Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0023418 (leukemia)
 93,477 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The purpose of our study was to derive an alternate end-point to death or moribund appearance for the frequently used L1210 model of murine leukemia. In reviewing the published literature, we were unable to identify a suitable intermediate marker of substantive disease that predicted outcome in the BDF1 recipient of the L1210 leukemia. In an attempt to refine the use of animals in our laboratory, we developed a scoring sheet for behavioral and physical changes that followed intravenous injection of L1210 lymphocytic leukemia cells into BDF1 recipients. At 12-h intervals for the first 2 days after tumor-cell injection and at 6-h intervals thereafter, animals were observed and scored for each parameter. When death was imminent, animals were euthanized by inhalation of methoxyflurane followed by decapitation. Changes in physical and behavioral characteristics then were correlated with the end-point of death. Changes occurred in the mice approximately 7 days after tumor cell inoculation and 24 h before death. The earliest of these signs was hunched posture, followed by one or more other characteristics including decreased activity, increased facial swelling, ears in backward position, abdominal swelling, squinting eyes, and labored breathing. From these data, we were able to develop criteria for early euthanasia. Use of these intermediate end-points likely will substantially reduce the stress on the animals without compromising scientific outcomes in experiments using this or related preclinical models of cancer.
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PMID:Determination of a humane endpoint in the L1210 model of murine leukemia. 1195 99

Sodium azide is a white crystalline solid used in the manufacture of the explosive lead azide. It is the principal chemical used to generate nitrogen gas in automobile safety airbags and airplane escape chutes and is a broad-spectrum biocide used in both research and agriculture. Toxicology and carcinogenicity studies were conducted by administering sodium azide (greater than 99% pure) in distilled water by gavage to groups of male and female F344/N rats once daily, 5 days per week for 14 days, 13 weeks, or 2 years. Genetic toxicology studies were conducted in Salmonella typhimurium and Chinese hamster ovary cells. 14-Day Studies: Rats received 0, 5, 10, 20, 40, or 80 mg/kg sodium azide. All male and female rats receiving 40 or 80 mg/kg and two of five female rats receiving 20 mg/kg died during the first week of the studies. Clinical findings of toxicity included lethargy and inactivity. No grossly observable lesions were present in any of the dose groups. 13-Week Studies: Rats received 0, 1.25, 2.5, 5, 10, or 20 mg/kg sodium azide. Seven of 9 males and all 10 females receiving 20 mg/kg died before the end of the studies. Final mean body weights of treated rats were within 10% of those of the controls. Compound-related clinical findings of toxicity in the 20 mg/kg dose groups included lethargy and labored breathing. Histopathologic lesions induced by sodium azide were limited to the brain (necrosis of the cerebrum and thalamus) and lung (congestion, hemorrhage, and edema), and were observed in rats receiving 20 mg/kg that died during the studies. Body Weights, Feed Consumption, and Survival in the 2-Year Studies: Because compound-related deaths were observed in the groups receiving 20 mg/kg in the 13-week studies, lower dose levels were used in the 2-year studies. Two-year studies were conducted by administering 0, 5, or 10 mg/kg sodium azide to groups of 60 male and 60 female rats. Dose-related depression in mean body weight was observed throughout the study period. Mean feed consumption values in low- and high-dose groups were lower than control values. Survival of high-dose rats of each sex was significantly (P<0.05) lower than controls (males-control, 24/60; low-dose, 27/60; high-dose, 9/60; females-37/60; 43/60; 21/59). The reduced survival was attributed to brain necrosis and cardiovascular collapse induced by sodium azide. Neoplastic and Nonneoplastic Effects in the 2-Year Studies: There were no compound-related increases in incidences of neoplasms in rats. Significantly decreased incidences were observed for certain neoplasms, including mononuclear cell leukemia in male rats (control, 33/60; low-dose, 28/60; high-dose, 14/60), adrenal gland pheochromocytoma in male rats (26/55; 16/56; 6/54), mammary gland fibroadenoma in female rats (20/60; 11/60; 8/59), and pituitary gland neoplasms in female rats (37/60; 28/60; 17/59). These decreases reflected to some extent, but could not be attributed solely to, the reduced survival of the high-dose groups. Compound-related nonneoplastic brain lesions (necrosis of the cerebrum and thalamus) were observed at significantly (P<0.001) increased incidences in high-dose male and female rats. The increased incidence of lung congestion observed in this dose group was considered due to cardiovascular collapse secondary to brain necrosis. Genetic Toxicology: Sodium azide was mutagenic in Salmonella typhimurium strains TA100 and TA1535, with or without exogenous metabolic activation (S9); it was not mutagenic in strain TA1537 or TA98. In cytogenetic tests with Chinese hamster ovary cells, sodium azide induced sister chromatid exchanges, but not chromosomal aberrations, in the presence and the absence of S9. Conclusions: Under the conditions of these 2-year gavage studies, there was no evidence of carcinogenic activity of sodium azide in male or female F344/N rats administered 5 or 10 mg/kg. Sodium azide induced necrosis in the cerebrum and the thalamus of the brain in both male and female rats. Synonyms: Azide, Azium, Smite
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PMID:NTP Toxicology and Carcinogeneis Studies of Sodium Azide (CAS: 26628-22-8) in F344 Rats (Gavage Studies). 1263 70

An 8-year-old castrated male Golden Retriever was evaluated for decreased appetite, lethargy, and labored breathing of 1-week duration. Bilateral pulmonary infiltrates, hepatomegaly, and splenomegaly were present. Results of a CBC revealed marked leukocytosis (62,600/microL; reference interval 4000-15,500/microL) and large numbers of atypical cells (30,700/microL) with abundant cytoplasm. There was no concurrent anemia, neutropenia, or thrombocytopenia. Morphology of the atypical cells was most consistent with a histiocytic origin. Similar cells were identified in bone marrow aspirates, and were morphologically suggestive of the macrophage variant of disseminated histiocytic sarcoma. However, flow cytometry of the abnormal circulating cells revealed CD1c, CD11c, and major histocompatibility complex (MHC) Class II expression without expression of CD11d or lymphoid markers, consistent with myeloid dendritic antigen-presenting cells. At necropsy, the splenic architecture was effaced by neoplastic histiocytes that were also infiltrating lung, liver, an abdominal lymph node, myocardium, an bone marrow. Immunohistochemistry of the splenic neoplastic cells confirmed dendritic cell origin (CD1c+, CD11c+, MHC II+, no expression of CD11d and lymphoid markers). To the authors' knowledge, this is the first report of canine dendritic cell leukemia-in this instance accompanied by marked tissue infiltration.
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PMID:Dendritic cell leukemia in a Golden Retriever. 1853 19