Direct and indirect antiparasitic effects of chloroquine against the virulent RH strain of Toxoplasma gondii: An experimental study.

BACKGROUND: Toxoplasmosis is a deleterious parasitic disease with harmful impact on both humans and animals. The present study was carried out to evaluate the antiparasitic effect of chloroquine (CQ), spiramycin (SP), and combination of both against the highly virulent RH HXGPRT (-) strain of Toxoplasma gondii (T. gondii) and to explore the mechanisms underlying such effect. METHODS: We counted the tachyzoites in the peritoneal fluid and liver smears of mice and performed scanning and transmission electron microscopy and immunofluorescence staining of tachyzoites. Moreover, relative caspase 3 gene expression was measured by real time polymerase chain reaction of liver tissues and immunoassay of anti-apoptotic markers [B cell lymphoma-2 (Bcl-2) and X-chromosome linked inhibitor of apoptosis (XIAP)] and interferon gamma (IFN-γ) was done in liver tissues by ELISA. In addition, we estimated serum levels of aspartate transaminase (AST) and alanine transaminase (ALT) and performed histopathological examination of liver sections for scoring of inflammation. RESULTS: We found that both CQ and CQ/SP combination significantly reduced parasitic load in the peritoneal fluid and liver smears, induced apical disruption of tachyzoites, triggered host cell apoptosis through elevation of relative caspase 3 gene expression and suppression of both Bcl-2 and XIAP. Also, they upregulated IFN-γ level, reduced serum AST and ALT, and ameliorated liver inflammation. CONCLUSIONS: Either of CQ and CQ/SP combination was more effective than SP alone against T. gondii with the CQ/SP combination being more efficient. Therefore, adding CQ to other anti-Toxoplasma therapeutic regimens may be considered in future research.

Impact of CD105 Flow-Cytometric Expression on Childhood B-Acute Lymphoblastic Leukemia.

BACKGROUND: CD105 (Endoglin) is a receptor of the transforming growth factor-Beta (TGF- ß) superfamily. It is expressed in angiogenic endothelial cells and is considered a powerful marker of angiogenesis and a potential main player in the pathogenesis of vascular diseases as well as tumor progression. CD105 expression was correlated with poor prognosis in many types of solid malignancies, however, its influence on hematological neoplasms is still an area of interest. PURPOSE: To assess the flow-cytometric expression of CD105 in childhood B-acute lymphoblastic leukemia (B-ALL) and its relation to disease response after the induction chemotherapy. SUBJECTS AND METHODS: Eighty children newly diagnosed with B-ALL were screened for flow-cytometric expression of CD105 at time of diagnosis, then they were followed up to detect their response to induction therapy. RESULTS: CD105 was expressed in 41.2% of B-ALL patients. Higher expression of CD105 was observed in high and very high-risk groups. The multivariate analysis considered CD105 positivity as an independent prognostic marker for response to induction therapy. Values higher than 2.5 Specific fluorescence indices (SFIs) and 35% expression were sensitive predictors to induction failure. CONCLUSION: CD105 can be considered as a potential prognostic marker for the detection of response to induction therapy in childhood B-ALL, and it can serve to optimize treatment decisions.