Transition of Historical Control Data for High Incidence Tumors in F344 Rats

Historical control data of tumor incidence were collected from the control groups (215 animals of each sex) in four recent carcinogenicity studies that were started between 2005 to 2009 (terminally sacrificed between 2007 and 2011) at BoZo Research Center Inc. (Gotemba, Shizuoka, Japan) using Fischer 344 rats (F344/DuCrlCrlj). These data were compared to the previous historical control data (from 1990 to 2004, previously reported) in the same facility. In the results, the incidence of C-cell adenoma in the thyroid tended to increase in both sexes in recent years (30.8% for males and 24.4% for females in 2005-2009) as compared with the previous data (17.4% and 20.1% for males and 11.5% and 11.8% for females in 1990–1999 and 2000–2004, respectively). In addition, the incidences of pancreatic islet cell adenoma in males and uterine adenocarcinoma tended to increase from around 2000 and remained high in recent years (incidences of islet cell adenoma in males of 10.5%, 17.1% and 20.5% in 1990–1999, 2000–2004 and 2005–2009; incidences of uterine adenocarcinoma of 3.3%, 12.0% and 13.5% in 1990–1999, 2000–2004 and 2005–2009, respectively). There was no apparent difference in the incidence of other tumors.     

Species Composition,Diversity and Productivity of Homesteads in Southeastern Bangladesh

A homestead is an integrated production system where trees, crops, livestock and poultry are found in and around the household residence in Bangladesh. It is a potential production unit that provides various product, service and ecological functions. Almost all people in Bangladesh including landless households have homesteads in which they grow trees and crops even in a small piece of land. This study characterizes the species composition, diversity and productivity of the homestead production system in the Teknaf peninsula, southeastern Bangladesh. Survey data collection was from a total of 180 homesteads covering five household categories: large, medium, small, marginal and landless. Vegetable, fruit, timber, and livestock and poultry were common components in the homestead production system. Various types of plants were mainly concentrated in back yards, front yards, boundaries and corners of homesteads. The mean number of tree species per homestead was about 15. In total, 189 tree and shrub species were recorded, and were distinctly high and low in the large (363.7) and landless (55.7) household categories. Species composition, diversity and productivity of homesteads were found to be related to household categories. Richness and diversity of tree and shrub species increased with household size. Betel nut was the dominant tree species followed by mango, jackfruit and coconut. Annual income from homesteads also varied among the household categories, with a mean contribution of the homestead to annual income of about 25 %. A large portion of homestead income came from betel nut trees. There is scope to increase species diversity and income by designing homesteads with the engagement of women and other family members.     

Highly metastatic ovarian yolk sac carcinoma in a rat

We investigated a highly metastatic ovarian yolk sac carcinoma in a 52-week-old female Crl:CD(SD) rat. Macroscopically, the present case had severe ascites, bilateral ovarian masses and numerous nodules in the abdominal and thoracic cavities. Histopathologically, these masses and nodules were generally composed of two types of cells mimicking a parietal and visceral yolk sac. The parietal cells were round to polygonal, contained eosinophilic droplets and were arranged in nests and cords in the eosinophilic matrix. Both the intracytoplasmic droplets and the matrix were stained positively with PAS. The visceral cells were cylindriform, and proliferated in papillary and tubular patterns and occasionally formed Shiller-Duval body-like structures. In the dissemination sites, the neoplastic cells proliferated on the surface of the various tissues and often infiltrated into deeper parts of the tissues. Immunohistochemically, both neoplastic cells were positive for α-fetoprotein and keratin, and the eosinophilic matrix was positive for laminin. Ultrastructurally, the parietal cells had dilated rough endoplasmic reticulums, which were filled with electron-lucent laminated structures. The visceral cells had poorly to moderately developed intracytoplasmic organelles and were interconnected with desmosomes. Taken together, the present tumor was diagnosed as yolk sac carcinoma arising from the ovary and was characterized by not only high metastasis but also invasive infiltration with biphasic proliferation of the parietal and visceral cells.     

Superficial eosinophilic gastritis in laboratory beagle dogs attributable probably to diet

Stomach tissues from 222 beagle dogs, which were used for toxicological studies, were examined histopathologically. Out of 190 dogs fed the same diet, 185 had gastric lesions, whereas all of 32 dogs fed another diet were free from them. The gastric lesions were noted as an accumulation of eosinophils, infiltration of inflammatory cells including lymphocytes, plasma cells and histiocytes in the gastric lamina propria, formation of foreign body type multinucleated giant cells, focal desquamation and papillary proliferation of mucosal epithelium. The lesions were confined to the superficial layer of the antral and pyloric mucosa, and neither desmoplasia nor clinical signs were seen. Multinucleated giant cells often contained amphophilic foreign bodies of varying appearance with inconsistent reaction for periodic acid-Schiff (PAS), but no definite causal agents were detected.     

Photomorphogenic mutants of tomato

Summary Two cloned cassava genes (pCAS6, pHNL) and a barley gene (pBLT63) which is highly conserved in higher plants, were evaluated as potential multilocus probes for RFLP analysis of phylogenetic relationships of species within the genus Manihot. For M. rubricaulis, M. chlorosticta and M. esculenta subsp. flabellifolia dendrograms based on 13 probe-restriction enzyme combinations show very little variation between accessions of the same species. A close relationship is demonstrated between the Mexican species M. chlorosticta and the M. esculenta subsp. flabellifolia accessions, which does not support the classification of flabellifolia as a true South American wild species.     

Stratospheric meteorological conditions in the arctic polar vortex, 1991 to 1992

Stratospheric meteorological conditions during the Airborne Arctic Stratospheric Expedition II (AASE II) presented excellent observational opportunities from Bangor, Maine, because the polar vortex was located over southeastern Canada for significant periods during the 1991-1992 winter. Temperature analyses showed that nitric acid trihydrates (NAT temperatures below 195 k) should have formed over small regions in early December. The temperatures in the polar vortex warmed beyond NAT temperatures by late January (earlier than normal). Perturbed chemistry was found to be associated with these cold temperatures.     

Spontaneous Malignant T-cell Lymphoma in a Young Adult Crl:CD (SD) Rat

We investigated a case of spontaneous malignant T-cell lymphoma observed in a 19-week-old male Crl:CD (SD) rat. The rat showed paralysis beginning 1 week before euthanasia. Hematological examination revealed marked lymphocytosis without distinct atypia. Macroscopically, hepatosplenomegaly and partial atrophy of the thoracic spinal cord were observed. Microscopically, neoplastic cells infiltrated into the liver, splenic red pulp, bone marrow and epidural space of the thoracic spinal cord, while no neoplastic cells were observed in the thymus and lymph nodes. Moreover, the spinal cord showed focal degeneration due to compression by marked infiltration of neoplastic cells in the subdural space. The neoplastic cells were generally small-sized round cells that had a round nucleus with/without a single nucleolus and scanty cytoplasm. Immunohistochemically, the neoplastic cells were positive for CD3 and CD8 and negative for CD79α. Judging from these results, the present tumor in this young adult rat was diagnosed as malignant T-cell lymphoma.     

Spontaneous eosinophilic granulated round cell tumors in rats

Morphologic and histochemical characteristics were noted for three spontaneous tumors with eosinophilic cytoplasmic granules that occurred in aged Fischer 344 rats. Macroscopic lesions were widely distributed in the body, mainly involving the intra-abdominal adipose tissue, pancreas, and mesenterium. These lesions were generally hard swellings with nodular and sclerosing areas. Bloody ascites was a concomitant finding. Histologically, the tumor cells were round, from 9 to 30 microm in diameter with one or two round to oval nuclei, and characterized by eosinophilic granules (0.5-2.0 microm) that stained definitely to weakly positive with the periodic acid-Schiff reaction and demonstrated no metachromasia with toluidine blue stain. Furthermore, the granules were characterized by a positive reaction with lectin histochemistry for concanavalin A (Con A), wheat germ agglutinin (WGA), phaseolus vulgaris agglutinin (PHA-E4), lens culinaris agglutinin (LCA), and recinus communis agglutinin (RCA-I) in all tumors and for ulex europaeus agglutinin (UEA-I), peanut agglutinin (PNA), and soybean agglutinin (SBA) in one tumor. Positive reactions for anti-rat mast cell protease II and CD8 were not demonstrated immunohistochemically. Abundant glycogen was noted in the large tumor cells from one rat. With electron microscopy, the cytoplasmic granules were identified as electron-dense homogenous bodies bounded by a single unit membrane. These characteristics are similar to those of granulated metrial gland cells, but further study is needed to clarify the cell of origin for these tumors.