BBG enhances OLT1177-induced NLRP3 inflammasome inactivation by targeting P2X7R/NLRP3 and MyD88/NF-κB signaling in DSS-induced colitis in rats

Chronic ulceration of the colon is associated with the activation of TLR4/NF-κB and P2X7R/NLRP3 signaling pathways. We investigated the effect of individual or combined administration of BBG, a P2X7R blocker, and OLT1177, a selective NLRP3 inhibitor, in the dextran sodium sulfate-induced ulcerative colitis (UC) rat model. The ulcerative rats were treated orally with brilliant blue G (BBG) (50 mg/kg/day) or OLT1177 (200 mg/kg/day) or a combination of both. Myd88 and NF-κB levels were measured by ELISA, qRT-PCR, and immunohistochemical staining. Cytokines known to be associated with TLR4/NF-κB or P2X7R/NLRP3 signaling were measured by ELISA. P2X7R and NLRP3 expression were measured by ELISA and qRT-PCR. The administration of BBG or OLT1177 ameliorated the toxic effects of DSS on the colon as they restored normal colonic macroscopic and microscopic morphology. BBG administration, but not OLT1177, reduced the expression of Myd88, NF-κB, IL-6, and TNF-α in addition to lowering P2X7R and oxidative stress levels. Individual BBG or OLT1177 administration decreased NLRP3 inflammasome recruitment and subsequent activation of caspase-1, IL-1β, and IL-18. However, the combined administration of OLT1177 with BBG potentiated its inhibitory effect on the NLRP3, which was reflected by the additional suppressive effect on caspase-1, IL-1β, IL-18 levels. In conclusion, BBG/OLT1177 exhibited complementary effects and effectively ameliorated UC. This novel approach provides a basis for the clinical application of this combination for the treatment of IBDs and might also be promising for the pharmacological intervention of other NLRP3 inflammasome-dependent inflammatory conditions.

Response of osteogenic sarcoma to the combination of etoposide and cyclophosphamide as neoadjuvant chemotherapy

A Phase II study of the combination of etoposide (VP-16) and cyclophosphamide (CPM) was conducted in an attempt to identify active and potentially less toxic agents for treating patients with osteogenic sarcoma (OS). VP-16 was given as a 72-hour infusion for a total dose of 600 mg/m2. CPM was given as six pulses of 300 mg/m2 every 12 hours for a total dose of 1800 mg/m2. Seventeen newly diagnosed patients, including five (29%) with metastatic disease, were evaluated before and after two courses of VP-16 and CPM for clinical, radiologic, and biochemical (serum alkaline phosphatase [SAP]) responses of the primary tumor and metastases. Fifteen (88%) patients achieved complete or partial clinical responses. Fourteen (82%) patients achieved radiologic responses. Thirteen (87%) of 15 patients with higher than normal SAP levels for their age showed partial or complete responses. Three (60%) of the five patients with metastatic disease achieved complete or partial responses. The only major toxicity was myelosuppression, which led to 21 (62%) brief admissions after 34 courses of chemotherapy for intravenous antibiotic therapy for fever and neutropenia, without associated mortality. It was concluded that the combination of VP-16 and CPM is effective chemotherapy for both primary and metastatic OS. Although myelosuppression is inevitable, it is rapidly reversible in the drug dosages used. Further studies are needed to evaluate the effect of these drugs in combination with established agents in improving the disease-free survival of patients with OS.

Severe hyperphosphatemia associated with tumor lysis in a patient with T-cell leukemia

Hyperphosphatemia is an infrequent complication of the tumor lysis following induction therapy for lymphoproliferative disorders that can result in acute renal failure. We report a case of severe hyperphosphatemia resulting in transient acute renal failure corrected rapidly by hemodialysis.

Metastatic retinoblastoma successfully treated with immunomagnetic purged autologous bone marrow transplantation

There are no documented cases of long-term, disease-free survival in retinoblastoma (RB) metastatic to the bone marrow. The following study details successful outcome in a 3-year-old child with extensive marrow replacement 7 months postenucleation in an otherwise untreated group V RB. Therapy consisted of combinations of vincristine, doxorubicin, and cyclophosphamide for 3 months. After demonstrating cross-reactivity by a panel of six monoclonal neuroblastoma (NB) antibodies with the patient's RB cells, her marrow was purged by using microsphere-linked monoclonal antibodies, and then reinfused as rescue therapy after ablative doses of etoposide and cyclophosphamide. The authors conclude that short-term induction therapy followed by marrow ablative combination chemotherapy and immunomagnetically purged autologous marrow rescue can (1) effect successful outcome in widely metastatic RB, and (2) eliminate the risk of therapy-induced second malignancies.

Distal embolisation from the surface of PTFE grafts in vivo and the effect of low molecular weight dextran

Platelet deposition onto the surface of biomaterial is an important component of the interaction between blood and a synthetic arterial graft. Once platelet deposition has occurred, the possibility of distal embolisation exists. Using PTFE interposition femoral grafts and Indium-III-levelled autologous platelets in 16 adult sheep we have studied platelet uptake onto the graft surface using a gamma camera. Radioactivity in the legs was measured by a miniature cadmium-Telluride counter and blood flow was simultaneously recorded. In 8 animals low molecular weight dextran (LMWD) was infused intravenously. It was found that platelet deposition onto PTFE grafts was significantly lower in the LMWD treated group than in controls (P less than 0.001). These differences were confirmed by histological examination and in vitro measurement of graft activity. Furthermore, distal embolisation was frequently seen in both groups with a simultaneous drop in graft activity seen in both groups with a simultaneous drop in graft activity with an increased activity in the peripheral circulation. This distal embolisation was less pronounced in the LMWD treated group.