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Recent studies have identified several mutations in the hemagglutinin (HA) protein that allow the highly pathogenic avian H5N1 influenza A virus to transmit between mammals by airborne route. Here, we determined the complex structures of wild-type and mutant HAs derived from an Indonesia H5N1 virus bound to either avian or human receptor sialic acid analogs. A cis/trans conformational change in the glycosidic linkage of the receptor analog was observed, which explains how the H5N1 virus alters its receptor-binding preference. Furthermore, the mutant HA possessed low affinities for both avian and human receptors. Our findings provide a structural and biophysical basis for the H5N1 adaptation to acquire human, but maintain avian, receptor-binding properties.

The piezoelectric effect of biological piezoelectric materials promotes bone growth. However, the material should be subjected to stress before it can produce an electric charge that promotes bone repair and reconstruction conducive to fracture healing. A novel method for in vitro experimentation of biological piezoelectric materials with physiological load is presented. A dynamic loading device that can simulate the force of human motion and provide periodic load to piezoelectric materials when co-cultured with cells was designed to obtain a realistic expression of piezoelectric effect on bone repair. Hydroxyapatite (HA)/barium titanate (BaTiO3) composite materials were fabricated by slip casting, and their piezoelectric properties were obtained by polarization. The d33 of HA/BaTiO3 piezoelectric ceramics after polarization was 1.3 pC/N to 6.8 pC/N with BaTiO3 content ranging from 80% to 100%. The in vitro biological properties of piezoelectric bioceramics with and without cycle loading were investigated. When HA/BaTiO3 piezoelectric bioceramics were affected by cycle loading, the piezoelectric effect of BaTiO3 promoted the growth of osteoblasts and interaction with HA, which was better than the effect of HA alone. The best biocompatibility and bone-inducing activity were demonstrated by the 10%HA/90%BaTiO3 piezoelectric ceramics.

The first 60 cases constitute the early stage of the learning curve for endoscopic thyroidectomy. The proficiency and stability of the operation reach the advanced level after 150 cases.

Spinal cord transection results in severe neurological sequelae, and to date, there is no effective treatment. Because of the limited capacity for axonal regeneration in the spinal cord, recovery is minimal. Recently, efforts have been made to establish, by grafting neural tissue, a functional relay-station between the severed stumps of the injured cord. Previously, we used co-transplantation of neural stem cells (NSCs) and Schwann cells (SCs) to improve functional recovery of transected spinal cord. However, this effort has been partially impeded by limited neuronal differentiation of transplanted NSCs. To circumvent this problem, we have pre-differentiated NSCs toward neurons in vitro with the application of retinoic acid (RA) prior to cell grafting. Further, we genetically modified SCs to overexpress human neurotrophin-3 (hNT-3). When these cells were co-transplanted into the transected spinal cord of rats, injured animals had partial improvement (both functionally and structurally), including improved Basso, Beattie, and Bresnahan (BBB) scores, increased axonal regeneration/remyelination, and reduced neuronal loss. However, this pre-differentiation of NSCs in vitro only mildly improved neuronal differentiation of NSCs in vivo.

A single D225G mutation in both H1s switches receptor binding specificity from ␣2,6 linkage binding to dual receptor binding. However, the molecular basis for this specificity switch is not fully understood. Here, we show via H1-ligand complex structures that the D225G substitution results in a loss of a salt bridge between amino acids D225 and K222, enabling the key residue Q226 to interact with the avian receptor, thereby obtaining dual receptor binding. This is further confirmed by a D225E mutant that retains human receptor binding specificity with the salt bridge intact.

Lonicerae japonicae flos, a widely used traditional Chinese medicine (TCM), has been used for several thousand years in China. Chinese Pharmacopeia once included Lonicerae japonicae flos of Caprifoliaceae family and plants of the same species named Lonicerae flos in general in the same group. Chinese Pharmacopeia (2005 Edition) lists Lonicerae japonicae flos and Lonicerae flos under different categories, although they have the similar history of efficacy. In this study, we research ancient books of TCM, 4 main databases of Chinese academic journals, and MEDLINE/PubMed to verify the origins and effects of Lonicerae japonicae flos and Lonicerae flos in traditional medicine and systematically summarized the research data in light of modern pharmacology and toxicology. Our results show that Lonicerae japonicae flos and Lonicerae flos are similar pharmacologically, but they also differ significantly in certain aspects. A comprehensive systematic review and a standard comparative pharmacological study of Lonicerae japonicae flos and Lonicerae flos as well as other species of Lonicerae flos support their clinical safety and application. Our study provides evidence supporting separate listing of Lonicerae japonicae flos and Lonicerae flos in Chinese Pharmacopeia as well as references for revision of relevant pharmacopeial records dealing with traditional efficacy of Lonicerae japonicae flos and Lonicerae flos.

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