[Measurement of prostaglandin E2 content in lung tissue of mouse]

A radioimmunoassay (RIA) was applied for the determination of PGE2 levels in the lung from 4 groups of male ICR mice 1) fed a standard diet, 2) fed a 20% corn oil-supplemented diet (HFD) for 2 weeks, 3) given a single s.c. injection of 15 mg/kg of 4NQO, a potent lung carcinogen and 4) given a s.c. injection of 4NQO and subsequently fed HFD for 2 weeks. Animals were sacrificed at week 3, and the lung was carefully excised and frozen in liquid nitrogen to prevent the postmortem synthesis of PGE2. PGE2, extracted from the lung tissue, was purified and then measured with or without adding a known amount of PGE2. The lung levels of PGE2 were shown to be significantly higher in the groups treated with HFD and/or 4NQO than the group fed a standard diet. These results show that the modified RIA method can be used for the measurement of PGE2 contents in the tissue of animals.

[A case of the thyroidea ima artery arising from the aortic arch]

The present report describes a case of the thyroidea ima artery observed in a 65-year-old Japanese male on dissection in 1988. The thyroidea ima artery arose from the aortic arch between the branchiocephalic trunk and the left common carotid artery. The thyroidea ima passed to the left lobe and isthmus of the thyroid gland for the supply of these. The inferior thyroid artery on the right side was of common type in its origin and course, though that on the left side was absent. Either of the superior thyroid arteries arose from the common carotid artery.

Visceral urate deposits in chicks inoculated with avian nephritis virus

Avian nephritis virus, G-4260 strain, was inoculated orally into one-day-old specific-pathogen-free chicks of two lines. Approximately 20 per cent of the chicks of both lines died with visceral urate deposits from eight to 12 days after infection, and the virus was isolated from the kidneys of the dead chicks. At 14 or 15 days of age the mean liveweight of the surviving infected chicks was approximately 16 per cent less than that of the uninfected control chicks.

Teratoma of the pituitary gland in a young male rat

A pituitary teratoma was found in a 5-week-old (37-day-old) male Donryu rat. The tumour (10 x 11 x 9 mm) was round in shape and white in colour. The cut surface was solid without haemorrhagic or cystic change. Histologically, it was composed of various kinds of tissue components including mature and immature elements derived from the three embryonic germ layers, i.e., nervous tissue, cartilage, bone, squamous epithelial element, glandular element lined by one or more layers of ciliated columnar or cuboidal epithelial cells, striated muscle tissue, adipose tissue and connective tissue. Neuroepithelial rosettes and immature or embryonal epithelium as well as immature cartilage were intermingled with mature somatic tissues.

[A case of sarcoidosis associated with membranous nephropathy]

A 59-year-old woman was admitted to the hospital with a complaint of right visual disturbance. At admission, she had proteinuria and microscopic hematuria. The pulmonary X-ray showed bilateral hilar lymphadenopathy (BHL) but tuberculin test were negative. Also, bronchoalveolar lavage (BAL) and renal biopsy were performed. Bronchoalveolar lavage fluid (BALF) contained a high percentage of OKT 4 positive cells. In renal biopsy, light microscopic study showed thickening glomerular basement membrane (GBM) with tubulo-interstitial legion. Immuno-fluorescent study revealed granular deposits of IgG along glomerular capillary wall. Electron microscopic study showed subepithelial electron dense deposits of GBM, which are characteristic for membranous nephropathy (MN). It is well known that both sarcoidosis and MN are associated with immunological abnormality. This case might be significant for the study of pathogenesis of sarcoidosis.

Carcinogenicity and organ specificity of N-trimethylsilylmethyl-N-nitrosourea (TMS-MNU), N-neopentyl-N-nitrosourea (neoPNU), and N-methyl-N-nitrosourea (MNU) in rats

The carcinogenicity and organ specificity of TMS-MNU and neoPNU, a carbon-analogue of TMS-MNU, in rats were investigated and compared with those of MNU. Compounds were dissolved in olive oil and rats in the experimental groups received 20 weekly intragastric intubations of 10 mg/kg of MNU or equimolar amounts of TMS-MNU or neoPNU in the same manner. The experiment was terminated when the survivors were sacrificed at the 52nd week after the final administration. In the TMS-MNU and MNU groups, tumors of the forestomach were induced and the incidence was 100% in the groups of both sexes. In addition, tumors of the glandular stomach, nervous system, kidney, and lung were also observed in these groups. Neurogenic tumors were found more frequently in the MNU group than in the TMS-MNU group. The incidence of lung tumors, however, was higher in the TMS-MNU group than in the MNU group. On the other hand, in the control and neoPNU groups, no tumor was found in these organs except the lung, and all tumors observed in these two groups were histologically similar to spontaneous ones in this strain of rats. These results indicate that the carcinogenicity of N-alkyl-N-nitrosoureas is dependent on the chemical structure of their alkyl chain. The result of the present study coincides with the previous result that the species of TMS-MNU in the alkylating step is the same as that of MNU, but different from neoPNU. The difference in the organ specificity between TMS-MNU and MNU demonstrates that the organ specificity is dominantly dependent on the distribution of the chemicals, since TMS-MNU may possibly be distributed differently from MNU because of its different partition property.

[A clinical experience of upper urinary tract disease using an endourological technic]

Fifty-three patients with upper urinary tract disease were treated by using endourological technique between July, 1986 and July, 1987; percutaneous nephrolithotripsy (PNL) in 26 cases, transurethral ureterolithotripsy (TUL) in 11 cases, endopyelotomy for ureteropelvic obstruction in 3 cases, dilation of ureteral stenosis in 3 cases and percutaneous nephrostomy in 10 cases. The stones could be successfully removed in 24 cases (92%) of PNL and 10 cases (91%) of TUL. No severe complications were seen in this series. The many reports of PNL and TUL were investigated in detail, but other endourological approach will need further long-term followup.

Lack of carcinogenicity of tartrazine (FD & C Yellow No. 5) in the F344 rat

The carcinogenicity of tartrazine (C. I. Food Yellow No. 4, FD & C Yellow No. 5), a food, drug and cosmetics colouring, was examined in F344 rats. Tartrazine was dissolved in distilled water at levels of 0, 1 or 2%, and groups of about 50 male and 50 female rats were given one of these solutions ad lib. as their drinking-water for up to 2 yr. No toxic lesions specifically caused by tartrazine were detected in any treated group of either sex. Many tumours developed in all groups including the control group, and the organ distribution of these tumours and their histological characteristics were similar to those of the spontaneous tumours that are known to occur in this strain of rats. Except for mesothelioma in males and endometrial stromal polyp in females, there were no significant increases in the incidences of any tumours over those in the corresponding control group. In males, mesotheliomas were found only in the group given 1% tartrazine and the incidence of this lesion was statistically significant (Fisher's exact test) in comparison with the other two groups (P less than 0.02). The incidence of endometrial stromal polyp was also significantly higher among females given the 1% dose than in the controls (P less than 0.05). However, no positive trend was noted in the occurrence of these two tumours using an age-adjusted statistical analysis. Mesothelioma and endometrial stromal polyp are frequently observed spontaneous tumours in this strain of rats, and their incidences in our historical controls are 4.1 and 21.9%, respectively. However in the present study mesothelioma occurred in none of the male control rats and the incidence of endometrial stromal polyp was only 10.6% in the female control group. Moreover, there was no significant difference between the control and treated groups in hyperplastic or pre-neoplastic changes in the mesothelium or endometrium. From these findings, we concluded that the significant increases in the incidences of mesothelioma and endometrial stromal polyp that occurred in the groups given 1% tartrazine were not attributable to tartrazine administration. Thus, it is concluded that tartrazine was not carcinogenic in F344 rats when administered continuously at doses of up to 2% in the drinking-water for up to 2 yr.

Long-term studies on carcinogenicity and promoting effect of phenylbutazone in DONRYU rats

The carcinogenicity and promoting effect of phenylbutazone were investigated in inbred DONRYU rats. In the carcinogenicity study, both sexes were administered the chemical at dietary levels of 0 (control), 0.125, or 0.25% for 2 years. Toxic lesions were associated with phenylbutazone treatment in the kidney and digestive tract, appearing to have an adverse effect on life expectancy. Various tumors were detected in all groups including the controls. With the exception of pheochromocytoma in the female high-dose group, no statistically significant increase in yield of any tumors, including leukemia, was apparent in the treated groups of either sex when the data were analyzed by Fisher's exact probability and/or chi-square tests. Application of an age-adjusted statistical analysis revealed a slight positive effect regarding the occurrence of pheochromocytomas, neoplastic liver nodules, and leukemias in females. However, these tumors are commonly observed to develop spontaneously in this rat strain, and no such effect was apparent in the male groups. In addition, no differences in incidences of relevant preneoplastic lesions were evident between control and treated groups. Thus phenylbutazone showed no carcinogenic activity in DONRYU rats when given continuously in the diet for 2 years. For the investigation of promoting effect, phenylbutazone was given as a dietary supplement for 2 years subsequent to initiation with N-ethyl-N-nitrosourea or N-propyl-N-nitrosourea. No enhancement of nitrosourea-induced leukemogenesis was apparent, although a slight promoting effect was demonstrated for renal and thyroid tumorigenesis.

Glandular changes associated with the spontaneous interstitial cell tumor of the rat testes

Testes of untreated F344 and Wistar rats in the control groups of carcinogenicity studies were histologically examined, and the histopathological characteristics and histogenesis of glandular changes in these testes were studied. In 266 testes of 2-year-old F344 rats, 263 had interstitial cell tumors (ICTs) (98.9%) and 39 had glandular changes (14.7%). These glandular changes were also found in 1 out of 38 1-year-old F344 rat testes (2.6%), and 3 in 154 2-year-old Wistar rat testes (1.9%). The changes were observed exclusively in the interstitial cell tumors (ICTs). These glandular changes showed variation in size, shape and number. They were composed of tubules or cysts lined by a layer of cuboidal or columnar epithelial cells, which had terminal bars, occasionally PAS- and alcian blue-positive brush borders, and rarely, alcian blue-positive cytoplasmic vacuoles. Serial sections revealed that the changes were not connected with the rete testes, but with the degenerative seminiferous tubules involved in the ICTs lined by a layer of flat endothelial-like cells. The findings suggest that the lesions constitute metaplastic changes of the Sertoli cells.

Possible infectious causes in 651 patients with acute viral hepatitis during a 10-year period (1976-1985)

Six hundred and fifty-one patients with acute viral hepatitis were identified serologically between January 1976 and December 1985. Of these, 109 (17%) had hepatitis A, 135 (21%) had hepatitis B, and 407 (62%) had hepatitis non-A, non-B. The possible infectious causes for acquisition of viral hepatitis occurring within 6 months before the onset of hepatitis were analysed. Approximately 80% of cases of hepatitis A and 70% of hepatitis B had no known risk factor, while in 67% of cases of hepatitis non-A, non-B possible risk factors for infection were documented. Infectious causes for hepatitis A were ingestion of raw shellfish (11%) and previous familial contact with patients with hepatitis A (10%). For hepatitis B, risk factors included medicare (24%), such as transfusion, surgical operation, accidental needle stick and acupuncture, and sexual contact (6%). For hepatitis non-A, non-B, the most important infectious cause was medical procedures (65%). The numbers of hospital employees were 2 (2%) with hepatitis A, 15 (11%) with hepatitis B and 14 (3%) with hepatitis non-A, non-B. These data suggest that hepatitis non-A, non-B can be a kind of nosocomial disease.

Lack of carcinogenicity of triethanolamine in F344 rats

The carcinogenic potential of triethanolamine was examined in F344 rats. Triethanolamine was dissolved in distilled water at levels of 0 (control), 1, and 2%, and groups of 50 males and 50 females were given these doses ad libitum as drinking water for 2 yr. The dose levels in females were reduced by half from wk 69, because of associated nephrotoxicity. A variety of tumors developed in all groups, including the control group, and all tumors observed were histologically similar to spontaneous tumors in this strain of rats. No statistically significant increase of the incidence of any tumor was observed in the treated groups of both sexes by the chi-square test. In this study, however, there was an increase in nephrotoxicity, which appeared to have an adverse effect on the life expectancy of the treated animals, especially of females. Therefore, an age-adjusted statistical analysis on incidences of main tumors or tumor groups of both sexes was also done by methods recommended by Peto et al. (1980). The result showed that a positive trend (p less than 0.05) was noted in the occurrence of hepatic tumors (neoplastic nodule/hepatocellular carcinoma) in males and of uterine endometrial sarcomas and renal-cell adenomas in females. These tumors, however, have been observed spontaneously in this strain of rats, and their incidences in the control group of the present study were lower than those of our historical controls. These results may indicate that a positive trend in the occurrence of these tumors is not attributable to triethanolamine administration. Increased incidence of renal tumors in the female high-dose group may have been connected with renal damage. Histological examination of renal damage observed in the treated groups, especially in the female high-dose group, revealed acceleration of so-called chronic nephropathy. In addition, mineralization of the renal papilla, nodular hyperplasia of the pelvic mucosa, and pyelonephritis with or without papillary necrosis were also observed. Thus, it is concluded that under these experimental conditions triethanolamine is not carcinogenic in F344 rats but is toxic to the kidneys.

Spontaneous neoplastic and non-neoplastic lesions in aging Donryu rats

Spontaneous neoplastic and non-neoplastic lesions in 95 male and 96 female Donryu rats which were observed up to 120 weeks of age, were examined. The incidence of spontaneous tumors was 73.7% in males and 88.5% in females. In males, the most frequent tumors were pituitary adenomas, followed by pheochromocytomas and insulinomas. In females, uterine adenocarcinomas, mammary fibroadenomas and pituitary adenomas were the most common. Other tumors with relatively high incidences in both sexes included cortical adenomas of the adrenal gland, histiocytic sarcomas of the hematopoietic organs and granular cell tumors of the brain. Various tumors were also found in many other organs and/or tissues, although their incidences were low. The organ distribution and incidences of spontaneous tumors observed in Donryu rats were different from those in other strains of rats such as the ACI, Wistar, F344 or Sprague-Dawley strains. The main non-neoplastic lesions were observed in the lung, cervical lymph nodes and kidney of both sexes. In addition, lesions were also observed in the urinary bladder, prostate and peripheral nerves (spinal nerve roots and peripheral nerves) and/or femoralis muscle of males. Histologically, the most characteristic lesion was radiculoneuropathy with degeneration of the peripheral nerves.

Carcinogenicity of N-alkyl-N-(1-hydroperoxyalkyl) nitrosamines after intravenous injections in F344 rats

As model compounds of alpha-hydroxy N-nitrosamines, four alpha-hydroperoxy N-nitrosamines were tested for their carcinogenic potential in F344 rats by i.v. injections. Correlation between chemical structure and carcinogenic potencies with respect to target organs was examined. Compounds used in this study were N-methyl-N-(hydroperoxymethyl)nitrosamine (MHPMN), N-ethyl-N-(1-hydroperoxyethyl)nitrosamine (EHPEN), N-propyl-N-(1-hydroperoxypropyl)nitrosamine (PHPPN) and N-butyl-N-(1-hydroperoxybutyl)nitrosamine (BHPBN). All chemicals were dissolved in distilled water and rats received 10 X 1 weekly i.v. injections of these chemicals (10 X 1 weekly injection of 5 mg/kg of MHPMN or equimolar amounts of other chemicals). Lung tumors were detected in all groups of both sexes and the incidences were 100% in each group. Thyroid tumors were also observed with relatively high incidences in treated groups except BHPBN. In the control group, tumors were observed mainly in the testis or uterus, and only two lung tumors and one thyroid tumor were observed in females. Histologically, all lung tumors in the MHPMN group were adenocarcinomas, squamous cell carcinomas or a mixture of both types. In the EHPEN, PHPPN and BHPBN groups, especially in females, incidences of carcinomas decreased as the length of the alkyl chain of the compounds, and most of lung tumors in females of the PHPPN and BHPBN groups were adenomas. Many of the thyroid tumors observed in the treated groups were follicular adenomas/carcinomas, whereas C-cell adenomas were the most common type of spontaneous thyroid tumors in this strain of rats. These target organs were similar to those of alpha-acetoxy N-nitrosamines reported previously. The results indicate that the carcinogenic activities of these chemicals depend on the length of the alkyl chain and that organ specificity of these chemicals may differ from those of their mother compounds.

Induction of Sertoli cell tumors in the rat ovary by N-alkyl-N-nitrosoureas

Relatively high incidences of Sertoli cell tumors of the ovary were induced in Donryu rats given a 400 ppm N-ethyl-N-nitrosourea solution as drinking water for 4 weeks or a single dose of 200 mg/kg N-propyl-N-nitrosourea by stomach tube. Typical Sertoli cell tumors were composed of solid areas showing tubular formation. Tubules were lined by tall, columnar cells having abundant, faintly eosinophilic, often vacuolated cytoplasm, and basally oriented round nuclei. In some cases, Sertoli cell tumors were found to be mixed with granulosa cell tumors.

Relation between development of leukemia and duration of N-nitroso-N-ethylurea treatment in DONRYU rats

N-Nitroso-N-ethylurea (NEU; CAS: 759-73-9) is a strong leukemogen that induces erythroblastic leukemia in inbred DONRYU rats. In the present experiments, relationships between development of leukemia, duration of NEU treatment, and sequential changes in the hematopoietic organs during carcinogen administration were examined. In experiment 1, groups of rats were given a 400-ppm NEU solution for 0, 2, 4, 6, 8, or 10 weeks, and the resultant incidence of leukemias was 0, 26, 40, 75, 95, and 100%, respectively. Of the various types of leukemia, the erythroblastic type was observed in 0, 0, 20, 40, 95, and 90% of rats, respectively. The average latent period showed an inverse correlation with the duration of NEU treatment. In experiment 2 the animals were divided into carcinogen-treated and control groups, and rats were sacrificed periodically for histopathologic examination. In the experimental group, the bone marrow became hypoplastic soon after commencement of NEU treatment and at the 6th week became severely aplastic, thereafter recovering slightly. At the 10th week, 2 rats out of 5 examined were leukemic. Relationships between incidence of leukemia, duration of NEU treatment, and sequential changes of the bone marrow during carcinogen administration are discussed.

Lack of evidence of carcinogenicity of technical-grade piperonyl butoxide in F344 rats: selective induction of ileocaecal ulcers

The carcinogenicity of technical-grade piperonyl butoxide was studied in F344/DuCrj rats fed a dietary level of 0.5 or 1% for 2 yr. Various tumours were detected in all groups, including the untreated control group, but no significant dose-related increase in the incidence of any tumour was found. Thus, it is concluded that under these experimental conditions piperonyl butoxide was not carcinogenic in F344 rats. Unexpectedly, however, ileocaecal ulcers were found in animals of both sexes in both experimental groups and the incidence was dose related. Further studies are required to establish the mechanism of induction of ileocaecal ulcers by piperonyl butoxide.

Effect of Nocardia rubra cell wall skeleton and/or cyclophosphamide on leukemogenesis induced by N-ethyl-N-nitrosourea in Donryu rats

The effect of Nocardia rubra cell wall skeleton (N-CWS) and/or cyclophosphamide (CP) on chemical carcinogenesis was examined in female Donryu rats exposed to N-ethyl-N-nitrosourea (ENU) in the drinking water for 6 weeks. Five administrations of N-CWS following ENU treatment caused a slight prolongation of the average survival of rats but did not reduce the incidence of leukemia. CP given on two occasions after ENU treatment caused a moderate prolongation of average survival period and a moderate reduction of the incidence of leukemia, but significant differences from ENU-treated control group values were not observed after statistical analysis. Combined treatment with N-CWS and CP after ENU treatment caused prolongation of the average survival period of rats and a statistically significant reduction in the incidence of leukemia. The present experiment indicates that combined treatment with N-CWS and CP effectively reduces induction of leukemia by ENU in rats, although other types of tumors were not affected.

Organ-specific carcinogenicity of N-methyl-N-nitrosourea in F344 and ACI/N rats

Male and female F344 rats were continuously administered N-methyl-N-nitrosourea (MNU) in their drinking water at concentrations of 200 or 100 ppm, and both sexes of ACI/N rats were given MNU at a concentration of 200 ppm. By the 42nd week of the experiment, high incidences of brain/spinal cord tumors were observed in both strains of rats. Histologically, many of them were astrocytomas or anaplastic astrocytomas. In addition, malignant neurinomas were also detected in the spinal nerve roots and trigeminal nerves, although their incidences were rather low. There was no difference in the type and incidence of these neurogenic tumors between the two strains of rats. Tumors of the tongue and esophagus were mainly observed in the high-dose group of F344 rats and those of the glandular stomach were observed in the low-dose group of F344 rats. In ACI/N rats, tumors of the heart and renal pelvis were detected. The organ-specific carcinogenicity of MNU in these two strains of rats was compared with that of MNU in Donryu rats. It was demonstrated that organ specificity of MNU given orally was influenced not only by the strain of rats but also by the dose level.

Cholinergic neuromodulation by ATP, adenosine and its N6-substituted analogues in guinea-pig ileum

The effects of ATP, adenosine and N6-substituted adenosines, adenosine receptor agonists, on the twitch contraction of guinea-pig ileum evoked by transmural stimulation were evaluated. Adenosine and ATP produced an immediate and concentration dependent inhibition of the twitch, IC50 being 1.1 X 10(-5) mol/l and 1.2 X 10(-5) mol/l, respectively. N6-l-phenylisopropyl adenosine (L-PIA), N6-cyclohexyl adenosine (CHA) and N6-allyl adenosine also induced inhibitions which were gradual and persistent, IC50 being 2.6 X 10(-8), 2.7 X 10(-8) and 5.4 X 10(-7) mol/l, respectively. Dipyridamole (10(-7) mol/l), an adenosine uptake inhibitor, markedly augmented the inhibition evoked by adenosine and ATP, but not that by three N6-substituted adenosines, while theophylline (10(-4) mol/l) almost completely antagonized the inhibitory effects of all purine compounds. IC50 value of adenosine in the presence of dipyridamole (5 X 10(-7) mol/l) was shifted to the left about 50 times from the control, whereas that of L-PIA was virtually unchanged. Tissue-medium ratios indicating uptake of [3H]adenosine, [3H]ATP and [3H]CHA into the segment were 3.23 (s.e.m. = 0.59), 3.59 (s.e.m. = 0.78) and 0.41 (s.e.m. = 0.04), respectively. These results suggest that not only adenosine and ATP but also these N6-substituted adenosines are potent agonists for the P1 receptor, implying a similarity between P1 and A1 receptor in a functional role and these purine compounds may thereby modulate cholinergic neurotransmission by altering adenylate cyclase activity.

A possible explanation for a greater discrepant suppression by adenosine and N6-cyclohexyl adenosine of the guinea-pig ileal contraction

Adenosine and N6-cyclohexyl adenosine (CHA) reduced dose-dependently a twitch contraction of guinea-pig ileum and their IC50 values were 1.0 X 10(-5) and 1.1 X 10(-8) M, respectively. By exposure to adenosine uptake and deaminase inhibitors, dipyridamole and erythro-9-(2-hydroxy-3-nonyl) adenine (EHNA), the adenosine-induced inhibition was enhanced, whereas the CHA-induced one was almost unchanged. Therefore, outstanding potency difference of the suppression by adenosine and CHA was minimized by concurrent addition of both the inhibitors. Uptakes of [3H]CHA into the guinea-pig ileum and taenia-coli were considerably lower than those of [3H]adenosine and were insensitive to dipyridamole. In the rat connective tissue segment, uptake of [3H]adenosine was smaller than that in the guinea-pig taenia-coli and ileal segments (especially, in the latter), and was virtually unaffected by 10(-5) M dipyridamole. These findings suggest that a greater discrepancy of the suppression by adenosine and CHA of the ileal twitch may substantially result from their different uptake and deamination in the synaptic region rather than their dissimilar intrinsic activity for the purinoceptor.

Malignant fibrous histiocytomas induced in rats by polymers

Five polymeric materials (3 polyvinyl chlorides, 1 polyhydroxyethyl methacrylate, and 1 dimethyl polysiloxane) were implanted into subcutaneous (SC) tissues of rats. Subcutaneous tumors developed in all experimental groups. The incidences of the tumors differed however, although the experimental conditions were the same for all these materials. This result indicates that chemical characteristics of the materials may influence the incidence of SC tumors. From the histological and electron-microscopic findings many of these tumors were diagnosed as malignant fibrous histiocytomas.

Development of thymic lymphomas by oral administration of N-nitroso-N-propylurea and establishment of transplantable lines of thymic lymphoma in F344 rats

Forty-eight female F344/DuCrj rats were given a 400-ppm solution of N-nitroso-N-propylurea (CAS: 816-57-9) continuously in their drinking water. Thymic lymphomas were induced most frequently (85%) followed by duodenal tumors (48%). Sixteen tumors were examined by the immunofluorescence inhibition test for murine leukemia virus-related antigens; 15 were negative and the other was weakly positive. Twenty-six tumors were intraperitoneally and subcutaneously transplanted syngeneically; 25 (96%) were successfully transplanted intraperitoneally and 24 (92%) subcutaneously. The serial intraperitoneal transplantation was continued, and 22 lines of transplantable lymphoma in an ascites form were established. In almost all tumor lines, tumor cells took in a high percentage of recipient rats and caused the death of the recipients within 12-23 days. The thymus, liver, spleen, greater omentum, and lymph nodes were frequently invaded by transplanted tumor cells. The tumor lines were considered to be of T-cell lineage.

Spontaneous tumors of the nervous system and associated organs and/or tissues in rats

Spontaneous tumors of the nervous system and associated organs and/or tissues in 346 male and 346 female F344/DuCrj rats and 200 male and 177 female Slc:Wistar rats were examined. The main neurogenic tumors observed were gliomas and neurinomas, which were detected in both strains of rats. Out of 7 gliomas, 6 were found in the brain and 1 in the spinal cord, and out of 4 neurinomas, 2 were in the trigeminal nerves and the other 2 were in the spinal nerves. In addition, other types of tumors (2 granular cell tumors in the brain, 1 pinealoma, 3 ganglioneuromas in the adrenal gland, 1 undifferentiated carcinoma in the nasal cavity and 1 chordoma in the posterior neck region) were observed.

Foreign-body tumorigenesis in rats by various kinds of plastics--induction of malignant fibrous histiocytomas

Five kinds of plastics (3 polyvinyl chlorides, 1 polyhydroxyethyl metacrylate and 1 dimethyl polysiloxane) were implanted into subcutaneous tissues of Wistar rats of both sexes. Subcutaneous tumors developed in all experimental groups. The incidences of the tumors, however, differed from each other, although these materials were tested on the same experimental condition. This result indicates that chemical characters of the materials may influence the incidence of subcutaneous tumors. Histologically, most of these subcutaneous tumors were mesenchymal tumors with spindle cells arranged in a storiform pattern, with sheets of histiocyte-like cells or pleomorphic giant cells. Electron microscopy showed mixture of fibroblastic cells, histiocytic cells and undifferentiated cells in these tumors. From these histological and electron microscopical findings, many of the tumors were diagnosed as malignant fibrous histiocytomas.

[A case of advanced gastric cancer which disappeared histopathologically after short-time chemotherapy]

Poorly differentiated adenocarcinoma was confirmed by endoscopic biopsy. Anticancer therapy was performed preoperatively, but was discontinued after the second intravenous administration of MFC because she developed nausea, vomiting and pancytopenia. On Jan. 18, 1980, gastrectomy with extended lymph node dissection was performed. Histologically, the excised stomach showed non-specific active ulcer (ul-IV) at the side of the tumor without evidence of residual cancer cells. The cause for the disappearance of the advanced carcinoma remains unknown. Although the dosage of the anticancer chemotherapy was quite small, this treatment may have promoted the regression of the tumor in conjunction with activated antitumor immunity of the host.

Carcinogenicity of low doses of N-ethyl-N-nitrosourea in F344 rats; a dose-response study

The threshold level of minimum carcinogenic dose of N-ethyl-N-nitrosourea (ENU) and the effect of dose on organ specificity were examined by continuous oral administration to both sexes of F344 rats of low doses of ENU at four concentrations (0.3, 1, 3 and 10 ppm) in the drinking water. ENU at 10 ppm selectively induced neurogenic tumors and tumors of the digestive tract, including duodenal tumors. Even at lower doses it enhanced the spontaneous development of some other tumors. A high dose of ENU (400 ppm) was previously found to induce duodenal tumors selectively. These results indicate that the organ specificity of ENU is influenced by the dose and that ENU has multi-potent carcinogenic activity in many organs and/or tissues. In this study, some specific tumors, such as those of the nervous system and digestive tract, seemed to require a minimum carcinogenic level of ENU (10 ppm) for their appearance. However, it seems that ENU is carcinogenic at much lower dose levels than 10 ppm because ENU enhanced the spontaneous development of some other tumors in many experimental groups. The so-called virtually safe doses inducing these specific tumors at a risk level of 10(-6) were calculated.

Induction of digestive-tract tumors in F344 rats by continuous oral administration of N-butyl-N-nitrosourea

Male and female F344/DuCrj rats were administered N-butyl-N-nitrosourea at a concentration of 400 ppm in their drinking water. By the 50th week of the experiment, the cumulative incidence of upper-digestive-tract tumors was as high as 35/39 (90%) and 34/39 (87%) in male and female rats, respectively. Among these, esophageal and forestomach tumors occurred most frequently. Except one female rat with fibroma, upper-digestive-tract neoplasms were of the epithelial type -- papilloma, squamous-cell carcinoma or adenocarcinoma. In female rats, vaginal tumors were induced in 16 (41%) animals. Ear-duct tumors and hematopoietic neoplasms were also induced in both sexes of rats, with incidence of less than 21%.

Reliability of HbA1 assay in the mass survey for diabetes mellitus, with special reference to the preservation and transportation of blood samples

Studies on the reliability of the HbA1 assay in mass surveys for diabetes mellitus were carried out with special reference to the preservation and transportation of blood samples. It is essential to confirm that the preservation and transportation of samples have no effect on values for HbA1, since most of the mass surveys are carried out as field works. In our experience the levels of HbA1 remained unchanged for one week, both in samples kept at 4 degrees C, and in frozen samples kept at -40 degrees C or -80 degrees C and transported on solid CO2. The levels of HbA1 in the samples transported from Manila to Wakayama by the above-mentioned methods did not differ from those obtained in corresponding fresh samples. There was a good correlation between levels of HbA1 and levels of plasma glucose obtained 1 or 2 hr after breakfast (PPG). It was concluded that the use of both criteria (HbA1 of more than 8.00% and PPG of more than 120 mg/100 ml) in the diagnosis of diabetes mellitus is more reliable than use of either one alone.

Neoplastic and non-neoplastic lesions in aging Slc: Wistar rats

Spontaneous neoplastic and non-neoplastic lesions in 98 male and 100 female Slc: Wistar rats, which have been widely used in Japan for toxicological studies, were examined. As spontaneous tumors, the most frequent tumors in males were testicular interstitial cell tumors, followed by tumors of the hematopoietic organs, adrenal gland, thyroid gland, preputial gland, pituitary gland, liver and mammary gland. Those in females were tumors of the pituitary gland, mammary gland, hematopoietic organs, uterus and thyroid gland. The organ distribution and histological types of spontaneous tumors observed in Slc: Wistar rats were very similar to those in F-344/DuCrj rats, although the incidences of some tumors differed slightly in the two strains. Various non-neoplastic lesions were also observed in the heart, kidney, liver and many other organs. These results should be useful in evaluating the results of toxicological and carcinogenic studies on this strain of rat.

Induction of tumors in the small intestine and mammary gland of female Donryu rats by continuous oral administration of N-carboxymethyl-N-nitrosourea

The carcinogenicity of N-carboxymethyl-N-nitrosourea (CMNU), a naturally occurring N-nitroso compound, was tested in female Donryu rats. Four groups of female Donryu rats were given 400, 200, 100, or 0 ppm of CMNU solution continuously as drinking water. The incidence of tumors was highest and the mean survival time shortest in the 400 ppm group. A dose-effect relationship was observed in the tumor incidence and the mean survival time and the incidences of tumors in all experimental groups were significantly different from those in the control group. In the 400 ppm group, tumors were detected most frequently in the small intestine, followed by the mammary gland. In contrast, most tumors were observed in the mammary gland in the other two experimental groups, although dose-dependent induction of tumors of the small intestine was also detected in these two groups. The organ specificity of CMNU is compared with that of other N-alkyl-N-nitrosourea derivatives.

Carcinogenicity study of ammonia-process caramel in F344 rats

The carcinogenicity of ammonia-process caramel, a food colouring, was examined in F344 rats. Caramel was dissolved in distilled water at levels of 0, 1 and 4% and groups of 50 male and 50 female rats were given 20-25 ml of one of these solutions/rat/day as their drinking water for 2 yr. There were no significant differences between the total incidences of tumours or mean survival times of control and experimental groups. A variety of tumours developed in all groups including the control group, and no dose-related effects were found either in the incidence or induction time of tumours in the various organs and tissues except in the pituitary gland of males, in which the incidence of tumours in males given 4% caramel solution was significantly higher than that in controls. Pituitary tumours are among the most common spontaneous tumours in ageing rats of this strain and have a variable incidence. In addition, almost all pituitary tumours detected in males given the 4% solution were microscopic tumours, and there was no significant difference between controls and treated groups in the incidence of hyperplasia or pre-neoplastic lesions in the pituitary gland. These results indicate that the significantly higher incidence of pituitary tumours in males given the 4% caramel solution was not related to caramel administration, but could be explained by the variability of the incidence of spontaneous pituitary tumours. Thus it is concluded that under these experimental conditions ammonia-process caramel was not carcinogenic in F344 rats.

Induction of angiogenic tumors in the duodenum of female Donryu rats by continuous oral administration of N-isobutyl-N-nitrosourea

Four groups of female Donryu rats were continuously given 400, 200, 100 or 0 ppm N-isobutyl-N-nitrosourea (iso-BNU) in their drinking water, and were examined for the development of tumors. The incidence of digestive tract tumors was 25/28 (89%), 14/24 (58%), 6/25 (24%) and 0/17 (0%), in the 400, 200, 100 and 0 ppm groups, respectively. The predominant type of digestive tract tumor was angiogenic, and a few were of the epithelial type. A dose-effect relationship was clearly demonstrated not only in the incidence of digestive tract tumors but also in the average survival period of rats with these tumors.

Carcinogenicity of N-alkyl-N-(acetoxymethyl)nitrosamines after subcutaneous injections in F-344 rats

As model compounds for metabolically activated N,N-dialkylnitrosamines, five N-alkyl-N-(acetoxymethyl)nitrosamines were synthesized and their carcinogenicity was tested in F-344 rats of both sexes. Compounds used in this study are N-methyl-(MAMN), N-ethyl-(EAMN), N-propyl-(PAMN), N-butyl-(BAMN), and N-isobutyl-N-(acetoxymethyl)nitrosamines (i-BAMN). All chemicals were dissolved in olive oil and rats received 10 weekly subcutaneous injections of these chemicals (10 X 5 mg MAMN or equimolar amounts of other chemicals) at the interscapular region. Subcutaneous tumors were detected in many rats of all groups treated with the chemicals, although no tumor was detected in the control group. Lung and/or thyroid tumors were also observed in many rats in the experimental groups. The incidence of subcutaneous tumors was highest in EAMN, followed in order by MAMN, PAMN, BAMN, and i-BAMN. On the contrary, the incidence of lung and thyroid tumors was highest in MAMN and decreased as the length of the alkyl chain of the chemicals increased. Histologically, almost all subcutaneous tumors were malignant fibrous histiocytomas. The results indicate that the chemicals possess systemic as well as local carcinogenicity in F-344 rats. The potent carcinogenic effects at the injection site of the alpha-acetoxy nitrosamines, coupled with their direct mutagenic activity reported previously, support the notion that these derivatives are useful as models for the ultimate form in the metabolic activation of N,N-dialkylnitrosamines.

Carcinogenicity studies of sodium nitrite and sodium nitrate in F-344 rats

The carcinogenicity of sodium and of sodium nitrate was examined in F-344 rats. Sodium nitrite was administered in the drinking-water for 2 yr at levels of 0.125 or 0.25%. Sodium nitrate was given in the diet at levels 2.5 or 5%. A variety of tumours occurred in all groups including the controls. The only significant difference between treated and control groups in the total number of tumours detected in either of the studies was a significant decrease in tumour incidence in the high-dose females given nitrite compared with controls. There was no positive dose-response relationship either in the incidence or in the induction time of tumours in either of the studies. The only significant result was a reduction in the incidence of mononuclear cell leukaemias in the experimental groups in both studies. It is concluded that sodium nitrite and sodium nitrate did not exert a carcinogenic effect that could be detected under the conditions of this study in which the animals showed a high incidence of spontaneous tumours.

Carcinogenicities of 1-ethyl- and 1-amyl-1-nitrosourethans in female donryu rats: dose-effect relations

Groups of female Donryu rats were given solutions of 100, 50, and 25 ppm of 1-ethyl-1-nitrosourethan (ENUR), and of 400, 200, and 100 ppm of 1-amyl-1-nitrosourethan (ANUR) continuously in the drinking water. The incidence of tumors was nearly 100% in all groups treated with ENUR or ANUR, but with both chemicals the rats showed dose-dependent mean survival times. In the groups treated with ENUR, tumors were most frequent in the upper digestive tract and duodenum, whereas in groups given ANUR tumors were induced only in the upper digestive tract, with none in the duodenum. Tumors of the forestomach were more frequent than those of the esophagus and oral cavity and/or pharynx in groups treated with ENUR. In contrast, the target organs of ANUR were the oral cavity and/or pharynx, and the esophagus, rather than the forestomach. The carcinogenicities of these two chemicals are discussed in comparison with those of other 1-alkyl-1-nitrosourethans.

Insulin-like activity of proteases. IV. Effect of partial digestion by an alkaline protease obtained from pronase on glucogen content in isolated mouse diaphragm

When an isolated mouse diaphragm was incubated with an insulin-like activity-possessing protease (ILAPP), the amount of Folin-positive materials released into medium increased as the incubation proceeded. However, the digestion by ILAPP did not affect the action of epinephrine on the glycogen content in diaphragm. Comparative studies on the effects of ILAPP and insulin on the glycogen content in diaphragm incubated in the presence or absence of ouabain at different concentrations of K+ increased in the incubation medium, that the glycogen-increasing effect of ILAPP or insulin was observed in each buffer containing K+ at a concentration of 0, 0.59, or 5.9 mM, and that the additive effect of ouabain used together with ILAPP or insulin was distinctly observed in the 5.9 mM K+-buffer but not in the 0.59 mM-buffer or K+-buffer. Thus, the effects of ILAPP resembled those of insulin. ILAPP probably digests the surface of diaphragm at a limited portion other than an epinephrine receptor to exhibit insulin-like activity.

Transplacental and neonatal carcinogenesis by 1-butyl-1-nitrosourethan in the ACI/N rat

1-Butyl-1-nitrosourethan (BNUR) and 1-butylurethane (BUR), a precursor of BNUR, were administered prenatally or neonatally to ACI/N rats. A few neurogenic tumors were induced in the offspring of mother rats that had received BNUR at the late stage of pregnancy and in the animals that had received one subcutaneous injection of BNUR within 24 hr after birth. No neurogenic tumors were observed in rats treated with BUR prenatally or neonatally.

Effect of steam temperature in the pelleting process of chicken food on the viability of contaminating bacteria

Pellet feeds were prepared at 70, 80, 83 and 90 degrees C under constant steam pressure of 4.0 kg/cm2. Under these conditions, the foods received 10 seconds of heat treatment, but treatment at 90 degrees C was found inappropriate since the food became slushy. Pelleting conditions examined in this study did not eliminate all contaminating bacteria, but coliforms from ingredients were killed when pelleting was conducted at over 80 degrees C. Concentrations of vitamins were not decreased during pelleting. The optimum temperature for pelleting food is considered to be 83 degrees C under the conditions investigated in this study.

Bacterial contamination in feed ingredients, formulated chicken feed and reduction of viable bacteria by pelleting

The number of bacteria in steam-pelleted or crumbled chicken food was compared with the number in individual ingredients and in mash. A few bacteria were detected in white-fish meal processed Alaska pollack. Highest yields were from alfalfa meal. Colonies numbering 3.5 x 10(3)-4.2 x 10(5) were obtained by heart-infusion agar culture, and 2.1 x 10(2)-7.0 x 10(4) with deoxycholate hydrogen sulphide lactose agar, from 1 g mash. After pelleting or crumbling the number of colonies in 1 g was reduced to 0-1.9 x 10(3) and 0-3.0 x 10(0) respectively. Bacteria in the lactose medium, mostly coliform, were observed in only 1 of 18 samples.

Performance of 3 successive generations of specified-pathogenfree chickens maintained as a closed flock

No antibodies against Salmonella pullorum, Mycoplasma gallisepticum, Mycoplasma synoviae, Haemophilus gallinarum, fowl pox virus, Marek's disease virus, herpes virus of turkey, infectious laryngotracheitis virus, avian adenovirus, avian reovirus, infectious bursal disease virus, reticuloendotheliosis virus, avian leukosis virus, avian encephalomyelitis virus and Newcastle disease virus were detectable in the sera obtained from these chickens in 3 generations at various ages. Antibodies against infectious bronchitis virus were detected in the sera of the 3rd generations at 66, 74 and 108 weeks of age. The performances of these chickens was nearly the same as that of conventional healthy chickens in the poultry industry, with no tendency to decline.

Mammary tumorigenic effect of a new nitrosourea, 1,3-dibutyl-l-nitrosourea (B-BNU), in female Donryu rats

Four groups (groups 1-4) of female Donryu rats were given continuously 400, 200, 100, or 0 ppm solution of 1,3-dibutyl-l-nitrosourea (B-BNU) as their drinking water, and were studied for the development of tumors. The incidence of mammary tumors was 15/19 (79%), 20/24 (83%), 21/26 (81%), and 8/25 (32%) in groups 1, 2, 3, and 4, respectively. In addition, hematopoietic neoplasms, uterine tumors, and vaginal tumors developed in 13, 11, and six rats, respectively in 69 treated rats. Other tumors were infrequent.