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Objective: To study a new quick method for detecting serum IgG against Trichinella spiralis (T.s)., Methods: Membrane antigen of muscle larva of T.s was isolated and combined with the nitrocellulose membrane. Goat anti-human IgG was conjugated with the golden pellets of colloidal state which was used as marked antibody for the experiment of dot-immunogold filtration assay to examine specific IgG., Results: T.s IgG and its corresponding antigen reacted on the membrane by filtration, and the result could be observed with naked eyes within 10 min. In the examination of 76 clinical serum samples, the positive rate was 94.7%. It was not significantly higher than that of ELISA (chi 2 = 2.83, P > 0.05)., Conclusion: The dot-immunogold filtration assay is rapid and simple for performing and reading in the detection of IgG against T.s with high sensitivity and specificity.

Stimulation of rat renal mesangial cells with cell-permeable C6-ceramide for 6 and 24h induces the expression of several genes as analyzed by a RNA fingerprinting arbitrarily primed-PCR method. Sequencing of the differentially expressed bands identified the serine/threonine protein kinase LIM kinase-1 (LIMK-1), which is involved in the regulation of cytoskeletal organization, as a ceramide-induced gene. The ceramide-triggered upregulation of LIMK-1 was verified by semiquantitative reverse transcriptase-PCR. A detailed time course reveals a first detectable increase in RNA level after 2h of ceramide stimulation which reaches maximal levels after 6h of stimulation and remains elevated up to 24 h. This ceramide-induced gene transcription of LIMK-1 is accompanied by enhanced LIMK-1 protein levels with maximal protein expression seen after 6h of stimulation. Furthermore, cofilin, which is a specific substrate of LIMK-1, shows an increased phosphorylation at Ser-3 in mesangial cells exposed to C6-ceramide. Mechanistically, the ceramide-induced LIMK-1 expression is blocked by the Rho kinase inhibitor Y27632, but not by a farnesyl transferase inhibitor, suggesting the involvement of the small G protein Rho, but not Ras and Rac, in the expressional upregulation. Similar to exogenously added ceramide, also interleukin-1beta which is an established activator of the neutral sphingomyelinase that leads to endogenous ceramide formation upregulates LIMK-1 protein expression and activity. In summary, these data demonstrate for the first time that LIMK-1 is a ceramide-induced gene, thus suggesting that LIMK-1 may act as a link between stress-induced ceramide formation and reorganization of the actin cytoskeleton.