Chronic circadian dysfunction impairs declarative memory in humans but has little effect in common rodent models of arrhythmia caused by clock gene knockouts or surgical ablation of the suprachiasmatic nucleus (SCN). An important problem overlooked in these translational models is that human dysrhythmia occurs while SCN circuitry is genetically and neurologically intact. Siberian hamsters (Phodopus sungorus) are particularly well suited for translational studies because they can be made arrhythmic by a one-time photic treatment that severely impairs spatial and recognition memory. We found that once animals are made arrhythmic, subsequent SCN ablation completely rescues memory processing. These data suggest that the inhibitory effects of a malfunctioning SCN on cognition require preservation of circuitry between the SCN and downstream targets that are lost when these connections are severed.
The three-dimensional (3D) structure of the intestine is a key determinant of differentiation and function; thus, preserving this architecture is an important consideration for studies of intestinal homeostasis and disease. Over the past decade, a number of systems for 3D intestinal organoid cultures have been developed and adapted to model a wide variety of biological phenomenon.
Purpose of this review
We discuss the current state of intestinal and colorectal cancer (CRC) 3D modeling, the most common methods for generating organoid cultures, and how these have yielded insights into intestinal physiology and tumor biology.
Recent findings
Organoids have been used to model numerous aspects of intestinal physiology and disease. Recent adaptations have further improved disease modeling and high-throughput therapeutic screening.
Summary
These studies show intestinal organoid models are a robust, highly tractable system which maintains many vital features of intestinal tissue, making them a pivotal step forward in the field of gastroenterology.
INTRODUCTION: A discriminatory ultrasound scoring system for appendicitis was developed with the aim of reducing radiation exposure through CT in pediatric patients. METHODS: The ultrasound scoring system alone, and in combination with the pediatric appendicitis score (PAS), was retrospectively analyzed over a 10.5 month period. After finding promising initial results, the protocol was implemented in the pediatric emergency department to test this prospectively. Data was collected from April to June of 2016. Each case of suspected appendicitis in patients 2-17 was assigned a PAS score by the responsible providers and an ultrasound was obtained. The ultrasound was assigned a score by pediatric imaging. The PAS and ultrasound score were combined with a maximum attainable score of 20. The data from 53 cases was then analyzed in the standard fashion using a p value of 0.05 for statistical significance. RESULTS: A combined score of 7 or greater had a sensitivity¼0.972, specificity¼0.882, positive predictive value¼0.946, and negative predictive value¼0.938 for appendicitis. A total score of 13 or greater had a sensitivity¼ 0.306, specificity¼1, PPV¼1, and NPV¼0.405. An ultrasound score of 2 or greater had a sensitivity¼0.778, specificity¼0.647, PPV¼0.823, and NPV¼0.579. Analysis of CT utilization revealed a 3% decrease in the number of CT scans ordered since the implementation of the protocol. The decrease was not statically significant, p¼0.635. CONCLUSIONS: The appendicitis protocol using the ultrasound scoring system is a valid, cost effective tool for diagnosing appendicitis in studied population and reducing radiation exposure.
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