherapy and/or biological therapies. Results: As of 1/10/2006, 101 patients have been entered in the database from 5 institutions. The median age of patients in these studies is 59 years old (range 26–82) with 22 female (22%) patients. The racial distribution was: 67% of Caucasian, 15% African American, 11% Asian, and 6% Hispanic. The median performance status of patients included in these phase II studies was ECOG 1 (PS 0/1/2: 41/56/4). A variety of cytotoxic and biological agents (either as a single agent or as combination) were included in the analysis including doxorubicin, epirubicin, gemcitabine, oxaliplatin, capecitabine, thalidomide, erlotinib, and bevacizumab. All patients had extensive disease, most of them with multiple lesions (51% ≥ 5 lesions) and bilobar involvement (69%). The mean size of lesions was 8.3 cm (range 1–20 cm). Within the population, 25% patents have hepatitis B and 44% have hepatitis C as their background diseases. Conclusions: This multi-institutional database for HCC treated on phase II clinical trials in the US is feasible. This database continues to expand through the support of the LCRG. As the data matures, future studies on outcomes related to biological and chemotherapeutic regimens will be presented.

No significant financial relationships to disclose.

Intravascular electric impedance spectroscopy of atherosclerotic lesions using a new impedance catheter system

Newer techniques are required to identify atherosclerotic lesions that are prone to rupture. Electric impedance spectroscopy (EIS) can characterize biological tissues by measuring the electrical impedance over a frequency range. We tested a newly designed intravascular impedance catheter (IC) by measuring the impedance of different stages of atherosclerosis induced in an animal rabbit model. Six female New Zealand White rabbits were fed for 17 weeks with a 5% cholesterol-enriched diet to induce early forms of atherosclerotic plaques. All aortas were prepared from the aortic arch to the renal arteries and segments of 5-10 mm were marked by ink spots. A balloon catheter system with an integrated polyimide-based microelectrode structure was introduced into the aorta and the impedance was measured at each spot by using an impedance analyzer. The impedance was measured at frequencies of 1 kHz and 10 kHz and compared with the corresponding histomorphometric data of each aortic segment.Forty-four aortic segments without plaques and 48 segments with evolving atherosclerotic lesions could be exactly matched by the histomorphometric analysis. In normal aortic segments (P0) the change of the magnitude of impedance at 1 kHz and at 10 kHz (|Z|(1 kHz) - |Z|(10 kHz), = ICF) was 208.5 +/- 357.6 Omega. In the area of aortic segments with a plaque smaller than that of the aortic wall diameter (PI), the ICF was 137.7 +/- 192.8 Omega. (P 0 vs. P I; p = 0.52), whereas in aortic segments with plaque formations larger than the aortic wall (PII) the ICF was significantly lower -22.2 +/- 259.9 Omega. (P0 vs. PII; p = 0.002). Intravascular EIS could be successfully performed by using a newly designed microelectrode integrated onto a conventional coronary balloon catheter. In this experimental animal model atherosclerotic aortic lesions showed significantly higher ICF in comparison to the normal aortic tissue.

The relationship between serum cobalamin concentration and mean red cell volume at varying concentrations of serum folate

There is concern that exposure of patients to folic acid may prevent the development of the macrocytosis of cobalamin deficiency and thus delay the detection of the neurological complications. We examined the relationship between low cobalamin levels and mean cell volume (MCV) at different serum folate concentrations in 63,472 blood samples tested in a community pathology laboratory over 2 years. We found no evidence that high serum folate levels masked the macrocytosis of cobalamin deficiency in this population with similar increases in MCV regardless of whether the serum folate was low, normal or high. Macrocytosis appears to retain its value as a marker of cobalamin deficiency in people with serum folate concentrations above the population average.

[Possibilities of regression in arteriosclerosis]

We studied the hypercholesterolemic rabbit model in order to evaluate potentials of regression of arteriosclerosis by measuring various blood and plaque parameters. After induction of arteriosclerosis by feeding a 2% cholesterol-enriched diet (CHF) for 6 weeks, the highly increased blood lipid levels decreased significantly under normal diet, while the cholesterol concentration, the lumen stenosis, and the number of smooth muscle cells in the plaques of the thoracic aorta still significantly increased. Sixty-eight weeks after reaching normal blood lipid levels, cellular density and number of macrophages significantly diminished; cholesterol concentration and lumen stenosis did not change significantly, whereas the smooth muscle cells further increased. Arteriosclerotic arteries of elderly people demonstrated a similar structure as seen after long-term regression in our experiments.

Glucose transport and apoptosis after gene therapy with HSV thymidine kinase

The relation between tumour metabolism and induction of apoptosis by gene therapy was investigated in a rat Morris hepatoma (MH3924A) model expressing the HSV thymidine kinase (HSVtk) gene. In vivo the amount of glucose transporter (GLUT1 and GLUT3 isoforms) expressing cells was determined in tumours of untreated and treated animals using immunohistochemistry. In vitro uptake studies with 2-fluoro-2-deoxy-D-glucose (FDG), 3-O-methylglucose and thymidine (TdR) and a TUNEL (TdT-mediated dUTP nick end labelling) assay for the assessment of apoptosis were done immediately and 24 h after treatment of the recombinant cells with different doses of ganciclovir (GCV). Immunohistochemistry revealed a significant increase in GLUT1 in treated tumours which showed enhanced transport activity for FDG. In vitro the FDG and 3-O-methylglucose uptake increased to 186% when compared with that of the non-treated cells immediately after incubation with GCV. However, 24 h later the FDG uptake had declined to its normal level, whereas the accumulation of 3-O-methylglucose remained elevated. The uptake of TdR, which was determined simultaneously, decreased in the acid-insoluble fraction of the cells to 27% and 11%, respectively, immediately and 24 h after therapy, while in the acid-soluble fraction it increased to 229% and to 167%, respectively. Employing the TUNEL technique, 25% of cells were found to be apoptotic 24 h after the termination of GCV treatment. Inhibition of glucose transport by cytochalasin B or competition with deoxyglucose resulted in a 78% (cytochalasin B) and 88% (deoxyglucose) decrease in FDG uptake in the recombinant hepatoma cells and in an increase in the apoptotic cell fraction. It is concluded that inhibition of enhanced glucose transport in GCV-treated cells increased apoptosis. Therefore, enhanced glucose transport seems to represent a stress reaction of tumour cells dedicated for the prevention of cell death.