STAT6 Expression and IL-13 Production in Association with Goblet Cell Hyperplasia and Worm Expulsion of Gymnophalloides seoi from C57BL/6 Mice

In intestinal helminth infections, Th2 immune respones are generally associated with mucin secretion for worm expulsion from the host intestine. In particular, IL-4 and IL-13 are the important cytokines related with intestinal mucus production via STAT6 signalling in nematode infections. However, this perspective has never been studied in Gymnophalloides seoi infection. The present study aimed to observe the STAT6 signalling and cytokine responses in C57BL/6 mice, a mouse strain resistant to infection with this trematode. The results showed that worm expulsion occurred actively during days 1-2 post-infection (PI), when goblet cells began to proliferate in the small intestine. The STAT6 gene expression in the mouse spleen became remarkable from day 2 PI. Moreover, G. seoi infection induced a significant increase of IL-13 from day 4 PI in the spleen of infected mice. Our results suggested that goblet cell hyperplasia and worm expulsion in G. seoi-infected mice should be induced by STAT6 signalling, in which IL-13 may be involved as a dominant triggering cytokine.

Efeito Anti-helmíntico do albendazole sobre a contagem e ovos de Eurytrema sp (Trematoda) em fezes de bovinos / Effect of anti-helmintic treatment with Albendazole on the egg counts per gram of faeces of Eurytrema sp (Trematoda) in cattle

Utilizaram-se 30 vacas mestiças Holandês x Zebu de diversas idades e naturalmente infectadas com Eurytrema sp, divididas em três grupos de 10 animais, os quais receberam os seguintes tratamentos com Albendazole por via oral: grupo A, 12,5 mg/kg PV; grupo B, 15,0 mg/kg PV e grupo C, 17,5 mg/kg PV. Realizaram-se colheitas de fezes no momento do tratamento e no 7§. 14§ e 21§ dia após. As fezes colhidas foram utilizadas para determinar a contagem de ovos de Eurytrema sp por grama de fezes (OPG). Os resultados foram convertidos para log x + 1. Näo houve diferença (P>0,05) entre as médias de OPG dos animais nos diversos grupos no dia do tratamento e nos dias subsequentes, assim como entre os grupos. A utilizaçäo do Albendazole em áreas endêmicas de Eurytrema sp é limitada, já que altas dosagens do produto, como 17,5 mg/kg PV, podem se tornar economicamente inviáveis ou mesmo ineficazes, pela limitada açäo do Albendazole sobre todas as formas evolutivas do Eurytrema sp em bovinos

Multi-dot enzyme-linked immunosorbent assay for serodiagnosis of trematodiasis.

A nitrocellulose membrane strip dotted with crude antigens of trematodes, such as Paragonimus miyazakii, P. westermani, Fasciola sp., Clonorchis sinensis and Schistosoma japonicum was applied for serodiagnosis of trematodiasis. With peroxidase conjugated anti-human IgG and 4-chloro-1-naphthol as a substrate, antibodies in trematodiasis patient sera were clearly detected on the strip as bluish purple spots. Densities of the spots correlated well with values obtained by standard micro-ELISA. Cross-reactions among the trematode antigens, which is occurred more frequently than by ELISA, were observed with this method. However, the darkest spot correlated with the infecting parasite in all cases. With the high reliability and advantage that crude antigens can be used, this simple method, multi-dot ELISA, is considered to be useful for serodiagnosis of trematodiasis.

Application of biotechnology methods to the study of trematodes.

Advances in biotechnology over the past decade offer renewed hope for solutions to trematode parasitoses in Thailand. Trematode diseases have remained the same, but the tools (1) to exploit the innate ability of cells to replicate and produce biological products upon demand, (2) to manipulate the genetic makeup of an organism, (3) and to biologically or synthetically manufacture peptides have provided scientists with new reagents for diagnosing, treating, preventing and controlling trematode diseases. Although recent applications have been focused on schistosomiasis, they have potential application to other trematode diseases (paragonimiasis, clonorchiasis, opisthorchiasis, fasciolopsiasis, and fascioliasis) endemic to Thailand. The optimism which new technology has generated must be tempered with realism and continued support for basic parasitology. Progress is dependent on a combination of approaches involving techniques at the molecular, cellular, organism and population levels. The new tools must be used in conjunction with old knowledge. Most of all there must be a rational strategy for the use of products of new technology. Defined vaccines alone will not be the answer, even if they become a reality. They must be applied in a manner that optimizes their effectiveness. The silver bullets may be out there, but they are still in a roughly molded stage. They must be finished, loaded in an appropriate epidemiological gun, and fired by an expert at specific targets.