Biochemical study of pyloric metaplasia in the mucosa regenerating over iodoacetamide-induced fundic ulcers in rat stomach

The molecular species and content of pepsinogen in regenerated mucosa over fundic ulcers induced in a rat stomach by iodoacetamide were found to be the same as those in normal pyloric mucosa, but different from those in normal fundic mucosa.

Lymphocyte subpopulation in neoplastic and non-neoplastic thymus and in blood of patients with Myasthenia gravis

The lymphocyte subpopulations in the thymus and in the blood were investigated in ten myasthenic patients who had been thymectomized. Histologically, the thymuses tested comprised three cases of thymoma including two cases with malignant characteristics, five cases of hyperplastic thymus with lymph follicles and germinal centres, and two cases of persistent thymus without lymph follicles. Virtually all lymphoid cells in the three thymomas formed spontaneous rosettes with sheep red blood cells as did normal thymocytes from non-myasthenic patients. There was no significant proportion of immunoglobulin Ig-bearing lymphocytes. While the majority consisted of cells forming spontaneous rosettes with sheep red blood cells, there was a certain proportion (2-17%) of Ig-bearing lymphocytes in four of five hyperplastic thymuses, in one of two persistent thymuses, and in a residual atrophic thymus of a thymoma. The myasthenic patients tested were for the most part normal, as compared with healthy individuals, in the proportion of rosette-forming lymphocytes and Ig-bearing lymphocytes in the blood collected immediately before and one to three months after thymectomy. The presence of Ig-bearing lymphocytes in the thymus was not necessarily related to the appearance of circulating antibody to striated muscle. The antibody to striated muscle was demonstrated in all myasthenic patients with thymoma.

Immunofluorescent demonstration of alpha- fetoprotein and other plasma proteins in yolk sac tumor

All seven pure yolk sac tumors of gonadal and extragonadal origin tested showed a bright positive fluorescence for alpha-fetoprotein in the tumor tissue. A positive reaction was seen in both the tumor cells and the hyaline globules. In all cases, however, the positive fluorescence was distributed in some focal areas of the tumor tissue. Certain tumor cells showed a strong granular intracytoplasmic fluorescence, whereas others showed a weak or a negative fluorescence. The fluorescence-positive tumor cells were located mainly in the areas rich in fluorescence-positive hyaline globules. Besides alpha-fetoprotein, certain plasma proteins--albumin, alpha-1 antitrypsin, and transferrin--were also demonstrated in all five yolk sac tumors tested. The pattern of the distribution of positive fluorescence was basically similar to that of alpha-fetroprotein. Other plasma proteins--orosomucoid, haptoglobin, Gc-globulin, alpha-2 macroglobulin, hemopexin, and ceruloplasmin--were present in certain tumors, and were distributed mainly in a limited number of hyaline globules. Both IgG and IgA were present in two tumors of ovarian origin. The immunoglobulins were for the most part present in extracellular hyaline globules, suggesting that these are taken up from the circulation. Test for fibrinogen, beta-lipoprotein, IgM, IgE, beta-1C/beta-1A and beta-1E globulins were negative or questionable. In a hepatoblastoma, tests for alpha-fetoprotein were positive, but those for other plasma proteins were negative. Fine granular fluorescence was seen in each hepatocellular tumor cell. Mesenchymal elements were virtually unstained.

Reversibility and irreversibility of liver tumors in mice induced by the alpha isomer of 1,2,3,4,5,6-hexachlorocyclohexane

The characteristics of liver tumors in mice induced by the alpha isomer of 1,2,3,4,5,6-hexachlorocyclohexane (alpha-BHC), were studied with emphasis on their reversibility of irreversibility. Male 8-week-old DDY mice were fed basal diet supplemented with 500 ppm of alpha-BHC for 16, 20, 24, and 36 weeks and then were fed basal diet without alpha-BHC for 4, 8, 12, 16, 24, or 36 weeks. At various intervals, 13 to 20 mice were killed for light and electron microscopic observations. The incidences of liver tumors in mice induced by alpha-BHC increased progressively on continuous administration of alpha-BHC, but when its administration was discontinued some tumors disappeared. Histologically, after alpha-BHC administration for 24 weeks, most tumors were nodular hyperplasias, and there were only a few well-differentiated hepatocellular carcinomas. However, 60 or 72 weeks after the beginning of the experiment, most of the liver tumors were hepatocellular carcinomas and there were only a few nodular hyperplasias. At a later stage, 60 or 72 weeks, the liver parenchymal tissue in nontumorous areas was essentially normal, but small foci were occasionally seen in nontumorous areas that were composed of remaining hyperplastic nodular cells, phagocytic cells, Kupffer cells, and leukocytes. These findings suggest that the reversible tumors were usually nodular hyperplasias whereas the irreversible tumors were hepatocellular carcinomas. After alpha-BHC administration was stopped, many mesenchymal cells infiltrated the nodular hyperplastic lesions, and degenerated liver cells were found. These observations indicate that mesenchymal cell elements may be important in reversing the growth of liver tumors induced by alpha-BHC.

Primary intracranial yolk sac tumor: immunofluorescent demonstration of alpha-fetoprotein synthesis

An autopsy case of 20-year-old male with primary intracranial yolk sac tumor (endodermal sinus tumor) is reported. Whereas the biopsy specimen obtained from the pineal region showed diffuse proliferation of atypical tumor cells, the metastatic subdural tumor removed from lumbar spinal region had the characteristic histologic appearance of yolk sac tumor. The histologic diagnosis was intracranial yolk sac tumor originating in the pineal gland. The elevated amount of alpha-fetoprotein in the cerebrospinal fluid and in the serum further supported the diagnosis. At autopsy, only metastatic tumor was present in the posterior fossa. The immunofluorescence study demonstrated the presence of intra- and extracellular alpha-fetoprotein globules in the tumor tissue. The intra- and extracellular distribution of alpha-fetoprotein, in general, appeared to coincide with that of the PAS-positive hyaline globules in the tumor.

Effect of plastic bead on gastric carcinogenesis in rats treated with N-methyl-N'-nitro-N-nitrosoguanidine

Experiments were made on induction of cancer of the glandular stomach of rats by a combination of oral administration of N-methyl-N'-nitro-N-nitrosoguanidine (MNNG) and insertion of a plastic bead into the gastric lumen. The incidence of cancer with this combination of treatments was greater than by administration of MNNG alone. Fluoroscopic examination showed that barium sulfate remained in the stomach longer when a bead had been inserted into the gastric lumen. This indicates that after insertion of a bead, MNNG must have remained in the stomach longer, and so the period of exposure of the gastric mucosa to the carcinogen must have increased.

Protective effect of mucin on experimental gastric cancer induced by N-methyl-N'-nitro-N-nitrosoguanidine plus sodium chloride in rats

Studies were made on the effect of mucin on the induction of gastric carcinomas by N-methyl-N'-nitro-N-nitrosoguanidine (MNNG), with or without sodium chloride, in male Wistar rats. Seven groups of rats were treated as follows: Group 4 was given continuously 50 mg MNNG/liter solution to drink and 1 ml of saturated sodium chloride once a week and fed on stock diet supplemented with 4% mucin. Group 2 was given 50 mg MNNG/liter solution and fed on stock diet supplemented with 4% mucin. Group 3 received 1 ml of saturated sodium chloride once a week and 50 mg MNNG/liter solution to drink. Group 1 was treated with MNNG only. Group 5 was fed on stock diet supplemented with 4% mucin. Group 6 was given sodium chloride only. Group 7 was untreated. The incidence of gastric cancer in Group 3 was significantly higher than that in Group 4 (P less than 0.05) or in Group 1 (P less than 0.05). The difference in the incidence of gastric cancer in Groups 2 and 4, and of intestinal tumors in Groups 1 to 4 were not statistically significant. No malignant tumors were seen in Groups 5, 6, and 7. Thus mucin reduced the high incidence of gastric cancer induced by MNNG and sodium chloride to the level induced by MNNG alone, but it had no effect on the incidence of intestinal tumors. The effect of mucin in preventing destruction of the gastric mucosal barrier by sodium chloride and so reducing the induction of gastric cancer is discussed.

Different susceptibilities of the urinary bladder epithelium of animal species to three nitroso compounds

Differences in the susceptibilities of the urinary bladder epithelium of Wistar rats, ICR mice, Syrian golden hamsters, and Hartley guinea pigs to three N-nitroso compounds, N-butyl-N-(4-hydroxybutyl)nitrosamine, N-ethyl-N-(4-hydroxybutyl)nitrosamine, and N-butyl-N-(3-carboxypropyl)nitrosamine, were examined histologically. The urinary bladder epithelium of rats was the most susceptible to all three compounds, and especially to N-ethyl-N-(4-hydroxybutyl)nitrosamine, and bladder cancers developed in all the rats given this compound. The bladder epithelium of mice was less susceptible than that of rats but, although the incidence of cancer was lower than in rats, that of cancer with invasion was higher. Hamsters were far less susceptible than mice, and cancer developed only in 3 of 41 animals given N-ethyl-N-(4-hydroxybutyl)nitrosamine. Guinea pigs were the least susceptible of the 4 species and no tumors were found. Hisotlogically, most of the tumors induced in rats and mice were transtitional cell carcinomas. The incidence of undifferentiated carcinoma was higher in mice than in rats and cellular or structural atypism of the cancer was also greater in mice. Cancers induced in hamsters were all transitional cell carcinomas showing invasion.

Effect of fundic ulcers induced by iodoacetamide on development of gastric tumors in rats treated with N-methyl-N'-nitro-N-nitrosoguanidine

The effect of ulcers induced by iodoacetamine on the development of gastric tumors by N-methyl-N'-nitro-N-nitrosoguanidine was studied in male Wistar rats. The ulcerative lesions induced by iodoacetamide were confined symmetrically to the fundic region along the limiting ridge in the stomach and the pyloric region was unaffected. Animals treated with iodoacetamide and N-methyl-N'-nitro-N-nitrosoguanidine produced a high incidence of tumors including adenocarcinoma in the fundic region. The incidence of tumors in the pyloric region in the control group was 80% but there were no tumors in the fundic region. The tumors in the fundic region were most frequently found in the same areas that ulcers had previously been induced. These findings suggest that ulceration and regeneration of the mucosa are important factors in gastric carcinogenesis induced in rats by N-methyl-N'-nitro-N-nitrosoguanidine.

Histological classification of urinary bladder cancers in rats induced by N-butyl-n-(4-hydroxybutyl)nitrosamine

Histological types and grades of 613 urinary bladder cancers induced in rats by N-butyl-N-(4-hydroxybutyl) nitrosamine(BBN) were analyzed. Most of them (95.1%) were transitional cell carcinomas, the remainder being squamous cell carcinomas (3.3%), undifferentiated carcinomas (2.5%), and carcinosarcomas (0.3%). Among the transitional cell carcinomas, 23.3% were Grade I anaplasia, 55.2% Grade II, and 21.5% Grade III. Among the squamous cell carcinomas, 20% each were Grade I and II, and 60% Grade III. Most of the undifferentiated carcinomas were Grade III. Some of the cases of transitional cell carcinoma had areas of squamous metaplasia and/or glandular metaplasia, and the incidence of metaplasia increased with the grade of anaplasia. Approximately 36% of the cases of transitional cell carcinoma were of the invasive type. Invasive types were twice as numerous among cases of squamous cell carcinoma as among those of transitional cell carcinoma and all of undifferentiated carcinomas were invasive. The incidence of invasive type was closely related to the grade of anaplasia. These results show that the morphological characteristics of urinary bladder carcinomas induced by BBN in rats are similar to those seen clinically in humans.

Ganglioneuroblastoma associated with malignant mesenchymoma

A case of ganglioneuroblastoma associated with malignant mesenchymoma is reported. The tumor originated from the retroperitoneum and was comprised not only of neuroblastoma and ganglioneuroma, but also of typical rhabdomyosarcoma, liposarcoma, undifferentiated mesenchymoma, as well as cartilaginous tissue. No distinct border existed between thses different components. The histogenesis of the tumor is discussed. We suggest that the tumor derived from a remnant of neural crest (ectomesenchyme).

Sequential morphological changes of ulceration in the glandular stomach of rats induced by iodoacetamide

Two groups of 25 male Wistar rats were given 0.1% iodoacetamide (IAM) with or without 0.4% Tween 60 in their drinking water for 12 weeks. Two or three rats from each group were sacrificed at intervals for sequential morphological observations on ulceration of gastric mucosa. The ulcers invariably developed in the fundic region adjacent to the limiting ridge, and they penetrated the muscle coats and extended to the serosal lining on continuous treatment with IAM for 9 weeks. The ulcers appeared chronic, but when IAM was discontinued the healing process began rapidly and the mucosa regenerated almost completely within six weeks. Regenerating epithelium on areas of ulcer differentiated progressively, and the renewed mucosa showed pyloric metaplasia.

Effects in rats of sodium chloride on experimental gastric cancers induced by N-methyl-N-nitro-N-nitrosoguanidine or 4-nitroquinoline-1-oxide

The effects were studied of NaCl on the production of gastric carcinomas by N-methyl-N-nitro-N-nitrosoguanidine (MNNG) and by 4-nitroquinoline-1-oxide (NQO) in male Wistar rats. Nine groups of rats were treated as follows: Group 1 was given 50 mg MNNG/liter and 6 g NaCl solution/liter to drink and was fed a stock diet supplemented with 10% NaCl. Group 2 received 1 ml saturated NaCl once a week and 50 mg MNNG/liter to drink. Group 3 was treated with MNNG alone. Group 4 was given a solution of 1 mg NQO once a week and fed a stock diet supplemented with 10% NaCl. Group 5 received a solution of 1 mg NQO saturated with NaCl. Group 6 was given NQO alone. Groups 7 and 8 were given NaCl alone. Group 9 was untreated. Adenocarcinomas developed in the glandular stomach in group 2 at a significantly higher incidence than in group 3. Poorly differentiated adenocarcinomas of the glandular stomach were detected in only groups 1 and 2. One poorly differentiated adenocarcinoma metastasized to the lymph nodes. A high incidence of squamous cell carcinomas of the forestomach was found in groups 4 and 5. No malignant tumors were seen in groups 6-9. NaCl given alone had no apparent carcinogenicity in rats but, when administered with MNNG or NQO, it enhanced the carcinogenic effects of MNNG and NQO in the stomach.

Characterizations of acylagmatine amidohydrolase and carboxypeptidase from Fusarium anguioides

Previously an enzyme, named acylagmatine amidohydrolase, hydrolyzing bleomycin B2 to bleomycinic acid and agmatine was found in the mycelia of Fusarium anguioides Sherbakoff. In this work the enzyme was purified further, but not completely. The crude enzyme preparation hydrolyzed various acylagmatines and also peptidyl arginine, but the latter activity could be separated from acylagmatine amidohydrolase activity by gel filtration on Sephadex G-100. The enzyme was inhibited by PCMB and its molecular weight was estimated as 65,000 by gel filtration. It showed substrate specificity with respect to the alkyl-chain length of the amine moiety. The other hydrolase fraction with activity toward Bz-Gly-Arg was found to be of a sort of carboxypeptidase, which preferentially hydrolyzed peptides with arginine or lysine at the carboxyl terminus, including bradykinin, but liberated neutral amino acids as well from the terminus when the penultimate residue of the substrates was phenylalanine. With Bz-Gly-Arg as substrate Fusarium carboxypeptidase was sensitive to chelating agents but not to diisopropyfluorophosphate, and its molecular weight was estimated to be 145,000.

Age-decrease of cells sensitive to an autoantibody-specific for thymocytes and thymus-dependent lymphocytes in NZB mice

NZB mice naturally produce an autoantibody which in the presence of complement is specifically cytotoxic for thymocytes and thymus-dependent lymphocytes (T-cells) in the peripheral lymphoid tissues (lymph nodes and spleen) and the circulation of mice. Using a direct cytotoxicity test with a NZB mouse serum pool which contained the high titred autoantibody, a progressive decrease was observed with age in the proportion of the autoantibody-sensitive cells in mesenteric lymph node, spleen, and blood of NZB mice in comparison with mice of other strains (C57BL/6J and NZW). The numerical decrease in the population of autoantibody-sensitive cells was evident at younger age and greater degree in the peripheral blood than in the lymph node and spleen. The age-decrease in the number of autoantibody-sensitive cells in lymph node and spleen contrasted with the numerical increase in nucleated cells in these organs. The age-decrease in the proportion and number of the autoantibody-sensitive cells in the blood exceeded the decrease in the blood lymphocyte count. This finding indicated that T-cells in the blood are selectively depleted with the ageing of NZB mice. A similar observation was made on the blood lymphocytes of (NZB × NZW)F₁ hybrid mice. The depletion of T-cells in the blood in association with the production of natural thymocytotoxic autoantibody is termed autoimmune thymus-dependent lymphocytopenia.

Natural cytotoxic autoantibody against thymocytes in NZB mice

NZB mice were found to produce natural thymocytotoxic autoantibody in high prevalence and antibody titre. This autoantibody in NZB mice was detectable by the cytotoxicity test at both 4°C and 37°C; the prevalence and antibody titre were generally higher at 4°C. Mice of other strains also produced natural thymocytotoxic autoantibody although in lower prevalence and antibody titre and in some instances the activity was greater at 37°C than at 4°C. Natural thymocytotoxic autoantibody in NZB mice reacted equally with the thymocytes of virtually all strains of mice tested but to a lesser degree with the thymocytes of SJL/J mice. A serum pool obtained from old NZB mice had an extremely high titre of natural thymocytotoxic autoantibody (1:1024 at 4°C). Nevertheless, the cells in lymph nodes, spleen and blood leucocytes were only partially sensitive to this serum pool, and bone marrow cells were for the most part negative. By absorption, the antigen reacting with natural thymocytotoxic autoantibody was found in thymus, lymph node, spleen and brain of adult mice, thymus of newborn mice and some leukaemias. Natural thymocytotoxic autoantibody in NZB mice was an IgM-globulin as determined by sensitivity to 2-mercaptoethanol treatment and by Sephadex G-200 column chromatography in contrast to other natural antibodies (antinuclear, antierythrocyte and G antibodies) of IgG-globulin class. NZB mice also produced natural antibodies against thymocytes of the rat and the hamster; these antibodies were species-specific and did not react with the thymocytes of any but the homologous species.

Natural thymocytotoxic autoantibody and reactive antigen in New Zealand black and other mice

Naturally occurring thymocytotoxic autoantibody (NTA) was detected by cytotoxic test in the sera of very young New Zealand Black mice (within 1 month after birth); the incidence was 100% at 3 months of age. Some mice from other strains also had NTA, but at an older age and with lower incidence and antibody titer. NTA had optimal activity at 4 degrees C but was also strongly reactive at 37 degrees C. It was cytotoxic for thymocytes of all strains of mice tested. Whereas only thymocytes were highly sensitive to NTA, the reactive antigen was demonstrated by absorption test in the thymus, lymph node, spleen, and brain of adult mice. It could be demonstrated only in the thymus of newborn mice.The distribution of NTA-reactive antigen suggests the presence of an antigen distinct from any so far described on the cell surface of mouse thymocytes. Gel filtration of NZB mouse serum suggests that NTA is an IgM. Mouse thymocytes sensitized with NTA in vitro became highly susceptible to phagocytosis by syngeneic macrophages.

Wild-type Gross leukemia virus and the pathogenesis of the glomerulonephritis of New Zealand mice

The pathogenesis of the spontaneous glomerulonephritis of NZB and (NZB x NZW) F(1) hybrid mice is related at least in part to the formation of natural antibody against antigens of the G (Gross) system, and apparently to the deposition in the glomeruli of immune complexes of G natural antibody with G soluble antigen (GSA), type-specific antigen specified by wild-type Gross leukemia virus. G natural antibody and GSA are detectable in the acid-buffer eluate of the kidneys of NZB mice during the course of the glomerulonephritis. (NZB x NZW) F(1) hybrid mice develop glomerulonephritis and produce GSA and free G natural antibody earlier in life than do NZB mice. The proteinuria manifestation of the gomerulonephritis of (NZB x NZW) F(1) hybrid mice becomes increasingly prevalent as GSA undergoes immune elimination from the circulation. Gross leukemia virus-specified antigens together with bound immunoglobulins are located in the glomerular lesions of (NZB x NZW) F(1) hybrid mice, both in the mesangium as observed in NZB mice and also in the wall of the peripheral capillary loops of the glomeruli.