No evidence for increased production of nitric oxide in C57BL/6J mice infected with Echinococcus multilocularis

The Effects of Nitric Oxide and Inhibitor, and Combination of Albendazole and Praziquantel On Liver in Mice Injected with Echinococcus granulosus Larvae

In this study, the role of nitric oxide (NO) in the pathogenesis of hydatidosis and the interaction with effects of anthelmintic drugs, albendazole and praziquantel, were examined in larval infection caused by protoscolices obtained from hydatid cysts of sheep liver in Albino Balb/c mice. Animals were divided into ten groups including controls and infected groups. Larval infection was established with intraperitoneal injection of protoscolices. Eight months after infection with protoscolices, the infected animals were divided into 6 groups. The infected animals were given a selective inhibitor of inducible nitric oxide synthase (iNOS) L-N⁶-(1-Iminoethyl) lysine-hydrochloride (L-NIL), NO donor sodium nitroprusside (SNP), albendazole and praziquantel as anthelmintic drugs for 7 days. In addition, control groups were composed of intact group, control, anthelmintic drugs + L-NIL, and anthelmintic drugs + SNP. The liver and blood samples were taken for cytological, histological, immunohistochemical and biochemical analyses 7 days after treatments at the end of experiment. The animals injected with protoscolices showed histopathological changes including inflammation areas, infiltration and accumulation of leukocytes, dilation of sinusoids, and damage in endothelial cells and hepatocytes at light microscopy. Electron microscopy were revealed severe damage in sinusoidal endothelial cells, leukocytes especially eosinophils in sinusoid lumens and disorganization in endoplasmic reticulum and nuclear membrane. Endothelial nitric oxide synthase (eNOS) and iNOS reactions were increased in the tissue. Anthelmintic drugs decreased inflammation areas and damages; however, it did not change NOS reactions in the animals given protoscolices. L-NIL and SNP diminished both iNOS and eNOS reactions. Unlike the group administered the inhibitor, SNP treated group exhibited less inflammation areas. Combination of these substances and drugs resulted in decreased inflammation areas. eNOS and iNOS reactions decreased in the drugs and SNP administered group, while only iNOS reaction was decreased in L-NIL given infection group. In addition, the infected groups which received SNP displayed expanded sinusoids and hepatocytes with vacuoles, intriguingly. While levels of serum nitrite/nitrate elevated only in the infection group given drugs and SNP, it decreased in the L-NIL administered group. Tissue level of malondialdehyde increased in infection groups with drugs and SNP. In conclusion, the results indicated that NO plays an important role in the pathogenesis of hydatidosis.

Comparison of Intravoxel Incoherent Motion Diffusion-Weighted Magnetic Resonance (MR) Imaging to T1 Mapping in Characterization of Hepatic Alveolar Echinococcosis

BACKGROUND The aim of this study was to compare intravoxel incoherent motion diffusion-weighted magnetic resonance imaging (IVIM DW MRI) to T1 mapping for characterization of hepatic alveolar echinococcosis (HAE). MATERIAL AND METHODS Eighteen HAE patients confirmed by surgery were examined with conventional MRI, IVIM DWI MRI with 10 b values (range: 0-1,000 sec/mm²), and longitudinal relaxation time (T1) mapping. Diffusion coefficient (D), perfusion fraction (f), pseudo-diffusion coefficient (D*), and T1 relaxation time were calculated in solid components, perilesional components, and background liver parenchyma of HAE patients. The correlation between T1 relaxation time and IVIM-derived parameters was assessed by using the Pearson correlation test. RESULTS T1 relaxation times were significantly higher in solid components (820.58±331.24 ms) compared to background components (551.52±182.93 ms) of HAE patients (p<0.05). IVIM-derived D values were significantly higher in solid components (1.30±0.28×10^-3 mm²/sec) compared to perilesional components (0.88±0.28×10^-3 mm²/sec) and background liver parenchyma (0.97±0.27×10^-3 mm²/sec) of liver parenchyma. There were significant differences in f values between solid components (13.70±7.66%), perilesional components (23.59±10.73%) and background liver parenchyma (30.78±10.18%). IVIM derived D* values were significantly lower in solid components (14.32±10.85×10^-3 mm²/sec) than in background liver parenchyma (30.06±15.68×10^-3 mm²/sec). Importantly, IVIM-derived f values were significantly correlated with T1 relaxation time: r=-0.337 (p<0.05). CONCLUSIONS Based on our image comparison, IVIM DWI MRI might be better than T1 mapping, and IVIM-derived f values might be a valuable index for characterization of HAE.

Cytokine gene expression in peripheral blood mononuclear cells (PBMC) from patients with pharmacologically treated cystic echinococcosis

The influence of pharmacological treatment on the immune response of patients with Echinococcus granulosus infection was evaluated by reverse transcriptase-polymerase chain reaction (RT-PCR) to determine mRNA expression for IL-12 p35, IL-12 p40, interferon-gamma (IFN-gamma), tumour necrosis factor-alpha (TNF-alpha) and IL-4 in PBMC from 12 patients before and after chemotherapy and from seven uninfected controls. Most patients' PBMC showed measurable amounts of IL-12 p35, IL-4, IFN-gamma and TNF-alpha mRNA in parasite antigen-stimulated and unstimulated cultures. Conversely, IL-12 p40 mRNA was detected almost exclusively in successfully treated patients (86%) after therapy. In these patients semiquantitative analysis of RT-PCR products showed a significant difference between IL-12 p40 mRNA mean levels before and after therapy (P = 0.03 in parasite antigen-stimulated cultures; P = 0.001 in unstimulated cultures). IL-4 mRNA was weakly expressed before therapy and more highly so after treatment in both groups of patients and under both culture conditions; IL-4 mRNA reached its highest level in post-therapy PBMC from patients in whom therapy failed (stimulated cultures). IFN-gamma and TNF-alpha mRNA expression increased in patients who responded to therapy and decreased in patients who did not. In contrast to IL-12 p35, IFN-gamma and TNF-alpha mRNAs, IL-12 p40 and IL-4 mRNAs were detected exclusively in patients, suggesting a close relationship between these two cytokines and cystic echinococcosis. Our findings indicate that chemotherapy influences the immune response, thus determining changes in Th1/Th2 cytokine mRNA patterns, predominantly in IL-12 p40 and IL-4 mRNA expression.