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

Sixteen necropsies and 4 cases of hepatic resection in which the liver had a solitary hepatocellular carcinoma smaller than 4.5 cm, or a few tumor nodules smaller than 3.5 cm, have been analyzed. Clinically, these patients presented with signs and symptoms compatible with cirrhosis and, of the 16 autopsy cases only 2 had been diagnosed correctly. In all but 4 cases, the noncancerous parenchyma showed advanced cirrhosis of the mixed type, with irregularly sized multilobular nodules and thin strands of stroma, different from typical alcoholic cirrhosis. The primary lesion was grossly encapsulated in the majority, suggesting a slow, expanding growth. Histologically, most primaries were relatively well differentiated. Serum alpha-fetoprotein was generally low, and it served as the major diagnostic clue in only 5 cases. In patients with mildly abnormal alpha-fetoprotein levels, continuous monitoring seems important in order to detect a steady rise, the first warning for tumor growth.
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PMID:Clinicopathological studies of minute hepatocellular carcinoma. Analysis of 20 cases, including 4 with hepatic resection. 6 81

Determinations of carcinoembryonic antigen (CEA), human chorionic gonadotropin (HCG), and alpha-fetoprotein (AFP) were done by use of frozen serum samples antedating the diagnosis of cancer for 9 pancreatic and 8 gastric carcinoma patients from the Framingham Heart Study. The longest intervals for elevated antigens before cancer diagnosis were 10 months for CEA and 26 months for HCG. (The single elevated AFP was found in a sample 10 days before clinical diagnosis.) Samples from 31 controls matched with the cancer subjects by age, sex, vital capacity, and smoking status showed over 20% "false" positive CEA elevations (all smokers with low vital capacities) and over 20% borderline false positive HCG elevations in postmenopausal females. Although 10-26 months' lead time could infer some potential for use of these tumor-associated antigens to help detect malignant neoplasms at an earlier stage, a serious problem of frequent false positives prevents CEA and HCG levels from being useful as cancer-screening tests at this time.
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PMID:Tumor-associated antigen levels (carcinoembryonic antigen, human chorionic gonadotropin, and alpha-fetoprotein) antedating the diagnosis of cancer in the Framingham study. 6 18

The Morris hepatocellular carcinoma 7777 is productive of extraordinarily high levels of the oncofetal protein, alpha-fetoprotein. Its chromosome composition was examined in detail since it represents the only near-diploid tumor of such productivity and has been reported to demonstrate a single unusual chromosomal alteration. The major finding is the presence of a submetacentric marker chromosome, composed of a No. 7 chromosome and a short arm that demonstrated a poorly defined banding pattern on Giemsa staining. This marker is unique to 7777 and is of particular interest in view of recent reports of an association between such unbanded chromosome arms and supraproduction of cell products.
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PMID:Chromosome analysis of hepatocellular carcinoma 7777 and correlation with alpha-fetoprotein production. 6 10

Serum levels of alpha-fetoprotein were determined in 33 patients with testicular germ cell tumors and were normal in 11 patients with seminoma and in one patient with matured teratoma; high levels were observed in 19 of 21 patients with embryonal carcinoma, teratocarcinoma, or a mixed type of these germ cell tumors. Tissues from the testicular germ cell tumors were cultivated with 14C-labeled leucine. After incubation, the culture media were subjected to immunoelectrophoretic and autoradiographic analyses. The results were: (i) Radioactive alpha-fetoprotein, albumin, transferrin, and alpha1-globulin appeared in the culture media of embryonal carcinomas obtained from two infants. (ii) Radioactive albumin and alpha1-globulin appeared in the culture media of a mixed type tumor metastasized from testis to retroperitoneal region. (iii) No such radioactive proteins appeared in the culture media of primary seminomas.
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PMID:Synthesis of alpha-fetoprotein and some other serum proteins in testicular tumors. 6 43

In vitro and in vivo experiments failed to identify a consistent "immunosuppressive" or "immunoregulatory" role for alpha-fetoprotein (AFP) in the rat. Both normal and AFP-rich sera inhibited Con A, PHA, and MLR proliferation responses of lymphocyte cultures in vitro equally well, in spite of up to 100,000-fold differences in AFP concentration. AFP-rich sera also had no effect on the antibody response of the rat in vivo. Purified AFP from amniotic fluid inhibited the PHA response at concentrations of 100 in chemical contexts is converted to microgram/ml. Purified albumin was also inhibitory, but at 1 log higher concentration. Purified AFP from tumor sera was not inhibitory at 100 in chemical contexts is converted to microgram/ml for Con A, PHA, or MLR reactions and only inhibited PHA stimulation at medium concentrations greater than 1000 in chemical contexts is converted to microgram/ml. The role of AFP as an immunosuppressive agent, particularly in reference to survival of mammalian fetuses, should be reconsidered.
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PMID:Effects of alpha-fetoprotein on murine immune responses. II. Studies on rats. 6 79

Antibodies to autologous alpha-fetoprotein (AFP) were produced in mice by immunization with rat AFP. C57L/J mice with or without such antibodies were inoculated sc or ip with controlled numbers of cells of the syngeneic, AFP-producing, BW 7756 hepatoma. There was a linear relationship between circulating AFP and tumor mass, with elevated AFP being detectable earlier than the tumor. The AFP levels of the immunized mice were generally lower than those of control mice, and tumors could be detected before elevated concentrations of AFP appeared in the circulation. An extensive series of transplantations with varying protocols for immunization did not protect against tumor and did not affect the rate of tumor growth.
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PMID:Effect of specific immunotherapy with preimmunization against alpha-fetoprotein on a mouse transplantable hepatoma. 6 32

By means of two different markers of differentiation, using immunofluorescene method, the authors have characterized changes in the population of hepatic cells 1-8 weeks following the start of 3'-methyl-4-dimethyl-aminoazobenzene or 2-acetyl-aminofluorene action. Alpha-fetoprotein served as a marker of embryonic hepatocyte differentiation; while ligandin-as a marker of high-differentiated mature hepatocytes. The toxic effect of the carcinogens on hepatic stem cells was accompanied with a decrease of ligandin content in centrilobular hepatocytes. Among newly proliferating elements "oval" cells, cells of bile tract epithelium and most of basophilic hepatocyte-like cells fail to contain either alpha-fetoprotein or ligandin. Small groups of basophilic hepatocyte-like cells would contein alpha-fetoprotein. In cells of high cylinder-shaped epithelium of intestinal type ligandin was found, but alpha-fetoprotein was not found. The latter was absent in oxyphilous hepatocytes of hyperplastic nodules. In terms of ligandin content three types of morphologically identical nodules were differentiated; a) ones not containing this protein, b) ones containing it in amounts common to normal mature hepatocyte, and c) hyperdifferentiated nodules containing abnormally high concentrations of ligandin. Within one nodule cell all cells were identical in ligandin content. Thus, it is shown that at early stages of chemical carcinogenesis there occure in the liver multiple foci of differentiation of various kind. These intensive processes are assumed to be essential for tumor evolution in the tissue.
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PMID:[Evolution of hepatocyte population in the process of chemical carcinogenesis]. 7 Jan 12

Pregnant WKA rats were laparotomized on the 12th day of gestation, and all fetuses were removed from the uteri, leaving the fetal membranes attached to placentas in situ, protruding into the peritoneal cavity. After 5 to 6 months, extrauterine tumors were observed in 80% of the operated rats, and elevated serum alpha-fetoprotein levels were detected in 80% of the tumor-bearing rats. The tumors in AFP-positive rats always contained yolk-sac tumor elements. In transplantable tumor lines established in the ascites form, numerous free-floating embryoid bodies were observed. The experiments demonstrate that yolk-sac tumors (endodermal sinus tumors) can be induced by simple fetectomy without infection by exogenous tumor virus.
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PMID:Experimental yolk-sac tumors produced by fetectomy without virus infection in rats. 7 Dec 78

In a previous study, we demonstrated three variants of human alphafetoprotein by crossed immunoelectrophoresis. In addition, we correlated the capacity of alpha-fetoprotein isolates from various hepatoma and fetal sources to suppress human lymphocyte transformation in vitro with the relative proportion of the electronegative variant, HAFP-3, present in each isolate. We have now isolated alpha-fetoprotein from the serum, ascitic fluid, and saline extract of tumor from a single hepatoma patient and from a homogenate of fetal livers. When tested for their capacity to inhibit human lymphocyte transformation in vitro, tumor and fetal liver alphafetoprotein were found to be extremely potent, serum alphafetoprotein had intermediate potency, and ascitic fluid alpha-fetoprotein was the least potent. Analysis of these isolates by crossed immunoelectrophoresis confirmed the correlation between the proportion of HAFP-3 and the immunosuppressive potency of each isolate. In addition, analysis of these isolates by isoelectric focusing in polyacrylamide gels containing 8 M urea revealed further evidence of microheterogeneity; at least six molecular variants were apparent. The proportion of one of these variants, termed HAFP-3a, in each isolate was correlated with the immunosupressive potency of the isolate. The sialic acid content of the various alpha-fetoprotein isolates did not vary significantly. Our data suggest that a postsynthetic modification of alphafetoprotein occurs, probably after secretion, which reduces immunosuppressive potency by converting the active electronegative species to an inactive electropositive form. This modification probably involves a charged moiety other than sialic acid on the molecule.
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PMID:A postsynthetic modification of human alpha-fetoprotein controls its immunosuppressive potency. 7 37

Immunofluorescence staining was applied to tissue with primary nonhepatic malignancies and/or their metastatic nodules in the liver. Tumor cells from the primary sites of two patients with carcinoma of the pancreas and one patient with Hodgkin's disease were found to be positive for alpha-fetoprotein (AFP). In five patients with gastrointestinal tract cancer, and two with nongastrointestinal tract carcinoma, the liver cells immediately adjacent to the metastiatic foci were positive for AFP. Negative results for AFP was found in seven patients with liver metastasis; of these seven patients, five had nongastrointestinal tract cancer, and two had cancer that arose in the gastrointestinal tract. It is unclear what influences the production of AFP in cases of liver metastasis, since some neoplasms from the same organ system do provoke this phenomenon, and others do not.
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PMID:Localization of alpha-fetoprotein synthesis in malignancies other than hepatoma. 7 86


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