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

Rat alpha-macrofetoprotein (AMF) and alpha-fetoprotein (AFP) are secreted by the fetal liver and become elevated in serum during hepatocarcinogenesis and in animals bearing hepatocellular carcinomas. It has been suggested that these fetal plasma proteins may be influenced by related control mechanisms. The experiments presented herein examined the early responses of these plasma proteins during hepatocarcinogenesis using the hepatocarcinogens acetylaminofluorene and diethylnitrosamine. Under these conditions, AFP serum concentrations were elevated within a few days of exposure to acetylaminofluorene, whereas AMF serum concentrations remained essentially normal. AFP became elevated after a number of weeks of exposure to diethylnitrosamine. In either regimen, AMF became elevated only later when large primary hepatocellular carcinomas were found. The time of appearance of AMF after transfer of an AFP-secreting Morris hepatoma indicated that AMF was elevated only in animals with extremely large, necrotic tumors. Thus, it appears that elevation of serum AFP resulted from either exposure to hepatocarcinogens or production by hepatocellular carcinomas, but that the elevations of serum AMF levels resulted from inflammatory injury or necrosis of tumor tissues.
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PMID:Rat alpha-macrofetoprotein (acute-phase alpha 2-macroglobulin) during hepatocarcinogenesis. 8 3

Serum alpha-fetoprotein (AFP) was measured in 10 cases of primary brain tumors in children (4 cases of medulloblastoma, 4 cases of germ cell tumor and 2 cases of astrocytoma). As a result, elevation in AFP was observed only in a case of embryonal carcinoma that showed partial mixture of germinoma. The absence of AFP elevation in 3 other cases of pure germinoma (atypical teratoma; pinealoma) agrees with reports which describe that, in the germ cell tumor of the gonads, a rise in AFP is not observed in pure seminoma but is found in embryonal carcinoma and endodermal sinus tumor (yolk sac tumor). The fluctuations in AFP in serum and cerebrospinal fluid are considered to be of significance in the diagnosis and treatment of primary intracranial malignant germ cell tumors.
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PMID:Radioimmunoassay of alpha-fetoprotein in children with primary intracranial tumors. 8 37

The expression of alpha-fetoprotein (AFP) was infestigated in a cloned cell culture derived from Morris hepatoma 7777, which shows a density-dependent variation in the AFP synthesis rate. The rate of secretion of AFP was found to be governed by the level of cytoplasmic mRNAAFP. Saturation hybridization of pulse-labeled RNA to excess cloned cDNAAFP was used to illustrate quantitatively how mRNAAFP is regulated in these tumor cells. It was found that the mRNAAFP level is primarily determined by its rate of transcription and mRNAAFP declines to 40% of its maximum level, and it accumulates at 20% of its maximum rate. The half-life of mRNAAFP was found to be 40 h, 5 to 6 times that of poly(A)-containing RNA. This difference in stability, in cells doubling every 20 h, results in a 2 1/2-fold increase in the fraction of mRNAAFP above that expected from the relative transcription rate of mRNAAFP. During maximal synthesis of AFP, mRNAAFP accumulates in the cytoplasm at a rate 25 times greater than an average middle abundance mRNA and 1000 times greater than the average low abundance mRNA. These results and the relatively high translational efficiency of mRNAAFP explain how cells can optimize production of an abundant protein.
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PMID:alpha-Fetoprotein gene expression. Control of alpha-fetoprotein mRNA levels in cultured rat hepatoma cells. 9 46

Lung tumor-associated antigens of approximately 32,000 daltons were recognized by the use of sensitive radioimmunoassays and rabbit antisera, one raised against an extract of pooled human malignant lung tissues and another raised against a cell line derived from a human squamous cell carcinoma of the lung. These antigens differ from antigens described previously, including carcinoembryonic antigen and alpha-fetoprotein. The antigens were detected on 13 of 13 lung tumors (of all histologic types), fetal tissue, normal brain, 2 of 8 colon tumors, 2 of 9 prostate tumors, and 2 of 3 breast tumors, as well as on cell lines derived from lung tumors, neuroblastoma, human amnion, colon adenocarcinoma, and bladder tumors. They were not detectable on normal lung, liver, kidney, colon, or prostate tissues or on cell lines derived from osteosarcoma, fetal lung fibroblasts, transitional cell carcinoma, and squamous cell carcinoma of the skin. Lung tumors of different histologic types were concluded to express common, tumor-associated oncofetal antigens that are found less often on tumors of other organs.
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PMID:Human lung tumor-associated antigens of 32,000 daltons molecular weight. 9 95

The tumor markers alpha-fetoprotein and human chorionic gonadotropin have proved to be useful in staging disease in patients with testicular carcinomas. Moreover, their detection has often had a bearing on the therapeutic regimen selected. The nature and value of these tumor markers are discussed in detail, and other potentially useful oncofetal gene products are reviewed.
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PMID:Tumor markers in testicular cancer. 9 89

Endodermal sinus tumors, as a specific entity, were first proposed and described by Teilum on the basis of morphological and histogenetic features. Recent work utilizing tumor markers (alpha-fetoprotein), immunofluorescent and electron microscopic studies have supported Teilum's original concept as to the origin of these tumors. Five typical presentations of endodermal sinus tumors seen in the pediatric age group were reviewed with reference to the original presentation, the utilization of tumor markers (alpha-fetoprotein) and the prognostic implications of this neoplasm.
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PMID:Endodermal sinus (yolk sac) tumors in infants and children. 9 61

Serum alpha-fetoprotein was identified in five patients with histologically verified teratomas and in one patient with a suspected malignant teratoma. Detection of serum alpha-fetoprotein is specifically indicative of malignant teratoma, as no other known type of intracranial tumor produces it.
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PMID:Alpha-fetoprotein in intracranial malignant teratoma. 9 10

The immunocellular response to fetal antigens was studied in ten patients with hepatocarcinomas. Homogenized extracts of human fetal liver and purified human alpha-fetoprotein were used as antigen substances. The control group included 15 patients with cirrhosis of the liver. The level of circulating T lymphocytes (E-rosettes) was also registered. Patients with hepatocarcinoma showed a definite response to both antigens, determined by the degree of inhibition of leukocyte migration. The migration indices were as follows: x = 0.65 +/- 0.16 for homogenized fetal liver antigen, and x = 0.79 +/- 0.13 for alpha-fetoprotein antigen. These values were 0.93 +/- 0.13 and 0.95 +/- 0.15 respectively in the cirrhotic patients. The differences in the migration indices for the two groups were statistically significant with both antigens (p less than 0.0005 and p less than 0.005). The decrease of the number of T lymphocytes in patients with hepatomas was also significant (p less than 0.005). The determination with homogenized fetal antigen was more sensitive than with alpha-fetoprotein (p less than 0.01). A significant relationship between the severity of the tumor and the immunocellular response could also be seen (r = 0.84; p less than 0.001). Response tended to diminish as the tumor progressed. The disappearance of immunocellular response seemed to depend at least in part on the decreasing number of T lymphocytes, since there was a significant inverse correlation between the two parameters (r = -0.75; p less than 0.01).
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PMID:[Immunocellular response to fetal antigens in patients with hepatoma (author's transl)]. 9 78

A case of embryonal carcinoma in the pineal region of a 17-year-old boy is presented. The tumor included elements of choriocarcinoma and endodermal sinus tumor, and the use of human chorionic gonadotropin and alpha-fetoprotein as tumor markers is discussed. The markers were demonstrated both within the tumor and in the cerebrospinal fluid (CSF) and blood. The patient was treated with a postoperative program of irradiation and cancer chemotherapy, and at follow-up examination 20 months after operation no signs of residual tumor were present. It is suggested that human chorionic gonadotropin and alpha-fetoprotein should be measured in the blood and CSF before the treatment of midline tumors.
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PMID:Value of tumor markers in the treatment of endodermal sinus tumors and choriocarcinomas in the pineal region. 9 53

A case of yolk sac tumor of the anterior mediastinum was studied by light and electron microscopy and found to have characteristic patterns which were similar to a neoplasm of gonadal origin. These findings, in addition to the immunohistochemical identification of alpha-fetoprotein in the tumor, indicated that the neoplasm was germ cell in origin. A brief review of previously reported cases is included. Prognosis of the patients with yolk sac tumor of the anterior mediastinum was generally dismal; however, those patients with tumors incidentally found but completely excised survived without evidence of reucrrence.
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PMID:Yolk sac tumor of the anterior mediastinum. Case report with light- and electron-microscopic examination and immunohistochemical study of alpha-fetoprotein. 9 18


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