Rare bioparticle detection via deep metric learning

Recent deep neural networks have shown superb performance in analyzing bioimages for disease diagnosis and bioparticle classification. Conventional deep neural networks use simple classifiers such as SoftMax to obtain highly accurate results. However, they have limitations in many practical applications that require both low false alarm rate and high recovery rate, e.g., rare bioparticle detection, in which the representative image data is hard to collect, the training data is imbalanced, and the input images in inference time could be different from the training images. Deep metric learning offers a better generatability by using distance information to model the similarity of the images and learning function maps from image pixels to a latent space, playing a vital role in rare object detection. In this paper, we propose a robust model based on a deep metric neural network for rare bioparticle (Cryptosporidium or Giardia) detection in drinking water. Experimental results showed that the deep metric neural network achieved a high accuracy of 99.86% in classification, 98.89% in precision rate, 99.16% in recall rate and zero false alarm rate. The reported model empowers imaging flow cytometry with capabilities of biomedical diagnosis, environmental monitoring, and other biosensing applications.

Conventional deep neural networks use simple classifiers to obtain highly accurate results. However, they have limitations in practical applications. This study demonstrates a robust deep metric neural network model for rare bioparticle detection.     

Severe infantile isolated exocrine pancreatic insufficiency caused by the complete functional loss of the SPINK1 gene

Exocrine pancreatic insufficiency (EPI) is rare in children, with most if not all cases occurring as part of syndromic conditions such as cystic fibrosis and Shwachman–Diamond syndrome. Here we report two cases, both presenting with severe EPI around 5 months of age. Characterized by diffuse pancreatic lipomatosis, they otherwise exhibited no remarkable deficiencies in other organs. Novel non‐identical homozygous variants (a deletion removing the entire SPINK1 gene and an insertion of a full‐length inverted Alu element into the 3′‐untranslated region of the SPINK1 gene) resulting in the complete functional loss of the SPINK1 gene (encoding pancreatic secretory trypsin inhibitor) were identified in each patient. Having correlated our findings with current knowledge of SPINK1's role in exocrine pancreas pathophysiology, we propose that complete and partial functional losses of the SPINK1 gene are associated with quite distinct phenotypes, the former causing a new pediatric disease entity of severe infantile isolated EPI.     

Ammonium accumulation and chemokine decrease in culture media of Gcdh−/− 3D reaggregated brain cell cultures

Glutaric Aciduria type I (GA-I) is caused by mutations in the GCDH gene. Its deficiency results in accumulation of the key metabolites glutaric acid (GA) and 3-hydroxyglutaric acid (3-OHGA) in body tissues and fluids. Present knowledge on the neuropathogenesis of GA-I suggests that GA and 3-OHGA have toxic properties on the developing brain.We analyzed morphological and biochemical features of 3D brain cell aggregates issued from Gcdh^?/? mice at two different developmental stages, day-in-vitro (DIV) 8 and 14, corresponding to the neonatal period and early childhood. We also induced a metabolic stress by exposing the aggregates to 10 mM l-lysine (Lys).Significant amounts of GA and 3-OHGA were detected in Gcdh^?/? aggregates and their culture media. Ammonium was significantly increased in culture media of Gcdh^?/? aggregates at the early developmental stage. Concentrations of GA, 3-OHGA and ammonium increased significantly after exposure to Lys. Gcdh^?/? aggregates manifested morphological alterations of all brain cell types at DIV 8 while at DIV 14 they were only visible after exposure to Lys. Several chemokine levels were significantly decreased in culture media of Gcdh^?/? aggregates at DIV 14 and after exposure to Lys at DIV 8.This new in vitro model for brain damage in GA-I mimics well in vivo conditions. As seen previously in WT aggregates exposed to 3-OHGA, we confirmed a significant ammonium production by immature Gcdh^?/? brain cells. We described for the first time a decrease of chemokines in Gcdh^?/? culture media which might contribute to brain cell injury in GA-I.     

Percutaneous biopsy in lung cancer

This paper presents current indications, contraindications, technical aspects, complications and yield of diagnosis of percutaneous lung biopsy in the setting of lung cancer. Percutaneous lung biopsy should be performed each time that the therapeutic strategy can be significantly influenced, when the procedure is technically feasible and to patients for which the benefits outweigh the risks, that are pneumothorax and pulmonary haemorrhage. Factors identified as potentially favouring post-biopsy pneumothorax are numerous whereas the use of a needle size larger than 18 gauge is the major risk factor of bleeding. Although a coaxial system is highly suitable in any case, two categories of needles can be used; those providing aspiration and those for core biopsies. Both offer similar yields for the diagnosis of malignancy, but core biopsies are more efficient for the specific diagnosis of benignity and lymphoma. Technical improvements of guidance, needle design and pathological techniques may contribute to lower the size limit of the nodule to be biopsied, to decrease the complication rate and their severity and to increase the yield of diagnosis.     

Airway remodeling in a mouse asthma model assessed by in-vivo respiratory-gated micro-computed tomography

The aim of our study was to evaluate the feasibility of non-invasive respiratory-gated micro-computed tomography (micro-CT) for assessment of airway remodelling in a mouse asthma model. Six female BALB/c mice were challenged intranasally with ovalbumin. A control group of six mice received saline inhalation. All mice underwent plethysmographic study and micro-CT. For each mouse, peribronchial attenuation values of 12 bronchi were measured, from which a peribronchial density index (PBDI) was computed. Mice were then sacrificed and lungs examined histologically. Final analysis involved 10 out of 12 mice. Agreement of measurements across observers and over time was very good (intraclass correlation coefficients: 0.94–0.98). There was a significant difference in PBDI between asthmatic and control mice (?210 vs. ?338.9 HU, P?=?0.008). PBDI values were correlated to bronchial muscle area (r?=?0.72, P?=?0.018). This study shows that respiratory-gated micro-CT may allow non-invasive monitoring of bronchial remodelling in asthmatic mice and evaluation of innovative treatment effects.     

Direct electrical stimulation as an input gate into brain functional networks: principles, advantages and limitations

Background  

While the fundamental and clinical contribution of direct electrical stimulation (DES) of the brain is now well acknowledged, its advantages and limitations have not been re-evaluated for a long time.