OBJECTIVES/GOALS: Primary graft dysfunction (PGD) is acute lung injury in the first three days after lung transplant. Patients that experience PGD have increased mortality and an increased risk of chronic lung allograft dysfunction. The pathogenesis is thought to be an ischemia-reperfusion injury but is incompletely understood and there are no specific therapies. We investigated the role of the microbiome in PGD and associations with inflammation and markers of aspiration. METHODS/STUDY POPULATION: We collected airway lavage samples from lung transplant donors before procurement and recipients after reperfusion. We extracted DNA, amplified the bacterial 16S rRNA gene, and sequenced on the Illumina MiSeq platform. QIIME2 and Deblur were used for bioinformatic analysis. R packages were used for downstream analysis and visualizations. The host response was quantified using the Milipore 41-plex Luminex and an ELISA for pepsin. Clinical data was collected by the Penn Lung Transplant Outcomes Group. PGD was assessed by degree of hypoxemia and chest X-ray findings in the 72 hours after transplant. RESULTS/ANTICIPATED RESULTS: There was no significant difference in alpha diversity (Shannon index, p = 0.51), biomass (via comparison of 16S amplicon PicoGreen, p = 0.6), or beta diversity (Weighted UniFrac, p = 0.472, PERMANOVA) between subjects with PGD grade 3 (n = 36) and those that did not (n = 96). On taxonomic analysis, we found an enrichment of Prevotella in donor and recipient lungs that went on to develop PGD (p = 0.05). To follow up this finding we measured immune response and pepsin concentrations in recipient lungs. We found elevated levels in 35/41 cytokines measured in subjects that developed PGD as well as an elevation in pepsin and a correlation between pepsin concentration and Prevotella relative abundance (Figure 1). Additionally, Prevotella relative abundance had statistically significant positive correlations with multiple cytokines such as IL-6 (Pearson’s = 0.26, p = 0.009) and eotaxin (Pearson’s = 0.24, p = 0.016). DISCUSSION/SIGNIFICANCE OF IMPACT: There is an enrichment of oral anerobes in lung allografts that eventually develop PGD. This is associated with elevated levels of pepsin and markers of inflammation. These lines of evidence suggest aspiration contributes to priming the allograft for PGD.

HIV-associated cognitive impairments are prevalent, and are consistent with injury to both frontal cortical and subcortical regions of the brain. The current study aimed to assess the association of HIV infection with functional connections within the frontostriatal network, circuitry hypothesized to be highly vulnerable to HIV infection. Fifteen HIV-positive and 15 demographically matched control participants underwent 6 min of resting-state functional magnetic resonance imaging (RS-fMRI). Multivariate group comparisons of age-adjusted estimates of connectivity within the frontostriatal network were derived from BOLD data for dorsolateral prefrontal cortex (DLPFC), dorsal caudate and mediodorsal thalamic regions of interest. Whole-brain comparisons of group differences in frontostriatal connectivity were conducted, as were pairwise tests of connectivity associations with measures of global cognitive functioning and clinical and immunological characteristics (nadir and current CD4 count, duration of HIV infection, plasma HIV RNA). HIV – associated reductions in connectivity were observed between the DLPFC and the dorsal caudate, particularly in younger participants (<50 years, N=9). Seropositive participants also demonstrated reductions in dorsal caudate connectivity to frontal and parietal brain regions previously demonstrated to be functionally connected to the DLPFC. Cognitive impairment, but none of the assessed clinical/immunological variables, was also associated with reduced frontostriatal connectivity. In conclusion, our data indicate that HIV is associated with attenuated intrinsic frontostriatal connectivity. Intrinsic connectivity of this network may therefore serve as a marker of the deleterious effects of HIV infection on the brain, possibly via HIV-associated dopaminergic abnormalities. These findings warrant independent replication in larger studies. (JINS, 2015, 21, 1–11)

Significant new opportunities for astrophysics and cosmology have been identified at low radio frequencies. The Murchison Widefield Array is the first telescope in the southern hemisphere designed specifically to explore the low-frequency astronomical sky between 80 and 300 MHz with arcminute angular resolution and high survey efficiency. The telescope will enable new advances along four key science themes, including searching for redshifted 21-cm emission from the EoR in the early Universe; Galactic and extragalactic all-sky southern hemisphere surveys; time-domain astrophysics; and solar, heliospheric, and ionospheric science and space weather. The Murchison Widefield Array is located in Western Australia at the site of the planned Square Kilometre Array (SKA) low-band telescope and is the only low-frequency SKA precursor facility. In this paper, we review the performance properties of the Murchison Widefield Array and describe its primary scientific objectives.