Motivation:Extraction of biomedical knowledge from unstructured text poses a great challenge in the biomedical field. Named entity recognition (NER) promises to improve information extraction and retrieval. However, existing approaches require manual annotation of large training text corpora, which is laborious and time-consuming. To address this problem we adopted deep learning technique that repurposes the 43,900,000 Entity-free-text pairs available in metadata associated with the NCBI BioSample archive to train a scalable NER model. This NER model can assist in biospecimen metadata annotation by extracting named-entities from user-supplied free-text descriptions.Results: We evaluated our model against two validation sets, namely data sets consisting of short-phrases and long sentences. We achieved an accuracy of 93.29% and 93.40% in the short-phrase validation set and long sentence validation set respectively.Availability: All the analyses, pre-trained model, environments, and Jupyter notebooks pertaining to this manuscript are available on Github: https://github.com/brianyiktaktsui/DEEP_NLP . Contact: hkcarter@ucsd.eduFig1. Repurposing public biospecimen data for NER training ( A ) Depiction of training NER model using pre-annotated Entity-free-text pairs available from public biospecimen annotation data (BioSamples) from NCBI ( A.1 ) Example of Entity-free-text pairs from BioSamples. In this example, the free-text phrase Glioblastoma stage 4 system is a Disease entity. ( A.2 ) Expected results of an NER model recognizing biomedical concepts from sentences. ( B ) Histogram of the 30 most frequently used entities (x-axis) available in the current set of BioSamples. These atomic named entities (blue labels) can be used to extract concepts from composite entities TITLE and DESCRIPTION (red labels).

Background Fungal ocular involvement can develop in patients with fungal bloodstream infections and can be vision-threatening. Ocular involvement has become less common in the current era of improved antifungal therapies. Retrospectively determining the prevalence of fungal ocular involvement is important for informing clinical guidelines, such as the need for routine ophthalmologic consultations. However, manual retrospective record review to detect cases is time-consuming. Objective This study aimed to determine the prevalence of fungal ocular involvement in a critical care database using both structured and unstructured electronic health record (EHR) data. Methods We queried microbiology data from 46,467 critical care patients over 12 years (2000-2012) from the Medical Information Mart for Intensive Care III (MIMIC-III) to identify 265 patients with culture-proven fungemia. For each fungemic patient, demographic data, fungal species present in blood culture, and risk factors for fungemia (eg, presence of indwelling catheters, recent major surgery, diabetes, immunosuppressed status) were ascertained. All structured diagnosis codes and free-text narrative notes associated with each patient’s hospitalization were also extracted. Screening for fungal endophthalmitis was performed using two approaches: (1) by querying a wide array of eye- and vision-related diagnosis codes, and (2) by utilizing a custom regular expression pipeline to identify and collate relevant text matches pertaining to fungal ocular involvement. Both approaches were validated using manual record review. The main outcome measure was the documentation of any fungal ocular involvement. Results In total, 265 patients had culture-proven fungemia, with Candida albicans (n=114, 43%) and Candida glabrata (n=74, 28%) being the most common fungal species in blood culture. The in-hospital mortality rate was 121 (46%). In total, 7 patients were identified as having eye- or vision-related diagnosis codes, none of whom had fungal endophthalmitis based on record review. There were 26,830 free-text narrative notes associated with these 265 patients. A regular expression pipeline based on relevant terms yielded possible matches in 683 notes from 108 patients. Subsequent manual record review again demonstrated that no patients had fungal ocular involvement. Therefore, the prevalence of fungal ocular involvement in this cohort was 0%. Conclusions MIMIC-III contained no cases of ocular involvement among fungemic patients, consistent with prior studies reporting low rates of ocular involvement in fungemia. This study demonstrates an application of natural language processing to expedite the review of narrative notes. This approach is highly relevant for ophthalmology, where diagnoses are often based on physical examination findings that are documented within clinical notes.

High-quality metadata annotations for data hosted in large public repositories are essential for research reproducibility and for conducting fast, powerful and scalable meta-analyses. Currently, a majority of sequencing samples in the National Center for Biotechnology Information’s Sequence Read Archive (SRA) are missing metadata across several categories. In an effort to improve the metadata coverage of these samples, we leveraged almost 44 million attribute–value pairs from SRA BioSample to train a scalable, recurrent neural network that predicts missing metadata via named entity recognition (NER). The network was first trained to classify short text phrases according to 11 metadata categories and achieved an overall accuracy and area under the receiver operating characteristic curve of 85.2% and 0.977, respectively. We then applied our classifier to predict 11 metadata categories from the longer TITLE attribute of samples, evaluating performance on a set of samples withheld from model training. Prediction accuracies were high when extracting sample Genus/Species (94.85%), Condition/Disease (95.65%) and Strain (82.03%) from TITLEs, with lower accuracies and lack of predictions for other categories highlighting multiple issues with the current metadata annotations in BioSample. These results indicate the utility of recurrent neural networks for NER-based metadata prediction and the potential for models such as the one presented here to increase metadata coverage in BioSample while minimizing the need for manual curation. Database URL: https://github.com/cartercompbio/PredictMEE