Rapid point-of-care detection of SARS-CoV-2 infection in exhaled breath using ion mobility spectrometry: a pilot study

BACKGROUND

An effective testing strategy is essential for pandemic control of the novel Coronavirus disease 2019 (COVID-19) caused by infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Breath gas analysis can expand the available toolbox for diagnostic tests by using a rapid, cost-beneficial, high-throughput point-of-care test. We conducted a bi-center clinical pilot study in Germany to evaluate breath gas analysis using multi-capillary column ion mobility spectrometry (MCC-IMS) to detect SARS-CoV-2 infection.

METHODS

Between September 23, 2020, and June 11, 2021, breath gas measurements were performed on 380 patients (SARS-CoV-2 real-time polymerase chain reaction (PCR) positive: 186; PCR negative: 194) presenting to the emergency department (ED) with respiratory symptoms.

RESULTS

Breath gas analysis using MCC-IMS identified 110 peaks; 54 showed statistically significant differences in peak intensity between the SARS-CoV-2 PCR-negative and PCR-positive groups. A decision tree analysis classification resulted in a sensitivity of 83% and specificity of 86%, but limited robustness to dataset changes. Modest values for the sensitivity (74%) and specificity (52%) were obtained using linear discriminant analysis. A systematic search for peaks led to a sensitivity of 77% and specificity of 67%; however, validation by transferability to other data is questionable.

CONCLUSIONS

Despite identifying several peaks by MCC-IMS with significant differences in peak intensity between PCR-negative and PCR-positive samples, finding a classification system that allows reliable differentiation between the two groups proved to be difficult. However, with some modifications to the setup, breath gas analysis using MCC-IMS may be a useful diagnostic toolbox for SARS-CoV-2 infection.

TRIAL REGISTRATION

This study was registered at ClinicalTrials.gov on September 21, 2020 (NCT04556318; Study-ID: HC-N-H-2004).

Abstract P3-14-01: Features of neoadjuvant and adjuvant chemotherapy in breast cancer – A population-based study on 39404 patients

Background: Neoadjuvant chemotherapy (NACT) is increasingly used globally in clinical trials for breast cancer patients. In Germany, NACT has been implemented as a standard option of care for almost a decade. In a population-based benchmark cohort study, the West German Breast Center (WBC) recorded approximately 50% of all breast cancer cases diagnosed in Germany between 2007 and 2010. We compare baseline and treatment pattern of patients treated either with adjuvant (ACT) or NACT.

Methods: Approx. 200 accredited breast centers treated 115169 primary breast cancer patients of whom 32609 received ACT and 6795 NACT. Pathological complete response (pCR) was stated if no invasive and no non-invasive tumor residues (ypT0 ypN0) were detected. Follow up information was available for 55% of patients.

Results: Use of NACT increased from 16.4% in 2007 to 19.1% in 2010 (p<.0001). Patients treated with NACT were younger, had higher clinical nodal involvement, fewer lobular-invasive cancers, more undifferentiated, hormone-receptor-negative, and HER2-positive cancers, and more multicentric tumors compared to patients treated with ACT (all p<0.002). 34% of patients in the NACT group had cT3/4 tumors compared to 7.7% of pT3/4 tumors in the ACT group. cN0 status was twice as frequent (70.6% vs 37.7%, p<.0001) whereas pN0 status was reported less frequently (47.4% vs 51.4%, p<0.0001) in the ACT and NACT group, respectively. Time between diagnosis and start of systemic treatment or surgery was in median 12 (range 1-902) and 22 (range 1-721) days in the ACT and NACT group, respectively (p<.0001). 66.2% and 91.4% of patients received ACT and NACT with a taxane, respectively (p<.0001). 9.7% and 37.5% of patients receiving treatment for > = 18 weeks, respectively. 35.2% and 69.9% of patients with HER2-positive tumors received adjuvant or neoadjuvant trastuzumab, respectively (p<.0001). 21.7% and 31.4% of patients were treated in ACT or NACT clinical trials, respectively (p<.0001). Breast conservation was possible in 69.4% and 55.2% in the ACT and NACT group, respectively (p<.0001). 30.5% and 37.5% needed two or more surgical interventions in the ACT and NACT group, respectively (p<.0001).

Multivariable logistic regression analysis confirmed taxane- and trastuzumab-based treatment, study participation, age, histologic type, grading, and hormone-receptor status as independent predictors of pCR. pCR rate was not dependent on the time between diagnosis and start of treatment or the time between end of chemotherapy and surgery.

In univariate analysis patients receiving NACT showed a 4-year overall survival rate of 78%, compared to 92% in patients receiving ACT (p<.0001). However, patients with a pCR after NACT showed a comparable survival to patients in the ACT group, whereas patients without a pCR showed a 4-year overall survival rate of 76%. In the hormone-receptor-positive/HER2-positive and even more in the triple-negative subgroup, survival of patients with a pCR appeared better than in patients with ACT.

Conclusion: In this population-based study, NACT was used in patients with unfavorable risk factors and was more intense than ACT. Outcome of patients with pCR after NACT was similar and in aggressive tumor subtypes even better than after ACT.

Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P3-14-01.

Differential expression of Rel/NF-kappaB and octamer factors is a hallmark of the generation and maturation of dendritic cells

A key feature of maturation of dendritic cells is the down-regulation of antigen-processing and up-regulation of immunostimulatory capacities. To study the differential expression of transcription factors in this process, we investigated the nuclear translocation and DNA binding of Rel/NF-kappaB and octamer factors during in vitro generation and maturation of dendritic cells compared with macrophage development. RelB was the only factor strongly up-regulated during the generation of both immature dendritic cells and macrophages. Cytokine-induced maturation of dendritic cells resulted in an increase in nuclear RelB, p50, p52, and especially c-Rel, whereas cytokine-treated macrophages responded poorly. This up-regulation of NF-kappaB factors did not correlate with lower levels of cytosolic NF-kappaB inhibitors, the IkappaBs. One IkappaB, Bcl-3, was strongly expressed only in mature dendritic cells. Furthermore, generation and maturation of dendritic cells led to a continuous down-regulation of the octamer factor Oct-2, whereas monocytes and macrophages displayed high Oct-2 levels. A similar pattern of maturation-induced changes in transcription factor levels was found in cultured murine epidermal Langerhans cells, suggesting a general physiological significance of these findings. Finally, this pattern of differential activation of Rel and octamer factors appears to be suitable in determining the maturation stage of dendritic cells generated by treatment with different cytokine combinations in vitro. (Blood. 2000;95:277-285)

Localisation of hyaluronate (HA) in primary tumors and nude mouse xenografts of human pancreatic carcinomas using a biotinylated HA-binding protein

A biotinylated hyaluronate (HA)-binding protein isolated from bovine cartilage was used to analyze the distribution of HA in nude mouse xenografts derived from human pancreatic adenocarcinoma cell lines as well as in primary human pancreatic adenocarcinomas. The most reproducible results for the localisation of HA were obtained using cryostat sections. When the biotinylated HA-binding protein was applied to histological sections of nude mouse xenografts, the specific staining found could be inhibited by preincubating the HA-binding protein with an excess of HA or by hyaluronidase treatment of the tissue before staining. The highest HA concentration was found at the tumor boundaries, while in the central part of the tumor staining was slight or absent. In cryostat sections of primary tumors HA was found predominantly in the connective tissue immediately around tumor cells or at the border between the tumor and normal pancreatic tissue.

The effect of long-term inhibition of mitochondrial protein synthesis on the oxidation capacity of mitochondria for NADH-linked substrates

Experiments are presented showing that specific inhibition of mitochondrial protein synthesis by tetracyclines decreases the activity of the NADH-dehydrogenase complex in liver mitochondria, if rats are treated for long periods with these antibiotics. The corresponding inhibition of this complex in tumor cells (Zajdela hepatoma) and tumor mitochondria (Leydig cell tumor) is even more pronounced. It is concluded that the mitochondrial genetic system is involved in the assembly of the NADH-dehydrogenase complex, most likely by coding for one or more subunits. It is argued that this information, contrary to the situation for cytochrome c oxidase, the cytochrome bc1 complex and ATPsynthase, has been missed in previous experiments employing differential inhibition of mitochondrial protein synthesis, because of the circumstance that the inhibition did not reach the level at which it became rate-limiting.

Choice of peptide and peptide length for the generation of antibodies reactive with the intact protein

N-terminal peptides of bovine ribonuclease (RNase) of 20, 13 and 7 amino acid residues were isolated by reversed-phase high-performance liquid chromatography (HPLC). Antibodies were raised in mice against these peptides coupled to bovine serum albumin (BSA). It was shown that antibodies against the peptides reacted with the intact protein and that the immune response decreased with decreasing size of peptide. In order to obtain a satisfactory reaction with the intact protein, the peptide immunogen should be longer than 7 amino acids.

Mastication of Rubber

As has been shown, peptizing agents act in the mechanochemical and thermooxidative breakdown of elastomers as radical acceptors at low temperatures and as oxidation catalysts at high temperatures. Modern peptizing agents usually consist of thiophenols or aromatic disulfides combined with metal complexes (chelates) of Fe, Cu, and Co, as catalysts for the oxidative breakdown. The composition must be such as not to affect the mechanical properties, stability, and aging of compounds and vulcanizates. Peptizing agents have practically no influence on the vulcanizate properties. Mastication can be carried out as a separate step or as an integrated part of the mixing process. When mastication is integrated with the mixing process, vulcanizate properties like flex fatigue resistance are improved. The principles discussed enable the compounder to select the most favorable mastication and mixing procedure for any given situation.

Self-inflicted haematuria and the syndrome of hospital addiction

Self-inflicted haematuria may occur as part of the so-called Münchhausen syndrome or, better, the syndrome of hospital addiction. This rare but important differential diagnosis must be kept in mind in the investigation of obscure urological cases with long-standing and polysymptomatic histories. Two patients with factitious haematuria and hospital addiction are described. Some practical viewpoints on aetiology, diagnosis and management are given. An early recognition of the syndrome is important in order to avoid unnecessary and expensive investigations.

Successful induction of follicular maturation and ovulation by prolonged treatment with LH-releasing hormone in women with anorexia nervosa

Four women with anorexia nervosa were treated with synthetic LH-releasing hormone (LRH) in an attempt to induce ovulation. All the women had very low pretreatment levels of gonadotropins and estrogens. Administration of LRH resulted in significant gonadotropin increases. The FSH response to LRH in relation to the LH response was higher than in regularly menstruating women. LRH (500 mug) was administered parenterally three times daily over about 4 weeks. During this period there were no significant effects on mood, eating behavior, weight, or libido. All the women responded with follicular maturation and ovulation to the prolonged LRH treatment.