Nutrients influence the dynamics of Klebsiella pneumoniae carbapenemase producing enterobacterales in transplanted hospital sinks

Antimicrobial resistance has been recognized as a threat to human health. The role of hospital sinks acting as a reservoir for some of the most concerning antibiotic resistant organisms, carbapenemase producing Enterobacterales (CPE) is evident but not well understood. Strategies to prevent establishment, interventions to eliminate these reservoirs and factors which drive persistence of CPE are not well established. We use a uniquely designed sink lab to transplant CPE colonized hospital sink plumbing with an aim to understand CPE dynamics in a controlled setting, notably exploiting both molecular and culture techniques. After ex situ installation the CPE population in the sink plumbing drop from previously detectable to undetectable levels. The addition of nutrients is followed by a quick rebound in CPE detection in the sinks after as many as 37 days. We did not however detect a significant shift in microbial community structure or the overall resistance gene carriage in longitudinal samples from a subset of these transplanted sinks using whole shotgun metagenomic sequencing. Comparing nutrient types in a benchtop culture study model, protein rich nutrients appear to be the most supportive for CPE growth and biofilm formation ability. The role of nutrients exposure is determining factor for maintaining a high bioburden of CPE in the sink drains and P-traps. Therefore, limiting nutrient disposal into sinks has reasonable potential with regard to decreasing the CPE wastewater burden, especially in hospitals seeking to control an environmental reservoir.

4-Azetidinyl-1-heteroatom linked cyclohexane antagonists of CCR2: patent evaluation

This application discloses a series of di- and tri-substituted cyclohexanes as CCR2 receptor antagonists which are stated to be useful in treating inflammation and autoimmune diseases, such as type 2 diabetes and asthma. Although receptor binding of the compounds to CCR2 is demonstrated, there are no data to support the idea that these molecules are functional antagonists.

Expression of Leukotrienes is Increased in Human MS and in a Mouse Adoptive Transfer Model of MS (B98)

Leukotrienes are well established as mediators of inflammation, however little is known regarding their role in the pathogenesis of multiple sclerosis (MS). In humans, elevated LTA4-h levels were reported in acute inflammatory lesions of a single primary progressive (PP) patient, while increased mRNA and protein levels of 5-lipoxygenase were seen in both PP-MS and relapsing remitting (RR) patients. LTB4 levels were higher in the cerebrospinal fluid of patients with active MS compared to controls, while levels of cysteinyl leukotrienes LTC4, LTD4, and LTE4 were not different. Beyond these preliminary disease association data, little is known about role of leukotrienes in MS. BLT1, the high affinity receptor for LTB4, has recently been reported to be expressed on both human and mouse antigen-experienced T lymphocytes. We show here that encephalitogenic T cells specific for a myelin antigen express functional BLT1. When transferred into naïve recipients these T cells are sufficient to induce disease. In addition, peripheral blood T cells from RR-MS patients express altered levels of the BLT1 receptor as compared to normal healthy controls. In the CNS, we show that demyelinating plaques in human MS brain tissues have up-regulated levels of LTA4-h and BLT1 by immunohistochemistry suggesting involvement of this pathway in the pathogenesis of MS and highlighting potential new targets for therapeutic intervention.

Design, synthesis, and activity of 2-imidazol-1-ylpyrimidine derived inducible nitric oxide synthase dimerization inhibitors

By the screening of a combinatorial library for inhibitors of nitric oxide (NO) formation by the inducible isoform of nitric oxide synthase (iNOS) using a whole-cell assay, 2-(imidazol-1-yl)pyrimidines were identified. Compounds were found to inhibit the dimerization of iNOS monomers, thus preventing the formation of the dimeric, active form of the enzyme. Optimization led to the selection of the potent, selective, and orally available iNOS dimerization inhibitor, 21b, which significantly ameliorated adjuvant-induced arthritis in a rat model. Analysis of the crystal structure of the 21b--iNOS monomer complex provided a rationalization for both the SAR and the mechanism by which 21b blocks the formation of the protein--protein interaction present in the dimeric form of iNOS.

An aspirin-triggered lipoxin A4 stable analog displays a unique topical anti-inflammatory profile

Lipoxins and 15-epi-lipoxins are counter-regulatory lipid mediators that modulate leukocyte trafficking and promote the resolution of inflammation. To assess the potential of lipoxins as novel anti-inflammatory agents, a stable 15-epi-lipoxin A(4) analog, 15-epi-16-p-fluorophenoxy-lipoxin A(4) methyl ester (ATLa), was synthesized by total organic synthesis and examined for efficacy relative to a potent leukotriene B(4) (LTB(4)) receptor antagonist (LTB(4)R-Ant) and the clinically used topical glucocorticoid methylprednisolone aceponate. In vitro, ATLa was 100-fold more potent than LTB(4)R-Ant for inhibiting neutrophil chemotaxis and trans-epithelial cell migration induced by fMLP, but was approximately 10-fold less potent than the LTB(4)R-Ant in blocking responses to LTB(4). A broad panel of cutaneous inflammation models that display pathological aspects of psoriasis, atopic dermatitis, and allergic contact dermatitis was used to directly compare the topical efficacy of ATLa with that of LTB(4)R-Ant and methylprednisolone aceponate. ATLa was efficacious in all models tested: LTB(4)/Iloprost-, calcium ionophore-, croton oil-, and mezerein-induced inflammation and trimellitic anhydride-induced allergic delayed-type hypersensitivity. ATLa was efficacious in mouse and guinea pig skin inflammation models, exhibiting dose-dependent effects on edema, neutrophil or eosinophil infiltration, and epidermal hyperproliferation. We conclude that the LXA(4) and aspirin-triggered LXA(4) pathways play key anti-inflammatory roles in vivo. Moreover, these results suggest that ATLa and related LXA(4) analogs may have broad therapeutic potential in inflammatory disorders and could provide an alternative to corticosteroids in certain clinical settings.

Cell cycle redistribution of cultured cells after treatment with chemical radiation protectors

The effect of two radioprotective agents (WR-1065 and WR-151326) was tested for their ability to modify cell cycle progression. Each protector was administered at a concentration of 4 mmol to exponentially growing cultures of V79 cells for periods of time up to 3 h. Under these conditions no cell toxicity was observed. At selected times up to and after removal of the protector, aliquots of cells were removed, counted and fixed in cold 70% ethanol. The cells were stained with DAPI in a 0.1% citrate solution and DNA histograms were obtained using a PARTEC PAS-II flow cytometer. The coefficient of variation of the G1 peaks obtained for unperturbed cell samples routinely ranged from 1.5 to 2.5%. During exposure, both radioprotectors effectively perturbed cell cycle progression, as characterized by a build-up of cells in S and G2 phases. After the protectors were removed, cells began to redistribute throughout the cell cycle. Twelve hours were required before cells exposed to WR-1065 approached levels commensurable with controls. In contrast, cells treated with WR-151236 required about 24 h to redistribute to control levels. These data demonstrate that different thiol-containing radioprotective compounds can differentially affect the progression and redistribution of exposed cells.

The three-dimensional architecture of the elastic-fiber network in canine hepatic portal system

The architectural arrangement of the elastic-fiber network in the wall of canine hepatic portal veins was observed with the scanning electron microscope (SEM). Selective NaOH sonication digestion and autoclaving were used to expose and isolate the networks of elastic fibers from six selected regions of the hepatic portal vessels from seven healthy dogs. Elastic stains of adjacent segments prepared for light microscopy demonstrated that the elastic fibers were concentrated in two areas within the intact portal wall. The innermost area corresponded to the internal elastic lamina (IEL) of the tunica intima, the internal muscular layer, and the connective tissue layer of the tunica media. The second area was in the tunica adventitia. SEM specimens revealed two sleeves of elastic fiber networks which corresponded to the above regions. Small scattered bundles of radially oriented elastic fibers spanned the gap between the two sleeves. Each tunica had a different architectural arrangement of elastic fibers. The IEL had circumferentially oriented fibers which branched and anastomosed to form a continuous network on the innermost surface. The architecture of the IEL was the most variable between the different regions. The network of the IEL was the most "open" in the caudal region (splenic vein) and became "denser" toward the liver. The large elastic fibers in the tunica media were oriented at approximately right angles to the primary fibers of the IEL. These longitudinally oriented fibers anastomosed with adjacent longitudinal fibers to form a continuous network. In the tunica adventitia, thick, longitudinally oriented fibers of the continuous network fused together to form incomplete layers of fibers. The architecture of the elastic-fiber network in the canine hepatic portal vein was compared to that previously described in the systemic canine saphenous vein.