Function of von Willebrand factor after crossed bone marrow transplantation between normal and von Willebrand disease pigs: effect on arterial thrombosis in chimeras.

von Willebrand factor (vWF) is essential for the induction of occlusive thrombosis in stenosed and injured pig arteries and for normal hemostasis. To separate the relative contribution of plasma and platelet vWF to arterial thrombosis, we produced chimeric normal and von Willebrand disease pigs by crossed bone marrow transplantation; von Willebrand disease (vWD) pigs were engrafted with normal pig bone marrow and normal pigs were engrafted with vWD bone marrow. Thrombosis developed in the chimeric normal pigs that showed normal levels of plasma vWF and an absence of platelet vWF; but no thrombosis occurred in the chimeric vWD pigs that demonstrated normal platelet vWF and an absence of plasma vWF. The ear bleeding times of the chimeric pigs were partially corrected by endogenous plasma vWF but not by platelet vWF. Our animal model demonstrated that vWF in the plasma compartment is essential for the development of arterial thrombosis and that it also contributes to the maintenance of bleeding time and hemostasis

A Convergent Synthesis of 14-Membered F-O-G Ring Analogs of the Teicoplanin Binding Pocket via Intramolecular SNAr Reaction

An intramol. SNAr reaction for efficient macrocyclization via biaryl ether formation was developed for syntheses of the 14-membered macrocycles I and II (R = NH2, NO2) related to F-O-G ring of teicoplanin. Chloride as well as fluoride could be used as the leaving group in this reaction. However, the latter was preferred since it required milder conditions. Both ortho and para nitro, fluoro disubstituted arom. rings were suitable for the macrocyclization reaction with tethered aryl oxides. The nonproteinogenic alpha -amino acid III, required for the synthesis of II, was prepd. via an asym. Strecker synthesis using (R)-phenylglycinol as a chiral auxiliary. The overall synthetic strategy was convergent, and the cyclization could be performed in the presence of the highly sensitive arylglycine unit without racemization. [on SciFinder (R)

N-myristoyltransferases inhibitory activity of ellagitannins from Terminalia bentzoe (L.) L. f. subsp. bentzoe.

N-myristoylation (Myr) is an eukaryotic N-terminal co- or post-translational protein modification in which the enzyme N-myristoyltransferase (NMT) transfers a fatty acid (C14:0) to the N-terminal glycine residues of several cellular key proteins. Depending on the cellular context, NMT may serve as a molecular target in anticancer or anti-infectious therapy, and drugs that inhibit this enzyme may be useful in the treatment of cancer or infectious diseases. As part of an on-going project to identify natural Homo sapiens N-myristoyltransferase 1 inhibitors (HsNMT1), two ellagitannins, punicalagin (1) and isoterchebulin (2), along with eschweilenol C (3) and ellagic acid (4) were isolated from the bark of Terminalia bentzoe (L.) L. f. subsp. bentzoe. Their structures were determined by means of spectroscopic analyses and comparison with literature data. Punicalagin (1) and isoterchebulin (2) showed significant inhibitory activity towards HsNMT1, and also against Plasmodium falciparum NMT (PfNMT) both in vitro and in cellulo, opening alternative paths for new NMT inhibitors development. This is the first report identifying natural products from a botanical source as inhibitors of HsNMT and PfNMT

Detection of Campylobacter jejuni by Culture and Real-Time PCR in a French Cohort of Patients with Guillain-Barré Syndrome▿

Bacteriological culture and real-time PCR (RT-PCR) were used to detect Campylobacter jejuni in fecal samples from a French cohort of 237 patients with Guillain-Barré syndrome (GBS). We provide evidence that diverse serotypes and genotypes of C. jejuni are a major trigger of GBS in France