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E Alpert

Publications and source records attributed to E Alpert.

At least 19 recordsLinked to original sources
PubMed1992

Characterization of a lung-cancer-associated auto-antigen.

An antigen, protein X (Px), was purified from immune complexes isolated from malignant pleural effusions from patients with adenocarcinoma of the lung by EDTA treatment, PEG 8000 precipitation, protein A affinity chromatography, and Sephadex G-200 separation in the presence of 3 M NaCl. The purified antigen had a M(r) 17,000 by SDS-PAGE, and consisted of isoelectric species of pI 6.3 and 6.6. Purified Px recombined with Ig isolated from pleural fluids from patients with lung adenocarcinoma, but not with Ig from patients with breast carcinoma. Using an autologous human and heterologous chicken antibody, Px was found, by immunohistology, in the cytoplasm of some of the well-differentiated lung adenocarcinoma cells, but was not seen in normal lung or a variety of other malignant tissues. A liquid-phase competitive-inhibition RIA was developed. Over 30 ng/ml of Px were found in 9 of 15 pleural fluids from patients with lung carcinoma, none of 20 from patients with breast, ovary, stomach or colon cancer, and in 3 of 15 patients with unknown primary tumor. Our data suggest that Px may be a lung-cancer-associated autoantigen which can elicit a host humoral response in vivo.

Antigen-Antibody Complex↗
PubMed1992

Maternal serum alpha-fetoprotein, beta-human chorionic gonadotropin, and unconjugated estriol levels in midtrimester trisomy 18 pregnancies.

OBJECTIVE: The purpose was to evaluate the levels of maternal serum human chorionic gonadotropin, alpha-fetoprotein, and unconjugated estriol in trisomy 18 pregnancies compared with normal singleton pregnancies. STUDY DESIGN: Sera from 14 trisomy 18 pregnancies (13 retrospectively and one prospectively ascertained) were analyzed for human chorionic gonadotropin, alpha-fetoprotein, and unconjugated estriol. RESULTS: The alpha-fetoprotein levels in the 10 trisomy 18 pregnancies without open neural tube or ventral wall defect had a median of 0.65 multiple of the median, although two had alpha-fetoprotein levels above 2.5 multiples of the median. The human chorionic gonadotropin levels had a median of 0.32 multiple of the median and the unconjugated estriol levels had a median of 0.56 multiple of the median. Although most women with trisomy 18 pregnancies had serum human chorionic gonadotropin levels that were less than 1.0 multiple of the median, three had markedly elevated human chorionic gonadotropin levels (greater than 5.0 multiples of the median). CONCLUSION: Our data are partially consistent with those previously published but suggest the possibility of a bimodal distribution of alpha-fetoprotein and human chorionic gonadotropin levels in trisomy 18-affected pregnancies, unrelated to a neural tube or abdominal wall defect. The efficiency of screening for trisomy 18 prospectively, using the three serum markers, requires further evaluation.

Adult↗
PubMed1992

Congenital deficiency of alpha-fetoprotein.

Although alpha-fetoprotein may play a role in fetal immune function or in maintenance of osmotic pressure, its exact function is unknown. We report two infants documented to have congenital deficiency of alpha-fetoprotein. One infant had cord blood levels less than 0.5 ng/ml. The second infant had a neonatal level of 120 ng/ml, which is about 2% of the usual concentration for a term newborn. These infants document the existence of congenital deficiency of serum alpha-fetoprotein. Because it is homologous to albumin, congenital deficiency of alpha-fetoprotein may be analogous to analbuminemia, a benign genetic trait.

Adult↗
PubMed1992

Alpha-fetoprotein levels in normal adults.

Alpha-fetoprotein (AFP) is a fetal specific glycoprotein normally produced primarily by the fetal liver. Normally, AFP levels decline rapidly after birth, reaching undetectable levels (less than 10 ng/ml) within several months after birth. The authors have developed a more sensitive radioimmunoassay, which has allowed them to study low levels of AFP in normal adults and to determine factors which may affect its normal level. Two hundred and seventy normal Houston blood donors were screened for the absence of hepatitis B and normal ALT levels. The mean AFP level was 3.04 ng/ml +/- 1.9 SD. There was a statistically significant higher level in men compared to women (p less than .004). Regression analysis demonstrated a statistically significant increase of AFP levels with age both in men (p less than .05) and in women (p less than .01). These data delineate the normal level of serum AFP in normal adults in the United States. With the normal level now defined, it becomes possible to compare levels in different populations including those exposed to hepatotoxins or hepatocarcinogens in the environment.

Adolescent↗
PubMed1992

Isolation and partial characterization of a specific alpha-fetoprotein receptor on human monocytes.

Since a large body of data has suggested a significant role for alpha-fetoprotein (AFP) in the regulation of the immune response at a number of levels, we examined the possibility of a specific receptor for AFP on the immune recognition cell, the monocyte/macrophage. Microscopic autoradiography exhibited an obvious binding of AFP almost exclusively on human peripheral monocytes but not on lymphocytes. In a human monocyte cell line (U937) Scatchard plot analysis indicated the presence of two distinct AFP-specific binding sites with a Kd of 5 x 10(-11) M, 49 binding sites per cell, and 2.5 x 10(-7) M, 7,800 binding sites per cell. 125I-ASD-AFP, AFP-radiolabeled bifunctional photoactivatable thio-cleavable cross-linker, was used to isolate the AFP binding protein from U937 cells. After ultraviolet photoactivation, 125I-sulfosuccinimidyl 2-(p-azido-salicylamido)ethyl-1,3'-dithiopropionate was covalently linked to the putative receptor. Autoradiography of SDS gradient PAGE under reducing conditions showed a major radiolabeled band at between 62 and 65 kD. To confirm the specificity of the finding, recombination of AFP with the isolated receptor was examined in artificially reconstituted membrane vesicles, which also resulted in a single band at approximately 62-65 kD by SDS-PAGE autoradiography. From the data above, we concluded that human monocytes possess a specific AFP binding protein on the membrane, a putative receptor, which may be involved with the physiological regulation of the immune response.

Cell Line↗
PubMed1979

Alteration in tryptic peptide patterns of ferritins purified from human colon carcinoma.

Ferritin from malignant tissue differs electrophoretically from normal ferritin. The molecular basis of this difference has not yet been defined. Malignant tissue contains a mixture of ferritins from normal cells, inflammatory cells as well as cancer cells. GW-39 is a pure colon carcinoma cell system that synthesizes human carcinoembryonic antigen. Therefore, ferritin was isolated from normal colon mucosa and colon cancer tissues, as well as from the colon carcinoma cell line, to clarify the molecular relationship between normal and malignant ferritins. Colon carcinoma ferritin differs in primary structure from normal colon mucosal ferritin and contains at least six additional different tryptic peptides. These six peptides were also found in the ferritin from the colon carcinoma cell line. These data suggest that the alteration in ferritin structure occurs at the cellular level and is associated with the malignant state.

Amino Acids↗
PubMed1979

Failure to detect circulating immune complexes in allergic patients on injection therapy.

Injection therapy for allergic diseases may create an environment conducive to circulating immune complex formation. Therefore, we examined the sera of eleven patients receiving injection therapy for the presence of circulating immune complexes. A sensitive Raji cell radioimmune assay was used to examine the sera prior to and 4, 8 and 24 hours after allergenic injection. Levels measured in these sera were compared to values obtained from forty-two healthy controls. Ten of eleven allergic patients receiving injection therapy had values within the normal range prior to maintenance injection. These ten patients also had normal values for circulating immune complexes at each interval after maintenance injection. The data suggest that circulating immune complexes are not a routine consequence of injection therapy for allergic disease.

Adult↗
PubMed1978

The immunochemical complexity of CEA: a golden dream or molecular nightmare?

Carcinoembryonic antigen is only a tumor assoicated antigen and is less clinically useful than the original report suggested. However, the CEA assays in clinical use utilize reagents operationally defined by old criteria. There is now abundant evidence that "CEA" consists of a heterogenous family of related glycoproteins with shared, as well as distinctive, antigenic determinants. Antigenic differences can be demonstrated between some cancer sera "CEA" and various operationally defined tissue "CEA" preparations. Further definition of the biochemical and antigenic characteristics of serum and tumor tissue "CEA" is required in order to determine whether a more tumor specific antigenic determinant can be identified.

Carcinoembryonic Antigen↗
PubMed1978

Immunosuppressive characteristics of human AFP: effect on tests of cell mediated immunity and induction of human suppressor cells.

Murine AFP has been reported to be immunosuppressive in a variety of systems. However, the extent and degree of inhibition has varied in different species and laboratories. Therefore, we have examined the potential suppressive effect of purified human AFP on several in vitro tests of cellular immunity and the potential mechanism of its action. AFP purified from fetal and liver cancer sera significantly inhibited mitogen and antigen-induced proliferative responses but had no effect on lymphocyte E rosetting, MIF production or mitogen induced T cell cytotoxicity to Chang target cells. Purified human AFP induced human suppressor cell activity, capable of suppressing a one-way mixed lymphocyte reaction (MLC). In contrast to Con A induced suppressor cells, AFP induced suppressor cell activity was overcome by mitogen augmentation of the proliferative response in MLC. These data suggest that the inhibition of lymphocyte proliferation by human AFP may be mediated by the induction of a subpopulation of human suppressor cells. Furthermore, mitogen induced cell mediated cytotoxicity was partially inhibited by primary liver cancer serum and completely inhibited by newborn cord serum, in contrast to purified fetal or tumor AFP which had no effect. These data suggest that there are other immunosuppressive factors in fetal and tumor serum which require further characterization. These other serum factors may be responsible for some of the immunosuppressive effects attributed to AFP. Although AFP is unlikely to play a major immunosuppressive role physiologically in vivo, its selective effect on proliferative responses, apparently mediated by suppressor cells, may prove to be a useful pharmacologic probe of the mechanism of these in vitro lymphocyte responses and biological interactions.

Humans↗
PubMed1978

Alpha-fetoprotein (AFP) in benign liver disease. Evidence that normal liver regeneration does not induce AFP synthesis.

One hundred sera samples, obtained during the early postoperative period from 11 patients after a partial hepatectomy, were assayed for alpha-fetoprotein (AFP). None were AFP-positive by radioimmunoassay, despite clinical and biochemical recovery associated with normal liver regeneration. AFP was elevated in 29% of patients with acute hepatitis, 34% of patients with chronic active hepatitis, and in 75% of patients with massive hepatic necrosis. The mechanism and significance of AFP elevations in some patients with acute and chronic hepatitis is uncertain but probably does not reflect normal liver regeneration.

Acute Disease↗
PubMed1977

Alpha1-fetoprotein in neonatal hepatobiliary disease.

It has been suggested that the quantitative estimation of serum alpha-1-fetoprotein may help in distinguishing the neonatal hepatitis syndrome from biliary atresia. We measured the serum AFP concentration in 52 neonates and infants with various hepatobiliary disorders, including neonatal hepatitis syndrome (group I), biliary atresia (group II), and other hepatopathies such as choledochal cyst (group III). The mean serum AFP concentration in patients with neonatal hepatitis was significantly greater than the mean concentration in the other two groups. There was no significant difference between the mean serum AFP concentrations in patients with biliary atresia and in group III patients. Patient age was noted to be an important factor: Serum AFP levels greater than 35 microgram/ml in infants one to four months of age suggpst the diagnosis of neonatal hepatitis syndrome. Serum AFP levels below 10 microgram/ml in infants less than four months of age suggest the diagnosis of biliary atresia or hepatopathies other than neonatal hepatitis. However, the variable and significant overlapping of serum AFP values between 10 and 35 microgram/ml limit the diagnostic value of this test.

Biliary Tract↗
PubMed1977

Multiple antigens as marker substances in germinal tumors of the testis.

Germinal cell tumors of the testis were studied for the presence of several tumor-associated antigens. Antisera were produced by immunizing rabbits with the purified antigens of alpha-fetoprotein (AFP), carcinoembryonic antigen (CEA), and hepatoma ferritin. Indirect immunofluorescence on embryonal carcinoma with or without teratoma components demonstrated that their staining range was 1--60 per cent with antiserum against AFP, 0--16 per cent with anti-serum against ferritin, and 0-40% with antiserum against CEA. Ferritin-like substances have not been described previously in germinal tumors of the testis. No staining was seen with seminoma cells or benign testicular tissues. Raised serum levels of AFP and the ferritin-like substance were related both to the presence of tumor and to dissemination of the disease. CEA occurred transiently in serum. Eleven patients with primary tumors had no antigen in their sera and have all survived, but the median survival time for 8 patients with either antigen in preoperative sera was 12 months. Five patients with advanced tumor in whom neither AFP nor ferritin was detected had a much longer median survival time (58 mo) than did 13 patients with high levels of serum AFP or ferritin (12 mo). The presence of either AFP or ferritin in sera of patients with primary or advanced disease, therefore, seemed to indicate a poor prognosis. The determination of both substances in serum may be useful in the follow-up of patients with certain types of testicular tumors. The proportion of cells containing each antigen varied in the different tumors. Similarly, each antigen could occur independently in serum. This suggested that certain germ cell tumors contained subpopulations of cells, which differed in their production and release of the antigens studied.

Antigens, Neoplasm↗