Effect Of Dimethylhydrazine Research Articles

Comparative Study between Curcumin and Nanocurcumin Loaded PLGA on Colon Carcinogenesis Induced Mice.

Colorectal cancer is the third most common cancer. Because curcumin (CUR) has anti-inflammatory and anticancer properties, research has been undertaken to indicate that nanocurcumin compounds can be used to treat a variety of cancers. CUR in nanoform has been found to have a stronger effect than conventional CUR. The purpose of this study was to show that CUR-loaded poly lactic-co-glycolic acid nanoparticles (PLGA) (CUR-loaded PLGA) have anti-inflammatory and anticancer effects on colon carcinogenesis in male dimethyl hydrazine (DMH) mice as a comparative study between the nanoform of curcumin and normal curcumin, focusing on the anticancer effect of nanocurcumin. Mice were separated into six groups: No treatment was given to Group I (negative Group-I). Group II was treated with CUR. Group III was treated with CUR-loaded PLGA. Group IV was treated with DMH. Group V received DMH and curcumin. Group VI received DMH and CUR-loaded PLGA. At the conclusion of the trial, the animals were slain (6 weeks). Inflammatory indicators and vascular endothelial growth factor (VEGF) levels all changed significantly in this study, as the following inflammatory markers as TNF showed percent of change compared to the DMH group. Recovery percentage for Groups V and VI, respectively, were 9.18 and 55.31%. In addition, IL1 was 7.45 and 50.37% for Groups V and VI, respectively. The results of IL6 were 4.86 and 25.79% for Groups V and VI, respectively. The vascular endothelial growth factor (VEGF) recovery percent was 16.98 and 45.12% for Groups V and VI, respectively. Following the effect of DMH on colon mucosa shape, the researchers looked at the effect of CUR-loaded PLGA on colon histology. It was shown that CUR-loaded PLGA affects the cell cycle and PCNA expression. We conclude that nanocurcumin is an important anti-inflammatory and cancer-fighting agent.

Effect of dimethylhydrazine on p‐type conductivity of as‐grown Mg‐doped GaN

AbstractMg dopants in GaN need post‐growth thermal activation to be activated. However, it was observed that GaN grown with dimethylhydrazine (DMHy) resulted in p‐type conductivity without activation. The reduction of NH3 flow by adding DMHy resulted in a very low hydrogen concentration of 2.8 × 1017 cm–3 in Mg‐doped GaN, which was even lower than the hole concentration. The low‐temperature infrared transmittance spectra also showed that many hydrogen atoms were captured by incorporated carbon impurities. The combined effect of low concentration of hydrogen and the preferred trapping of hydrogen at carbon impurities is attributed to the p‐type conductivity of as‐grown Mg‐doped GaN when a mixture of DMHy and NH3 was used for group V sources. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)

Effects of dimethylhydrazine on Zn, C, and H doping of GaP

Surfactants are beginning to be used during vapor-phase growth to provide control of the materials characteristics of epitaxial layers. This paper reports the effects of utilizing N, from pyrolysis of dimethylhydrazine (DMHy), as a surfactant during the organometallic vapor-phase epitaxial growth of GaP. Nitrogen is isoelectronic with the group V host element; thus, it generates no free carriers. Additionally, due to its small size, N is strongly rejected from the solid, so little incorporation is expected. This is confirmed by the determination of the very low N distribution coefficient (3.2×10 −5). Using secondary ion mass spectroscopy analysis, we observe an increase in the distribution coefficient of the acceptor Zn when DMHy is added during growth, resulting in an increase in the doping efficiency by nearly an order of magnitude. Furthermore, the Zn doping efficiency increases linearly with the amount of DMHy added during growth over the range of partial pressures from 2.83×10 −4 to 2.20×10 −3 atm. The increase of doping for Zn is believed to be mainly a N surfactant effect. The addition of DMHy also leads to increases in both H and C incorporation. The concentrations of both are linear functions of DMHy concentration. Both H and C incorporation most likely arise mainly from pyrolysis of the DMHy. We propose a simple mechanism for the surfactant effect due to an increase in the Zn incorporation coefficients at the step edge induced by the presence of N (and probably H) on the surface.

Effects of sodium cholate on experimental carcinogenesis and cell proliferation in an excluded colonic segment.

Bile salts appear to be important promoters of colon carcinogenesis. This study was designed to assess the importance of the fecal stream in cholic acid-induced colon tumor promotion. Male Sprague-Dawley rats underwent transverse colostomy after induction with dimethylhydrazine (DMH) and the excluded distal colon was irrigated with saline or sodium cholate (23 microM) 5 times per week until sacrifice. Controls initially injected with saline were similarly treated. All surviving animals were sacrificed at 28 weeks after the last DMH injection. Five animals from each group were randomly chosen to assess tritiated thymidine labeling and distribution by autoradiography in normal appearing colon mucosa of irrigated bowel. Cholate irrigation failed to increase tumor yield or modify the proportion of adenomas and adenocarcinomas in this model. Paradoxically, fewer tumors per affected rat were noted with sodium cholate irrigation. Cholate irrigation also failed to affect crypt cellularity, thymidine labeling indices, and labeling distribution in DMH-treated rats and controls. An effect of DMH was seen, however, with an increase in thymidine labeling index and increased labeling in the top half of the crypt in all DMH-treated groups. This study suggests that tumor promotion with primary bile salts is not a direct affect and may result from further bile salt metabolism within the fecal stream. DMH-induced changes in cell proliferation were reproduced with this model. Use of an excluded colon segment to assess the effect of suspected tumor promoters on carcinogenesis or colon mucosal cell proliferation is feasible and may be a useful model for future studies.

The effects of dimethylhydrazine and small bowel resection on crypt cell proliferation in the rat colon

The effects of dimethylhydrazine and small bowel resection on crypt cell proliferation in the rat colon