Search for Advocacy: A measure of local attentiveness to homelessness

From urban capitals to rural countryside, and every locality in between, homelessness is a national phenomenon that affects every community. Each locality responds to it differently through the variety of homeless programs and services it offers. By doing such, each locality displays a certain level of attentiveness to their homeless population. This article explores how 10 small southeastern cities respond to their local homelessness and seeks to compare the homeless attentiveness of Bowling Green, Kentucky to similar localities. An evaluative measure of municipal attentiveness based on a range of homelessness program areas is used to score each city’s response to its homelessness. A non-parametric test finds that there is not a significant difference in the attentiveness of evaluated localities, and in turn concludes that Bowling Green’s attentiveness to its homelessness is not significantly less than that of the other cities. However, an analysis of the descriptive statistics reveal the strengths and weaknesses of Bowling Green’s response to homelessness, identifying prevention and emergency services as areas needing more attention. This research and its following discussion serve as a starting point for the ten localities examined, as well as other similar localities, to examine their own response to local homelessness

The permeation of dynorphin A 1–6 across the blood brain barrier and its effect on bovine brain microvessel endothelial cell monolayer permeability

Dynorphin A 1–17 (Dyn A 1–17) is an endogenous neuropeptide known to act at the kappa opioid receptor; it has been implicated in a number of neurological disorders, including neuropathic pain, stress, depression, and Alzheimer’s and Parkinson’s diseases. The investigation of Dyn A 1–17 metabolism at the blood-brain barrier (BBB) is important since the metabolites exhibit unique biological functions compared to the parent compound. In this work, Dyn A 1–6 is identified as a metabolite of Dyn A 1–17 in the presence of bovine brain microvessel endhothelial cells (BBMECs), using LC-MS/MS. The transport of Dyn A 1–6 at the BBB was examined using this in vitro cell culture model of the BBB. Furthermore, the permeation of the BBB by the low molecular weight, permeability marker fluorescein was characterized in the presence and absences of Dyn A 1–6

Target-Based Identification of Whole-Cell Active Inhibitors of Biotin Biosynthesis in Mycobacterium tuberculosis

SummaryBiotin biosynthesis is essential for survival and persistence of Mycobacterium tuberculosis (Mtb) in vivo. The aminotransferase BioA, which catalyzes the antepenultimate step in the biotin pathway, has been established as a promising target due to its vulnerability to chemical inhibition. We performed high-throughput screening (HTS) employing a fluorescence displacement assay and identified a diverse set of potent inhibitors including many diversity-oriented synthesis (DOS) scaffolds. To efficiently select only hits targeting biotin biosynthesis, we then deployed a whole-cell counterscreen in biotin-free and biotin-containing medium against wild-type Mtb and in parallel with isogenic bioA Mtb strains that possess differential levels of BioA expression. This counterscreen proved crucial to filter out compounds whose whole-cell activity was off target as well as identify hits with weak, but measurable whole-cell activity in BioA-depleted strains. Several of the most promising hits were cocrystallized with BioA to provide a framework for future structure-based drug design efforts

Target-Based Identification of Whole-Cell Active Inhibitors of Biotin Biosynthesis in Mycobacterium tuberculosis

SummaryBiotin biosynthesis is essential for survival and persistence of Mycobacterium tuberculosis (Mtb) in vivo. The aminotransferase BioA, which catalyzes the antepenultimate step in the biotin pathway, has been established as a promising target due to its vulnerability to chemical inhibition. We performed high-throughput screening (HTS) employing a fluorescence displacement assay and identified a diverse set of potent inhibitors including many diversity-oriented synthesis (DOS) scaffolds. To efficiently select only hits targeting biotin biosynthesis, we then deployed a whole-cell counterscreen in biotin-free and biotin-containing medium against wild-type Mtb and in parallel with isogenic bioA Mtb strains that possess differential levels of BioA expression. This counterscreen proved crucial to filter out compounds whose whole-cell activity was off target as well as identify hits with weak, but measurable whole-cell activity in BioA-depleted strains. Several of the most promising hits were cocrystallized with BioA to provide a framework for future structure-based drug design efforts

Mycobacterium tuberculosis IMPDH in Complexes with Substrates, Products and Antitubercular Compounds

Tuberculosis (TB) remains a worldwide problem and the need for new drugs is increasingly more urgent with the emergence of multidrug- and extensively-drug resistant TB. Inosine 5’-monophosphate dehydrogenase 2 (IMPDH2) from Mycobacterium tuberculosis (Mtb) is an attractive drug target. The enzyme catalyzes the conversion of inosine 5’-monophosphate into xanthosine 5’-monophosphate with the concomitant reduction of NAD+ to NADH. This reaction controls flux into the guanine nucleotide pool. We report seventeen selective IMPDH inhibitors with antitubercular activity. The crystal structures of a deletion mutant of MtbIMPDH2 in the apo form and in complex with the product XMP and substrate NAD+ are determined. We also report the structures of complexes with IMP and three structurally distinct inhibitors, including two with antitubercular activity. These structures will greatly facilitate the development of MtbIMPDH2-targeted antibiotics

Targeting Mycobacterium tuberculosis Biotin Protein Ligase (MtBPL) with Nucleoside-Based Bisubstrate Adenylation Inhibitors

Mycobacterium tuberculosis (Mtb), responsible for both latent and symptomatic tuberculosis (TB), remains the second leading cause of mortality among infectious diseases worldwide. Mycobacterial biotin protein ligase (MtBPL) is an essential enzyme in Mtb and regulates lipid metabolism through the post-translational biotinylation of acyl coenzyme A carboxylases. We report the synthesis and evaluation of a systematic series of potent nucleoside-based inhibitors of MtBPL that contain modifications to the ribofuranosyl ring of the nucleoside. All compounds were characterized by isothermal titration calorimetry (ITC) and shown to bind potently with KDs ≤ 2 nM. Additionally, we obtained high-resolution cocrystal structures for a majority of the compounds. Despite fairly uniform biochemical potency, the whole-cell Mtb activity varied greatly with minimum inhibitory concentrations (MIC) ranging from 0.78 to >100 μM. Cellular accumulation studies showed a nearly 10-fold enhancement in accumulation of a C-2'-α analogue over the corresponding C-2'-β analogue, consistent with their differential whole-cell activity

Methionine Antagonizes para-Aminosalicylic Acid Activity via Affecting Folate Precursor Biosynthesis in Mycobacterium tuberculosis

para-Aminosalicylic acid (PAS) is a second-line anti-tubercular drug that is used for the treatment of drug-resistant tuberculosis (TB). PAS efficacy in the treatment of TB is limited by its lower potency against Mycobacterium tuberculosis relative to many other drugs in the TB treatment arsenal. It is known that intrinsic metabolites, such as, para-aminobenzoic acid (PABA) and methionine, antagonize PAS and structurally related anti-folate drugs. While the basis for PABA-mediated antagonism of anti-folates is understood, the mechanism for methionine-based antagonism remains undefined. In the present study, we used both targeted and untargeted approaches to identify factors associated with methionine-mediated antagonism of PAS activity. We found that synthesis of folate precursors as well as a putative amino acid transporter, designated MetM, play crucial roles in this process. Disruption of metM by transposon insertion resulted in a ≥30-fold decrease in uptake of methionine in M. bovis BCG, indicating that metM is the major facilitator of methionine transport. We also discovered that intracellular biotin confers intrinsic PAS resistance in a methionine-independent manner. Collectively, our results demonstrate that methionine-mediated antagonism of anti-folate drugs occurs through sustained production of folate precursors

Effects of Dietary Amino Acid Density and Exogenous Protease Inclusion on Growth Performance and Apparent Ileal AA Digestibility in Broilers

Protein is one of the most expensive nutrients in poultry diets. In an effort to minimize feed costs, protein digestion and utilization by the animal must be carried out as efficiently as possible. Therefore, the objective of this study was to evaluate the effects of dietary AA density and exogenous protease inclusion on growth performance and AA digestibility in broilers. Treatments consisted of a 2 × 4 factorial design with main effects of commercial protease (with or without) and digestible Lys (1.12, 1.15, 1.18, or 1.21%). Broiler chicks were housed in 4 Petersime batteries and treatments were randomly assigned to 80 cages within location block, resulting in 10 cages per treatment with 6 chicks per cage at placement. A commercial enzyme complex with 3 proteolytic activities was added to the protease diets at 0.25 lb/ton, and the same inclusion of sand was added to the diets without protease. Diets were balanced by energy and Lys:amino acid ratios. Titanium dioxide was included in the diets at 0.5% as an indigestible marker. On d 20, ileal contents from 2 chicks per cage were collected and composited by cage for calculation of apparent ileal AA digestibility. Growth performance metrics were calculated from cage weights and feed consumption was recorded throughout the experiment, and AA digestibility data were obtained from analysis of ileal contents. Data were analyzed using SAS 9.4 with cage as the experimental unit and cage location as the blocking factor. There was no evidence of an amino acid density × protease interaction (P \u3e 0.05) for BW, ADG or ADFI. There was an amino acid density × protease interaction (quadratic, P \u3c 0.05) for feed conversion ratio (FCR). Chicks fed 1.12 and 1.21% digestible Lys diets with added protease had a 2-point improvement in FCR compared to chicks fed these diets without protease. There was no difference in FCR between birds consuming diets with or without protease when fed 1.15 and 1.18% digestible Lys diets. There was no evidence of difference (P \u3e 0.10) in ADG or ADFI due to dietary amino acid density throughout the feeding period. However, broiler FCR was improved (linear, P \u3c 0.01) by increasing dietary amino acid density from 1.12 to 1.21% digestible Lys. There was no evidence (P \u3e 0.10) of main effect of added protease on BW, ADG, ADFI, or FCR. There was not an amino acid density × protease interaction (P \u3e 0.09) or main effect of dietary amino acid density or protease inclusion (P \u3e 0.12) on apparent ileal digestibility (AID) of Lys, Arg, Met, Cys, Thr, Ile, Leu, Val, or Trp. In conclusion, increasing dietary amino acid density improved FCR in broiler chicks, and the rate of improvement was dependent on the inclusion of an exogenous protease

Bright Opportunities for Atmospheric Characterization of Small Planets: Masses and Radii of K2-3 b, c, and d and GJ3470 b from Radial Velocity Measurements and Spitzer Transits

We report improved masses, radii, and densities for four planets in two bright M-dwarf systems, K2-3 and GJ3470, derived from a combination of new radial velocity and transit observations. Supplementing K2 photometry with follow-up Spitzer transit observations refined the transit ephemerides of K2-3 b, c, and d by over a factor of 10. We analyze ground-based photometry from the Evryscope and Fairborn Observatory to determine the characteristic stellar activity timescales for our Gaussian Process fit, including the stellar rotation period and activity region decay timescale. The stellar rotation signals for both stars are evident in the radial velocity data and is included in our fit using a Gaussian process trained on the photometry. We find the masses of K2-3 b, K2-3 c, and GJ3470 b to be 6.48{}-0.93+0.99, 2.14{}-1.04+1.08, and 12.58{}-1.28+1.31 M ⊕, respectively. K2-3 d was not significantly detected and has a 3σ upper limit of 2.80 M ⊕. These two systems are training cases for future TESS systems; due to the low planet densities (ρ < 3.7 g cm-3) and bright host stars (K < 9 mag), they are among the best candidates for transmission spectroscopy in order to characterize the atmospheric compositions of small planets