Isolation, identification and fibrolytic characteristics of rumen fungi grown with indigenous methanogen from yaks (Bos grunniens) grazing on the Qinghai-Tibetan Plateau.

AIM: To obtain co-cultures of anaerobic fungi and their indigenously associated methanogens from the rumen of yaks grazing on the Qinghai-Tibetan Plateau and investigate their morphology features and ability to degrade lignocellulose. METHODS AND RESULTS: Twenty fungus-methanogen co-cultures were obtained by Hungate roll-tube technique. The fungi were identified as Orpinomyces, Neocallimastix and Piromyces genera based on the morphological characteristics and internal transcribed spacer 1 sequences analysis. All methanogens were identified as Methanobrevibacter sp. by 16S rRNA gene sequencing. There were four types of co-cultures: Neocallimastix with Methanobrevibacter ruminantium, Orpinomyces with M. ruminantium, Orpinomyces with Methanobrevibacter millerae and Piromyces with M. ruminantium among 20 co-cultures. In vitro studies with wheat straw as substrate showed that the Neocallimastix with M. ruminantium co-cultures and Piromyces with M. ruminantium co-cultures exhibited higher xylanase, filter paper cellulase (FPase), ferulic acid esterase, acetyl esterase activities, in vitro dry matter digestibility, gas, CH4 , acetate production, ferulic acid and p-coumaric acid releases. The Neocallimastix frontalis Yak16 with M. ruminantium co-culture presented the strongest lignocellulose degradation ability among 20 co-cultures. CONCLUSIONS: Twenty fungus-methanogen co-cultures were obtained from the rumen of grazing yaks. The N. frontalis with M. ruminantium co-cultures were highly effective combination for developing a fermentative system that bioconverts lignocellulose to high activity fibre-degrading enzyme, CH4 and acetate. SIGNIFICANCE AND IMPACT OF THE STUDY: The N. frontalis with M. ruminantium co-cultures from yaks grazing on the Qinghai-Tibetan Plateau present great potential in lignocellulose biodegradation industry.

Airway changes and prevalence of obstructive sleep apnoea after bimaxillary orthognathic surgery with large mandibular setback.

This study used three-dimensional computed tomography and polysomnography to evaluate the effect of a large mandibular setback on the postoperative pharyngeal airway space and obstructive sleep apnoea (OSA). Twelve patients who underwent bimaxillary surgery for a mandibular setback movement of >9mm were included in this study. Changes in the pharyngeal airway space and polysomnography parameters based on the surgical movements were analyzed. The median mandibular setback movement was 11.08mm. The total pharyngeal, oropharyngeal, and hypopharyngeal volumes, and the retroglossal cross-sectional area were significantly decreased postoperatively (P=0.006; P=0.005; P=0.012; P=0.005, respectively). The apnoea-hypopnoea index (AHI) increased significantly after surgery (P=0.021). There were significant positive correlations between the preoperative inferiorly located hyoid bone and both AHI and respiratory disturbance index (RDI) postoperative (P=0.008 and P=0.027) and between the postoperative inferiorly dislocated retropalatal level and both AHI and RDI postoperative (P=0.002 and P=0.014). Four patients (33.3%) developed new onset OSA postoperatively. Large mandibular setback movements significantly reduced the pharyngeal airway space in the setting of bimaxillary surgery (P=0.006).

Treatment with peginterferon plus ribavirin vs. interferon plus ribavirin for 48 weeks in Chinese patients with chronic hepatitis C.

INTRODUCTION: Virological responses to interferon (IFN) treatment for chronic hepatitis C (CHC) have been found to be correlated with racial differences. Furthermore, higher sustained virological response (SVR) rates were obtained in many randomised clinical trials (RCT) in Caucasian patients with CHC after treating with peg-IFN than those with IFN. However, it is not clear whether this conclusion can be adapted to patients of Chinese descent. METHODS: A search of MEDLINE and China National Knowledge Infrastructure between 1966 and 2008 was performed. Trials comparing the use of peg-IFN plus ribavirin vs. IFN plus ribavirin in treating Chinese patients with CHC were assessed. RESULTS: Of the 94 studies screened, seven RCTs including 398 patients (peg-IFN therapy 232, IFN therapy 166) were analysed. The SVRs obtained in patients treated with peg-IFN plus ribavirin were significantly higher than in patients treated with IFN plus ribavirin [70% vs. 35%, relative risk, 1.76; 95% confidence interval: 1.21-2.56; p (0.01)]. Withdrawal rates were similar between patients treated with peg-IFN plus ribavirin and IFN plus ribavirin. CONCLUSION: Chinese patients with CHC also have a greater likelihood of achieving an SVR with peg-IFN plus ribavirin.

Efficacy of rhBMP-2/Hydroxyapatite on Sinus Floor Augmentation: A Multicenter, Randomized Controlled Clinical Trial.

The aim of this randomized single-blinded active-controlled clinical study was to evaluate the early efficacy of low-dose Escherichia coli-derived recombinant human bone morphogenetic protein 2 (rhBMP-2) soaked with hydroxyapatite granules (BMP-2/H) as compared with an inorganic bovine bone xenograft (ABX) in maxillary sinus floor augmentation. In a total of 127 subjects who were enrolled at 6 centers, maxillary sinus floors were augmented with 1 mg/mL of rhBMP-2 (0.5 to 2.0 mg per sinus) and BMP-2/H (0.5 to 2.0 g; n = 65) or with ABX alone (0.5 to 2.0 g; n = 62). Core biopsies were obtained 3 mo after the augmentation surgery and were analyzed histomorphometrically. The mean new bone formation with BMP-2/H and ABX augmentation was 16.10% ± 10.52% and 8.25% ± 9.47%, respectively. The BMP-2/H group was noninferior to the ABX group; the lower limit of the 1-sided 97.5% confidence interval for the difference between the 2 groups was calculated as 4.33%, which was greater than the prespecified noninferiority margin of -3.75%. An additional test with the Wilcoxon rank-sum test with a 2-sided 5% significance level showed that bone formation between the 2 groups was significantly different (P < 0.0001). The soft tissue and residual graft areas showed no significant differences between the groups. With regard to safety, no significant difference between the 2 groups was observed; there was no significant increase in the amount of rhBMP-2 antibody in the serum after BMP-2/H grafting. Our study suggested that low-dose Escherichia coli-derived rhBMP-2 with hydroxyapatite was effective in early stages for enhanced bone formation after maxillary sinus floor augmentation without harmful adverse events (Clinicaltrials.gov NCT01634308).

Polymer-protein conjugates. I. Effect of protein conjugation on the cloud point of poly (N-isopropylacrylamide).

Poly (N-isopropylacrylamide) (p(NIPAAm] exhibits a cloud point around 32 degrees C. In this study we have conjugated several proteins to p(NIPAAm), and the effects of protein molecular weight, pH and ionic strength on the cloud point of the p(NIPAAm)-protein conjugates have been studied. The cloud points of p(NIPAAm)-protein conjugates appear to be unaffected by the molecular weight or isoelectric point (pl) of the proteins, the pH or ionic strength.

Intramolecular disulfide bonds enhance the antimicrobial and lytic activities of protegrins at physiological sodium chloride concentrations.

Protegrins are 2-kDa antimicrobial peptides that contain 16-18 amino acid residues and two intramolecular disulfide bonds. We studied the contribution of these disulfide bonds to the bactericidal activity of protegrins in physiological concentrations of NaCl by comparing protegrin PG-1 with variants that lacked one or both cysteine disulfides. Whereas the bactericidal and liposome-lytic properties of protegrin PG-1 were enhanced by adding 100 mM NaCl to the phosphate-buffered medium, NaCl addition strongly inhibited the effects of its linearized, disulfide-free variant, [A6, A8, A13, A15]protegrin-1. Whereas protegrin PG-1 manifested beta-sheet structure by CD (circular dichroism) and ATR-FTIR (attenuated-total-reflectance-Fourier-transform-infrared) spectroscopy in buffer or membrane-mimetic environments, [A6, A8, A13, A15]protegrin-1 manifested disordered structure in phosphate buffer and alpha-helical characteristics in membrane-mimetic environments. Both single-disulfide protegrin variants, [A8, A13]protegrin-1 and [A6, A15]protegrin-1, assumed beta-sheet conformations with liposomes that simulated bacterial membranes, and both retained substantial bactericidal activity when 100 mM NaCl was present. These findings demonstrate that the intramolecular disulfide bonds of protegrins are required for their antiparallel beta-sheet conformation in membrane-mimetic environments and for their potent antimicrobial activity in media containing NaCl concentrations comparable to those found in serum and extracellular fluids.

Founder's Award, Society for Biomaterials. Sixth World Biomaterials Congress 2000, Kamuela, HI,May 15-20, 2000. Really smart bioconjugates of smart polymers and receptor proteins.

Over the past 18 years we have been deeply involved with the synthesis and applications of stimuli-responsive polymer systems, especially polymer-biomolecule conjugates. This article summarizes our work with one of these conjugate systems, specifically polymer-protein conjugates. We include conjugates prepared by random polymer conjugation to lysine amino groups, and also those prepared by site-specific conjugation of the polymer to specific amino acid sites that are genetically engineered into the known amino acid sequence of the protein. We describe the preparation and properties of thermally sensitive random conjugates to enzymes and several affinity recognition proteins. We have also prepared site-specific conjugates to streptavidin with temperature-sensitive polymers, pH-sensitive polymers, and light-sensitive polymers. The preparation of these conjugates and their many fascinating applications are reviewed in this article.