Vitreous and Chorioretinal Lesions in People Who Inject Drugs and Are Hospitalized with Bloodstream and Related Infections.

PURPOSE: To determine the prevalence of and to characterize vitreous and chorioretinal lesions, to identify causative organisms, and to correlate symptoms with ophthalmic involvement in people who inject drugs and are hospitalized with bloodstream infection (BSI), related metastatic foci of infection (MFI), or both. DESIGN: An academic hospital-based cross-sectional study. PARTICIPANTS: Patients admitted with BSI or MFI related to injection drug use (IDU). METHODS: Patients underwent a complete eye examination within 72 hours of enrollment. Characteristics including gender; age; race; injection drug of choice (DOC); presence of coinfection with hepatitis B, hepatitis C, or human immunodeficiency virus; pathogen causing systemic infection and type of infection; and history of prior infection related to IDU were recorded. MAIN OUTCOME MEASURES: Presence of vitreous or chorioretinal findings, or both. RESULTS: Ninety-one unique patients with 96 separate hospitalizations for systemic infection were enrolled from March 28, 2018, through March 30, 2020. Vitreous or chorioretinal involvement was identified in 16 of 96 patients (16.7%). The most common ocular findings were intraretinal or white-centered hemorrhage in 9 of 96 patients, chorioretinal infiltrate in 8 of 96 patients, endophthalmitis in 5 of 96 patients, and cotton wool spots in 3 of 96 patients. Of the patients with ocular involvement, only 7 of 16 patients (44%) were symptomatic, and 5 of these were patients with endophthalmitis; the others showed chorioretinal infiltrates or intraretinal or white-centered hemorrhage and cotton wool spots. Staphylococcus aureus was the most common causative pathogen in patients with and without ocular findings. Presence of ocular symptoms, worse visual acuity, and injection DOC of methamphetamine were correlated with the presence of ocular findings. CONCLUSIONS: Patients without ocular symptoms with systemic infections related to IDU may have chorioretinal findings. Further study is needed to characterize better the epidemiologic features of these infections and to identify risk factors for ocular involvement in people who inject drugs.

Characterization of an oxaliplatin sensitivity predictor in a preclinical murine model of colorectal cancer.

Despite advances in contemporary chemotherapeutic strategies, long-term survival still remains elusive for patients with metastatic colorectal cancer. A better understanding of the molecular markers of drug sensitivity to match therapy with patient is needed to improve clinical outcomes. In this study, we used in vitro drug sensitivity data from the NCI-60 cell lines together with their Affymetrix microarray data to develop a gene expression signature to predict sensitivity to oxaliplatin. To validate our oxaliplatin sensitivity signature, patient-derived colorectal cancer explants (PDCCE) were developed in nonobese diabetic/severe combined immunodeficient (NOD/SCID) mice from resected human colorectal tumors. Analysis of gene expression profiles found similarities between the PDCCEs and their parental human tumors, suggesting their utility to study drug sensitivity in vivo. The oxaliplatin sensitivity signature was then validated in vivo with response data from 14 PDCCEs treated with oxaliplatin and was found to have an accuracy of 92.9% (sensitivity = 87.5%; specificity = 100%). Our findings suggest that PDCCEs can be a novel source to study drug sensitivity in colorectal cancer. Furthermore, genomic-based analysis has the potential to be incorporated into future strategies to optimize individual therapy for patients with metastatic colorectal cancer.

A methodology for utilization of predictive genomic signatures in FFPE samples.

BACKGROUND: Gene expression signatures developed to measure the activity of oncogenic signaling pathways have been used to dissect the heterogeneity of tumor samples and to predict sensitivity to various cancer drugs that target components of the relevant pathways, thus potentially identifying therapeutic options for subgroups of patients. To facilitate broad use, including in a clinical setting, the ability to generate data from formalin-fixed, paraffin-embedded (FFPE) tissues is essential. METHODS: Patterns of pathway activity in matched fresh-frozen and FFPE xenograft tumor samples were generated using the MessageAmp Premier methodology in combination with assays using Affymetrix arrays. Results generated were compared with those obtained from fresh-frozen samples using a standard Affymetrix assay. In addition, gene expression data from patient matched fresh-frozen and FFPE melanomas were also utilized to evaluate the consistency of predictions of oncogenic signaling pathway status. RESULTS: Significant correlation was observed between pathway activity predictions from paired fresh-frozen and FFPE xenograft tumor samples. In addition, significant concordance of pathway activity predictions was also observed between patient matched fresh-frozen and FFPE melanomas. CONCLUSIONS: Reliable and consistent predictions of oncogenic pathway activities can be obtained from FFPE tumor tissue samples. The ability to reliably utilize FFPE patient tumor tissue samples for genomic analyses will lead to a better understanding of the biology of disease progression and, in the clinical setting, will provide tools to guide the choice of therapeutics to those most likely to be effective in treating a patient's disease.