Clarisse Djukom

Beneficial effect of a hydrogen sulphide donor (sodium sulphide) in an ovine model of burn- and smoke-induced acute lung injury

Background and purpose:  The present study investigated whether the pathophysiological changes induced by burn and smoke inhalation are modulated by parenteral administration of Na2S, a H2S donor.

Implementation of a Critical Pathway for Complicated Gallstone Disease: Translation of Population-Based Data into Clinical Practice

BACKGROUND Evidence-based guidelines recommend cholecystectomy during initial hospitalization for complicated gallstone disease. Previous studies and quality initiative data from our institution demonstrated that only 40% to 75% of patients underwent cholecystectomy on index admission. STUDY DESIGN In January 2009, we implemented a critical pathway to improve cholecystectomy rates for all patients emergently admitted for acute cholecystitis, mild gallstone pancreatitis, or common bile duct stones. We compared cholecystectomy rates during initial hospitalization, time to cholecystectomy, length of initial stay, and readmission rates in prepathway (January 2005 to February 2008) and postpathway patients (January 2009 to May 2010). RESULTS Demographic and clinical characteristics were similar between prepathway (n = 455) and postpathway patients (n = 112). Cholecystectomy rates during initial hospitalization increased from 48% to 78% after pathway implementation (p < 0.0001). There were no differences in operative mortality or operative complications between the 2 groups. For patients undergoing cholecystectomy on initial hospitalization, the mean length of stay decreased after pathway implementation (7.1 days to 4.5 days; p < 0.0001), primarily due to a decrease in the time from admission to cholecystectomy (4.1 days to 2.1 days; p < 0.0001). Thirty-three percent of prepathway and 10% of postpathway patients required readmission for gallstone-related problems or operative complications (p < 0.0001), and each readmission generated an average of

CD133+ colon cancer cells are more interactive with the tumor microenvironment than CD133− cells

19,000 in additional charges. CONCLUSIONS Implementation of a multidisciplinary critical pathway improved cholecystectomy rates on initial hospitalization and lowered costs by shortening length of stay and markedly decreasing readmission rates for gallstone-related problems. Broader implementation of similar pathways offers the potential to translate evidence-based guidelines into clinical practice and minimize the cost of medical care.

THE CD133-POSITIVE COLON CANCER CELL PHENOTYPE IS MORE INTERACTIVE WITH THE TUMOR MICROENVIRONMENT COMPARED TO CD133-NEGATIVE CELL

Experimental data indicate that colorectal cancer cells with CD133 expression exhibit enhanced tumorigenicity over CD133-negative (CD133−) cells. We hypothesized that CD133-positive (CD133+) cells, compared with CD133−, are more tumorigenic because they are more interactive with and responsive to their stromal microenvironment. Freshly dissected and dissociated cells from a primary colon cancer were separated into carcinoma-associated fibroblasts (CAF) and the epithelial cells; the latter were further separated into CD133+ and CD133− cells using fluorescence-activated cell sorter. The CD133+ cells formed large tumors in non-obese diabetic-severe combined immunodeficient (NOD-SCID) mice, demonstrating the phenotypic cellular diversity of the original tumor, whereas CD133− cells were unable to sustain significant growth. Affymetrix gene array analyses using t-test, fold-change and multiple test correction identified candidate genes that were differentially expressed between the CD133+ vs CD133− cells. RT-PCR verified differences in expression for 30 of the 46 genes selected. Genes upregulated (+ vs – cells) included CD133 (9.3-fold) and CXCR4 (4-fold), integrin β8 and fibroblast growth factor receptor 2. The CAF highly express the respective ligands: stromal-derived factor-1 (SDF-1), vitronectin and FGF family members, suggesting a reciprocal relationship between the CD133+ and CAF cells. SDF-1 caused an increase in intracellular calcium in cells expressing both CD133 and CXCR4, confirming functional CXCR4. The CD133+/CXCR4+ phenotype is increased to 32% when the cells are grown in suspension compared with only 9% when the cells were allowed to attach. In Matrigel 3-D culture, the CD133+/CXCR4+ group treated with SDF-1 grew more colonies compared with vehicle, as well as significantly larger colony sizes of tumor spheres. These data demonstrate proof of principle that the enhanced tumorigenic potential of CD133+, compared with CD133−, cells is due to their increased ability to interact with their neighboring CAF.Experimental data indicate that colorectal cancer cells with CD133 expression exhibit enhanced tumorigenicity over CD133− cells. We hypothesized that CD133+ cells, compared to CD133−, are more tumorigenic because they are more interactive with and responsive to their stromal microenvironment. Freshly dissected and dissociated cells from a primary colon cancer were separated into carcinoma –associated fibroblasts (CAF) and the epithelial cells; the latter were further separated into CD133+ and – cells using FACS. The CD133+ cells formed large tumors in NOD-SCID mice, demonstrating the phenotypic cellular diversity of the original tumor, whereas CD133− cells were unable to sustain significant growth. Affymetrix gene array analyses using t-test, fold-change, and multiple test correction identified candidate genes that were differentially expressed between the CD133+ vs. − cells. RT PCR verified differences in expression for 30 of the 46 genes selected. Genes upregulated (+ vs − cells) included CD133 (9.3-fold) and CXCR4 (4-fold), integrin β8 and fibroblast growth factor receptor 2 (FGFR2). The CAF highly express the respective ligands: SDF-1, vitronectin, and FGF family members, suggesting a reciprocal relationship between the CD133+ and CAF cells. SDF-1 caused an increase in [Ca2+]I in cells expressing both CD133 and CXCR4, confirming functional CXCR4. The CD133+/CXCR4+ phenotype is increased to 32% when the cells are grown in suspension, compared to only 9% when the cells were allowed to attach. In Matrigel 3-D culture, the CD133+/CXCR4+ group treated with SDF-1 grew both more colonies compared to vehicle as well as significantly larger colony sizes of tumor spheres. These data demonstrate proof of principle that the enhanced tumorigenic potential of CD133+, compared to CD133−, cells is due to their increased ability to interact with their neighboring CAF.

Pulmonary vascular permeability changes in an ovine model of methicillin-resistant Staphylococcus aureus sepsis

Experimental data indicate that colorectal cancer cells with CD133 expression exhibit enhanced tumorigenicity over CD133-negative (CD133−) cells. We hypothesized that CD133-positive (CD133+) cells, compared with CD133−, are more tumorigenic because they are more interactive with and responsive to their stromal microenvironment. Freshly dissected and dissociated cells from a primary colon cancer were separated into carcinoma-associated fibroblasts (CAF) and the epithelial cells; the latter were further separated into CD133+ and CD133− cells using fluorescence-activated cell sorter. The CD133+ cells formed large tumors in non-obese diabetic-severe combined immunodeficient (NOD-SCID) mice, demonstrating the phenotypic cellular diversity of the original tumor, whereas CD133− cells were unable to sustain significant growth. Affymetrix gene array analyses using t-test, fold-change and multiple test correction identified candidate genes that were differentially expressed between the CD133+ vs CD133− cells. RT-PCR verified differences in expression for 30 of the 46 genes selected. Genes upregulated (+ vs – cells) included CD133 (9.3-fold) and CXCR4 (4-fold), integrin β8 and fibroblast growth factor receptor 2. The CAF highly express the respective ligands: stromal-derived factor-1 (SDF-1), vitronectin and FGF family members, suggesting a reciprocal relationship between the CD133+ and CAF cells. SDF-1 caused an increase in intracellular calcium in cells expressing both CD133 and CXCR4, confirming functional CXCR4. The CD133+/CXCR4+ phenotype is increased to 32% when the cells are grown in suspension compared with only 9% when the cells were allowed to attach. In Matrigel 3-D culture, the CD133+/CXCR4+ group treated with SDF-1 grew more colonies compared with vehicle, as well as significantly larger colony sizes of tumor spheres. These data demonstrate proof of principle that the enhanced tumorigenic potential of CD133+, compared with CD133−, cells is due to their increased ability to interact with their neighboring CAF.Experimental data indicate that colorectal cancer cells with CD133 expression exhibit enhanced tumorigenicity over CD133− cells. We hypothesized that CD133+ cells, compared to CD133−, are more tumorigenic because they are more interactive with and responsive to their stromal microenvironment. Freshly dissected and dissociated cells from a primary colon cancer were separated into carcinoma –associated fibroblasts (CAF) and the epithelial cells; the latter were further separated into CD133+ and – cells using FACS. The CD133+ cells formed large tumors in NOD-SCID mice, demonstrating the phenotypic cellular diversity of the original tumor, whereas CD133− cells were unable to sustain significant growth. Affymetrix gene array analyses using t-test, fold-change, and multiple test correction identified candidate genes that were differentially expressed between the CD133+ vs. − cells. RT PCR verified differences in expression for 30 of the 46 genes selected. Genes upregulated (+ vs − cells) included CD133 (9.3-fold) and CXCR4 (4-fold), integrin β8 and fibroblast growth factor receptor 2 (FGFR2). The CAF highly express the respective ligands: SDF-1, vitronectin, and FGF family members, suggesting a reciprocal relationship between the CD133+ and CAF cells. SDF-1 caused an increase in [Ca2+]I in cells expressing both CD133 and CXCR4, confirming functional CXCR4. The CD133+/CXCR4+ phenotype is increased to 32% when the cells are grown in suspension, compared to only 9% when the cells were allowed to attach. In Matrigel 3-D culture, the CD133+/CXCR4+ group treated with SDF-1 grew both more colonies compared to vehicle as well as significantly larger colony sizes of tumor spheres. These data demonstrate proof of principle that the enhanced tumorigenic potential of CD133+, compared to CD133−, cells is due to their increased ability to interact with their neighboring CAF.

Dual inhibition of PI3K and mTOR signaling pathways decreases human pancreatic neuroendocrine tumor metastatic progression.

IntroductionEndothelial dysfunction is a hallmark of sepsis, associated with lung transvascular fluid flux and pulmonary dysfunction in septic patients. We tested the hypothesis that methicillin-resistant Staphylococcus aureus (MRSA) sepsis following smoke inhalation increases pulmonary transvascular fluid flux via excessive nitric oxide (NO) production.MethodsEwes were chronically instrumented, and randomised into either a control or MRSA sepsis (MRSA and smoke inhalation) group.ResultsPulmonary function remained stable in the control group, whereas the MRSA sepsis group developed impaired gas exchange and significantly increased lung lymph flow, permeability index and bloodless wet-to-dry weight-ratio (W/D ratio). The plasma nitrate/nitrite (NOx) levels, lung inducible nitric oxide synthases (iNOS) and endothelial nitric oxide synthases (eNOS), vascular endothelial growth factor (VEGF) protein expressions and poly-(ADP)-ribose (PAR) were significantly increased by MRSA challenge.ConclusionsThese results provide evidence that excessive NO production may mediate pulmonary vascular hyperpermeability in MRSA sepsis via up regulation of reactive radicals and VEGF.

CD133|[plus]| colon cancer cells are more interactive with the tumor microenvironment than CD133|[minus]| cells

Objectives Patients with advanced pancreatic neuroendocrine tumors have limited therapeutic options. Everolimus (RAD001), an inhibitor of the mammalian target of rapamycin (mTOR) pathway, has been shown to increase progression-free survival, but not overall survival, indicating a need to identify additional therapeutic targets. Inhibition of mTOR complex 1 by RAD001 may induce upstream AKT upregulation. We hypothesized that dual inhibition of AKT along with mTOR will overcome the limited activity of RAD001 alone. Methods The BON cell line has been used as a model to study pancreatic neuroendocrine tumor cell biology. Western blots and cell growth assays were performed with mTOR inhibitor RAD001 (50 nM), mitogen-activated protein kinase inhibitor PD0325901 (50 nM), PI3K (phosphatidylinositol 3-kinase) inhibitor LY294002 (25 &mgr;M), or vehicle control. Nude mice were treated daily for 6 weeks with RAD001 (oral gavage) and with LY29400 (subcutaneous) 1 week after intrasplenic injection of BON cells. Results Cellular proliferation was most attenuated with the combination therapy of LY29400 and RAD001. Similarly, the volume of liver metastasis was lowest in the group treated with both LY29400 (100 mg/kg per week, subcutaneous) and RAD001 (2.5 mg/kg per day) compared with that in the vehicle group (P = 0.04). Conclusion The combination therapy of LY29400 and RAD001 decreased the cell growth in vitro and progression of liver metastasis in vivo compared with vehicle or with single-drug therapy.

Surveillance of Pancreatic Cancer Patients after Surgical Resection

Experimental data indicate that colorectal cancer cells with CD133 expression exhibit enhanced tumorigenicity over CD133-negative (CD133−) cells. We hypothesized that CD133-positive (CD133+) cells, compared with CD133−, are more tumorigenic because they are more interactive with and responsive to their stromal microenvironment. Freshly dissected and dissociated cells from a primary colon cancer were separated into carcinoma-associated fibroblasts (CAF) and the epithelial cells; the latter were further separated into CD133+ and CD133− cells using fluorescence-activated cell sorter. The CD133+ cells formed large tumors in non-obese diabetic-severe combined immunodeficient (NOD-SCID) mice, demonstrating the phenotypic cellular diversity of the original tumor, whereas CD133− cells were unable to sustain significant growth. Affymetrix gene array analyses using t-test, fold-change and multiple test correction identified candidate genes that were differentially expressed between the CD133+ vs CD133− cells. RT-PCR verified differences in expression for 30 of the 46 genes selected. Genes upregulated (+ vs – cells) included CD133 (9.3-fold) and CXCR4 (4-fold), integrin β8 and fibroblast growth factor receptor 2. The CAF highly express the respective ligands: stromal-derived factor-1 (SDF-1), vitronectin and FGF family members, suggesting a reciprocal relationship between the CD133+ and CAF cells. SDF-1 caused an increase in intracellular calcium in cells expressing both CD133 and CXCR4, confirming functional CXCR4. The CD133+/CXCR4+ phenotype is increased to 32% when the cells are grown in suspension compared with only 9% when the cells were allowed to attach. In Matrigel 3-D culture, the CD133+/CXCR4+ group treated with SDF-1 grew more colonies compared with vehicle, as well as significantly larger colony sizes of tumor spheres. These data demonstrate proof of principle that the enhanced tumorigenic potential of CD133+, compared with CD133−, cells is due to their increased ability to interact with their neighboring CAF.Experimental data indicate that colorectal cancer cells with CD133 expression exhibit enhanced tumorigenicity over CD133− cells. We hypothesized that CD133+ cells, compared to CD133−, are more tumorigenic because they are more interactive with and responsive to their stromal microenvironment. Freshly dissected and dissociated cells from a primary colon cancer were separated into carcinoma –associated fibroblasts (CAF) and the epithelial cells; the latter were further separated into CD133+ and – cells using FACS. The CD133+ cells formed large tumors in NOD-SCID mice, demonstrating the phenotypic cellular diversity of the original tumor, whereas CD133− cells were unable to sustain significant growth. Affymetrix gene array analyses using t-test, fold-change, and multiple test correction identified candidate genes that were differentially expressed between the CD133+ vs. − cells. RT PCR verified differences in expression for 30 of the 46 genes selected. Genes upregulated (+ vs − cells) included CD133 (9.3-fold) and CXCR4 (4-fold), integrin β8 and fibroblast growth factor receptor 2 (FGFR2). The CAF highly express the respective ligands: SDF-1, vitronectin, and FGF family members, suggesting a reciprocal relationship between the CD133+ and CAF cells. SDF-1 caused an increase in [Ca2+]I in cells expressing both CD133 and CXCR4, confirming functional CXCR4. The CD133+/CXCR4+ phenotype is increased to 32% when the cells are grown in suspension, compared to only 9% when the cells were allowed to attach. In Matrigel 3-D culture, the CD133+/CXCR4+ group treated with SDF-1 grew both more colonies compared to vehicle as well as significantly larger colony sizes of tumor spheres. These data demonstrate proof of principle that the enhanced tumorigenic potential of CD133+, compared to CD133−, cells is due to their increased ability to interact with their neighboring CAF.