An invading pathogen must be held in check by the innate immune system until a specific immune response can be mounted. In the case of Gram-negative bacteria, the principal stimulator of the innate immune system is lipopolysaccharide (LPS), a component of the bacterial outer membrane. In vitro, LPS is bound by lipopolysaccharide-binding protein (LBP) and transferred to CD14--the LPS receptor on the macrophage surface--or to high-density lipoprotein (HDL) particles. Transfer to CD14 triggers an inflammatory response which is crucial for keeping an infection under control. Here we investigate how LBP functions in vivo by using LBP-deficient mice. Surprisingly, we find that LBP is not required in vivo for the clearance of LPS from the circulation, but is essential for the rapid induction of an inflammatory response by small amounts of LPS or Gram-negative bacteria and for survival of an intraperitoneal Salmonella infection.
Methanol and hot-aqueous extracts of 25 different plant species, used in Yemeni traditional medicine and growing, partly as endemic plants, on the island Soqotra have been investigated for their antiviral activity. In addition, the phytochemical identification of the main chemical constituents was performed. The extracts were assayed in two in vitro viral systems, which used influenza virus type A/MDCK cells and herpes simplex virus type 1/Vero cells, at non-cytotoxic concentrations. The herpes simplex virus type 1 showed more sensitivity than the influenza virus type A against the extracts investigated. The methanol extracts of Boswellia ameero, Boswellia elongata, Buxus hildebrandtii, Cissus hamaderohensis, Cleome socotrana, Dracaena cinnabari, Exacum affine, Jatropha unicostata and Kalanchoe farinacea showed anti-influenza virus type A activity with 50% inhibition (IC50) concentrations ranging from 0.7 to 12.5 microg/mL. In addition, 17 plants of the 25 investigated exhibited anti-HSV-1 activity. The antiviral activity of some active extracts was also observed on a molecular level.
Four sterols and 10 triterpenes were isolated from the fruiting bodies of Ganoderma pfeifferi, including the three new triterpenes 3,7,11-trioxo-5alpha-lanosta-8,24-diene-26-al (lucialdehyde D, 1), 5alpha-lanosta-8,24-diene-26-hydroxy-3,7-dione (ganoderone A, 2), and 5alpha-lanosta-8-ene-24,25-epoxy-26-hydroxy-3,7-dione (ganoderone C, 3). The structures of 1-3 were determined on the basis of spectroscopic evidence. Antibacterial, antifungal, and antiviral activity were studied for some of the isolated compounds. Ganoderone A (2), lucialdehyde B (4), and ergosta-7,22-dien-3beta-ol (7) were found to exhibit potent inhibitory activity against herpes simplex virus.
Respiratory syncytial virus (RSV) is one of the most important virus respiratory pathogens in infants and young children. A rapid and sensitive diagnosis is essential to focus any outbreak due to this virus. A real-time RT-PCR method was designed using a primer/probe pair from the F gene. Simultaneously with nested RT-PCR and antigen ELISA, 71 consecutive specimens from hospitalized children with clinical symptoms of acute respiratory distress were evaluated to confirm the incidence of RSV infection. RSV was detected in 25 (35·2 %) specimens by real-time RT-PCR and in 19 (26·7 %) by nested RT-PCR. The assay was specific for RSV. The procedure offers a rapid and sensitive alternative to conventional RT-PCR. Closed-tube detection eliminates the risk of contamination.
Six new naphthalenone derivatives, balticols A-F and the known metabolite altechromone A were isolated from the AcOEt extract of the culture broth of fungal strain 222 belonging to the Ascomycota, which was found on driftwood collected at the coast of the Greifswalder Bodden, Baltic Sea, Germany. All structures were elucidated on the basis of NMR spectroscopic data and mass spectrometric analyses. The balticols were found to exhibit inhibitory activity against influenza virus A and herpes simplex virus. The most potent antiviral activity was observed for balticol E with an IC(50) value of 0.01 microg/ml against Herpes simplex virus type I.
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