To evaluate the effects of continuous low-level ionizing radiation on humans, the follow-up data (1980-85) on Japanese thorotrast-exposed patients were analyzed. The patients were 241 war-wounded military personnel registered with and cared for by the Ministry of Health and Welfare since 1979. During this period, a total of 1144 person-years, 94 patients died. Compared with the expected number of deaths calculated from age- and cause-specific death rates in Japan during the same period, the thorotrast-exposed patients were at three times greater risk of death from all causes (P less than 0.001), had 47 times the risk of liver cancer (P less than 0.001), 12 times the risk of leukemia (P less than 0.05), and 20 times the risk of liver cirrhosis (P less than 0.001). Age at time of thorotrast injection, drinking and smoking habits had little effect on these statistics. Analyses of 30 autopsied patients with liver cancer showed statistically significantly increases in hemangiosarcoma and cholangiocarcinoma. The thorotrast-exposed patients' estimated risk of liver cancer by histological type was 21 times that of the general population for hepatocellular carcinoma, 303 times that for cholangiocarcinoma and 3129 times that for hemangiosarcoma.
This paper reports the presence of GM2 ganglioside containing N-glycolylneuraminic acid (NeuGc) in human colon cancer tissues. GM2(NeuGc) was detected by two-dimensional thin layer chromatography (2d-TLC)/enzyme-immunostaining using affinity-purified chicken antibody against GM3(NeuGc) and horseradish peroxidase-conjugated rabbit anti-chicken IgG antibody. Like usual GM2 ganglioside containing N-acetylneuraminic acid (NeuAc) isolated from Tay-Sachs brain, GM2(NeuGc) in colon cancer could be converted into GM3(NeuGc) by human kidney beta-N-acetylhexosaminidase A in the presence of a GM2-specific activator protein isolated from guinea pig kidney. Three of 7 specimens of Hanganutziu-Deicher (HD) antigen-positive human colon cancer tissues so far examined expressed this unique ganglioside. In order to detect and determine specifically GM2(NeuGc) on human colon cancers, specific antibody against GM2 (NeuGc) has been prepared by immunizing chickens. By a sensitive TLC/immunostaining method using the antibody, the amounts of the antigen were determined to be 0.3-3% of total lipid-bound sialic acid. NeuGc-containing gangliosides were also detected in meconium and fetal intestinal tissues. Three species of antigenic gangliosides in pooled meconium were tentatively identified as GM3(NeuGc), sialylparagloboside and sialylhexaosylceramide on the basis of their migration positions on 2d-TLC and the results of endo-beta-galactosidase treatment. GM3(NeuGc) was the sole HD-active ganglioside in fetal intestinal tissue from one of 3 individuals tested; the other two showed no HD-active ganglioside at all. GM2(NeuGc), however, could not be detected in either meconium or fetal tissues so far examined, suggesting that this unique ganglioside is a tumor-specific antigen, at least for human intestinal tissues.
To study the carcinogenic action of N-methyl-N-nitrosourea (MNU) on the stomach, MNU in distilled water at a concentration of 400 ppm was provided as drinking water to F344 male rats for 25 weeks (group I) or 15 weeks (group II). Twenty weeks following the cessation of the administration, invasive adenocarcinomas were found in the glandular stomach in 100% of 16 rats in group I and 38% of 21 rats in group II. Bone formation occurred within the stroma of carcinoma in 5 rats in group I. No neoplastic lesions developed in the esophagus, forestomach or duodenum of any rat. Thus, MNU in drinking water selectively induces glandular stomach carcinoma in high incidence in these rats.
The inductions of ornithine decarboxylase (ODC) and DNA synthesis in the pyloric mucosa of the stomach of male F344 rats after oral administrations of chemicals were studied. The glandular stomach carcinogens N-methyl-N'-nitro-N-nitrosoguanidine, N-ethyl-N'-nitro-N-nitrosoguanidine, N-propyl-N'-nitro-N-nitrosoguanidine, 4-nitroquinoline 1-oxide and N-nitroso-N-methylurethane induced up to 100-fold increase in ODC activity in the pyloric mucosa of the stomach; the activity was maximal 24 hr after administration and returned to the control level after 48 to 72 hr. These compounds also induced 14- to 30-fold increase in DNA synthesis in the pyloric mucosa of the stomach; synthesis was maximal 16 to 24 hr after administration and returned to the control level after 144 hr. The non-gastric carcinogens 2-acetylaminofluorene, dimethylnitrosamine and 3-amino-1-methyl-5H-pyrido[4,3-b]indole (Trp-P-2) did not induce ODC or DNA synthesis in the pyloric mucosa of the stomach. Ethyl alcohol also did not induce ODC or DNA synthesis in the pyloric mucosa of the stomach. These results and previous findings that stomach-tumor promoters such as NaCl, taurocholate, glyoxal, K2S2O5 and formaldehyde induced ODC and DNA synthesis in the pyloric mucosa of the stomach of F344 rats suggest that the inductions of ODC and DNA synthesis in the glandular stomach mucosa are markers of promotive activities of complete carcinogens and tumor promoters in the glandular stomach.
DNA damage in the urinary bladder epithelium of male F344 rat was tested by alkaline elution assay after an intravesical injection of o-phenylphenol (OPP) or its non-conjugated urinary metabolites. DNA damage, as represented by an increase of the elution rate constant, was induced by the injection of 2-phenyl-1,4-benzoquinone (PBQ) at the concentration of 0.05-0.1%, but was not observed after the injection of either OPP or 2,5-dihydroxyphenyl at 0.05%. Histopathologically, a single intravesical injection of 0.05% or 0.1% PBQ was shown to induce epithelial hyperplasia of the bladder epithelium on day 5 after the treatment.
A systematic analysis of the cellular components of intestinal metaplasia (i.e., goblet cells with or without brush border cells and Paneth cells) was performed in endoscopic gastric biopsies from 984 patients without gastric ulcer or carcinoma; 359 Swedish and 625 Japanese patients. The Japanese patients, matched for age and sex, had twice as much intestinal metaplasia as the Swedes. The frequency of goblet cells and columnar cells with brush (absorptive) border increased with increasing age in both ethnic groups. Complete intestinal metaplasia (i.e. the presence of at least two or all three cellular components) was twice as frequent in the Japanese. This may reflect differences in the environment (including food habits) of the gastric mucosa in the two populations. Structural mucosal changes (i.e. pseudo-villus formations) were found more than twice as often in the Japanese. Since pseudo-villus changes occurred as often as goblet cells and brush border cells in both groups, it is suggested that the above-mentioned mucosal structural change should be considered for inclusion among the histological criteria of intestinal metaplasia of the stomach. Incomplete intestinal metaplasia (i.e. the occurrence of goblet cells without the other cellular components) occurred in similar proportions in the two populations. The present findings support the theory that incomplete intestinal metaplasia may be a para- rather than a preneoplastic phenomenon.
Human immunodeficiency virus (HIV) was isolated from a Japanese hemophilia B patient with AIDS. This isolate, HIV[GUN-1], was infectious to several mature T-cell lines. Proteins with apparent molecular weights of 160, 55 and 25 kilodaltons were detected. Restriction enzyme cleavage patterns of the proviral genome indicated that HIV[GUN-1] is related to but clearly different from HTLV-III or ARV-2.
An experimental tumor system consisting of single cells, spheroids, and solid tumors was developed using the EMT6/KU cell-line for evaluation of new hypoxic cell sensitizers. This paper describes the radiation dose-survival curves of the system and the effects of four sensitizers [misonidazole, Ro 03-8799, KB-11 (a sulfonyltetrazole derivative), and DNIE (a dinitroimidazole derivative)] in this system. Dose-survival curves of the spheroids varied significantly depending on the irradiation conditions, but it was found that the spheroids could model the solid tumors when they were irradiated in flat-bottomed flasks. These spheroids and solid tumors contained substantial fractions of hypoxic cells, and hence were suitable for testing hypoxic cell sensitizers. Misonidazole at a concentration of 1 mM or 1 mmol/kg showed a constant enhancement ratio (ER) of 1.55 in all of the systems. The ERs of the other three compounds for single cells, spheroids, and solid tumors were 2.1, 1.9, and 1.65, respectively, for Ro 03-8799 (1 mM or 1 mmol/kg); 2.6, 1.6, and 1.0, respectively, for KB-11 (0.5mM or 0.5 mmol/kg); 1.8, 1.2, and 1.1, respectively, for DNIE (0.5mM or 0.5 mmol/kg). These results indicated that the ER for spheroids is closer to the ER for solid tumors than is the ER for single cells in most cases. It was also suggested that an efficient sensitizer in vivo shows little or no difference between its ER for single cells and that for spheroids.
A total of 137 consecutive gastrectomy specimens from Japanese patients having either chronic peptic ulcer, focal (elevated) dysplasia or intramucosal carcinoma were scrutinized under high-power examination (X 1000) for the presence of ciliated cells. In 48 specimens (35.0%) ciliated cells were found in non-neoplastic dilated pyloric glands. The highest percentage was found in cases with focal (elevated) dysplasia (42.6%) or intramucosal carcinomas of intestinal type (41.6%) and the lowest in cases with intramucosal carcinoma of the diffuse type (15.4%) or chronic peptic ulcer (16.0%). Ciliated cells in the gastric mucosa seem therefore to be a common phenomenon in Japanese subjects and appear to be a new indication that the gastric mucosa of Japanese patients may differ from the gastric mucosa of Europeans.
Yoshida sarcoma cells were incubated with each of 4 different saturated and 17 different unsaturated fatty acid methyl and ethyl esters in order to modify the fatty acid composition of the cell membrane, and a possible correlation between the lipid fluidity of the cell membrane and the metastatic efficiency was studied. Almost all the unsaturated fatty acids used were incorporated into the tumor cell membrane, resulting in an increase of fluidity. In contrast, the incorporation of saturated fatty acids brought no change in fluidity. Exogenous treatment of the cells with palmitoleic acid (16:1, cis) induced a remarkable increase of membrane lipid fluidity resulting in easier passage of modified cells through capillary vessels, which was detected in an in vitro perfusion test of the lung. Intravenous injection of the modified cells resulted in fewer metastatic foci in the lung as compared with that of unmodified cells. A similar effect on lung metastasis was also observed in exogenous modification of the cells by linoleic acid (18:2, cis) or linolenic acid (18:3, n-3). On the other hand, although exogenous eicosapentaenoic acid (20:5, n-3) and docosahexaenoic acid (22:6, n-3) treatments induced a slight increase in the lipid fluidity of the cells, intravenous injection of the cells produced a significant increase in their metastatic potential in the lung. Interestingly, the treatment with 20:5 and 22:6 produced increased stickiness of the cells to a glass surface and reduced cellular passage through the vessels as detected by the lung perfusion test. Thus, the present results suggested that selective modification of membrane fatty acid may be a useful method for artificial regulation of the ability of circulating tumor cells to pass through vessels.
The antimetastatic effect of biological response modifiers (BRM) in a new experimental mouse model was studied. Intratumoral administration of BRMs (PSK, OK-432, interferon alpha A/D) strongly inhibited the growth of Meth-A solid tumors in male BALB/c mice and led to a complete regression of tumors and resistance to reinoculated tumors. Subsequently, the antimetastatic effect of BRMs was examined in the "double grafted tumor system," in which mice first received simultaneous intradermal inoculations of Meth-A in the right (10(6) cells) and left (2 X 10(5) cells) flanks and were then injected with BRMs in the right tumor on day 3. PSK and interferon (IFN) significantly inhibited the growth of the left (non-treated) tumor. This finding suggests that intratumoral BRM immunotherapy in one region has an effect on tumor growth in another region. Immunized spleen cells were taken from mice which had been cured by the intratumoral administration of BRMs and had rejected reinoculated tumors. One hour after intravenous injection of cyclophosphamide (2 mg/mouse), immunized spleen cells (2 X 10(7) cells/mouse) were injected into the Meth-A tumor on day 3. Adoptive transfers of PSK and IFN immunized spleen cells caused the complete regression of Meth-A tumors. These results suggest that the intratumoral administration of BRMs might induce cytotoxic cells in the left non-treated tumor of the "double grafted tumor system" and bring about the regression of metastatic tumors.
Smoked dry bonito (katsuobushi), an everyday food item for most Japanese people, was found to contain 2-amino-3,8-dimethylimidazo[4,5-f]quinoxaline (MeIQx), the content of which was estimated at about 2 ng/g. This content is similar to the known MeIQx content of cooked beef. The katsuobushi also contained another mutagenic component, the total activity of which was 1/6-1/3 that of the MeIQx. This component was similar to 2-amino-3,4,8-trimethylimidazo[4,5-f]quinoxaline (4,8-DiMeIQx) with respect to its behavior in high-pressure liquid chromatography and its ultraviolet absorption spectrum.
The effects of DNA-crosslinking agents (mitomycin C and cisplatin), a DNA-intercalating agent (adriamycin) and monofunctional psoralen adducts (4-methyl-4',5'-dihydropsoralen plus near-UV radiation or 8-methoxypsoralen plus narrow band 395 nm light) on DNA replication and cell-cycle progression of cultured mouse mammary carcinoma cells were studied and compared at a dose of each agent sufficient to cause complete inhibition of cell growth. In cells treated with the DNA-crosslinking agents, inhibition of incorporation of [8H]thymidine occurred progressively upon incubation of the treated cells, and finally the cells were arrested at the G2 phase. However, although the mode of inhibition of DNA replication or cell-cycle traverse was the same as that of the crosslinking agents, adriamycin did not completely block cell progression at the G2 phase and some of the cells entered the G1 phase. In contrast to these agents, monofunctional psoralen adducts inhibited DNA replication immediately after treatment and no shift in the distribution of cells in the cell-cycle was observed during incubation. These results suggested different responses of the cells to different types of DNA damage.
A study of acetaminophen (AAP) for possible carcinogenicity was conducted by administering the test chemical in pelleted diets to F344/DuCrj rats of each sex. Groups of 50 rats were administered AAP at one of two doses, either 0.45 or 0.9% for males and 0.65 or 1.3% for females. The rats were treated for 104 weeks, and then observed for 26 weeks. Control groups of 50 rats were fed basal diet throughout the study. Mean intakes of AAP by low- and high-dose rats were 195.4 and 402.1 in the males, and 335.7 and 688.0 mg/kg/day in the females, respectively. The survival rates at week 104 of each group were 86 to 90% in the males and 80 to 82% in the females. No pathologic or statistical evidence of induction of tumors by AAP was found. It is concluded that, under the conditions of this study, acetaminophen is not carcinogenic to F344/DuCrj rats of either sex.
By screening sera obtained from 5015 pregnant women under the care of 9 gynecology/obstetrics departments of hospitals or clinics in Nagasaki City and its surrounding areas, 187 were found to be positive for antibody against adult T-cell leukemia-associated antigen (ATLA). The prevalence of seropositive pregnant women was consistent with that of blood donors in the age group of 16 to 29 years, taken as controls. Essentially all cord blood samples (113/115) of babies born from these seropositive mothers were positive for anti-ATLA of IgG class. These IgG antibodies in the babies diminished rapidly after delivery, and were detectable only in 3 cases at 2, 3, and 5 months of ages out of 38 babies up to 21 months. None of 115 cord bloods so far tested was positive either for anti-ATLA of IgM class or for ATLA-bearing lymphocytes after short-term cultures of the rosette-forming T-lymphocytes. Two of the babies born from 38 seropositive mothers were found seroconverted between the ages of 12 and 19 months. Three out of 20 elder siblings were found seropositive at ages of 3 to 6 years. The seropositive rate in these siblings was significantly higher than that of controls. Moreover, 12 out of 13 mothers traced back from seropositive students were found seropositive. These data indicate strongly that HTLV-I is transmitted from seropositive mothers to their children as a major pathway.
Using a beta-chain cDNA probe of the T-cell receptor, we detected T-cell receptor gene rearrangement in leukemic cells from an adult patient with common acute lymphocytic leukemia (cALL). The leukemic cells expressed non-T, non-B cell marker profiles (CALLA+, J5+, Leu-1-, Leu-4-, Ia+, B1-, c-Ig mu- and TdT+). This is the first reported case of cALL with T-cell receptor gene rearrangement and/or deletion.
In order to investigate the role of T cells in the production of tumor necrosis factor (TNF), a reconstitution experiment was performed with nude mice (Balb/c, nu/nu). The results obtained were as follows: 1) The cytotoxic activity of tumor necrosis serum (TNS) from Balb/c, nu/nu mice treated with Propionibacterium acnes-LPS was 1/22 of that from Balb/c, nu/+ mice. 2) TNF activity increased 14 times in reconstituted nude mice as compared to Balb/c, nu/nu mice. 3) The production of the cytotoxic activity per cell was investigated using T cell and macrophage fractions separated from the spleens of both Balb/c, nu/nu and Balb/c, nu/+ mice treated with P. acnes as a priming agent. Elicitation with LPS was done in vitro. Release of cytotoxic activity into the culture medium was observed in the macrophage fraction, but not in the T cell fraction. However, no significant species difference was found. 4) With P. acnes treatment, the population of macrophages in the spleens from Balb/c, nu/+ mice increased 25.5 times, whereas that from Balb/c, nu/nu mice only increased 6.8 times. The above results suggest that the mechanism of the incremental effect of T cells on TNF production was due to the promotion of macrophage proliferation during the priming period after injection of P. acnes.
A short-term study was made for the urinary mutagenicity caused by cigarette smoking in several volunteers. In order to concentrate the mutagens from urine, cotton linked to a copper-phthalocyanine derivative (blue cotton) was used as an adsorbent. The mutagenicity as measured by the Ames test on Salmonella typhimurium TA98 in the presence of S9 increased rapidly after the start of smoking. When smoking was stopped, the activity began to decrease, and after 6 to 13 hr reached the non-smoking level. There was no great difference among individuals regarding this time-dependent response. These studies have shown that the appearance and disappearance of mutagenicity in urine in relation to cigarette smoking are rapid processes.
