Synergistic effects of irinotecan and flavonoids on Ehrlich ascites tumour-bearing mice

Swiss albino mice were given Ehrlich ascites tumour cells (1 × 10(6)) intraperitoneally. For survival analysis and tumour growth analysis, the mice were administered quercetin and naringin (100 mg/kg) daily for 3 consecutive days, beginning on the third day after intraperitoneal (i.p.) injection of Ehrlich ascites tumour cells (1 × 10(6)). Irinotecan was administered ip at a dose of 50 mg/kg on days 1, 13 and 19. For the analysis of cell types and differential count of cells present in the peritoneal cavity, peripheral whole-blood leucocyte count and the comet assay, the mice were treated therapeutically with quercetin and naringin (100 mg/kg) and irinotecan (50 mg/kg) daily for 3 consecutive days beginning on third day after i.p. injection of Ehrlich ascites tumour cells (1 × 10(6)). We observed the synergistic anti-tumour effect expressed as the median survival time of mice treated with naringin in combination with irinotecan. All test components inhibited tumour growth and increased lifespan of mice except quercetin. The total number of cells present in the peritoneal cavity of mice significantly decreased in all treatments except quercetin. Single irinotecan and irinotecan combined with naringin had the highest DNA-damaging potential on peripheral blood leucocytes and lowest primary DNA damage, both in the kidney and liver cells as measured by the alkaline comet assay. Our results showed enhanced anti-tumour activity of irinotecan in combined treatment with flavonoids to reduce the deteriorating reaction of cytostatic drugs.     

Estimation of DNA Integrity in Blood Cells of Eastern Mosquitofish (Gambusia holbrooki) Inhabiting an Aluminium-Polluted Water Environment: an Alkaline Comet Assay Study

To estimate the impacts of an Al-contaminated aquatic environment on DNA integrity in the blood cells of eastern mosquitofish Gambusia holbrooki Girard 1859 inhabiting Lake Njivice (Island of Krk, Croatia), an evaluation using the alkaline comet assay was carried out. Genome integrity was studied in parallel with the same fish species inhabiting the nearby, unpolluted Lake Ponikve. The amount of DNA damage in cells was estimated from three different parameters: comet tail length as the extent of genetic material migration, tail intensity (% DNA in the comet tail) and tail moment. The results indicate the loss of genome integrity in blood cells of mosquitofish inhabiting Lake Njivice and the genotoxicity of this aquatic environment. Using the same assay, acute genotoxicity of contaminated water and sediment was evaluated and confirmed on fish, mouse and human blood cells treated ex vivo. Results of the present study indicate that the alkaline comet assay applied to fish blood cells is a valuable tool for determining the potential genotoxicity of water pollutants and confirm its usefulness in the evaluation of DNA damage in fish living in Al-polluted waters.     

Computational prediction of methylation status in human genomic sequences

Epigenetic effects in mammals depend largely on heritable genomic methylation patterns. We describe a computational pattern recognition method that is used to predict the methylation landscape of human brain DNA. This method can be applied both to CpG islands and to non-CpG island regions. It computes the methylation propensity for an 800-bp region centered on a CpG dinucleotide based on specific sequence features within the region. We tested several classifiers for classification performance, including K means clustering, linear discriminant analysis, logistic regression, and support vector machine. The best performing classifier used the support vector machine approach. Our program (called hdfinder) presently has a prediction accuracy of 86%, as validated with CpG regions for which methylation status has been experimentally determined. Using hdfinder, we have depicted the entire genomic methylation patterns for all 22 human autosomes.     

Cytotoxicity of composite materials polymerized with LED curing units

The proper intensity and illumination time of a curing light is of great importance for the complete polymerization of resin composites and long-lasting resin composite restorations. Inadequately cured resin composites can have a cytotoxic effect on pulp tissue by releasing unreacted monomers. This study determined whether there is any difference in cytotoxicity between composite materials illuminated with different curing modes of LED curing units. Thin layers of two composite materials were polymerized using three different modes of the Bluephase C8 LED curing unit: a high intensity mode (HIP-800 mW/cm2, 20 seconds), a soft-start mode (SOF-650 mW/cm2 first 5 seconds, 800 mW/cm2 next 25 seconds) and a low intensity mode (LOP-650 mW/cm2, 30 seconds). Lymphocyte cultures were treated with both polymerized and unpolymerized composites using one of the modes stated above. Cells were analyzed using the trypan blue exclusion test, the acridine orange/ethidium bromide dying technique and an alkaline comet assay. Significant cytotoxicity was observed for 120 mg of unpolymerized composites and those polymerized with the HIP polymerization mode. A significant level of DNA damage was detected for 120 mg of unpolymerized composites. However, curing via the LOP program exhibited the lowest genotoxicity. Longer curing time with lower intensity results in less cytotoxicity than shorter curing exposure using a higher intensity of light emitted from the curing light source.     

Evaluation of radioprotective effects of propolis and its flavonoid constituents: in vitro study on human white blood cells

This in vitro study aimed to evaluate the possible radioprotective effects of the natural substances WSDP, caffeic acid, chrysin and naringin on γ‐irradiated human white blood cells. The effectiveness of tested compounds was evaluated using the alkaline comet assay, the analysis of structural chromosome aberration and the cytokinesis‐block micronucleus assay. The results obtained by the alkaline comet study indicate favourable toxicity profiles of propolis and its polyphenolic components, and confirmed the radioprotective abilities comparable to the chemical radioprotector AET. WSDP and its polyphenolic components were able to reduce the number of necrotic cells. None of tested compounds induced significant genotoxicity, but all of them offered a quite measurable protection against DNA damage. WSDP was found to be the most effective in diminishing the levels of primary and more complex cytogenetic DNA damage in white blood cells. Considering its complex composition, to undoubtedly explain the underlying mechanisms of cyto/radioprotective effects, further studies are needed. Copyright © 2009 John Wiley & Sons, Ltd.     

Thrombendvenectomy for Organized Portal Vein Thrombosis at the Time of Liver Transplantation

OBJECTIVE: To determine the efficacy of portal thrombendvenectomy in cases of portal vein thrombosis at the time of orthotopic liver transplantation. SUMMARY BACKGROUND DATA: Portal vein thrombosis (PVT) has been reported to have an incidence of 2% to 39% in end-stage liver disease. Multiple techniques have been suggested to treat this finding. Several reports have suggested suboptimal results after liver transplantation in recipients with PVT. METHODS: The authors prospectively collected data on 1,546 patients who underwent an initial orthotopic liver transplant at the authors' institution between December 1984 and October 1999. There were 820 male patients and 726 female patients. All recipients received either cyclosporine or tacrolimus immunosuppression. Intraoperative flows of the portal vein and hepatic artery were routinely measured. Duplex sonography was routinely performed on the first postoperative day and routinely 1, 2, 5, and 10 years after transplantation. Eighty-five patients underwent thrombendvenectomy for organized thrombus partially or completely occluding the portal vein. Postoperative treatment included low-molecular-weight dextran for 48 hours and daily aspirin for 3 months. There were 53 male patients and 32 female patients. The PVT group was compared with a control group consisting of transplant recipients without PVT. RESULTS: When compared with the control group, PVT patients were older at the time of transplantation and had a higher incidence of liver disease secondary to cryptogenic cirrhosis and Laennec's cirrhosis. There were no significant differences among both groups for 1-, 3-, and 6-year patient and graft survival rates. CONCLUSIONS: Thrombendvenectomy provides a rapid resolution of an otherwise complex problem. It is the authors' procedure of choice in cases of organized PVT at the time of transplantation. Operative time and length of stay in the intensive care unit are not prolonged, and patient and graft survival rates are not compromised.     

Influence of glass and anticoagulant concentration on improvement of factor X deficiency tests

Normal human blood received in 0.02 M sodium oxalate (1 part to 9 parts of blood) in 16 × 100 mm glass tubes, at 37 °C, always clotted. Blood from severe Factor X deficiency received in 0.02 M sodium oxalate did not clot. The prothrombin time of the 0.02 M oxalate Stuart plasma was much shorter than the prothrombin time of the 0.1 M oxalate Stuart plasma. The prothrombin time of the 0.1 M oxalate Stuart plasma was shorter with 0.02 M than with 0.01 M CaCl₂. The Stypven Time of this 0.1 M oxalate plasma was very prolonged but was almost normal with the 0.02 M oxalate plasma. Almost normal prothrombin time (with human brain thromboplastin) of a ten times concentrated 0.02 M oxalate Stuart plasma was observed. With 0.01 ml of a 1 % 0.02 M oxalate Stuart plasma for 0.1 ml of Factor VII deficient plasma the prothrombin time became normal. Same experiment with 0.1 M oxalate Stuart plasma did not normalize the prothrombin time.

Very abnormal kaolin partial thromboplastin time for the 0.1 M oxalate Stuart plasma and completely normal for the 0.02 M oxalate Stuart plasma was observed. We can postulate that the activation of the contact factors (F-XII, F-XI) occurs with traces of calcium ions not removed by the anticoagulant. Consequently, a condition can be generated which makes more manifest the limited amounts of normal F-X molecules in the deficient plasma.