Evaluation of the inhibitory effects and the mechanism of terpenoids on Toxoplasma gondii tachyzoites.

BACKGROUND: Currently, symptomatic toxoplasmosis is treated with a combination of sulfadiazine and pyrimethamine. However, significant adverse effects and drug resistance have been reported. Terpenoids are widely found in nature, with numerous studies demonstrating that they have effective inhibitory effects on a variety of parasites. METHODS: In this study, we employed intermediates or derivatives of lindenane sesquiterpenoids to evaluate their intracellular and extracellular inhibitory effects on Toxoplasma gondii tachyzoites and their cytotoxicity on macrophages. RESULTS: We demonstrated that two of these target terpenoids could effectively reduce the number of extracellular tachyzoites, probably by inducing tachyzoite apoptosis through altering tachyzoites mitochondrial membrane potential and calcium homeostasis. In addition, the two target terpenoids were able to promote intracellular tachyzoites elimination, possibly by enhancing macrophage activities. CONCLUSIONS: Two derivatives of lindenane sesquiterpenoids with low cytotoxicity to macrophages demonstrated direct and indirect antitoxoplasma effects.

Clinical significance of sphingosine kinase-1 expression in human astrocytomas progression and overall patient survival.

PURPOSE: To characterize the expression of sphingosine kinase-1 (SPHK1) in human astrocytomas and to investigate the association between SPHK1 expression and progression of astrocytomas. EXPERIMENTAL DESIGN: The expression of SPHK1 in normal human astrocytes, astrocytoma cell lines, and four pairs of matched astrocytoma tissues and their adjacent normal brain tissues were detected by quantitative reverse transcription-PCR and Western blot. In addition, SPHK1 protein expression was examined in 243 cases of histologically characterized astrocytomas by immunohistochemistry. Statistical analyses were applied to test for prognostic and diagnostic associations. RESULTS: SPHK1 in astrocytoma cell lines was elevated at both mRNA and protein levels, and the SPHK1 mRNA and protein were significantly up-regulated by up to 6.8- and 40-fold, respectively, in primary astrocytomas compared with those in the adjacent noncancerous brain tissues. Immunohistochemical analysis showed that 100 of 243 (41.2%) paraffin-embedded archival astrocytoma biopsies exhibited high expression of SPHK1. Statistical analysis suggested that the up-regulation of SPHK1 was significantly correlated with the histologic grade of astrocytoma (P=0.000) and that patients with high SPHK1 level exhibited shorter survival time (P<0.001). Multivariate analysis revealed that SPHK1 up-regulation might be an independent prognostic indicator for the survival of patients with astrocytoma. CONCLUSIONS: SPHK1 might represent a novel and useful prognostic marker for astrocytoma and play a role during the development and progression of the disease.

Therapeutic embolization of meningiomas with Onyx for delayed surgical resection.

BACKGROUND: Liquid embolic agents can achieve penetration of capillaries in tumors and thus may be even more effective at creating tumor necrosis than small particles. This study assesses the safety and efficacy of preoperative embolization of meningiomas with Onyx liquid embolic agent (Micro Therapeutics, Inc, Irvine, Calif) for delayed surgical resection. METHODS: Three cases of hypervascular intracranial meningiomas were treated by preoperative embolization with Onyx embolic agent using superselective catheterization of the feeding arteries from the ECA and the reflux-hold-reinjection technique. RESULTS: Meningiomas were devascularized successfully, and these patients did not present the symptoms of postembolization tumor swelling or hemorrhage before complete resection of the tumors 10 days later. Massive tumor necrosis was observed in all 3 cases of pathologic specimens, and shrinkage of tumor was seen by MRI as early as 8 days in 1 case. All patients had no recurrence of tumor at 12-month follow-up. CONCLUSION: Preoperative embolization with Onyx may be a useful tool for treatment of meningiomas. Palliative embolization treatment of nonresectable hypervascular intracranial tumors with Onyx warrants future clinical investigation.

[Study on inhibitory effect of arsenic trioxide on growth of rat C6 glioma cells].

OBJECTIVE: To explore the inhibitory effect of arsenic trioxide (A(s2)O3) on the growth of rat C6 glioma cells (C6 cells) as well as finding out the feasibility of using As2O3 as chemotherapy of gliomas. METHOD: C6 cells were treated by different dose of As2O3 (1, 2, 4, 6 and 8 micromol L(-1)). MTT assay and staining for PCNA were used for cell proliferation. Cell apoptosis was determined by TUNEL method and Bcl-2 expression was studied by Western blot. Parental rat C6 cells (5 x 10(5)/15 microL) were implanted into right caudate nucleus of male SD rats as control group. Rats bearing cerebral C6 gliomas as treated group were treated with 1 mmol x L(-1) As2O3. The general manifestation, survival time, MRI dynamic scanning and histopathological changes of all rats were observed. RESULT: All the treated cells showed decreased proliferation in vitro as detected by MTT method (P < 0.01) and staining for PCNA. In situ labeling apoptotic DNA fragment of the treated cells demonatrated that the cell apoptosis significantly increased following treatment with As2O3 (P < 0.01). Western blot showed that the expression of Bcl-2 protein was decreased. All rats in control group died of cerebral gliomas within 3 weeks after implantation of C6 cells (17.8 +/- 0.92) d. Eight out of 10 rats in treated group died within 24-36 days (32.1 +/- 1.35) d and other 2 ones kept alive beyond 120 days with one treated rat being totally disappear of the tumor foci and another having a little residue of tumor. CONCLUSION: The result demonstrates the potential efficacy of As2O3 in the treatment of gliomas. It also suggests that As2O3 may be a good candidate for chemotherapy of human gliomas.

An in vitro culturing model for rabbit dural cells.

The objectives of this study were (a) to construct an in vitro model of rabbit dural healing, (b) to test the influence of collagen, laminin, and poly-L-lysine on the migration and proliferation of dural cells, and (c) to study the healing mechanism of duraplasty. Rabbit dural pieces (1.5 cm x 1.5 cm) were perforated in their central part with a 2 mm punch to mimic a dural defect. The dural pieces were cultured in 24-well plates that had been coated with collagen, laminin, or poly-L-lysine, and the influence of different extracellular matrices on migration and proliferation of dural cells was observed. Cells were subcultured on slides for immunocytochemistry to study their characteristics; dural healing was observed by scanning electron microscopy. The results demonstrated that only the dural pieces that were cultured on collagen-coated wells showed migration of cells into the central defect after a period of 8 to 10 days and that healing of the dural defect occurred by 13 to 15 days. The cultured dural cells stained strongly positive with an antibody to vimentin, but negative with an antibody to factor VIII. New collagen fibers were observed in the dural defects. This report demonstrates that an in vitro model for dural healing was successfully constructed in collagen-coated wells; the results implicate cellular migration of fibroblasts from the dural defect margin as an important mechanism of wound healing following duraplasty.

Umbilical cord-derived mesenchymal stem cells with forced expression of hepatocyte growth factor enhance remyelination and functional recovery in a rat intracerebral hemorrhage model.

BACKGROUND: Spontaneous intracerebral hemorrhage (ICH) carries a high mortality rate, with survivors commonly left with permanent neurological deficits. Mesenchymal stem cell (MSC) transplantation promotes functional recovery in experimental ICH, and treatment with hepatocyte growth factor (HGF) is beneficial in ischemic stroke. OBJECTIVE: We hypothesize that transplantation of MSCs with previous transduction of HGF has an additive effect in promoting neurological recovery through myelin and axonal regeneration. METHODS: HGF transduction to human umbilical cord-derived MSCs using lentiviral plasmid pWPI-HGF-GFP was prepared. One week after a collagenase-induced ICH, 80 male Sprague-Dawley rats were divided into 3 groups for stereotactic injection of phosphate-buffered saline (group I), MSC transplant (group II), and HGF-transduced MSC transplant (group III), respectively, into the left ventricle. The animals were assessed weekly for 5 weeks using the Rotarod motor function test, at which time they were killed for Luxol fast blue myelin staining and appropriate immunohistochemistry and Western blotting. RESULTS: Animals receiving transplanted HGF-transduced MSCs (group III) exhibited significantly better motor function recovery than animals treated with MSCs alone (group II), which in turn performed better than the phosphate-buffered saline controls at 2 weeks after transplantation. Luxol fast blue staining of myelin displayed significantly less demyelination and significantly higher reactivity in myelin basic protein and growth-associated protein-43 in immunohistochemistry and Western blotting and significantly reduced myelin-associated glycoprotein activity in group III animals. CONCLUSION: Animals transplanted with HGF-transduced MSCs 1 week after experimental ICH were shown to achieve a better neurological recovery. This improved neurological recovery from ICH is attributed to nerve fiber remyelination and axonal regeneration.

Combined covered stent and onyx treatment for complex dural arteriovenous fistula involving the clivus and cavernous sinus.

BACKGROUND: Complex DAVFs involving both the clivus and cavernous sinus are rare, especially when associated with brainstem compression from a large varix. In this report, we describe the use of a covered stent in combination with a liquid embolic agent to cure a complex clival-cavernous DAVF. METHODS: A 46-year-old man presented with 6 months of dizziness, dysphagia, and progressive dysarthria. Magnetic resonance imaging showed tortuous and enlarged right cavernous and preclival flow voids. There were also bilateral prepontine varices compressing the ventral pons, which led to marked dorsal pontine edema. A cerebral angiogram revealed a clival DAVF supplied by multiple branches of the right ECA, as well as the MHT of the right ICA. RESULTS: An endovascular cure was achieved by deploying a covered stent in the right cavernous ICA, followed by transarterial embolization of the feeding arteries originating from the ECA with Onyx (ev3, Irvine, Calif). This combined approach resulted in complete occlusion of the fistula. His 1-month follow-up angiogram confirmed persistent occlusion of the fistula and preserved patency of the right ICA. The patient made a full recovery without any new symptoms, and he remained neurologically intact at 18-month follow-up. CONCLUSION: The combined technique of covered stent placement and Onyx transarterial embolization is valuable for the management of complex DAVFs supplied by branches of both the external and internal carotid arteries.

[Therapeutic effect of embolization of brain arteriovenous malformation with non-adhesive liquid embolic agent].

OBJECTIVE: To observe the clinical and pathological characteristics of brain arteriovenous malformations (BAVM) embolized with the non-adhesive aqueous embolic agent Onyx and evaluate its application in comprehensive treatment of BAVM. METHODS: Thirty-four patients underwent BAVM embolization using Onyx, and their clinical manifestations, architecture of the malformed vessels, emblization procedure, and complications associated with the procedures were recorded. The resected tissues after embolization with Onyx were observed with electron microscope, and the prognosis of the patients was estimated with modified Rankin Score (mRS). RESULTS: These patients included 21 male and 13 female patients with a mean age of 30.45-/+11.81 years and an estimated mean size of the nidus of 3.98-/+1.43 cm. The patients received a total of 52 endovascular treatment procedures with Onyx to embolize 86 feeding pedicals, which resulted in an average estimated size reduction of the nidus of (72.35-/+21.26)%. Complications associated with the procedure occurred in 7 patients, and 23 patients received surgical resection or radiosurgery after embolization. Follow-up of the patients for 6 months to 4 years showed that the mRS was below 3 in 32 cases and > or =3 in 2 cases. Vasodilatation, brain tissue edema surrounding the nidus, and inflammatory cell infiltration were observed in the resected tissues after embolization. In some major feeding pedicals, thrombus recanalization was observed after embolization with Onyx (diameter> or =3 mm). CONCLUSION: Endovascular treatment of BAVM with Onyx can achieve high occlusion rate, enhance the safety of operation and radiosurgery, and improve the clinical prognosis of the patients.