Flow-injection chemiluminescence method for the determination of naphazoline hydrochloride and oxymetazoline hydrochloride.

A sensitive and simple flow-injection chemiluminescence (FI-CL) method, which was based on the CL intensity generated from the redoxreaction of potassium permanganate (KMnO4)-formaldehyde in vitriol (H2SO4) medium, has been developed, validated and applied for the determination of naphazoline hydrochloride and oxymetazoline hydrochloride. Besides oxidants and sensitizers, the effect of the concentration of H(2)SO(4), KMnO4 and formaldehyde was investigated. Under the optimum conditions, the linear range was 1.0 x 10(-2)-7.0 mg/L for naphazoline hydrochloride and 5.0 x 10(-2)-10.0 mg/L for oxymetazoline hydrochloride. During seven repeated inter-day and intra-day precision tests of 0.1, 1.0 and 10.0 mg/L samples, the relative standard deviations all corresponded to reference values. The detection limit was 8.69 x 10(-3) mg/L for naphazoline hydrochloride and 3.47 x 10(-2) mg/L for oxymetazoline hydrochloride (signal-to-noise ratio < or = 3). This method has been successfully implemented for the determination of naphazoline hydrochloride and oxymetazoline hydrochloride in pharmaceuticals.

Cloning, characterization and expression analysis of interleukin-10 from the zebrafish (Danio rerion).

Cytokines are proteins produced by many different cells of the immune system and play a significant role in initiating and regulating the inflammatory process. In this research, an important cytokine, interleukin-10 (IL-10) gene, has been identified and characterized from zebrafish (Danio rerio) genome database. Zebrafish IL-10 is located within a 2690 bp fragment and contains five exons and four introns, sharing the same organization with mammalian IL-10 genes. An open reading frame of 543 bp was found to encode a putative 180 amino acid protein with a signal peptide of 22 amino acids, which shares 29.7-80.9 % homology with amino acid sequences of other known IL-10. The signature motif of IL-10 is also conserved in zebrafish IL-10. The predicted transcript was finally confirmed by sequencing of cDNA clones. Multi-tissue reverse transcriptase PCR (RT-PCR) was performed to examine the tissue distribution and expression regulation of this gene in seven organs of normal and lipopolysaccharide (LPS) stimulation zebrafish. The results demonstrated that this gene was expressed slightly in normal kidney, gill and gut, no expression was detected in other four tissues. The expression was clearly upregulated after LPS stimulation. Using the ideal zebrafish model, further study of IL-10 characterization and function may provide insight on the understanding of the innate immune system.

Molecular cloning, recombinant expression, and growth-promoting effect of mud carp (Cirrhinus molitorella) insulin-like growth factor-I.

A full-length cDNA encoding insulin-like growth factor-I (IGF-I) was cloned from mud carp (Cirrhinus molitorella) liver tissue using reverse transcription polymerase-chain reaction (RT-PCR) and rapid amplification of cDNA ends (RACE) techniques. The IGF-I precursor cDNA consists of 822 bp in size with a 218 bp 5'-untranslated region and 118 bp 3'-untranslated region. The 486 bp open reading frame encodes a 161 amino acid peptide with a molecular weight of 17.9 kDa. The deduced IGF-I amino acid sequence shared 82.5-97% and 82.5-84% sequence identity with fish and mammalian counterparts, respectively. The mature IGF-I was overexpressed in Escherichia coli, and the expression level of recombinant mcIGF-I reached to 34.1% of the cell total protein. After purification and refolding of recombinant mcIGF-I, growth-promoting effect of recombinant mcIGF-I was investigated, the results showed that the recombinant mcIGF-I significantly enhanced the growth rate of juvenile tilapia. After 6-week treatment, the growth rates of group 1 and 2 were 53 and 67.3% higher than the saline-treated control group. The recombinant mcIGF-I was more effective than recombinant mcGH to enhance the growth rate of juvenile tilapia. The recombinant mcIGF-I-treated fish revealed no significant changes of content of protein, lipid, ash and moisture in muscle.