Preservation of Intrinsically Photosensitive Retinal Ganglion Cells (ipRGCs) in Late Adult Mice: Implications as a Potential Biomarker for Early Onset Ocular Degenerative Diseases.

Purpose: Intrinsically photosensitive retinal ganglion cells (ipRGCs) play a crucial role in non-image-forming visual functions. Given their significant loss observed in various ocular degenerative diseases at early stages, this study aimed to assess changes in both the morphology and associated behavioral functions of ipRGCs in mice between 6 (mature) and 12 (late adult) months old. The findings contribute to understanding the preservation of ipRGCs in late adults and their potential as a biomarker for early ocular degenerative diseases. Methods: Female and male C57BL/6J mice were used to assess the behavioral consequences of aging to mature and old adults, including pupillary light reflex, light aversion, visual acuity, and contrast sensitivity. Immunohistochemistry on retinal wholemounts from these mice was then conducted to evaluate ipRGC dendritic morphology in the ganglion cell layer (GCL) and inner nuclear layer (INL). Results: Morphological analysis showed that ipRGC dendritic field complexity was remarkably stable through 12 months old of age. Similarly, the pupillary light reflex, visual acuity, and contrast sensitivity were stable in mature and old adults. Although alterations were observed in ipRGC-independent light aversion distinct from the pupillary light reflex, aged wild-type mice continuously showed enhanced light aversion with dilation. No effect of sex was observed in any tests. Conclusions: The preservation of both ipRGC morphology and function highlights the potential of ipRGC-mediated function as a valuable biomarker for ocular diseases characterized by early ipRGC loss. The consistent stability of ipRGCs in mature and old adult mice suggests that detected changes in ipRGC-mediated functions could serve as early indicators or diagnostic tools for early-onset conditions such as Alzheimer's disease, Parkinson's disease, and diabetes, where ipRGC loss has been documented.

Best Practices for Effective Management of Point of Care Testing.

With the recent COVID-19 pandemic, point-of-care testing has gained tremendous attention, particularly in acute care settings. The point-of-care testing landscape is rapidly expanding and being contemplated for any crucial test with a central laboratory turnaround time >25% of the clinical decision time. A typical point-of-care testing program within a large hospital system encompasses a multitude of operators utilizing a wide range of devices across multiple testing sites. Thus, managing a large point-of-care testing network remains a daunting task with challenges related to staffing, standardization, quality management, training and competency assessment, and data management. This review will focus on understanding the general organization as well as the roles and responsibilities of various point-of-care testing stakeholders in addressing these challenges. More importantly, it will discuss the strategies and best practices for effective point-of-care testing management based on consensus recommendations from professional societies as well as our experience at Texas Childrens Hospital.

Pandemic-Associated Trends in Measurement of HbA1c in Children with Diabetes Mellitus and Validation of Dried Blood Spot as an Alternative Sample Matrix.

OBJECTIVE: Routine monitoring of hemoglobin A1c (HbA1c) is the standard of care in diabetes mellitus (DM), but adhering to regular laboratory appointments may be challenging when access to care is limited, such as during the initial wave of the COVID-19 pandemic in the United States in 2020. MATERIALS: We evaluated trends in patient encounters and laboratory testing for DM in a pediatric healthcare system from March to September 2019 and during the same period in 2020. RESULTS: Evaluation of 17,367 patient encounters illustrated that the pandemic was associated with significantly fewer in-person office visits and point-of-care HbA1c tests for patients with DM in 2020 relative to 2019. A separate analysis of 7,193 HbA1c results measured by point-of-care testing in the general population found a significant increase in the number of measured HbA1c >14 % in May 2020 relative to 2019, but other measured HbA1c values did not differ. As a means to address lapses in the monitoring of HbA1c due to the pandemic, we evaluated the use of the dried blood spot (DBS) matrix for measurement of HbA1c by the Vitros 5600 chemistry analyzer. DBS HbA1c was well correlated to whole blood (r=0.9889) and exhibited intra- and inter-assay precision from 0.5-3.5%. CONCLUSION: DBS measurement of HbA1c presents a viable alternative to routine in-person laboratory monitoring of DM.