Cerebrospinal fluid flushing as a means of neuroprotection.

Central nervous system (CNS) injury or disease states are often difficult to treat due to the closed system of the dura mater/blood-brain barrier and the bony skull and vertebrae. The closed system results in at least partial containment of any pro-inflammatory molecules, pathogens, or toxic byproducts in the case of brain or spinal cord lesions, which can result in a destructive feedback loop. Cervical-approach access techniques (lateral C1-C2, suboccipital and lateral atlanto-occipital space punctures) are less-common methods of cerebrospinal fluid (CSF) sampling due to the relative ease and safety of lumbar spinal taps. However, with improved image-guidance, these cervical-level CSF access points are still useful when there are certain contraindications and difficulties when attempting to sample the CSF via the typical lumbar spinal approach. With the advent of microcatheters and minimally invasive techniques, combined with body fluid filtration technology, the question arises: could dual microcatheters be introduced for inflow and outflow of purified or artificial CSF to break the destructive feedback loop and thus diminish CNS damage?. We hypothesize that intrathecal spinal catheters could be placed in 2 positions (e.g., via a cervical route and the typical lumbar spinal route) to allow for both an input and output to more effectively filter or "flush" the CSF. This could have broad implications in the treatment of strokes, traumatic brain or spinal cord injury, infections, autoimmune diseases, and even malignancies within the CNS-in short, any disease with abnormalities detectable in the CSF.

Outcomes of Simulation in Resident Imaging-Guided Breast Biopsy Training.

Introduction We evaluate diagnostic radiology residents' perceptions of an ultrasound-guided and stereotactic breast biopsy simulator used at an academic medical center. This simulator is low-cost and easily reproducible. We aim to understand if this simulator improves residents' self-reported confidence in performing breast biopsy procedures on live patients. Methods Twenty-eight diagnostic radiology residents were instructed in how to perform ultrasound-guided breast biopsies and stereotactic breast biopsies using real biopsy and imaging equipment, but with tissue models in lieu of live persons. The hands-on experience was preceded by a didactic lecture. The ultrasound-guided tissue model was created with blueberries that were inserted in tofu, and the stereotactic tissue model was created by placing crushed calcium carbonate tablets into cored eggplant. Residents were asked to fill out a survey before and after participating in the simulation, where they self-reported their confidence level at performing ultrasound-guided and stereotactic breast biopsies. Results Twenty-eight diagnostic radiology residents participated in the simulation. All residents completed the pre-simulation survey and of these residents, twenty-one completed the post-simulation survey. Prior to the simulation residents reported a median confidence level of 3.5 out of 10 in performing ultrasound-guided breast biopsies, and a median confidence level of 1.0 out of 10 in performing stereotactic-guided breast biopsies. After the simulation, residents reported a median confidence level of 7.0 out of 10 in performing ultrasound-guided breast biopsies, and a median confidence level of 3.0 out of 10 in performing stereotactic-guided breast biopsies. Increases in resident confidence level were statistically significant for both biopsy types (p < 0.01).  Conclusion Simulated biopsies can increase the confidence of diagnostic radiology residents that are learning to perform breast biopsies before they perform real biopsies on live patients. Providing simulation training and thereby improving resident confidence may help reduce physician error and patient harm due to poor biopsy techniques.

Social context has differential effects on acquisition of nicotine self-administration in male and female rats.

RATIONAL: Smoking typically begins during adolescence or early adulthood in a social context, yet the role of social context in animal models is poorly understood. OBJECTIVES: The present study examined the effect of social context on acquisition of nicotine self-administration. METHODS: Sixty-day-old male and female Sprague-Dawley rats were trained to press a lever for nicotine (0.015 mg/kg, IV) or saline infusions (males only) on a fixed ratio (FR1) schedule of reinforcement across nine sessions in duplex chambers that were conjoined with either a solid wall or a wall containing wire mesh creating a social context between rat dyads (social visual, auditory, and olfactory cues). In a subsequent experiment, sex differences and dose-dependent effects of nicotine [0 (saline), 0.015 or 0.03 mg/kg, IV] were directly compared in rats trained in the isolated or social context on a schedule progressing from FR1 to FR3. These rats were given 20 sessions followed by 3 extinction sessions. RESULTS: We consistently found transient social facilitation of low-dose nicotine self-administration in males during the first session. However, across training overall, we found social suppression of nicotine intake that was most prominent in females during later sessions. CONCLUSIONS: Collectively, these findings suggest that at the age of transition from adolescence to adulthood, a social context enhances the initial reinforcing effects of nicotine in males, but protects against nicotine intake during later sessions especially in females. These findings highlight the importance of sex and social context in studying neural mechanisms involved in initiation of nicotine use.