Soluble expression and one-step purification of recombinant mouse interferon-λ3 in Escherichia coli.

Interferon (IFN)-λ3, a member of the type III IFN family, is a pleiotropic cytokine that exhibits potent antiproliferative, antiviral, and immunoregulatory activities. For further functional study of IFN-λ3, we developed an efficient procedure that includes cloning, expression, and purification to obtain relatively large quantity of mouse IFN-λ3 fusion protein. The mature IFN-λ3 protein-coding region was cloned into the prokaryotic expression vector pET-44. IFN-λ3 contains a hexahistidine tag at its C-terminus. We used Ni(2+)-nitrilotriacetic acid agarose-affinity chromatography to purify the expressed soluble protein. The purified IFN-λ3 inhibited significantly IL-13 production in stimulated RAW264.7 macrophages. Our findings show that the production of soluble IFN-λ3 proteins by the pET-44 vector in Escherichia coli is a good alternative for the production of native IFN-λ3 and could be useful for the production of other IFN proteins.

[The Wuhan Twin Birth Cohort Study].

The prevalence of child and adolescent growth and mental-behavior related diseases are increasing, and the pathogenesis are complex. Twins are excellent natural resources for complex chronic diseases research as they share the maternal intrauterine environment, born at the same time and share the same family environment in early years, which could benefit the adjust ment of confounding factors, such as age, genetic factors and early family environmental factors. Birth cohort with twin families involved could be more effective in exploring the genetic and environmental factors for complex chronic diseases at the very beginning of life. This paper summarizes the objective, content, progress, strengths and potential problems of Wuhan Twin Birth Cohort, with emphasis on the overall design and progress of the study.

24xi-Methyl 5 alpha-cholestane-3 alpha,6 beta,9 alpha,25-tetrol 24-monoacetate, a novel polyhydroxylated steroid from the soft coral Sarcophyton tortuosum.

A novel polyhydroxylated steroid, named sartortuosterol A, with rare 3 alpha- and 6-hydroxyl groups, was isolated from the South China Sea soft coral Sarcophyton tortuosum Tixier-Durivault, and its structure was established as 24xi-methyl 5 alpha-cholestane-3 alpha, 6 beta, 9 alpha,25-tetrol 25-monoacetate from spectroscopic data and chemical conversions.

New tetraterpenoid from the soft coral Sarcophyton tortuosum.

A novel tetraterpenoid named methyl tortuoate C (1) has been isolated from the soft coral Sarcophyton tortuosum Tix.-Dur. The structure of 1 was determined on the basis of spectroscopic methods.

[Simultaneous determination of catecholamine levels in plasma by high performance liquid chromatography].

OBJECTIVE: To use a high performance liquid chromatography with electrochemical detection to simultaneously determine catecholamine(CA) levels in plasma and to diagnose chromaffin cell tumors and neuroblastoma. METHODS: The plasma samples after flowing extraction by ion-moderated partition were determined with electrochemical method to detect CA levels in plasma; the lowest detective limit, the precision, recovery, sensitivity of CA levels were tested and a reference range was established based on the respective data of 18 healthy persons. RESULTS: The recovery rates of epinephrine and norepinephrine were 86.2% and 90.5%. The method of testing epinephrine was linear at the range of 0.2 to 10.6 nmol.L-1 with 0.05 nmol.L-1 of the lowest detective limit. The intra- and inter-assay coefficients of variation were lower than 10.7% and 11.1%, respectively. CONCLUSION: The method is simple, accurate, sensible in the clinical diagnosis of CA levels.

Scalarane-type bishomosester terpenes from the sponge Phyllospongia foliascens.

Five new 20,24-bishomoscalarane sesterterpenes, phyllactones A [1], B [2], C [3], D [4], and E [5], are reported from the sponge Phyllospongia foliascens collected in the waters of the Nansha Islands in the South China Sea. Structural elucidation of these compounds is based on spectral data and chemical conversions. Phyllactones A and B show moderate cytotoxicity against KB cells (IC50 20 micrograms/ml).

Stellettin A, a new triterpenoid pigment from the marine sponge Stelletta tenuis.

A new isomalabaricane triterpenoid, stellettin A [1], was isolated from the sponge Stelletta tenuis collected off Hainan Island, People's Republic of China. Its structure and stereochemistry were established by analysis of its spectral data and reference to related compounds.

Flavonone and chalcone derivatives from Cryptocarya kurzii.

Four complex flavanones, kurziflavolactones A [2], B [3], C [4], and D [5] and a complex chalcone 6 with an unprecedented carbon side chain on the flavanone or chalcone A ring have been isolated from a Malaysian plant, Cryptocarya kurzii (Lauraceae). Their structures were determined by extensive spectroscopic analysis, especially 2D nmr experiments. Compounds 3 and 6 showed slight cytotoxicity against KB cells, with IC50 values of 4 and 15 micrograms/ml, respectively. A biosynthetic pathway for the formation of these compounds is suggested.