Serum lactate dehydrogenase isoenzyme 1 in patients with advanced testicular cancer

Abnormal levels of serum lactic dehydrogenase-1 (LD-1) activity have been observed in 81% (34/42) of patients with stage III germ cell malignancy of the testis. The criteria for evaluation the electrophoretic isoenzyme patterns of these patients were, as follows: For criterion 1 elevations the LD-1 value in absolute units was greater than 52.0 U/I with the LD-1/Total LD ratio greater than 37.2%. Criterion 2 elevations had absolute values of LD-1 less than 52.0 U/I, but the LD-1/Total LD ratio was greater than 37.2%. For criterion 3 elevations of LD-1, the absolute value was greater than 52 U/I and the LD-1/Total LD ratio was less than 37.2% activity with the LD-5/LD-1 ratio less than 0.5; or when the LD-5/LD-1 ratio was greater than 0.5 but the LD-1 is equal to or greater than the LD-2. The frequency of LD-1 elevation correlated well with the extent of the disease (stage II-B-1 and 2, 50%; stage III-B-3, 86%; stage III-B-4, 91%; stage III-B-5, 93%). LD-1 elevation occurred in groups I, II, IV and V histopathologic cell types (Dixon and Moore Classification) and there did not appear to be any correlation between the histologic cell type and the frequency of elevation of LD-1. Interpretation of LD-1 activity only on the basis of its relative ratio to the total LD value (criterion 1 and 2) identified a total of 28 patients (67%). A criterion 3 elevation was demonstrated in 6 (14%) additional patients. All patients with persistent elevations or recurrent elevations of LD-1 have shown progressive or recurrent disease and patients with no clinical evidence of disease have demonstrated normal LD-1 values. In those patients with elevated LD-1 activity, serial measurements of serum. LD-1 isoenzyme reflect the response of the patient to therapy.

A micro-assay for estrogen receptor in breast tumor with use of 125I-labeled estradiol

The concentration of estrogen receptor protein in breast-tumor tissue is generally expressed in units of femtomoles of estradiol bound by the receptor per milligram of cytosol protein. The sensitivity of the estrogen receptor radioligand assay is therefore related to the specific activity of the steroid label used for the binding assay, the amount of the receptor protein in the volume of cytosol used, and the protein concentration in the cytosol. In this paper, we discuss factors affecting the sensitivity of the estrogen receptor assay and present various approaches for optimizing the assay. We also describe a procedure that involves a radioiodinated estradiol of high specific activity, a micro-technique for preparing tumor cytosol, and a micro-assay procedure with which the estrogen receptor protein can be measured in as little as 50 mg (wet weight) of tissue.

A micro-assay for estrogen receptor in breast tumor with use of 125I-labeled estradiol

The concentration of estrogen receptor protein in breast-tumor tissue is generally expressed in units of femtomoles of estradiol bound by the receptor per milligram of cytosol protein. The sensitivity of the estrogen receptor radioligand assay is therefore related to the specific activity of the steroid label used for the binding assay, the amount of the receptor protein in the volume of cytosol used, and the protein concentration in the cytosol. In this paper, we discuss factors affecting the sensitivity of the estrogen receptor assay and present various approaches for optimizing the assay. We also describe a procedure that involves a radioiodinated estradiol of high specific activity, a micro-technique for preparing tumor cytosol, and a micro-assay procedure with which the estrogen receptor protein can be measured in as little as 50 mg (wet weight) of tissue.

CSF carcinoembryonic antigen in meningeal carcinomatosis from breast cancer

Levels of CSF carcinoembryonic antigen (CEA) were determined in 23 patients with breast cancer and meningeal carcinomatosis. Levels greater than 1.5 ng/mL were observed in 16 patients; seven patients had undetectable levels. The meningeal disease of seven patients with elevated CSF CEA levels completely responded to treatment, and their CSF CEA levels concurrently decreased. Two patients whose meningeal disease responded poorly to treatment had persistently elevated levels of CSF CEA. In two other patients, a rising CSF CEA level was detected before there was any other evidence of meningeal relapse. Serial measurement of CSF CEA may play an important role in the clinical management of meningeal carcinomatosis in patients with breast cancer.

A direct competitive binding radioimmunoassay for carcinoembryonic antigen

We have incorporated commercially available CEA standard and antiserum into the triple isotope double antibody radioimmunoassay and we have evaluated this assay for the routine determination of CEA. The competitive protein binding (CPB) assay for CEA can be performed directly on serum or plasma without perchloric acid extraction. The assay sensitivity was 0.98 ng/ml, and the day-to-day precision as defined by the coefficient of variation was 12.5% and 13.3% for mean values of 7.6 and 23.9 ng CEA/ml, respectively. The normal range (X +/- 2 S.D.) for CEA determined with the direct CPB method was 3.2--6.2 ng CEA/ml for non-smokers. The upper limit of normal for smokers was 10.0 ng/ml. A method comparison study (Roche perchloric acid extraction vs. direct CPB) showed excellent agreement between the methods for plasma samples containing less than 20.0 ng CEA/ml. The least square analysis parameters were: N = 116, slope = 1.01, y-intercept = 3.5 ng/ml, Sy/x -2.05 ng/ml, and the correlation coefficient was 0.79. Recovery and dilution studies showed no demonstrable non-specific interference due to serum proteins in the direct CPB assay. The clinical significance of the direct CPB assay for CEA was assessed by correlating serial CEA values with the clinical status of patients with breast and colorectal cancer. Increasing CEA values correlated with progressive or recurrent neoplastic disease, and decreasing CEA values correlated with response of the patient to therapy. No false positive direct CPB values for CEA were observed in the clinical study or in the method comparison study. Our laboratory and clinical evaluation demonstrate that the direct CPB method is an accurate and reliable method for the quantitation of CEA. In addition, the method permits high volume analysis and eliminates the hazards to safety that are associated with perchloric acid.

Carcinoembryonic antigen levels in malignant pleural fluids obtained from patients with mammary cancer

The clinical usefulness of the carcinoembryonic antigen test for defining the malignant origin of pleural fluids obtained from patients who have mammary cancer was evaluated. Of 57 malignant pleural fluids obtained from 51 patients who had mammary cancer, 31 (54.4%) demonstrated a significantly elevated carcinoembryonic antigen content: the ratio of pleural fluid to serum carcinoembryonic antigen values ranged from .24 to 3.55; whereas for 14 of 23 patients who had normal levels of both serum and pleural fluid carcinoembryonic antigen, the ratio ranged from 0.25 to 2.30. This study indicates that the pleural fluid carcinoembryonic antigen value may be significantly elevated in only 50-60% of mammary cancer patients having documented malignant pleural fluids, and that the pleural fluid to serum carcinoembryonic antigen ratio is of no value in defining the malignant origin of pleural fluids obtained from these patients.

Tyrosinase activity in the sera of patients with malignant melanoma: method and specificity

Serum tyrosinase activity has been measured by adapting the [3]tyrosine assay for tyrosinase and significant elevations of serum tyrosinase activity were found in patients with malignant melanoma. In contrast to findings in a study which utilized [14C]tyrosine, augmented levels of tyrosinase activity were not observed in sera from patients with other malignancies, including subjects with carcinoma of the breast. The results of the examinations for soluble tyrosinase activity in human malignant melanoma tissue-cultured lines were all positive, whereas human cell lines from carcinoma of the breast, carcinoma of the colon and sarcoma uniformly showed no activity. The method employed for detecting tyrosinase activity holds promise as a specific diagnostic test and may be valuable for monitoring the response to clinical treatment of patients with malignant melanoma.

Enzymatic endpoint analysis of glucose with the hexokinase method and the Union Carbide fast centrifugal analyzer

1. We describe an enzymatic endpoint method for glucose using the hexokinase reaction and the Union Carbide fast centrifugal analyzer. The new method permits the direct spectrophotometric measurement of serum blanks, and eliminates the need for separate blank determinations or computer-assisted calculation of the sample blank absorbance values. 2. The direct automatic blanking is accomplished by measuring the absorbance of the test solution 2 seconds after the reactants have been mixed. Our studies show that no appreciable conversion of glucose occurs during this time interval. 3. The results of the new method agree well with the results from the conventional hexokinase assay. In addition, the method requires only 5 microliters of serum, and has a high sample throughput rate.

The determination of serum immunoglobulins by automated nephelometric analysis

We have evaluated the Technicon Automated Immunopreciptin System for the determination of immunoglobulins G, A and M in human serum. The new method is based on the nephelometric measurement of complexes formed during the antigen-antibody reaction. In this paper, we review the principles of nephelometry and describe its application to the measurement of antigen-antibody complexes. We have found the nephelometric method to be reliable for routine clinical use. The new method gives immunoglobulin test results which are highly reproducible, and agree well with the results determined by a radial immunodiffusion method.

Cellulose Acetate Electrophoresis of Alkaline Phosphatase Isoenzymes in Human Serum and Tissue

We describe a new electrophoretic method for the characterization of human serum and tissue alkaline phosphatases on cellulose acetate plates. Enzymes are localized fluorometrically with the substrate α-naphthol AS-MX phosphate or colorimetrically by coupling the reaction product with Fast Blue RR. Both localization techniques are sensitive enough to demonstrate isoenzyme patterns in micro-scale samples of normal sera. Our electrophoretic studies indicate that sera of children and adults normally contain isoenzymes originating from both liver and bone. The high sensitivity of the method allows the use of normal sera as markers rather than tissue extracts, and isoenzyme patterns may be visually assessed after heat inactivation and chemical inhibition. The method is suitable for the electrophoretic fractionation of alkaline phosphatase in large numbers of sera, with equipment and technique familiar to many laboratories.