Estimation of effective dose of propofol mono-sedation for successful insertion of upper gastrointestinal endoscope in healthy, non-obese Chinese adults.

WHAT IS KNOWN AND OBJECTIVE: Propofol is effective in sedation for upper gastrointestinal (UGI) endoscopy. However, the optimum dose is ill-defined. This study aimed to estimate the effective dose of propofol mono-sedation for successful endoscope insertion in healthy, non-obese Chinese adults undergoing single UGI endoscopy. METHODS: Twenty-six adult patients undergoing elective single UGI endoscopy were enrolled in this study. A modified Dixon's up-and-down method was utilized to assess the effective dose of propofol for successful endoscope insertion. The initial dose of propofol administered, 1.6 mg/kg, was adjusted with 0.1 mg/kg as a step size. The patient's responses to endoscope insertion were classified as either 'movement' or 'no movement'. When patient's responses were changed from 'movement' to 'no movement' or from 'no movement' to 'movement', a crossover was defined. After eight crossovers had been obtained, patient recruitment was stopped. The mean of midpoints of all crossovers obtained by the modified Dixon's up-and-down method in all 26 patients was defined as calculated median effective dose (ED50 ) of propofol for successful endoscope insertion. Furthermore, probit regression analysis was used to determine the dose of propofol where 50% (ED50 ) and 95% (ED95 ) of endoscope insertion attempts were successful. RESULTS: The calculated ED50 of propofol for successful endoscope insertion was 1.89 ± 0.12 mg/kg. The probit regression analysis showed that ED50 and ED95 of propofol for successful endoscope insertion were 1.90 mg/kg (95% CI, 1.78-2.10 mg/kg) and 2.15 mg/kg (95% CI, 2.01-3.56 mg/kg), respectively. No any patient had hypoxaemia and gag reflex during the UGI endoscopy with propofol mono-sedation. WHAT IS NEW AND CONCLUSION: In healthy, non-obese Chinese adults, propofol mono-sedation can provide excellent conditions of UGI endoscopy and the estimated ED50 of propofol for successful endoscope insertion is 1.89 ± 0.12 mg/kg.

Vib-PT, an Aromatic Prenyltransferase Involved in the Biosynthesis of Vibralactone from Stereum vibrans.

Vibralactone, a hybrid compound derived from phenols and a prenyl group, is a strong pancreatic lipase inhibitor with a rare fused bicyclic ß-lactone skeleton. Recently, a researcher reported a vibralactone derivative (compound C1) that caused inhibition of pancreatic lipase with a half-maximal inhibitory concentration of 14 nM determined by structure-based optimization, suggesting a potential candidate as a new antiobesity treatment. In the present study, we sought to identify the main gene encoding prenyltransferase in Stereum vibrans, which is responsible for the prenylation of phenol leading to vibralactone synthesis. Two RNA silencing transformants of the identified gene (vib-PT) were obtained through Agrobacterium tumefaciens-mediated transformation. Compared to wild-type strains, the transformants showed a decrease in vib-PT expression ranging from 11.0 to 56.0% at 5, 10, and 15 days in reverse transcription-quantitative PCR analysis, along with a reduction in primary vibralactone production of 37 to 64% at 15 and 21 days, respectively, as determined using ultra-high-performance liquid chromatography-mass spectrometry analysis. A soluble and enzymatically active fusion Vib-PT protein was obtained by expressing vib-PT in Escherichia coli, and the enzyme's optimal reaction conditions and catalytic efficiency (Km /kcat) were determined. In vitro experiments established that Vib-PT catalyzed the C-prenylation at C-3 of 4-hydroxy-benzaldehyde and the O-prenylation at the 4-hydroxy of 4-hydroxy-benzenemethanol in the presence of dimethylallyl diphosphate. Moreover, Vib-PT shows promiscuity toward aromatic compounds and prenyl donors.IMPORTANCE Vibralactone is a lead compound with a novel skeleton structure that shows strong inhibitory activity against pancreatic lipase. Vibralactone is not encoded by the genome directly but rather is synthesized from phenol, followed by prenylation and other enzyme reactions. Here, we used an RNA silencing approach to identify and characterize a prenyltransferase in a basidiomycete species that is responsible for the synthesis of vibralactone. The identified gene, vib-PT, was expressed in Escherichia coli to obtain a soluble and enzymatically active fusion Vib-PT protein. In vitro characterization of the enzyme demonstrated the catalytic mechanism of prenylation and broad substrate range for different aromatic acceptors and prenyl donors. These characteristics highlight the possibility of Vib-PT to generate prenylated derivatives of aromatics and other compounds as improved bioactive agents or potential prodrugs.

The effect of plant extracts on growth and photosynthetic fluorescence characteristics of Microcystis flos-aquae.

The cyanobacteria Microcystis flos-aquae can cause harmful algal blooms in waterbodies, which threaten the normal functioning of aquatic ecosystems and human health. Some plant extracts are considered as promising algaecides. In this study, the effects of ten plant extracts (Cinnamomum camphora, Ginkgo biloba, Firmiana platanifolia, Salix babylonica, Euphorbia humifusa, Erigeron annuus, Solidago canadensis, Alternanthera philoxeroides, Thalia dealbata and Eichhornia crassipes) against M. flos-aquae were investigated. The results showed that all ten plant extracts had a significant inhibitory effect on M. flos-aquae growth after 96 h (P < 0.01). The inhibition rates of S. babylonica, E. humifusa, S. canadensis and A. philoxeroides were over 70.00%. Furthermore, the E. humifusa extract had the best inhibitory effect on the photosynthesis of M. flos-aquae, with the effective quantum yield of photosystem II and maximal relative electron transport rate decreasing by 97.50% and 97.00%, respectively, after 96 h. Additionally, the E. humifusa extract was found to be non-toxic to non-target organisms such as Brachydanio rerio and Vallisneria spiralis within 96 h. This study contributes to the existing knowledge and data of freshwater cyanobacteria blooms, and provides insights for their control and the restoration of freshwater systems affected by cyanobacteria blooms.

Does really selection of nostril affect performance of nasotracheal intubation with nasotracheal Airtraq®?

No abstract.

[Study on anti-osteoporosis effect of Eucommiae Cortex based on GC-MS metabonomics].

Based on GC-MS metabolomics and biochemical index analysis, the mechanism of bone mass loss in osteoporosis and the evaluation of anti-osteoporosis in Eucommiae Cortex were studied. The OVX rats model was established by bilateral ovariectomized. The routine indexes such as BMC, BMD, BGP and TRAP5 b were determined. The GC-MS technique was used to analyze the metabolism profile of serum samples between the control group, model group and medicine group, and multiple statistical analysis methods including principal component analysis(PCA), partial least squares-linear discriminant analysis(PLS-LDA) and subwindow rearrangement analysis(SPA) were used to screen and identify biomarkers. Five metabolites were selected as potential biomarkers, glycine, lysine, tryptophan, docosahexaenoic acid and glucose. Except for the significant increase of tryptophan in serum of OVX rats, the other four metabolites were significantly decreased. Moreover, the five biomarkers of the medicine group had a trend of returning to rats in control group. The significantly altered metabolite levels indicated that Eucommiae Cortex may relieve the symptoms of osteoporosis by regulating amino acid metabolism and oxidative stress.

[Cannabinoid receptor system regulates ion channels and synaptic transmission in retinal cells].

Endocannabinoid receptor system is extensively expressed in the vertebrate retina. There are two types of cannabinoid receptors, CB1 and CB2. Activation of these two receptors by endocannabinoids N-arachidonoylethanolamide (anandamine, AEA) and 2-arachidonyl glycerol (2-AG) regulates multiple neuronal and glial ion channels, thus getting involved in retinal visual information processing. In this review, incorporating our results, we discuss the modulation of cannabinoid CB1 and CB2 receptors on retinal neuronal and glial ion channels and retinal synaptic transmission.