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Query: UMLS:C0027651 (tumor)
 685,946 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Sindbis virus is an alphavirus with a very wide host range, being able to infect many birds and mammals as well as mosquitoes. We have isolated a monoclonal antibody that largely blocks virus binding to mammalian cells. This antibody was found to be directed against the C-terminal domain of the high-affinity laminin receptor, a 67-kDa protein present on the cell surface that binds with high affinity to basement membrane laminin and that is known to be important in development and in tumor invasion. This receptor is believed to be formed from a 295-amino-acid polypeptide that is modified in some unknown way after translation. The primary sequence of this 295-amino-acid protein is highly conserved among mammals. We found the hamster amino acid sequence to be identical to a mouse sequence and to differ at only two amino acids from a human sequence and at two amino acids from a bovine sequence. To verify the importance of the laminin receptor for infection by Sindbis virus, hamster cells were stably transfected with the gene encoding the 295-amino-acid protein under the control of a high-efficiency promoter. Such transfected hamster cells overexpressed the laminin receptor at the cell surface, bound severalfold more Sindbis virions than did the parental cells, and became infected by Sindbis virus with a higher efficiency. In contrast, cells transfected with the antisense gene expressed less laminin receptor on the surface and were less susceptible to the virus. Binding of the virus varied linearly with the amount of laminin receptor on the cell surface, whereas infectivity measured with a plaque assay varied with the 1.4 power of the receptor concentration, suggesting that interaction with more than one receptor aids virus penetration. By these criteria, the laminin receptor functions as the major receptor for Sindbis virus entry into mammalian cells. We also found that the anti-laminin receptor antibody partially blocked Sindbis virus binding to mosquito cells, suggesting that the laminin receptor is conserved in mosquitoes and functions as a Sindbis virus receptor in this host. The wide distribution of this highly conserved receptor may be in part responsible for the broad host range exhibited by the virus, which infects a wide range of mammals and birds as well as its mosquito vector and can infect many different tissues within these hosts.(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:High-affinity laminin receptor is a receptor for Sindbis virus in mammalian cells. 138 35

The influence of dietary selenium of the incidence of esophageal tumor induced by NMBzA and the immune function during carcinogenesis were studied in rats fed with Torula yeast diet and survived for 18 weeks. The incidences of esophageal tumors were statistically not significant among rats on normal, high and low selenium intake (P greater than 0.05). The level of plaque forming cells (PFC), delayed type hypersensitivity (DTH), natural killer cell activity (NK) were significantly higher in the high selenium diet group than those of the low selenium diet group (P less than 0.05). The authors believe that the modulation of dietary selenium can alter the immune function of animals during carcinogenesis but the anticarcinogenic effect of selenium still needs further study.
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PMID:[Influence of dietary selenium level on immune function of rats with esophageal tumors induced by methylbenzylnitrosamine (NMBzA)]. 139 46

Recent studies using both normal and tumoral pituitary cell cultures have demonstrated that growth hormone (GH) and prolactin (PRL) secreting populations contain cells which release either one or both of these hormones. In order to determine whether these two cell types can be differentially regulated by hypothalamic factors we performed the following study employing plaque assays for GH and PRL. Using cultures of GH3 cells, a rat tumor cell line which contains both of these cell types, we found that the hypothalamic factors vasoactive intestinal peptide (VIP) and thyrotropin releasing hormone (TRH) when used together had a greater influence on plaque formation than when each was used individually. This suggested that cells were present in culture that responded to one peptide but not the other. Estradiol-treated cultures (which contain only dual-secreting cells) were then evaluated for VIP and TRH responsiveness and found to respond to TRH but not VIP. Finally, we assessed the peptide sensitivity of cultures that were exposed to a conjugate of VIP and the A-chain of ricin (a potent cytotoxin). In addition to eliminating VIP-responsive cells, this treatment markedly reduced the proportions of cells secreting GH-only while having no appreciable influence on dual-hormone secretors. When taken together, our findings indicate that single and dual secretors respond differently to at least two hypothalamic secretagogues and suggest that regulatory differences between these cell types may be important in the control of GH and PRL secretion.
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PMID:Single and dual hormone secretors in GH3 cultures respond differently to hypothalamic factors. 144 81

Soluble forms of receptors for the Fc portion of IgG (sFc gamma R) were detected in biological fluids from mice and humans. In mouse bearing tumors, circulating amounts of sFc gamma R increased concurrently with tumor growth. Tumors secreting IgG2a, IgG2b or IgG3 led to a 5- to 10-fold increase in serum sFc gamma R levels whereas tumors secreting IgG1, IgGA or other types of tumors (non Ig B cell tumors, T cell lymphoma and a melanoma) increased 2- to 3-fold the levels of circulating sFc gamma R. In the human, sFc gamma R were also detected in whole unstimulated saliva. Levels of sFc gamma RII and of sFc gamma RIII were variable and did not seem to depend on the dental status of the individuals. Finally, a murine recombinant sFc gamma R (rsFc gamma R) composed of the two extracellular domains of Fc gamma RII was produced by culture of transfected L cells in bioreactors. The purified rsFc gamma R was found to inhibit antibody production in vitro in anti-SRBC responses and by cultures of small B cells stimulated by anti-IgM antibodies in the presence of IL-4 and IL-5. Moreover, the i.p. injection of this material into adult mice immunized with SRBC led to a decrease of IgG antibody production by splenocytes, as measured by a hemolytic plaque assay, and in serum, as measured by antigen-specific ELISA.
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PMID:Soluble Fc gamma R (sFc gamma R): detection in biological fluids and production of a murine recombinant sFc gamma R biologically active in vitro and in vivo. 145 2

Fifty-six globes that had to be enucleated following ruthenium plaque therapy were examined histopathologically. These eyes account for 10% of all uveal melanomas treated at the University Eye Clinic Essen up until 1985. All but one revealed at least some supposedly viable tumor cells. The most prominent findings within the tumors were tumor cell necrosis, vacuolization and balloon cell degeneration, vascular obstruction and fibrosis of the tumor stroma with accumulation of pigmented macrophages. Tumor necrosis was complete or nearly complete in five cases. Tumor regression correlated with cell type and pigmentary characteristics of the tumor, with epithelioid and heavily pigmented tumor cells being more radiosensitive. Tumor regression was inhomogeneous, possibly due to polyclonality, with tumor cells of varying radiosensitivity, or due to patchy areas of vascular obliteration. Among other ocular structures, extensive subretinal gliosis, chorioretinal atrophy and scarring of the sclera within the field of radiation were observed. Scleral necrosis was present in only five cases and was limited to areas in which the tumor had infiltrated the deep scleral layers. The findings described were considered to reflect radiation injury rather than spontaneous tumor regression when compared to 70 control eyes that had been enucleated without prior treatment for uveal melanoma.
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PMID:Histopathologic findings in eyes treated with a ruthenium plaque for uveal melanoma. 150 75

A 60-year-old man came for treatment of a sharply outlined erythematous plaque on the gluteal area (45 x 20 mm) of 20 years' duration. Eccentrically located on the plaque was a nodule, 20 mm in diameter. Histological study of the plaque showed a superficial platelike tumor with basaloid bland cytology and sebaceous gland differentiation. Histologic study of the nodule found an undifferentiated adenocarcinoma whose ductlike glandular structures opened to the skin surface and infiltrated the whole depth of the dermis. Study of other areas of the lesion detected two more neoplasms. A nodule of squamous cell carcinoma was found within the superficial band of the benign sebaceous tumor. The fourth neoplastic pattern consisted of epithelial islands composed of basaloid cells within a fibroblastic stroma. There was prominent palisading of epithelial cell nuclei at the periphery of the islands, which usually were surrounded by a sheath of mesenchymal cells. In this complex adnexal tumor of the primary epithelial germ, sebaceous and follicular differentiation both simulate neoplastic patterns recently described as separate entities: superficial epithelioma with sebaceous differentiation and immature trichoepithelioma. The undifferentiated adenocarcinoma may represent differentiation toward the third component of the germ, that is, the apocrine gland.
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PMID:Complex adnexal tumor of the primary epithelial germ with distinct patterns of superficial epithelioma with sebaceous differentiation, immature trichoepithelioma, and apocrine adenocarcinoma. 151 Feb 22

During an 8-year period, 85 patients with uveal melanomas were treated with episcleral plaque radiotherapy (EPRT). The T-stage was: T1-3 (4%), T2-29 (34%) and T3-53 (62%). The mean tumor elevation was 6.1 mm. Radiation dose was prescribed at the tumor apex and at D5mm. The mean D5mm dose was 150.1 Gy (range 70.5-430 Gy) and the mean dose at the apex was 102.6 Gy (range 29.8-200 Gy). Useful vision (greater than 5/200) was maintained in 73% of patients. The 5-year actuarial survival was 88%. Metastatic disease developed in 9 (11%) patients, 6 of whom died of their disease. Basal tumor dimensions were important factors predicting metastatic disease, p = 0.002. A decrease in tumor evaluation was seen in 82%. There was a much lower incidence of decrease in tumor radial and circumferential dimensions, 47.5 and 46%, respectively, p less than 0.001. Treatment complications were common (56%), particularly in patients with large tumors (72%), p = 0.04. The incidence of complications was higher in patients treated prior to 1988 as compared to those who were treated more recently (67 vs 35%, p = 0.010). There were 13 (15%) patients who had enucleation. This included 12 treated before 1986 and 1 patient treated subsequently (46 vs 2%, p less than 0.001). In a univariate analysis, tumor height and radiation dose at D5mm were important factors predicting enucleation, p = 0.004. In a multivariate analysis, however, the most important factor predicting enucleation was treatment administration prior to 1986, p less than 0.001). A sharp decrease in the incidence of severe complications, including enucleation, as seen after 1985, is likely due to a major effort in treatment optimization.
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PMID:Episcleral plaque radiotherapy in the treatment of uveal melanomas. 152 63

We have previously reported on the design and content of a screening battery involving a "tier" approach for detecting potential immunotoxic compounds in mice (Luster et al., 1988, Fundam. Appl. Toxicol. 10, 2-19). This battery has now been utilized to examine a variety of compounds by the NIEHS Immunotoxicology Laboratory, the National Toxicology Program-sponsored laboratories, and by the Cell Biology Department at the Chemical Industry Institute of Toxicology. The database generated from these studies, which consists of over 50 selected compounds, has been collected and analyzed in an attempt to improve future testing strategies and provide information to aid in quantitative risk assessment for immunotoxicity. Studies presented here have established the ability of each of the tests or test combinations in the screening battery to detect immunotoxic compounds. Efforts are currently underway using this database to determine the relationships between these immune tests and susceptibility to challenge with infectious agents or transplantable tumor cells. The present analyses indicated that the performance of only two or three immune tests are sufficient to predict immunotoxic compounds in rodents (greater than 90% concordance). The tests that showed the highest association with immunotoxicity were the splenic antibody plaque forming cell response (78%) and cell surface marker analysis (83%). The relationship between immunotoxicity and carcinogenicity, as well as genotoxicity, was also determined. These analyses suggested that potential immunotoxic compounds are likely to be rodent carcinogens (p = 0.019) although for compounds that are not immunotoxic the carcinogenic status is unclear. There was no relationship observed between immunotoxicity and mutagenicity as determined using in vitro genotoxicity tests. The significance of these observations is discussed in terms of the relationship between immunotoxicity tests and biological/toxicological processes concerned with human health (e.g., infectious disease).
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PMID:Risk assessment in immunotoxicology. I. Sensitivity and predictability of immune tests. 153 77

Cytotoxicity of peritoneal macrophages (pMs) and peritoneal natural killer (pNK) cells toward xenogenic tumor cells was studied in anemic, suckling rats. Dams were fed 6, 12, or 250 mg Fe/kg diet ad libitum throughout gestation and lactation. Pups were injected intraperitoneally with 10(5) plaque-forming units of virus. Four days later cytotoxicity of pMs and pNK cells against YAC-1 mouse lymphoma cells was measured. Body weight, hemoglobin, hematocrit, and viable cell yield of pups were significantly decreased with decreasing dietary iron. pM cytotoxicity was significantly impaired in anemic pups at pM-target-cell ratios of 10:1 and 30:1 at 4 and 16 h (P less than or equal to 0.03). pNK-cell cytotoxicity was significantly impaired in anemic pups at pNK-target-cell ratios of 10:1 and 50:1 at 16 h. Iron-deficient diet consumed by dams throughout gestation and lactation resulted in anemic offspring whose immunologic defense by pMs and pNK cells against xenogenic tumor cells was significantly reduced.
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PMID:Maternal-iron-deficiency effects on peritoneal macrophage and peritoneal natural-killer-cell cytotoxicity in rat pups. 155 51

Diffuse, continuous abdominal pain and weight loss of 10 kg in 3 months were observed in a 57-year-old female patient. A CT examination of the abdomen was requested to rule out a malignant gynecological tumor. The CT study, however, showed a small amount of ascites and a thick sheet-like mass covering the internal anterior abdominal wall. On the basis of these CT findings, a peritoneal mesothelioma was suspected, which was confirmed by diagnostic laparotomy. The patient's history revealed exposure to asbestos at work from 21 to 24 years of age. The following signs of asbestosis and asbestos-related pleural disease were observed in the chest X-ray film: small opacities in the lower zones of both lungs, diffuse pleural thickening, a plaque on the right diaphragm, and small bilateral pleural effusions. In cases of suspected occupational illness such as that presented here, each physician concerned including the radiologist involved in the diagnosis, is required to advise the social insurance institution responsible.
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PMID:[Asbestosis accompanied by primary peritoneal mesothelioma]. 156 87


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