Effect of Pluronic-F68 fog solution on performance and morbidity of newly received heifer calves.

Morbidity and mortality from bovine respiratory disease (BRD) of newly received feedlot cattle continue to be problems for the feedlot industry. The objective of this study was to evaluate the effects of utilizing a novel breathing treatment containing a nonionic surfactant (Pluronic-F68) on performance and morbidity of high-risk calves during a 45-d receiving period. Angus/Angus-cross heifer calves (n = 240) were acquired in Delhi, LA, and transported (14 h) to the research facility. Heifers were allowed 21-h rest with access to water and RAMP prior to processing. Heifers were sorted into 16 pens by processing order and randomized by pen into one of two treatments: novel breathing treatment containing 6.25% Pluronic-F68 solution, 28.13% glycerin, and 65.62% water (FOG; n = 8 pens per treat and 15 heifers per pen) and control (CON; n = 8 pens per treat and 15 heifers per pen). Control heifers were held in an enclosed stock trailer for 10 min and followed by FOG heifers, during which time treatment was administered. The person responsible for identifying signs of morbidity was blinded to treatment assignments. Data were analyzed as a completely randomized design using MIXED (continuous) or GLIMIX (binomial) models of SAS 9.4. Average daily gain was similar between treatments (P = 0.91). No differences were found in dry matter intake (P = 0.14) nor in gain efficiency (P = 0.58). There were no differences (P = 0.74) in final body weights. Morbidity was similar at first, second, and third antimicrobial administration regardless of treatment (P ≥ 0.34). The number of antimicrobial treatments required or the management of BRD was similar between treatments (P = 0.72). There was no difference (P = 0.44) in mortality between FOG and CON groups. The Pluronic-F68 solution did not improve performance or reduce morbidity of newly received heifer calves; however, further research with a different concentration and/or duration of fogging may be warranted.

Influence of lipoplex surface charge on siRNA delivery: application to the in vitro downregulation of CXCR4 HIV-1 co-receptor.

OBJECTIVE: Cationic lipidic formulations have been successfully used to deliver small interfering RNA (siRNA) into cells but they show limitations for in vivo application due to their cytotoxicity and instability in the presence of serum. To overcome these limitations, the authors developed an anionic lipid-based carrier named Neutraplex (Nx). Here, they wanted to investigate the influence of the lipoplex (Lx) surface charge on cytotoxicity, delivery and silencing activity of siRNAs. METHODS: The efficiency of three Nx formulations (cationic, close to neutrality and anionic) to deliver anti-CXCR4 siRNAs in MAGI cells was investigated and compared with the cationic commercial transfection reagent Lipofectamine RNAiMAX. Cellular uptake and intracellular localization of a fluorescent siRNA was monitored in live cells using fluorescence microscopy and silencing activity was measured by flow cytometry and RT-PCR analysis. RESULTS: The authors found that the Lx surface charge influenced cellular uptake and silencing activity of siRNA in cell cultures. Although cationic Lx formulations were the most efficient carriers to deliver active silencing siRNAs, negatively charged lipoplexes were taken up by cells, delivered active siRNAs and presented low cytotoxicity. CONCLUSIONS: Altogether, the findings support further investigation for in vivo delivery of therapeutic siRNAs using Nx. Furthermore, this study indicates that anionic delivery systems may have potential for in vivo RNAi therapeutics.

Discovery of indoline-based, natural-product-like compounds as probes of focal adhesion kinase signaling pathways.

With the goal of identifying small molecule modulators of protein-protein interactions, we developed a solid-phase synthesis method, which was then successfully utilized in a library generation of 164 aminoindoline-derived, natural-product-like compounds. This library and several other related intermediates synthesized during this project were then subjected to different biological assays in search of small molecule modulators of focal adhesion kinase (FAK)-mediated signaling pathways. This study included (i) an in vitro, full length FAK inhibition assay, (ii) a cell proliferation assay, and (iii) a wound healing assay. In FAK inhibition assay, eight library members (5-12) and three aminoindoline derivatives (13, 14, and 2) were identified as promising candidates. Compounds 13 and 2 inhibited the FAK activity by 25-45% at 10 microM. These two lead compounds also showed activity in a wound healing assay. To our knowledge, these aminoindoline-derived small molecules belong to a new family of FAK inhibitors.

Building skeletally diverse architectures on the Indoline Scaffold: the discovery of a chemical probe of focal adhesion kinase signaling networks.

Inspired by bioactive indoline alkaloid natural products, here, we report a divergent synthesis approach that led to skeletally diverse indoline alkaloid-inspired compounds. The natural product-inspired compounds obtained were then subjected to a series of in vitro and cellular assays to examine their properties as modulators of focal adhesion kinase (FAK) activity. This study resulted in the identification of a promising lead inhibitor of FAK (42), which also showed activity in a wound healing and cell invasion assay. The in silico study of the lead compound (42) was also undertaken.

A solid phase library synthesis of hydroxyindoline-derived tricyclic derivatives by Mitsunobu approach.

Hydroxyindoline-derived scaffold, 9, was synthesized with the goal of generating a library of indoline-based natural product-like tricyclic derivatives to be utilized as small-molecule chemical probes. The tricyclic ring was obtained by a Mitsunobu reaction of the N-nosyl amino acid conjugate with the primary hydroxyl group. The solid-phase synthesis was achieved by immobilizing scaffold 9 onto the solid support giving a compound, 15. This was then subjected to a series of reactions on solid phase, including the Mitsunobu reaction, leading to the desired indoline-derived tricyclic derivative. The final product has two diversity sites: (i) amino acid as the first diversity and (ii) amidation of the secondary amine for the second diversity. These two diversity sites were utilized in the library generation by IRORI split-and-mix approach.