High-throughput screening of caterpillars as a platform to study host-microbe interactions and enteric immunity

Mammalian models of human disease are expensive and subject to ethical restrictions. Here, we present an independent platform for high-throughput screening, using larvae of the tobacco hornworm Manduca sexta, combining diagnostic imaging modalities for a comprehensive characterization of aberrant phenotypes. For validation, we use bacterial/chemical-induced gut inflammation to generate a colitis-like phenotype and identify significant alterations in morphology, tissue properties, and intermediary metabolism, which aggravate with disease progression and can be rescued by antimicrobial treatment. In independent experiments, activation of the highly conserved NADPH oxidase DUOX, a key mediator of gut inflammation, leads to similar, dose-dependent alterations, which can be attenuated by pharmacological interventions. Furthermore, the developed platform could differentiate pathogens from mutualistic gastrointestinal bacteria broadening the scope of applications also to microbiomics and host-pathogen interactions. Overall, larvae-based screening can complement mammals in preclinical studies to explore innate immunity and host-pathogen interactions, thus representing a substantial contribution to improve mammalian welfare.

Patterns of use, effectiveness and safety of gadolinium contrast agents: a European prospective cross-sectional multicentre observational study

Background

The EU gadolinium-based contrast agents (GBCA) market has changed in recent years due to the European Medicines Agency decision to suspend the marketing authorisation of linear GBCA and the marketing authorisation of new generic macrocyclic GBCA. The study aims to understand the patterns of (GBCA) use, and to study the effectiveness and safety of GBCA in routine practice across Europe.

Methods

Prospective, cross-sectional, multicentre, observational study in patients undergoing contrast-enhanced magnetic resonance. Reported usage patterns included indication, referral and examination details. Assessment of effectiveness included changes in radiological diagnosis, diagnostic confidence and image quality. Safety data were collected by spontaneous patient adverse event (AE) reporting.

Results

2118 patients were included from 8 centres across 5 European countries between December 2018 and November 2019. Clariscan, Dotarem (gadoteric acid), Gadovist (gadobutrol) and ProHance (gadoteridol) were utilised in 1513 (71.4%), 356 (16.8%), 237 (11.2%) and 12 (0.6%) patients, respectively. Most were performed in CNS-related indications (46.2%). Mean GBCA doses were 0.10 mmol/kg body weight, except for Gadovist (mean 0.12 mmol/kg). GBCA use increased confidence in diagnosis in 96.2% of examinations and resulted in a change in radiological diagnosis in 73.9% of patients. Image quality was considered excellent or good in 96.1% of patients and across all GBCA. Four patients reported AEs (0.19%), with only 1 (0.05%) considered serious.

Conclusions

This European study confirmed that GBCAs are used appropriately in Europe for a wide range of indications. The study demonstrated a significant increase in diagnostic confidence after GBCA use and confirmed the good safety profile of GBCAs, with comparable results for all agents used.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12880-021-00600-9.

Positron emission mammography in the diagnosis of breast cancer. Is maximum PEM uptake value a valuable threshold for malignant breast cancer detection?

AIM

To evaluate the diagnostic value (sensitivity, specificity) of positron emission mammography (PEM) in a single site non-interventional study using the maximum PEM uptake value (PUVmax).

PATIENTS, METHODS

In a singlesite, non-interventional study, 108 patients (107 women, 1 man) with a total of 151 suspected lesions were scanned with a PEM Flex Solo II (Naviscan) at 90 min p.i. with 3.5 MBq 18F-FDG per kg of body weight. In this ROI(region of interest)-based analysis, maximum PEM uptake value (PUV) was determined in lesions, tumours (PUVmaxtumour), benign lesions (PUVmaxnormal breast) and also in healthy tissues on the contralateral side (PUVmaxcontralateral breast). These values were compared and contrasted. In addition, the ratios of PUVmaxtumour / PUVmaxcontralateral breast and PUVmaxnormal breast / PUVmaxcontralateral breast were compared. The image data were interpreted independently by two experienced nuclear medicine physicians and compared with histology in cases of suspected carcinoma.

RESULTS

Based on a criteria of PUV>1.9, 31 out of 151 lesions in the patient cohort were found to be malignant (21%). A mean PUVmaxtumour of 3.78 ± 2.47 was identified in malignant tumours, while a mean PUVmaxnormal breast of 1.17 ± 0.37 was reported in the glandular tissue of the healthy breast, with the difference being statistically significant (p < 0.001). Similarly, the mean ratio between tumour and healthy glandular tissue in breast cancer patients (3.15 ± 1.58) was found to be significantly higher than the ratio for benign lesions (1.17 ± 0.41, p < 0.001).

CONCLUSION

PEM is capable of differentiating breast tumours from benign lesions with 100% sensitivity along with a high specificity of 96%, when a threshold of PUVmax >1.9 is applied.

Abstract P4-01-24: Positron emission mammography (PEM) does increase specificity in diagnosis of breast cancer

Purpose:

To determine the diagnostic performance of PEM, a HR-PET with intrinsic resolution of 1.6 mm in detection of breast cancer (B-Ca).

Methods and Material:

PEM was performed in 122 lesions with suspicious breast lesions 90 min after i.v. application of 3.5 MBq F-18-FDG per KG body weight. A ROI marked the target lesion, measured the maximum PEM uptake value (PUVmax) and was correlated with a corresponding non-target ROI in the contra lateral healthy breast determining the target/non-target ratio. Two independent readers analysed images of all 122 lesions and compared the results to histopathology (11 PEM-Biopsies/8 Breast-Cancers) later. The group analyses for all malignant, benign, corresponding non-target lesions and the mean target/non-target ratio were calculated by paired Student t-Test.

Results:

22 out of 122 lesions were malignant. Mean of PUVmax was measured 4.3±2,7 in malignant lesions and 1.1±0.4 for the contra-lateral healthy breast (p = 0.001). The mean target/non-target ratio in patients with B-Ca of 3.7±1.5 was also significantly higher compared to benign lesions 1.1±0.4 (p = 0.001).

Considering a PUVmax &gt;1.9, PEM was true-positive in all 22 cancers resulting in a sensitivity of 100%, specificity of 97%, PPV of 88% and NPV of 100%.

Detecting of B-Ca by PEM was at it´s best observed with a PUVmax cut-off level of &gt;1.9 combined with a target/non-target ratio of &gt;1.4.

Conclusion:

PEM can detect breast cancer with high accuracy using PUVmax as well as target/non-target ratio with high specificity. The results shown have to be confirmed in larger patient cohort. The higher specificity causes a lower rate of biopsies, surgery, chemotherapy and costs, therefore a evidence based medicine study will start in Germany.

Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P4-01-24.