In situ, in-liquid, all-electrical detection of Salmonella typhimurium using lead titanate zirconate/gold-coated glass cantilevers at any dipping depth

Most biosensing techniques are indirect, slow, and require labeling. Even though silicon-based microcantilever sensors are sensitive and label-free, they are not suitable for in-liquid detection. More recently lead zirconate titanate (PZT) thin-film-based microcantilevers are shown to be sensitive and in situ. However, they require microfabrication and must be electrically insulated. In this study, we show that highly sensitive, in situ, Salmonella typhimurium detection can be achieved at 90% relative humidity using a lead zirconate titanate (PZT)/gold-coated glass cantilever 0.7 mm long with a non-piezoelectric 2.7 mm long gold-coated glass tip by partially dipping the gold-coated glass tip in the suspension at any depth without electrically insulating the PZT. In particular, we showed that at 90% relative humidity and with a dipping depth larger than 0.8 mm the PZT/gold-coated glass cantilever showed virtually no background resonance frequency up-shift due to water evaporation and exhibited a mass detection sensitivity of Δm/Δf = −5 × 10⁻¹¹ g/Hz. The concentration sensitivities of this PZT/gold-coated glass cantilever were 1 × 10³ and 500 cells/ml in 2 ml of liquid with a 1 and 1.5 mm dipping depth, respectively, both more than two orders of magnitude lower than the infectious dose and more than one order of magnitude lower than the detection limit of a commercial Raptor sensor.     

Imidazolyl benzimidazoles and imidazo[4,5-b]pyridines as potent p38alpha MAP kinase inhibitors with excellent in vivo antiinflammatory properties

Herein we report investigations into the p38alpha MAP kinase activity of trisubstituted imidazoles that led to the identification of compounds possessing highly potent in vivo activity. The SAR of a novel series of imidazopyridines is demonstrated as well, resulting in compounds possessing cellular potency and enhanced in vivo activity in the rat collagen-induced arthritis model of chronic inflammation.     

SIEVE TUBES AND CALLOSE IN ELODEA LEAVES

Detachment and incubation of Elodea leaves promoted callose synthesis in all cells, especially in epidermal pits and in sieve tubes. Phloem was detected in the midrib by fluorescent staining of callose induced to form on sieve plates. In EM views of mature sieve elements nucleus and tonoplast were lacking, mictoplasm replaced cytoplasm, mitochondria were fewer in number, and large plastids contained crystalline inclusion bodies. Slime was present as compact aggregates and as individual fibrils in mictoplasm and sieve pores. Deposition of callose is considered in relation to the blockage concept of callose function.     

The construction and operation of a low-cost poultry waste digester

A simple and low-cost poultry waste digester (PWD) was constructed to treat the waste from 4000 caged laying hens on University Research Unit No. 2 at North Carolina State University. The system was built basically of a plastic lining with insulation, a heating system, a hot-water tank, and other metering equipment. It was operated at 50 degrees C and pH 7.5-8.0. The initiation of methane production was achieved using the indigenous microflora in the poultry waste. At an optimal loading rate (7.5 kg volatile solids/m(3) day), the PWD produced biogas (55% methane) at a rate of 4.0 m(3)/m(3) day. The PWD was biologically stable and able to tolerate temporary overloads and shutdowns. A higher loading rate failed to maintain a high gas production rate and caused drops in methane content and pH value. Under optimal conditions, a positive energy balance was demonstrated with a net surplus of 50.6% of the gross energy. For methane production, the PWD system was proved to be technically feasible. The simple design and inexpensive materials used for this model could significantly reduce the cost of digestion compared to more conventional systems. More studies are needed to determine the durability, the required maintenance of the system, and the most economical method of biogas and solid residue utilization.     

Acacetin, a flavonoid, inhibits the invasion and migration of human prostate cancer DU145 cells via inactivation of the p38 MAPK signaling pathway

Acacetin (5,7-dihydroxy-4′-methoxyflavone), a flavonoid compound, has anti-peroxidative and anti-inflammatory effects. The effect of acacetin on antimetastasis in human prostate cancer DU-145 cells was investigated. First, the result demonstrated acacetin could exhibit an inhibitory effect on the abilities of the adhesion, invasion, and migration by cell–matrix adhesion assay, wound-healing assay, and Boyden chamber assay. Data also showed acacetin could inhibit the phosphorylation of p38 mitogen-activated protein kinase (p38 MAPK) involved in the downregulation of the expressions of matrix metalloproteinase-2 (MMP-2), matrix metalloproteinase-9 (MMP-9), and urokinase-type plasminogen activator (u-PA) at both the protein and mRNA levels. Next, acacetin significantly decreased the nuclear levels of nuclear factor kappa B (NF-κB), c-Fos, and c-Jun. Also, the treatment with acacetin to DU145 cells also leads to a dose-dependent inhibition on the binding ability of NF-κB and activator protein-1 (AP-1). Furthermore, the treatment of inhibitors specific for p38 MAPK (SB203580) to DU145 cells could cause reduced expressions of MMP-2, MMP-9, and u-PA. These results showed acacetin could inhibit the invasion and migration abilities of DU145 cells by reducing MMP-2, MMP-9, and u-PA expressions through suppressing p38 MAPK signaling pathway and inhibiting NF-κB- or AP-1-binding activity. These findings proved acacetin might be offered further application as an antimetastatic agent.     

Pyrazole compound BPR1P0034 with potent and selective anti-influenza virus activity

Background

Influenza viruses are a major cause of morbidity and mortality around the world. More recently, a swine-origin influenza A (H1N1) virus that is spreading via human-to-human transmission has become a serious public concern. Although vaccination is the primary strategy for preventing infections, influenza antiviral drugs play an important role in a comprehensive approach to controlling illness and transmission. In addition, a search for influenza-inhibiting drugs is particularly important in the face of high rate of emergence of influenza strains resistant to several existing influenza antivirals.

Methods

We searched for novel anti-influenza inhibitors using a cell-based neutralization (inhibition of virus-induced cytopathic effect) assay. After screening 20,800 randomly selected compounds from a library from ChemDiv, Inc., we found that BPR1P0034 has sub-micromolar antiviral activity. The compound was resynthesized in five steps by conventional chemical techniques. Lead optimization and a structure-activity analysis were used to improve potency. Time-of-addition assay was performed to target an event in the virus life cycle.

Results

The 50% effective inhibitory concentration (IC₅₀) of BPR1P0034 was 0.42 ± 0.11 μM, when measured with a plaque reduction assay. Viral protein and RNA synthesis of A/WSN/33 (H1N1) was inhibited by BPR1P0034 and the virus-induced cytopathic effects were thus significantly reduced. BPR1P0034 exhibited broad inhibition spectrum for influenza viruses but showed no antiviral effect for enteroviruses and echovirus 9. In a time-of-addition assay, in which the compound was added at different stages along the viral replication cycle (such as at adsorption or after adsorption), its antiviral activity was more efficient in cells treated with the test compound between 0 and 2 h, right after viral infection, implying that an early step of viral replication might be the target of the compound. These results suggest that BPR1P0034 targets the virus during viral uncoating or viral RNA importation into the nucleus.

Conclusions

To the best of our knowledge, BPR1P0034 is the first pyrazole-based anti-influenza compound ever identified and characterized from high throughput screening to show potent (sub-μM) antiviral activity. We conclude that BPR1P0034 has potential antiviral activity, which offers an opportunity for the development of a new anti-influenza virus agent.     

Flavonoids protect pancreatic beta-cells from cytokines mediated apoptosis through the activation of PI3-kinase pathway

The preventive effects of four phenolic compounds against cytokines-induced β-cell destruction were assessed in this study. Treatment of INS-1 (832/13) cells with pro-inflammatory cytokine mixtures (interleukin-1β (IL-1β), tumor necrosis factor-α (TNF-α) and interferon-γ (IFN-γ)) resulted in an increased apoptosis. While resveratrol or myricetin failed to prevent cell apoptosis, quercetin or naringenin treatment exhibited an about 40% less in cell death induced by cytokines-mediated damage. This protective effect of quercetin or naringenin might be mediated partially via the activation of the downstream pAkt and pBad pathways, an outcome which was abolished by pretreatment with a specific PI3-kinase inhibitor. Cellular protein levels of p-p38 MAPK and inducible NO synthase (iNOS) were enhanced after cytokines addition; however, the presence of quercetin or naringenin could not suppress their expression. While cytokines induced MnSOD, quercetin or naringnin did not further enhance expression of this protective protein. In addition, the loss of mitochondria membrane potential (MMP) after cytokines treatment might be partially corrected with quercetin or naringenin. However, none of the phenolic compounds tested in this study reversed the blunted glucose-stimulated insulin secretion after cytokines treatment. These results suggest that quercetin or naringenin might possibly be able to protect β-cells from cytokines toxicity by enhancing cell survival through PI3-kinase pathway, independent of p-p38 MAPK or iNOS.