A new steroid from Selaginella pulvinata

A new steroid, 3beta, 16alpha-dihydroxy-(5alpha)-cholestan-21-oic acid , was isolated from the aerial parts of Selaginella pulvinata. Its structure was elucidated on the basis of spectral analysis.     

低植酸与高植酸含量日粮中植酸酶的添加量对于生长猪在粗蛋白、氨基酸及能量消化力上的影响

添加微生物植酸酶通常可以提高植物性饲料中磷的消化率和利用率。对于植酸酶的添加是否影响氨基酸的消化同样作了测定,但结果不一致。本研究测定植酸酶(Natuphos)的添加量(每千克日粮添加2000单位的植酸酶,设计两种基础日粮)对于GE、CP和AA回肠表观消化率(AID)以及CP和GE全消化道表观消化率(ATTD)的影响。两种基础日粮含CP18%,一种含较低量(0.22%)的植酸磷,另一种含较高量(0.48%)的植酸磷。高植酸含量的日粮含有20%的米糠,富含植酸而本身植酸酶活性较低。试验按照4×4拉丁方设计,对初始平均重为40.6 kg的8头阉猪回肠末端安装简易T型套管并饲喂4种日粮。饲喂2次/d,时间分别在8:00和20:00,每次的量相同,ME是维持需要量的2.4倍。每组试验期为14 d。第12、13及14 d收集回肠消化物,时间为8:00到20:00。粪便的收集是从第8 d的8:00到第12d的8:00。Cr2O3作为消化率测定的标记物。结果表明:高植酸含量日粮的GE、CP和AA回肠表观消化率(AID)以及CP和GE全消化道表观消化率(ATTD)低于低植酸含量的日粮(P<0.01);除谷氨酸外,植酸酶的添加量不会影响CP和AA的回肠表观消化率(P>0.10);植酸酶的添加量不影响CP和GE的全消化道表观消化率(P>0.05)。这些结果提示添加植酸酶的效果和日粮植酸含量无关。     

Population pharmacokinetics of mavacoxib in osteoarthritic dogs

Cox, S. R., Liao, S., Payne‐Johnson, M., Zielinski, R. J., Stegemann, M. R. Population pharmacokinetics of mavacoxib in osteoarthritic dogs. J. vet. Pharmacol. Therap. 34 , 1–11. Mavacoxib (Trocoxil?) is an oral long‐acting COX‐2 inhibitor approved for the treatment of osteoarthritis in dogs. Two field trials were conducted in client‐owned dogs suffering from osteoarthritis, with dosages of 4 mg/kg body weight (BW) (Study 1) or 2 mg/kg BW (Study 2). Mavacoxib plasma concentrations were determined from trough blood samples and from blood samples collected at 4–10 months after the last dose. A one‐compartment linear model was fitted to the concentration data (1317 concentration records from 286 patients), and parameters for oral clearance (Cl/F), apparent volume of distribution (V_d/F) and their between‐subject variabilities (BSV) were estimated. Covariates were included in the model based on the outcomes of stepwise regression procedures. In the final model, the typical value of Cl/F was a function of BW, age and breed. German shepherds and Labrador retrievers were found to have 31% higher values of Cl/F than patients from different breeds with similar ages and BWs. The typical value of V_d/F was found to be dependent only on BW. The two field studies appeared to differ similarly with respect to Cl/F and V_d/F. The explanation for this difference is not known, but the difference was accounted for in the final model as a 23.9% lower bioavailability in Study 2. Mavacoxib exhibited relatively broad BSV in Cl/F and V_d/F, with coefficients of variation of 47% and 19%, respectively. The typical value for mavacoxib’s terminal elimination plasma half‐life (t_1/2) was 44 days, but a minority of patients (approximately 5%) had empirical Bayes estimates of t_1/2 exceeding 80 days. Simulations with the model indicated that the majority of patients treated with mavacoxib 2 mg/kg will maintain trough plasma mavacoxib concentrations associated with efficacy. Results of the population pharmacokinetic analysis helped to reduce the dose from 4 to 2 mg/kg and thus increased the therapeutic index for this molecule.     

Pretreatment with an ethanolic extract of Taiwanofungus camphoratus (Antrodia camphorata) enhances the cytotoxic effects of amphotericin B

Taiwanofungus camphoratus, a well-known Chinese medicine used in Taiwan, possesses several pharmacological functions, including anticancer effects. In the present study, we aimed to investigate a novel anticancer effect by pretreating cancer cells with an ethanolic extract of T. camphoratus (TCEE) followed by the administration of an antifungal agent amphotericin B (AmB). Both TCEE and AmB showed significant dose-dependent cytotoxicity in HT29 cells. Pretreatment with a nontoxic dose of TCEE enhanced the cytotoxicity of AmB. Furthermore, significant apoptotic cell death was found in cells treated with TCEE and AmB. A combination treatment with AmB plus TCEE resulted in a significant repression of tumor growth in HT29 xenografts. Collectively, our results indicated that combined treatment with AmB and TCEE effectively induced apoptosis and inhibited tumor growth. In the future, TCEE may serve as a potential complementary and alternative medicine to treat patients suffering from colorectal cancer.     

Involvement of serine proteinase in infectious pancreatic necrosis virus capsid protein maturation and NS proteinase cleavage in CHSE-214 cells

An investigation of virus-specific protein maturation in infectious pancreatic necrosis virus (IPNV) infected Chinook salmon embryo cells (CHSE-214) was undertaken. The precursor protein (pVP2-1) of the major mature capsid protein (VP2) was processed sequentially from pVP2-1 to pVP2-2 and VP2. Experiments using serine proteinase inhibitors showed that the maturation of the VP2 was blocked in the pVP2-1 post-translational cleavage steps. A protinin, a potent proteinase inhibitor, at 800 μg ml(-1) blocked pVP2-2 to VP2 and the cleavage of VP4 (28 kDa) to VP4-1 (25 kDa). Therefore, our data showed that the maturation of the capsid protein (VP2) and cleavage of VP4 (NS proteinase) can be blocked by serine proteinase inhibitors.     

A Determination Method of Anchorage Length of Compression Anchor

The distribution of the axial stress and shear stress on the anchorage segment and the formulation for calculating the anchorage length were derived based on the stress analysis of the anchorage segment of compression anchor. And the effects of parameters, including the elastic modulus, poisson ratio, cohesion, and internal fiction angle of rock mass, on the anchorage length were studied. The results show that the anchorage length decreases with the increase of the elastic modulus, cohesion and internal friction angle of rock mass; and the anchorage length increases linearly but limited with increasing of poisson ratio of rock mass; and it also increases with increasing load.     

Refined Probabilistic Model of Resistance of RC Eccentric Compression Members

The probabilistic model of resistance in the current unified standard for reliability design is imprecise for RC members subjected to eccentric compression. The reason is that it lacks full considerations of influences of varying eccentricities. An improved probabilistic model of resistance with different eccentricities and reinforcement ratios is obtained by using the Monte Carlo sampling method and the current probabilistic models of all resistant factors. The results indicate that it is accurate to fit the probabilistic distribution of resistance with normal distribution. Given that, the applicability of the improved model is analyzed for reliability analysis of RC members subjected to eccentric compression with random eccentricities. It shows that when the design value of eccentricity is close to or larger than the eccentricity producing balanced failure, there would be large errors in reliability analysis if the probabilistic model of resistance given in the current reliability unified standard is used. However, it is accurate when using the proposed probabilistic model. The results also show that the design of RC members subjected to large eccentric compression is unsafe based on the current reliability unified standard because it lacks full considerations of effects that the resistance decreases as eccentricity increases.     

Performance Experiment and Prediction Model of Latent Heat Storage Unit Used in Telecommunications Base Stations

energy saving potential of latent heat storage unit was studied(LHSU) by using neural network. Experiments were conducted in an enthalpy difference laboratory to simulate the performance of LHSU. Different neural network structures were built to predict the influence of nonlinear factors including air flow rate, air temperature. Coefficient of performance (COP), energy storage and discharge rates on the unit’s operation performance. Results showed that the predictions agreed well with the experimental data with correlation coefficients in the range of 0.99~1.00, mean relative errors below 2% and very low root mean square errors.     

Gelsemium alkaloids, immunosuppressive agents from Gelsemium elegans

Bioassay-guided isolation of the stems of Gelsemium elegans has led to the isolation of two new Gelsemium alkaloids, 21-(2-oxopropyl)-koumine (1) and 11-methoxygelselegine (2), and two known alkaloids, koumine (3) and gelselegine (4). The structures of 1-2 were determined by spectroscopic (for both) and single-crystal X-ray diffraction (for 1) analysis. All compounds isolated were evaluated for their potential as immunosuppressive agents and the data suggested that Gelsemium alkaloids of different structural types possibly have potential as immunosuppressive agents.     

Triterpenoids of Euphorbia kansuensis Proch

Phytochemical investigation of the ethanol extract of Euphorbia kansuensis Proch. led to the isolation of three new triterpenoids, along with ten known compounds. Their structures were established by extensive 1D and 2D NMR, as well as other spectrum analysis. Biological activities of the three new compounds against Hela cell, Hep-G2 cell, C. albicans ATCC10231 cell and SC5314 cell were evaluated. They showed strong anti-tumor and moderate anti-inflammatory activities with MIC values ranging from 13 to 25μg/ml and from 30 to 128μg/ml.