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K R McIntire

Publications and source records attributed to K R McIntire.

At least 19 recordsLinked to original sources
PubMed1979

Immunochemical characterization of tumor-associated surface antigens on a Moloney leukemia virus-lymphoma, MBL-2.

Tumor-associated surface antigens (TASA) on a Moloney leukemia virus (M-MuLV)-induced lymphoma, MBL-2, in C57BL/6 mice (B6) were characterized. The surface proteins of MBL-2 cells were selectively radioiodinated and then extracted by Nonidet P40. The solubilized materials were then reacted with a variety of antisera: monospecific antisera to murine leukemia viral proteins (anti-gp69/71, anti-p30, anti-p15, anti-p12 and anti-p10), sera from B6 which regressed murine sarcoma tumors induced by murine sarcoma virus (anti-MSV) and a rabbit anti-MBL-2 antiserum. The resulting radioimmune precipitates were analyzed and compared in sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). The following results were obtained. (1) Among all anti-viral protein antisera tested only anti-gp69/71 was active and detected a protein doublet of gp69/71 and its degradation fragments of 42,000 and 35,000 daltons. (2) Radioimmune precipitates prepared with anti-MSV showed a SDS-PAGE pattern similar to that seen with anti-gp69/71. This result indicated that the surface antigen detected by the anti-MSV serum on MBL-2 tumor cell was probably a viral envelope antigen. (3) The rabbit anti-MBL-2 serum detected on the cell membrane an antigen of approximately 95,000 daltons which was tumor-associated and did not appear to be related to virion components. The anti-MBL-2-serum still reacted with the 95,000 dalton antigen after absorption with disrupted M-MuLV virus and with gp69/71 and p30 purified from the virus.

Animals↗
PubMed1979

Further studies on a human lung tumor-associated antigen. Comparison of antigens from different tumors.

A human lung tumor-associated antigen was purified to homogeneity from a crude cell-free extract of a human lung adenocarcinoma using standard biochemical procedures. In order to facilitate monitoring the recovery of antigen, trace amounts of previously purified and radioiodinated antigen from another lung tumor were added to the crude extract. The purified antigen was a glycoprotein and contained sialic acid. The antigen had a molecular weight of 76,000 and appeared to contain three subunits, each with a molecular weight of 25,000. The antigen had the following physical properties: Stokes radius, 39.4 A; S20,w, 4.24 S; D20,w, 5.15 x 10(-7) cm2 S-1; and a frictional ratio of 1.40. In addition, the purified, radioiodinated antigen retained complete immune reactivity since it could be quantitatively precipitated with specific immune serum. All of these properties were in close agreement with the properties of another antigen which was purified from a separate human lung tumor. Thus, it appeared from the biochemical and immunochemical criteria presented in this report that a common and identical antigen was isolated from two distinct human lung tumor extracts.

Adenocarcinoma↗
PubMed1979

Sensitive and convenient quantitation of antibody binding to cellular antigens using glutaraldehyde preserved cells.

As a preliminary step in the identification and isolation of antibodies to human cancers, we have developed a sensitive and convenient assay for antibody binding to cellular antigens. The basis for the method is antibody binding to glutaraldehyde-fixed cells (AbGfC) and quantitation with radioiodinated staphylococcal protein A (SpA). Glutaraldehyde fixation of intact cells, which does not appear to effect the ability to form antigen-antibody complexes, provides a convenient and standard supply of target cells which may be stored at 4 degrees C and used in the assay over a period of several months. The amount of antibody specifically bound to the cells is quantitated by the addition of 125I-labeled SpA. The sensitivity of the method was compared with two complement-dependent cytotoxicity methods (trypan blue exclusion and 51Cr release assays) and tested with two antisera to human lung cancer and one antiserum to a membrane antigen of a murine lymphoma. These comparisons indicated much greater sensitivity when compared with the trypan blue exclusion assay and equivalent sensitivity with greater dose response characteristics when compared with the 51Cr release assay.

Aldehydes↗
PubMed1979

Isolation of human alpha-fetoprotein in two fractionation steps and demonstration of homogeneity.

Human alpha-fetoprotein (hAFP) has been isolated from cord serum in 40% yield using an isolation procedure consisting of only two major steps: affinity chromatography followed by preparative polyacrylamide gel electrophoresis (PAGE). The final product appeared homogeneous on the basis of five independent criteria for purity. Sodium dodecyl sulfate gel electrophoresis (SDS-PAGE) demonstrated a single polypeptide chain with molecular weight of 71,000. The protein exhibited an apparent isoelectric point (pI') of 4.85, molecular radius of 3.0 nm and a valence (net H+/molecule) of 21.9 derived from computation of analytical PAGE data. The two-step isolation procedure made it possible for a single operator to isolate milligram amounts of hAFP in a matter of weeks.

Buffers↗
PubMed1978

Human chorionic gonadotropin (HCG) and alpha-fetoprotein (AFP) in sera and tumor cells of patients with testicular seminoma: a prospective study.

The HCG and AFP have been quantitated in the sera of 130 patients with the diagnosis of testicular seminoma utilizing a specific double antibody radioimmunoassay. These tumor markers also were localized in tumor cells of some of these patients utilizing an indirect immunoperoxidase technique. 11 of 130 patients had elevated serum levels of HCG. The HCG molecules have been localized in the syncytiotrophoblastic giant cell (STGC) that is occasionally observed in seminomas. None of the patients with pure seminoma had an elevated level of serum AFP. We have concluded that in patients with pure seminoma the level of serum HCG can be elevated (10 of 130 or 7.6%), but we have not observed elevated serum levels of AFP in these patients.

Chorionic Gonadotropin↗
PubMed1978

The role of the radioimmunoassay of serum alpha-fetoprotein and human chorionic gonadotropin in the intensive chemotherapy and surgery of metastatic testicular tumors.

Quantitative measurement of serum alpha-fetoprotein and human chorionic gonadotropin by double antibody radioimmunoassays reflects the efficacy of surgical, radiation and/or chemotherapeutic regimens in patients with bulky disseminated testicular tumors. When these therapies are effective they produce an immediate decrease in serum levels of these markers that reflects the decrease in tumor size and could be as rapid as the catabolic decay rate for alpha-fetoprotein or human chorionic gonadotropin. The alpha subunit of human chorionic gonadotropin has a short half-life (20 minutes) and has been used for the first time to localize a recurrent metastatic testicular tumor. Cellular localization of these markers by immunochemical techniques has helped us to understand the natural history of this cancer and the cell types responsible for production of the markers.

Adult↗
PubMed1978

In vitro alpha-fetoprotein synthesis by monkey hepatocellular carcinoma.

Five monkeys were treated ip with N-nitrosodiethylamine (DENA), and one was treated with 1-nitrosopiperidine (PIP), starting within 2 months of birth, until hepatocellular carcinoma (HCC) developed. All animals except the PIP-treated monkey had much elevated serum alpha-fetoprotein (AFP) values. Fresh, minced, biopsy-derived tumor was cultured with L-[14C]leucine and L-[14C]lysine. Synthesis of AFP was determined by radioimmunoassay and by specifically precipitable [14C]AFP. Good agreement between these two parameters was obtained for the 4 DENA-induced tumors synthesizing AFP in culture. Tumor from 1 DENA-treated monkey did not synthesize AFP. In addition, neither normal liver nor tumor from the PIP-treated monkey showed AFP synthesis. Rates of synthesis were 0.37-5.50 ng AFP/mg tumor/day, or 0.0012-0.0183 pg AFP/cell/day (if one assumes 3.0 X 10(5) cells/mg tissue) over 48 or 72 hours. Different nodules from the same animal had similar rates of synthesis. For tumors that synthesized AFP in culture, a positive correlation was generally found between rate of synthesis and serum AFP level. The rate of in vitro AFP synthesis observed was lower than that of immunoglobulin synthesis in human myeloma or of AFP synthesis in a rat HCC, but it was close to the estimated rate of AFP synthesis in a monkey HCC line in long-term culture.

Animals↗
PubMed1978

Purification and characterization of a human lung tumor-associated antigen.

A human lung tumor-associated antigen was purified from a saline extract of a lung adenocarcinoma. The antigen was demonstrated in extracts of lung adenocarcinoma. The antigen was demonstrated in extracts of lung tumors with the use of an absorbed antiserum by double-diffusion immunoprecipitation. The antiserum did not react with extracts of normal lung or other normal tissues, and the antigen was immunologically distinct from other tumor-associated antigens. Purification was achieved by antibody affinity chromatography and preparative polyacrylamide gel electrophoresis. Isolation procedures were monitored by immunoreactivity with absorbed monospecific antiserum. The antigen was labeled with 125I and judged homogeneous by 1) polyacrylamide gel elecrophoresis in detergent and nondetergent gels, 2) molecular sieve chromatography, 3) ion exchange chromatography, and 4) sucrose gradient sedimentation analysis. A molecular weight of 77,000 was calculated from the s20.w value of 4.24S and from the D20.w value of 5.0X10(-7) cm2/sec. Sodium dodecyl sulfate gel electrophoresis indicated a subunit molecular weight of 42,000. The Stokes radius of the antigen was 40 A and the frictional ratio was 1.42, indicating a nonspherical molecule. The purified radioiodinated antigen could be quantitatively precipitated with specific antiserum.

Adenocarcinoma↗
PubMed1978

Immunochemical determination of human chorionic gonadotropin and alpha-fetoprotein in sera and tumors of patients with testicular cancer.

In several prospective studies during the past 5 years, we evaluated 400 patients with nonseminomatous and 60 with seminomatous testicular tumors with the use of serum and cellular AFP and HCG at the NCI. Ninety percent of the patients with nonseminomatous testicular tumors had elevated levels of either HCG and/or AFP that have been useful in detection, staging, prognosis, and monitoring the efficacy of the therapeutic modalities. Although 5% of the patients with pure seminoma had an elevated level of serum HCG, one must search for elements of nonseminomatous testicular tumor in these patients by serial section of the seminoma specimen. Elevated serum AFP in patients with designations of seminoma indicates the presence of an element of embryonal carcinoma and/or teratoma. We have localized these markers in various tumor cells by using the technique of indirect immunoperoxidase. The HCG is localized in syncytiotrophoblastic component of choriocarcinoma and syncytiotrophoblastic giant cells occasionally found in association with embryonal carcinoma, teratoma, and seminoma. The AFP is localized in embryonal and endodermal sinus tumor.

Adult↗
PubMed1977

Cellular localization of alpha-fetoprotein and human chorionic gonadotropin in germ cell tumors of the testis using and indirect immunoperoxidase technique.

An immunohistologic study of 21 patients with germ cell tumors of the testis with measured serum levels of chorionic gonadotropin (HCG) and alpha-feto protein (AFP) was undertaken to correlate the various types of neoplasms with the presence of these tumor markers in the tissue and serum. AFP was demonstrated in mononuclear embryonal cells within embryonal carcinoma and endodermal sinus tumor. HCG was identified within syncytiotrophoblastic giant cells, frequently in association with embryonal carcinoma, and rarely with endodermal sinus tumor and seminoma, as well as in the syncytiotropho-blastic component of choriocarcinoma. Eighteen of the 21 patients (86%) had elevated tumor markers in their serum; serum HCG alone was elevated in five (24%), AFP alone in five (24%) and both were elevated in eight (38%). There was tissue localization of HCG in 12 of the 13 patients (92%) with elevated serum HCG while AFP was identified in the tumor in eight of the 13 patients (53%) with elevated serum AFP levels. Based on these findings, a tentative immunohistologic classification of germ cell tumors utilizing AFP and HCG is proposed. Thus, embryonal carcinoma, adult type, is frequently associated with both AFP and HCG, endodermal sinus tumor with AFP and choriocarcinoma with HCG, whereas pure seminoma and teratoma are unlikely to be associated with either marker.

Chorionic Gonadotropin↗
PubMed1977

alpha-Fetoprotein values in monkey (Macaca mulatta) pregnancy.

The pregnant rhesus monkey's (Macaca mulatta) potential as a model for understanding the dynamics of alpha-fetoprotein (AFP) metabolism in human pregnancy was evaluated. AFP levels in maternal and fetal serum and amniotic fluid were determined by radioimmunoassay. Significant correlations were found between decreasing maternal serum, fetal serum and amniotic fluid AFP concentrations and increasing gestational age. However, these data are not consistent with the AFP changes reported in human pregnancy. It appears that this animal has limited applicability as a model in this aspect of human pregnancy.

Amniotic Fluid↗
PubMed1977

Alpha-fetoprotein and human chorionic gonadotropin in the management of testicular tumors.

Alpha-fetoprotein and human chorionic gonadotropin levels were measured by radioimmunoassays in 260 patients with genitourinary diseases, including 93 patients with testicular tumors. Elevations of alpha-fetoprotein and human chorionic gonadotropin were associated only with non-seminomatous germ cell testicular tumors. Our 32-month experience with serial measurements of the 2 markers in patients with these tumors shows that alpha-fetoprotein and human chorionic gonadotropin must be determined and that together they serve as accurate and sensitive indicators of metastases and are helpful in determining the effectiveness of therapy. However, they have limited value in the differential diagnosis of scrotal masses.

Adult↗
PubMed1977

A rapid and effecient method for the isolation of proteins from polyacrylamide cells.

A procedure is described for the rapid and efficient electrophoretic elution of protein from polyacrylamide gels which is then collected in a dialysis bag tied to the end of a tube containing the gel slices. To illustrate the method a heterogeneous preparation of alkaline phosphatase was used from which a single homogeneous component was isolated in six hours with a recovery of 86%. The eluted protein is collected in a volume which can easily be kept below 1.5 ml, thus eliminating the need for subsequent concentration. The method has also been used successfully in two other systems in which a human lung tumor-associated antigen and glycogen synthetase from yeast were isolated. Since the method utilizes a standard analytical gel electrophoresis apparatus with no modifications or accessories, it should be immediately applicable for the isolation of many different proteins from polyacrylamide gels.

Alkaline Phosphatase↗
PubMed1977

Tumor-associated antigen levels (carcinoembryonic antigen, human chorionic gonadotropin, and alpha-fetoprotein) antedating the diagnosis of cancer in the Framingham study.

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.

Adult↗
PubMed1977

Fetal hemoglobin and alpha-fetoprotein in various malignancies.

Fetal hemoglobin (HbF) concentrations were measured by a radial immunodiffusion assay in 233 patients with various malignancies. In 96 of these, alpha-fetoprotein (AFP) was also measured by radioimmunoassay. The concentration of HbF exceeded 2 SDs above the normal mean in 39 of 233 patients, most notably in patients with leukemia, lymphomas, multiple myeloma and testicular tumors. The proportion of HbF was not correlated with the total hemoglobin concentration or with serum AFP concentration.

Fetal Hemoglobin↗