| 1. |
- Bauer, H G, et al.
(författare)
-
Effect of two kinds of pectin and guar gum on 1,2-dimethylhydrazine initiation of colon tumors and on fecal beta-glucuronidase activity in the rat
- 1981
-
Ingår i: Cancer Research. - 0008-5472. ; 41:6, s. 23-2518
-
Tidskriftsartikel (refereegranskat)abstract
- The effect of 5% low-methoxylated pectin, high-methoxylated pectin, and guar gum on 1,2-dimethylhydrazine initiation of colon cancer was investigated using groups of 30 rats. The growth of the rats in the different groups was very similar to that of control group fed a fiber-free diet. Both kinds of pectin increased the multiplicity of color tumors, whereas guar gum did not significantly influence carcinogenesis. Bacterial beta-glucuronidase activity in feces and colonic content was the same in pectin-fed rats and controls but significantly lower in the guar gum group. Thus, it was not related to the number of tumors in each group.
|
|
| 2. |
- Breimer, Michael, 1951
(författare)
-
Adaptation of mass spectrometry for the analysis of tumor antigens as applied to blood group glycolipids of a human gastric carcinoma.
- 1980
-
Ingår i: Cancer research. - 0008-5472. ; 40:3, s. 897-908
-
Tidskriftsartikel (refereegranskat)abstract
- Total neutral (nonacidic) glycolipid fractions have been isolated from a gastric adenocarcinoma and the surrounding normal gastric tissue removed at laparotomy of a Blood Group B human individual. Each glycolipid mixture was fractionated by silicic acid column chromatography into ten different partly purified glycolipid fractions. These fractions were analyzed by thin-layer chromatography and tested for Blood Group A and B activity. Blood group B activity was found in several fractions from both tumor and normal tissue. Two of the tumor glycolipid fractions reacted with some batches of commercial anti-A antisera, but other antisera tested did not react. No such Blood Group A reactivity was found in the fractions from the normal gastric tissue. The two Blood Group A-active tumor glycolipid fractions were methylated and methylated-reduced, and these two derivatives were analyzed by mass spectrometry. It was shown that these two fractions were mixtures of glycosphingolipids with five to nine sugars. The dominating glycosphingolipids were blood group Leb and B-like hexaglycosylceramides, a B-similar heptaglycosylceramide with an additional fucose, an H-like heptaglycosylceramide, and a Leb-like octaglycosylceramide. Evidence for small amounts of a Blood Group A-similar heptaglycosylceramide with an additional fucose was also found. The finding of a Blood Group A-similar glycolipid in a fraction which reacts with some anti-A antisera is the first chemical evidence for a heterolog blood group antigen in human cancer which has previously been found by histoimmunological techniques. The clinical significance of this finding is discussed in relation to diagnostic procedures and immunotherapy.
|
|
| 3. |
- Hirsch, Jan M, et al.
(författare)
-
Inhibition of herpes simplex virus replication by tobacco extracts
- 1984
-
Ingår i: Cancer Research. - 0008-5472 .- 1538-7445. ; 44:5, s. 1991-1997
-
Tidskriftsartikel (refereegranskat)abstract
- Herpes simplex virus type 1 (HSV-1) has been associated with the genesis of leukoplakias, epithelial atypia, and oral cancer. Tobacco habits, such as snuff dipping, are also definitely correlated with this type of lesion. The normal cytolytic HSV-1 infection can, after in vitro inactivation, transform cells. Extracts of snuff were prepared and assayed for their ability to inhibit HSV-1 replication. Plaque formation assays of HSV-1 in the presence of snuff extract showed that a reduced number of plaques was formed. Different batches of one brand of snuff were tested for inhibition of herpes simplex virus (HSV) production. More than 99% inhibition of 24-hr HSV production was obtained with undiluted batches. The 1:5 dilutions of snuff had an inhibitory effect of 85% and 1:25 dilutions, 39%. In agreement, the attachment of the virus to the host cell and penetration of the virus to the cell nuclei were found to be inhibited as was the synthesis of viral DNA. Nicotine had an inhibitory effect, while aromatic additions to snuff were found to have no major inhibitory effect on HSV replication. Snuff extracts were prepared from different brands of snuff reported to contain high and low quantities of tobacco-specific N-nitrosamines. Brands with reported high levels of tobacco-specific N-nitrosamines had significantly greater ability to inhibit HSV replication. In conclusion, this study has shown that extracts of snuff have inhibitory effects on the production of cytolytic HSV-1 infections. A chronic snuff dipper keeps tobacco in the mouth for the major part of the day. Thus, virus shed in the oral cavity in connection with a reactivated latent HSV-1 infection has great possibilities of being affected by snuff or derivatives of snuff. It is suggested that an interaction between tobacco products and HSV-1 might be involved in the development of dysplastic lesions in the oral cavity.
|
|
