RESUMEN
Translational diffusion coefficients of carbon monoxide (CO), diphenylacetylene (DPA), and diphenylcyclopropenone (DPCP) were determined in mixtures of 1-butyl-3-methylimidazolium tetrafluoroborate ([C4mim]BF4) and water using transient grating spectroscopy at different mole fractions of water (xw). While DPA exhibited a larger diffusion coefficient than DPCP at low water mole fractions (xw < 0.7), as observed for conventional liquids and ionic liquids (ILs), it was smaller at high mole fractions (xw > 0.9). The apparent molecular radius of DPA determined using the Stokes-Einstein equation at xw > 0.9 is close to the radius of an IL cluster in a water pool as determined from small-angle neutron scattering experiments (J. Bowers et al., Langmuir, 2004, 20, 2192-2198), suggesting that the DPA molecules are trapped in IL clusters in the water pool and move together. The solvation state of DPCP in the mixture was studied using Raman spectroscopy. Dramatically strong water/DPCP hydrogen bonding was observed at higher water mole fractions, suggesting that DPCP is located near the cluster interfaces. The large diffusion coefficient of DPCP suggests that hopping of DPCP between IL clusters occurs through hydrogen bonding with water.
RESUMEN
Three hundred and forty-nine autopsy cases of schistosomiasis japonica were divided into two groups, based on the pathomorphology. Frequent regressive hepatic lesions such as active schistosomal lesion and destruction of limiting plates characterized the first group. The second group showed reparative hepatic lesions such as regeneration of the collapsed parenchyma, newly formed limiting plates and subsequent narrowing and disappearance of fibrous septa. Complications of liver cirrhosis and hepatocellular carcinoma related to viral hepatitis B and/or C also increased. Clonorchiasis was consistently found in both groups.
Asunto(s)
Esquistosomiasis Japónica/patología , Animales , Autopsia , Humanos , Japón/epidemiología , Hígado/parasitología , Hígado/patología , Schistosoma japonicum/aislamiento & purificación , Esquistosomiasis Japónica/sangre , Esquistosomiasis Japónica/epidemiologíaRESUMEN
The formation of granulomas in host tissues in response to trapped Schistosoma japonicum eggs is central to the etiology of schistosomiasis. However, analysis of the host hypersensitivity reactions that result in granuloma formation, in schistosome infection, is not without difficulty. This is due, in part, to the fact that the parasites continuously deposit their eggs as clusters. In order to synchronize host reactions, we established an experimental model of hepatic granuloma formation whereby in vitro laid schistosome eggs are implanted directly into normal and cytokine-deficient mice livers. This model, validated by comparison with an infection model, was used to analyze cytokine regulation of granuloma formation around S. japonicum eggs. Combined models of implantation and cercarial infection were also studied. With special reference to IL-4, IL-13, IFN-gamma and IL-18, our in vitro schistosome egg implantation model has shed new light on the roles of cytokines in both the acute and chronic stages of schistosome egg-induced granuloma formation.
Asunto(s)
Citocinas/fisiología , Granuloma/parasitología , Schistosoma japonicum/inmunología , Esquistosomiasis Japónica/inmunología , Animales , Modelos Animales de Enfermedad , Femenino , Interleucina-13/fisiología , Interleucina-4/fisiología , Ovulación , Óvulo , Schistosoma japonicum/fisiologíaRESUMEN
The present study was designed to investigate the role of neutrophils during the development of Schistosoma japonicum egg granulomas, in C57BL/6 and CBA mice. Laid eggs were implanted into the liver and monoclonal antibody, RB6-8C5, was used to eliminate neutrophils. After daily antibody treatment between days 9 and 13 of egg implantation, both strains of mice showed a marked decrease in neutrophil infiltration and coagulative hepatocyte necrosis at 2 weeks. At 4 weeks, after antibody administration every other day between days 16 and 26, granuloma formation in C57BL/6 mice was not affected by the treatment, whereas CBA mice exhibited a significant increase of reactions. Neutropenia augmented the Th2 cytokine response (IL-4, IL-13 and IL-5), but not for IFN-gamma at any time point examined and in either strain of mice. Higher levels of IL-4 and IL-13 were noted in CBA mice at early and late stages of granuloma formation, compared to C57BL/6 mice. There was also a striking difference in IL-13 production between the two strains. Our results indicate that neutropenia is associated with a significant augmentation of S. japonicum egg-induced granuloma formation in CBA mice, probably through increase in Th2 cytokines, however, the effects differ between early and late stages and between high and low responders.