Effects of Junk Food Diet and High Fat Diet Manipulation on Working Memory of Sprague Dawley Rats

Obesity has become not only a nationwide problem, but a cause for worldwide concern as the prevalence of processed junk-food is currently on the rise. Along with numerous physical ailments induced by obesity, emerging evidence suggests that consumption of a high-fat diet has negative neurological implications. The prefrontal cortex (PFC), known to play an important role in mediating “executive” functions such as inhibitory control, working memory, and decision-making is one region that appears to be affected by consumption of a junk food diet. In this study, we explored the effects of a junk-food diet and a high fat diet on PFC function. Rats were fed either a junk-food diet (19.6% fat) intended to mimic a typical Western diet, a high fat diet (60% fat), or a standard chow diet. Behavioral testing were then conducted following a 4 week exposure to the diets and included the Egocentric Morris Water Maze, Spontaneous Alternation, Novel Object Recognition and Attentional Set Shift. These behavioral tests were performed in order to identify any differences in working memory or attention between groups

Isolation of 18 Novel Mycobacteriophages and Genomic Analyses of Krueger and Phrappuccino

Eighteen new mycobacteriophages were isolated from soil samples collected around the state of Michigan and parts of the United States. All phages were capable of infecting Mycobacterium smegmatis and were isolated through either enrichment or direct plating at 25°C. A variety of plaque morphologies were produced based on size, shape, and clarity; both lytic and temperate phages appear represented in this collection. Two mycobacteriophages, Krueger and Phrappuccino, were chosen for complete genome sequencing and comparative genomic analyses. The predominant plaque produced by Krueger at 32°C was circular and 2 mm in diameter. The predominant plaque produced by Phrappuccino at 32°C was 1 mm in diameter, and took 48 hours to appear. Complete genome sequence for Krueger revealed relationships to members of the novel Subcluster K6, while Phrappuccino was not closely related to any known phage and is currently classified as a Singleton. The genome of Krueger is 60.3 Kb, 66.5% GC, and contains 101 genes, including 1 tRNA(Lys-TTT) gene; the genome of Phrappuccino is 136.3 Kb, 67.4% GC, and contains 200 genes. While Phrappuccino is a Singleton, there is strong evidence at the morphological (Myoviridae) and genomic levels for a relationship to Cluster C phages. Despite this relationship, Phrappuccino does not carry any tRNA genes. Forty (39.6%) and thirty-six (18%) protein coding genes were assigned functions in Krueger and Phrappuccino, respectively, based on comparative analyses. A detailed analysis of the complete genome sequences and comparison with sequenced mycobacteriophages is the subject of the second semester of this yearlong course and is presented

Salvage Stereotactic Radiosurgery for Recurrent WHO Grade 2 and 3 Meningiomas: A Multicenter Study (STORM)

The role of stereotactic radiosurgery (SRS) in the management of grade 2 and 3 meningiomas is not well elucidated. Unfortunately, local recurrence rates are high, and guidelines for management of recurrent disease are lacking. To address this knowledge gap, we conducted STORM, a multicenter retrospective cohort study of patients treated with primary SRS for recurrent grade 2 and 3 meningiomas. Data on patients with recurrent grade 2 and 3 meningioma treated with SRS at first recurrence were retrospectively collected from eight academic centers in the United States. Patients with multiple lesions at the time of initial diagnosis or more than two lesions at the time of first recurrence were excluded from this analysis. Patient demographics and treatment parameters were extracted at time of diagnosis, first recurrence, and second recurrence. Oncologic outcomes including progression-free survival (PFS) and overall survival (OS) as well as toxicity outcomes were reported at the patient level. From 2000-2022, 108 patients were identified (94% grade 2, 6.0% grade 3). 106 patients (98%) had upfront surgical resection (60% gross-total resection) with 18% receiving adjuvant radiotherapy (RT). Median time to first progression was 2.5 years (IQR 1.34-4.30). At first recurrence, patients were treated with single or fractionated SRS to a median marginal dose of 16 Gy to a maximum of two lesions (87% received single fraction SRS). Median follow-up time after SRS was 2.6 years. 1-, 2-, and 3-year PFS was 90%, 75%, and 57%, respectively after treatment with SRS. 1-, 2-, and 3-year OS was 97%, 94%, and 92%, respectively. On multivariable analysis, grade 3 disease (HR 6.80; 95% CI 1.61-28.6), male sex (HR 3.48; 95% CI 1.47-8.26), and receipt of prior RT (HR 2.69; 95% CI 1.23-5.86) were associated with worse PFS. SRS dose and tumor volume were not correlated with progression. Treatment was well-tolerated, with a 3.0% incidence of grade 2+ radiation necrosis. This is the largest multi-center study to evaluate salvage SRS in recurrent grade 2 and 3 meningiomas. In this select cohort of patients with primarily grade 2 meningioma with potentially more favorable natural history of delayed, localized first recurrence amenable to salvage SRS, local control rates and toxicity profiles were favorable, warranting further prospective validation