Is the Medium Still the Message? Culture-Independent Diagnosis of Gastrointestinal Infections.

Infectious diarrhea is caused by a variety of pathogens, including viruses, bacteria, and parasitic organisms. Though the causative agent of diarrhea has historically been evaluated via stool cultures, recently, culture-independent diagnostic tests (CIDT) have been developed and utilized with increasing frequency. Current practice guidelines recommend their use as adjuncts to stool cultures for diagnosing acute and chronic diarrhea. The three principal CIDT are microscopy, enzyme-based immunoassays (EIAs), and molecular based polymerase chain reaction (PCR). This review explores the common causes of infectious diarrhea, the basics of stool culture, the diagnostic utility of these three culture-independent modalities, and the strengths and weaknesses of all currently available clinical techniques. It also outlines considerations for specific populations including returning travelers and those with inflammatory bowel disease.

Short-duration transient visual evoked potentials and color reflectivity discretization analysis in glaucoma patients and suspects.

AIM: To evaluate the use of short-duration transient visual evoked potentials (VEP) and color reflectivity discretization analysis (CORDA) in glaucomatous eyes, eyes suspected of having glaucoma, and healthy eyes. METHODS: The study included 136 eyes from 136 subjects: 49 eyes with glaucoma, 45 glaucoma suspect eyes, and 42 healthy eyes. Subjects underwent Humphrey visual field (VF) testing, VEP testing, as well as peripapillary retinal nerve fiber layer optical coherence tomography imaging studies with post-acquisition CORDA applied. Statistical analysis was performed using means and ranges, ANOVA, post-hoc comparisons using Turkey's adjustment, Fisher's Exact test, area under the curve, and Spearman correlation coefficients. RESULTS: Parameters from VEP and CORDA correlated significantly with VF mean deviation (MD) (P<0.05). In distinguishing glaucomatous eyes from controls, VEP demonstrated area under the curve (AUC) values of 0.64-0.75 for amplitude and 0.67-0.81 for latency. The CORDA HR1 parameter was highly discriminative for glaucomatous eyes vs controls (AUC=0.94). CONCLUSION: Significant correlations are found between MD and parameters of short-duration transient VEP and CORDA, diagnostic modalities which warrant further consideration in identifying glaucoma characteristics.