Accounting for effects of system dynamics to improve accuracy of emissions reported in e-cig vaping machines.

Laboratory emissions testing of electronic cigarettes continues to be a focus in the tobacco research community. In particular, to inform policy regarding appropriate test protocols to regulate the manufacture, marketing and sale of tobacco products. This study aims to enhance current understanding of the way laboratory systems used to generate topography profiles and capture resultant emissions from inhaled tobacco products may interact with the device under test. A programmable emission system (vaping machine) is introduced and characterized. The operating envelope of this system is presented. This study demonstrates that the performance of an emissions system may be influenced by various factors, resulting in discrepancies between command puff parameter inputs and the observed puffs generated. The study findings conclude that any emissions system should be characterized with the desired test device to determine the effective operating range of the system under "Load" conditions. Furthermore, reporting emissions from electronic cigarettes as a function of "command" puff flow rate and cumulative volume result in under-estimation bias and may give rise to incorrect conclusions regarding the impact of product characteristics on emissions. Conversely, reporting emissions in terms of "observed" puff flow rate and cumulative volume reduces bias errors and limits opportunity for intentional misrepresentation of results.

Effect of oral supplementation with vitamin E on the oxido-reductive status of red blood cells in normal mice and mice subject to oxidative stress by chronic administration of adriamycin.

The effect of oral vitamin E supplementation on the oxido-reductive status of red blood cells in normal mice and those subject to oxidative stress by chronic administration of the anti-tumour drug Adriamycin was investigated. Mice were randomly separated into three groups of 20 animals each and maintained on diets identical in all respects except for vitamin E content. Group 1 received a low vitamin E diet that provided 10 mg vitamin E/kg body weight/day, group 2 received a normal mice chow diet (45 mg vitamin E/kg body weight/day) while group 3 received a high vitamin E diet (200 mg vitamin E/kg body weight/day). In comparison with the normal mice in group 1, their counterparts in groups 2 and 3 exhibited significantly higher (P < 0.001) activities of superoxide dismutase (SOD) in red blood cells (79.4% higher in group 2 and 114.2% higher in group 3, respectively) and produced lower concentrations of malondialdehyde (MDA) (22.9% less in group 2 and 51.2% less in group 3, respectively), with little difference in the glutathione peroxidase (GPX) activity. In Adriamycin-treated animals on the low vitamin E diet (group 1) the red blood cell SOD activity and MDA production were 46.2% and 200.7% higher (P < 0.001), respectively, and the GPX activity was 39.1% lower than in the red blood cells of untreated (normal) animals in the same group. The Adriamycin-induced changes were significantly less in animals receiving higher doses of vitamin E (groups 2 and 3). Thus, in the group maintained on the high vitamin E diet (group 3), Adriamycin administration resulted in only a 38.9% increase in the MDA production above that generated by red blood cells of normal mice in the same group, with no significant change in the SOD or GPX activities. Thus, in normal conditions as well as in conditions of oxidative stress, high doses of vitamin E appear to be able to protect the oxido-reductive status of red blood cells by modulating the extent of lipid peroxidation as well as the activities of antioxidant enzymes.

Evaluation of the hypoglycemic and hypolipidemic effects of an ethylacetate fraction of Artocarpus heterophyllus (jak) leaves in streptozotocin-induced diabetic rats.

Aqueous extracts of mature leaves of Artocarpus heterophyllus (jak) are used by traditional medical practitioners in Sri Lanka and India for the treatment of diabetes. This study was conducted to investigate the hypoglycemic and hypolipidemic effects of an ethylacetate (EA) fraction of the mature leaves of A. heterophyllus in a streptozotocin (STZ) induced diabetic rat model. In normoglycemic rats, administration of a single dose (20 mg/kg) of the EA fraction resulted in a significant (P < 0.05) reduction in the fasting blood glucose concentration and a significant improvement in glucose tolerance (P < 0.05), compared to the controls. In STZ-induced diabetic rats, chronic administration of the EA fraction of A. heterophyllus leaves daily for 5 weeks resulted in a significant lowering of serum glucose, cholesterol and triglyceride (TG) levels. Compared to control diabetic rats, the extract-treated rats had 39% less serum glucose, 23% lower serum total cholesterol and 40% lower serum TG levels and 11% higher body weight at the end of the fifth week. The percentage reductions in the serum parameters mediated by the test fraction were comparable with those produced by glibenclamide (0.6 mg/kg), the reference drug used in this study. It can be concluded that the EA fraction of A. heterophyllus leaves contains one or more hypoglycemic and hypolipidemic principles which have the potential to be developed further for the treatment of diabetes specifically associated with a hyperlipidemic state.

Cell-mediated immune responses (CMIR) to Rhinosporidium seeberi in mice.

There is no published data on Cell Mediated Immune Responses in experimental animals to Rhinosporidium seeberi the causative agent of human and animal rhinosporidiosis. The quantitative mouse foot-pad model was used to assay the Delayed-Type Hypersensitivity (DTH) cell-mediated immune response to extracts of purified endospores and sporangia of R. seeberi. Histological examination was used to confirm that the foot-pad reactions were compatible with DTH reactions in the mouse. We report that sonically disintegrated rhinosporidial endospores/sporangia induced DTH responses in the foot-pads of sensitized mice which were comparable in intensity and histological profile to that induced by sheep red blood cells in SRBC sensitized mice. Anti-rhinosporidial antibody was also induced. Filtrates of the soluble antigens in sonicated suspensions failed to evoke a DTH-foot-pad (DTH-FP) response in sensitized mice although an anti-rhinosporidial antibody response to this preparation was detected. Prolonged pre-treatment with sonicated suspensions of endospores and sporangia resulted in a decrease of DTH reactivity as compared with reactions following pre-treatment of a shorter duration.

Inhibition of chemically induced liver carcinogenesis in Wistar rats by garlic (Allium sativum).

The effects of garlic on diethylnitrosoamine (DEN)-induced hepatocarcinogenesis were examined in male Wistar rats using the medium term bioassay system of Ito based on the two-step model of hepatocarcinogenesis. Carcinogenic potential was scored by comparing the number and area/cm(2) of induced glutathione S-transferase placental form (GST-P) positive foci in the liver with those of the corresponding group (control) of rats given diethylnitrosoamine alone. Treatment with garlic (therapeutic dose 20 mg/kg body wt/day) reduced significantly the number (50% reduction, p < 0.003) and area (48% reduction, p < 0.0007) of GST-P positive foci compared with the control group of animals receiving distilled water. Histopathological examination of rat livers using H & E staining indicated that there was no significant difference between the control group and the garlic treated group in the two pathological parameters namely granularity and vacuolation of the cytoplasm. Our results provide strong supportive evidence for the anticarcinogenic activity of garlic.

Protection by garlic against adriamycin induced alterations in the oxido-reductive status of mouse red blood cells.

The effects of oral garlic supplementation on the activities of (a) the antioxidant enzymes superoxide dismutase (SOD) and glutathione peroxidase (GPX) and (b) lipid peroxidation, as assessed by malondialdehyde (MDA) production in red blood cells of normal mice and those subject to oxidative stress by chronic administration of the anti-tumour drug adriamycin has been investigated. As expected, adria-mycin administration resulted in a significant increase in MDA generation (by 105.4%) and a decrease in GPX activity (by 23.8%) in the red blood cells. Although garlic had no significant effects on the basal levels of the antioxidant enzymes or MDA generation in red blood cells of normal mice (untreated with adriamycin), at doses of 20 mg/kg or 100 mg/kg, garlic was able to decrease significantly the adriamycin induced changes in the oxido-reductive status of the red blood cells. Thus, on administration of adriamycin to mice fed diets containing 20 mg/kg or 100 mg/kg garlic, the drug-induced increase in MDA generation was 38.2% and 22.5% respectively, less than that produced by adriamycin in mice fed normal diets, containing no garlic (105.4%). Similarly, in mice fed diets providing 20 mg/kg and 100 mg/kg garlic, adriamycin was able to decrease GPX activity by only 15.1% and 7.6% respectively, less than that produced by adriamycin in rats fed normal diets, containing no garlic (23.9%).