Real-World Data and Paper-Based Disease Registries in the Small Island Developing State of Barbados During the COVID-19 Pandemic.

Significant data is being produced on the impact of COVID-19 on aspects of clinical care. However, less is known about the impact on real-world health data. The US Food and Drug Administration defines real-world data as "data relating to patient health status and/or the delivery of health care routinely collected from a variety of sources," including disease registries.1 The methodology used by the Barbados National Registry (BNR)-active pursuit of first-hand clinical data using paper-based charts from multiple sources-makes it an ideal example of real-world data. Real-world data can overcome the barriers to clinical trials often present in small island developing states. This paper reviews the impact of the COVID-19 pandemic on the data of the BNR within the context of the real-world data cycle. Data collected retrospectively for 2016-2018, undergoing traceback during the pandemic, demonstrated a greater reliance on death certificate registration. A 38% reduction in the collection of new cases was noted in the postpandemic period compared to data collected in previous periods. The lack of access to source data delayed cancer registry reporting. We conclude that, given the challenges highlighted during the COVID-19 pandemic, more effort should be placed on providing timely access to real-world data for public health decision-making, particularly in small island developing states.

Consistent opening of the blood brain barrier using focused ultrasound with constant intravenous infusion of microbubble agent.

The blood brain barrier (BBB) is a major obstacle to the delivery of therapeutics to the brain. Focused ultrasound (FUS) in combination with microbubbles can non-invasively open the BBB in a targeted manner. Bolus intravenous injections of microbubbles are standard practice, but dynamic influx and clearance mechanisms prevent delivery of a uniform dose with time. When multiple targets are selected for sonication in a single treatment, uniform serum concentrations of microbubbles are important for consistent BBB opening. Herein, we show that bubble infusions were able to achieve consistent BBB opening at multiple target sites. FUS exposures were conducted with different Definity microbubble concentrations at various acoustic pressures. To quantify the effects of infusion on BBB opening, we calculated the MRI contrast enhancement rate. When infusions were performed at rates of 7.2 µl microbubbles/kg/min or below, we were able to obtain consistent BBB opening without injury at all pressures. However, when infusion rates exceeded 20 µl/kg/min, signs of injury occurred at pressures from 0.39 to 0.56 MPa. When compared to bolus injections, a bubble infusion offers a more controlled and consistent approach to multi-target BBB disruption.

Perceptual and neuronal boundary learned from higher-order stimulus probabilities.

During an early epoch of development, the brain is highly adaptive to the stimulus environment. Exposing young animals to a particular tone, for example, leads to an enlarged representation of that tone in primary auditory cortex. While the neural effects of simple tonal environments are well characterized, the principles that guide plasticity in more complex acoustic environments remain unclear. In addition, very little is known about the perceptual consequences of early experience-induced plasticity. To address these questions, we reared juvenile rats in complex multitone environments that differed in terms of the higher-order conditional probabilities between sounds. We found that the development of primary cortical acoustic representations, as well as frequency discrimination ability in adult animals, were shaped by the higher-order stimulus statistics of the early acoustic environment. Our results suggest that early experience-dependent cortical reorganization may mediate perceptual changes through statistical learning of the sensory input.