Segmental liver volume determination by computed tomographic scan was carried out preoperatively in nine donors for living related liver transplantation. The calculated volume was compared with the graft size actually obtained by three types of donor hepatectomy. The volume of the left lateral segment (175 to 241 ml) and the left lobe (310 to 490 ml) varied markedly among the donors. The ratio of the left lobar to total liver volume also showed a wide range of values (23.2% to 35.9%). The value of the left lobar volume did not correlate positively with the donor's body weight, suggesting that graft size cannot be predicted only on the basis of the donor's body size. Segmental graft liver volume was estimated by use of computed tomographic scan, with acceptable accuracy on comparison with the graft volume actually obtained. In living related liver transplantation, the type of donor hepatectomy should be selected on the basis of the segmental liver volume of the donor in addition to the recipient's body size so that liver failure can be prevented in recipients and the donor's safety can be assured as far as possible.

The establishment of persisting

An animal model of stomach carcinogenesis was established using Mongolian gerbils with Nmethyl-N-nitrosourea (MNU) and N-methyl-N′ ′ ′ ′-nitro-N-nitrosoguanidine (MNNG) as the carcinogens. In addition, the sensitivity of these gerbils to Helicobacter pylori (H. pylori) was confirmed. One hundred and sixty specific pathogen-free male MGS/Sea animals, 7 weeks old, were treated with MNU in the drinking water (30 ppm for alternate weeks to give 10 weeks exposure, or 10 ppm or 3 ppm for 20 weeks continuous exposure), or given MNNG in the drinking water at 400 ppm or 200 ppm for 20 weeks, or orally inoculated with ATCC43504 H. pylori (1.7× × × ×10 8 CFUs/animal). Adenocarcinomas in the glandular stomach were found in 2 out of 12 effective animals (2/ 12) treated with 30 ppm MNU at week 20, although all were dead or moribund by week 30 due to MNU toxicity. At week 50, the incidences of gastric adenocarcinomas in groups treated with 10 ppm MNU, 3 ppm MNU, 400 ppm MNNG, and 200 ppm MNNG were 2/21 (9.5%), 1/23 (4.3%), 7/ 11 (63.6%), and 1/10 (10.0%). The lesions were generally well differentiated, although poorly differentiated adenocarcinoma was also found in a single gerbil in each of the 10 ppm MNU and 400 ppm MNNG groups. In control animals no tumors were found. In the infection study, the animals were killed at week 20, and H. pylori was detected in all cases, causing multiple erosions with marked inflammatory cell infiltration in the lamina propria and submucosa, and frequent formation of lymphoid follicles. Thus, MNU and MNNG in the drinking water induced neoplastic lesions in the glandular stomach epithelium of H. pylori-sensitive gerbils.

The Mongolian gerbil model for Helicobacter pylori infection is an animal model that mimics human disease. We examined the serum immune response to H. pylori infection in gerbils by enzyme-linked immunosorbent assay (ELISA) and Western blotting, both with whole-cell (H. pylori) extracts. A total of 66 7-week-old specificpathogen-free male gerbils were inoculated orogastrically with H. pylori strain ATCC 43504. Sera were collected 1, 2, 4, 8, 12, 26, 38, and 52 weeks after H. pylori inoculation. Sixty-nine noninfected gerbils and their sera were used as controls. The specificity of the ELISA was 95.7%. The frequency of seropositivity increased over time: 2 of 10 (20%), 7 of 10 (70%), and 7 of 7 (100%) samples of sera from inoculated gerbils were positive for H. pylori at 2, 4, and 8 weeks postinoculation, respectively. Western blot assays showed that the primary immunoglobulin G (IgG) response against low-molecular-mass (25-, 30-, and 20-kDa) proteins appeared after a lag period of 2 to 8 weeks after inoculation. Antibodies against 160-, 150-, 110-, 120-, 80-, 66-, and 63-kDa proteins were observed 12 weeks after inoculation. The early reactive 30-kDa protein was identified as a urease ␣ subunit by N-terminal amino acid sequencing. After 26 weeks, two groups of animals could be distinguished: one group developed ulcers (n ‫؍‬ 5), and the other developed hyperplastic polyps without ulcers (n ‫؍‬ 19). Gerbils in the gastric ulcer group showed significantly higher serum anti-H. pylori IgG levels than did gerbils in the hyperplastic group (P ‫؍‬ 0.001) as measured by ELISA. Furthermore, a higher proportion of animals developed antibodies to H. pylori proteins of 26, 25, and 20 kDa in the ulcer group than those animals with hyperplastic polyps (75 to 100% versus 17 to 50%) in Western blot assays. These results highlight the importance of the immune response of the host in the development of H. pylori-related gastric lesions.