Decreased colony forming ability of human cells persistently infected with baboon endogenous virus. Brief report

Plating efficiency (PE), i.e. colony forming ability, of primary human embryonic lung fibroblasts persistently infected with baboon endogenous virus (BaEV) decreased to less than 10 per cent of that of the uninfected cells. A line of human amnion (FL) cells showed a 55 per cent reduction of PE after the establishment of BaEV carrier state. No decrease of PE did occur as a result of BaEV persistent infection in a rhabdomyosarcoma cell line (A204) and in fibroblasts derived from adult human skin. This characteristic reduction of PE in the infected primary embryonic fibroblasts was completely abolished by cultivation of the cells with conditioned medium from confluent either virus-infected or uninfected culture.

Polyglucosan bodies in the digestive tract of the aged dog

In our recent studies on aging phenomena in animals, polyglucosan bodies (PGB) were found within the smooth muscle in the digestive tract of aged dogs without neurologic signs. PGB were basophilic, round, or oval bodies which appeared to have a homogeneous or concentric shape. Their histochemical properties were characterized by the presence of glucose polymers (polyglucosan). Electron microscopy revealed that PGB were composed mainly of irregularly clustered, short branching filaments measuring about 90 A in width. PGB were histochemically and ultrastructurally identical to the previously reported Lafora-like bodies in the CNS of aged dogs. PGB were found in all aged dogs and were disseminated throughout the digestive tract, especially in the cecum.

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.

Topographic distribution pattern of Lafora-like bodies in the spinal cord of some animals

The topographic distribution pattern and morphological features of Lafora-like bodies in the spinal cord of the dog, cat, fox, and baboon were examined by light and electron microscopy. The caudal lumbar and the coccygeal parts of the spinal cords were the predilection sites for the bodies in all animals and were very prominent in the ventral columns and intermediate substance. The bodies mainly composed of branching filaments were preferentially located in neuronal processes and rarely in astocytes. The histochemical characteristics of the bodies were identical in all animals and consisted mainly of polyglucosan.

Antitumor effect of pyridine N-oxides having 1-(2-chloroethyl)-1-nitrosoureidoalkyl and 1-methyl-1-nitrosoureidoalkyl groups

Pyridine N-oxides having 1-(2-chloroethyl)-1-nitrosoureidoalkyl or 1-methyl-1-nitrosoureidoalkyl groups were evaluated for their antitumor activity against AH13 hepatoma and L1210 leukemia. Among them, 1-(2-chloroethyl)-1-nitroso-3-(2-pyridylmethyl)urea N-oxide (1), its tosylate (2), 1-(2-chloroethyl)-1-nitroso-3-(2-pyridylethyl)urea N-oxide (4), and 1-(2-chloroethyl)-1-nitroso-3-(3-pyridylmethyl)urea N-oxide (6) were highly active against both tumors in ip-ip system. These compounds were also active in ip-iv and ip-po systems of L1210. On the other hand, pyridine N-oxides having 1-methyl-1-nitrosoureidoalkyl group were all inactive against AH13 and weakly active against L1210. Effect on blood cells in Donryu rats bearing EDEN-5 erythroblastic leukemia cells was tested with these 1-(2-chloroethyl)-1-nitrosoureidoalkylureas. These compounds caused leucopenia and compound (4) was only slightly effective against EDEN-5.

Carcinogenic effect of N-ethyl- and N-amyl-N-nitrosourethans on female Donryu rats

Carcinogenic effect of N-ethyl-N-nitrosourethan (ENUR) and N-amyl-N-nitrosourethan (ANUR) was examined by continuous oral administration or topical application to female Donruy rats. Oral administration of 100 ppm solution of ENUR induced 100% of tumors in the forestomach, 46%, 80%, 71%, and 51% in the oral cavity and pharynx, esophagus, duodenum, and liver, respectively. On the other hand, the incidence of forestomach tumors was 78%, that of oral cavity and pharynx, and esophagus was 93% and 98%, respectively, in rats given 400 ppm suspension of ANUR. In addition, topical application of ENUR induced tumors of the skin as well as tumors of the forestomach and liver.

Lafora-like bodies in a cat. Case report suggestive of glycogen metabolism disturbances

Lafora-like bodies in an 8-year-old cat were studied light and electron microscopically and histochemically. In addition ot Lafora-like bodies composed of branching filaments, glycogen granules and electron-dense materaisl, abnormal accumulations of glycogen granules attracted attention. The most remarkable features were the developmental processes of the branching filaments originating directly from glycogen granules. Lafora-like bodies in the present study showed ultrastructural, histochemical, and enzymatic similarities to those described in the previous reports in Lafora's disease, glycogenosm is considered to be probably related to the productive mechanism of Lafora-like bodies.

Tumors of the upper digestive tract of ACI/N rats given N-propyl-N-nitrosourethan in the drinking water

Three groups of ACI/N rats of both sexes were given 400, 200, or 100 ppm of N-propyl-N-nitrosourethan (PNUR) continuously in the drinking water. The incidence of tumors in the upper digestive tract was 100% in all 3 groups. These tumors were observed most frequently in the forestomach, followed by the esophagus, oral cavity, and pharynx. Histologically, all the tumors were papillomas or squamous cell carcinomas. A few tumors were detected in the small intestine and glandular stomach. The study on morphogenesis of squamous cell carcinomas arising from the upper digestive tract indicates that the majority of tumors of the esophagus and forestomach may pass through acanthosis or hyperkeratosis, leukokeratosis, and papilloma, and finally develop into invasive squamous cell carcinoma, but many carcinomas of the oral cavity and pharnyx, especially the tongue, may develop without passing through a papillomatous stage.

The effect of electrical stimulation of the hypothalamus and other brain areas on urea cycle enzymatic activities in the liver in rabbits--experimental studies on brain and liver interrelationship--

Changes in urea cycle enzymatic activities in the liver induced by intracerebral electrical stimulation in rabbits with chronically implanted electrodes in the hypothalamus, the thalamus, and the limbic area were studied in comparison with these activities in non-stimulated controls. In stimulating the ventromedial nucleus of the hypothalamus, the two-hour sessions were followed by significantly reduced activity in arginase and the arginine synthetase system in the liver, but the six-hour stimulation sessions were followed by normal range activity in these enzymes. In stimulating the lateral hypothalamic area, the two-hour sessions were followed by only slightly reduced activity in the arginine synthetase system in the liver. Stimulation of the center median nucleus of the thalamus, the medial area of the amygdala and the dorsal hippocampus produced no significant changes in urea cycle enzymatic activities in the liver. The possibility that ammonia metabolism in the liver may be modified through some functional linkage between the brain and the liver was suggested.