Serum antibodies to retinal antigens in lung cancer and sarcoidosis.

OBJECTIVE: Autoantibodies to various neuronal proteins frequently accompany lung cancer and their appearance may precede cancer symptoms. In this study we examined which retinal antigens (RAs) are recognized by sera of patients with lung cancer and whether the occurrence of serum antibodies to particular RAs is characteristic for cancer in comparison with a noncancer lung disease. METHODS: Sera of 72 patients with non-small-cell lung cancer (NSCLC), 29 with small-cell lung cancer (SCLC), 27 with sarcoidosis (S), and sera of 32 healthy donors were examined in immunoblotting using retinal extracts and purified RAs as antigens. RESULTS: 69.0% of SCLC, 45.8% of NSCLC, and 44.4% of S sera displayed anti-RAs reactivity. Significantly less (p < 0.05; chi(2) test) percent of healthy control sera reacted with RAs. Lung cancer sera recognized mainly 46-, 56-, and 36-kD and to a smaller extent also 96-, 72-, 43-, and 26-kD proteins. Most of them were recognized with about 2-fold lower frequencies by S and control sera. Only lung cancer sera contained very high-titer antibodies to 46- and 26-kD RAs, identified as alpha-enolase and recoverin, respectively. CONCLUSION: Antibodies to RAs occur more frequently and in higher titers in lung cancer (especially SCLC) than in sarcoidosis or control sera. Although antibodies to retinal alpha-enolase, recoverin and other RAs are present mainly or exclusively in lung cancer sera, none of them seems to be a specific marker of a particular disease.

Influence of some factors on immunoassays of human myoglobin.

Six ELISA variants exploiting two monoclonal antibodies, one rabbit antibody and their peroxidase conjugates were applied in assays of purified human myoglobin, apomyoglobin and the protein in human muscle extracts. The myoglobin was accurately determined with monoclonal antibody no. 82 used for coating of ELISA plates while assays performed with monoclonal antibody no. 49 or rabbit antibody used for coating were weak or none. Determinations of human apomyoglobin with ELISA variants were somewhat more sensitive than those of myoglobin. Obtained in this work results were compared with those done using commercial Seratec kit for immunoassay of human myoglobin. Addition to the muscle extracts not only concentrated salts but also acetone, ethanol, sodium dodecyl sulfate or some other denaturing agents markedly increased assays of myoglobin by ELISA with monoclonal antibody no. 49 and antibody no. 82 conjugated with peroxidase. Removal of acetone or ammonium sulfate from extracts resulted in dramatic decrease of the estimated myoglobin. Filtration of the extract through Bio-Gel A5m column did not affect low assays of myoglobin in fractions without pretreatment with acetone. Myoglobin was isolated from human heart extract by immunoaffinity chromatography on Sepharose-antibody no. 82 column and the isolated protein was identified by gel electrophoresis and Western blot.

Some parameters influencing immunoassay of human and horse myoglobins.

It was noted that human and horse sera as well as human heart and skeletal muscle homogenates or extracts distinctly decrease immunoassays of purified myoglobins. The assays of homogenate and extract myoglobins could be many times increased by precipitation certain proteins with concentrated ammonium sulfate or sodium chloride. Also in homogenates and extracts incubated for several days increased assays of myoglobins were noted. The obtained results indicate that both myoglobins occur in complex with other tissue component(s).

Antigenicity of human and horse myoglobins.

Rabbit antisera against human myoglobin and horse myoglobin cross-reacted with both myoglobins but only one of them recognized human hemoglobin. Two mouse monoclonal antibodies anti-human myoglobin were obtained, but only one of them (No. 49) cross-reacted with horse myoglobin. Antibody No. 49 and rabbit antibodies reacted also with apo-, FITC- and treated with hydrochloric acid or TPCK-trypsin horse myoglobin, but their binding to myoglobin pretreated with NaOH was reduced. Thirteen peptides overlapping sequence of human myoglobin were synthesized on polyethylene pins. Rabbit and mouse polyclonal antibodies reacted with some of these peptides but no reaction was noted with mouse monoclonal antibodies. Two monoclonal antibodies were applied for specific immunoassay of human myoglobin.

Stability of human lutropin studied with immunoenzymatic technique.

Characteristics of two monoclonal antibodies against human lutropin and their use in enzyme immunoassays of the hormone are presented. Diluted solution of pituitary lutropin was unstable in buffered saline and could be stabilized with some proteins. Concentration of the lutropin in woman urine, collected during "lutropin-peak", was markedly increased during long time storage at 5 degrees C or at room temperature. Using HPLC it was demonstrated that pituitary lutropin, normal urine lutropin and "increased" urinary lutropin were eluted from ion exchange column almost with the same retention time.

Search for antibodies for immunoenzymatic assay of human lutropin.

Five peptides corresponding to human lutropin (hLH) subunit fragments were synthesized by a solid phase method and their physicochemical characteristics are presented. Antibodies induced in rabbits with 3 peptides of beta hLH fragments coupled to thyrotropin did not bind hLH and human chorionic gonadotropin (hCG). Also 2 synthetic peptides of alpha hLH fragments did not react with rabbit anti-hLH, anti-hCG and anti-alpha hCG antibodies. Using 2 monoclonal anti-alpha hCG and anti-beta hLH antibodies a sensitive sandwich ELISA technique was elaborated. Using this technique stability of hLH was investigated. The ELISA was also applied for assays of urine hLH in normal and ovulation days.

The use of antibodies labelled with dyes for fast and simple assay of some human proteins by immunofiltration technique.

Immunofiltration technique with polyclonal and monoclonal antibodies for semi-quantitative assays of human albumin, chorionic gonadotropin, immunoglobulin G and transferrin was elaborated. An amount of antibody was immobolized in the form of 6 radially located small bars on a dry test filter made of glass microfibre sheet. The other amount of antibody, used in solution, was labelled with some dyes like commercial disperse dyes, colloidal elements, formazans and polypyrrole. Number of colour bars appearing on the test filter showed ranged of analyte concentration. Good results were obtained using antibodies labelled with colloidal gold, Disperse Red 11 and formazan from MTT. Assays with monoclonal antibodies were more sensitive than with polyclonal antibodies.

Colorimetric method for assay of serum gamma-glutamyltransferase activity with some L-gamma-glutamyl-carboxyanilides.

A simple method for the assay of serum gamma-glutamyltransferase activity with soluble L-gamma-glutamyl-carboxyanilides is presented. It is based on transformation of aminobenzoic acid liberated by the enzyme into colour complex with 4-dimethyl-aminobenzaldehyde or with 4-dimethylaminocinnamaldehyde in acid medium. Among three carboxyanilides studied the highest enzyme activity was noted with L-gamma-glutamyl-3-carboxyanilide and no activity with L-gamma-glutamyl-2-carboxyanilide. A good correlation was demonstrated for serum gamma-glutamyltransferase activity determined by the new colorimetric method and by the standard one with L-gamma-glutamyl-3-carboxy-4-nitroanilide.

Phenylalkylsulfonyl derivatives as covalent inhibitors of penicillin amidase.

It was demonstrated that phenylmethanesulfonyl fluoride-a very potent inhibitor of penicillin amidase from Escherichia coli-binds covalently to the enzyme in molar ratio 1:1. The chloride, the azide and the N-hydroxysuccinimide ester of phenylmethanesulfonic acid are also very strong inactivators of the amidase. Weaker inhibition was noted with para-substituted phenylmethanesulfonyl chlorides and with phenylethanesulfonyl and alkylsulfonyl chlorides. The inactivated amidase could be reactivated by incubation either with 6-amino-penicillanic acid or with proteins from E. coli extract. Benzyl isocyanate is also a potent covalent inhibitor of the amidase but inactivated amidase could be not reactivated in this way. It was demonstrated that representatives of all inactivator types bind to one active site of the amidase. Interdependence between inactivation rate and stability of some sulfonyl inhibitors was observed. No inhibition was noted the amide, the hydrazide and the methyl ester of phenylmethanesulfonic acid.

Two immunologically different penicillin amidases synthetized by Escherichia coli PCM 271.

From Escherichia coli PCM 271 cells two penicillin amidases were separated by affinity chromatography on immunoadsorbent column. In cells grown in organic medium the activities of the amidase 1 and 2 were 30 and 70% respectively, whereas the activity of the amidase 1 in the cells grown in inorganic medium increased up to 98%. The amidase 1 migrated faster in polyacrylamide gel electrophoresis and was retained on DEAE-cellulose in 10 mM phosphate buffer, pH 8. No catalytic differences were demonstrated between the amidases.

Enzyme-linked immunosorbent assay (ELISA) and colorimetric determination of cow gamma-glutamyltransferase.

Using specific antibodies of anti-heavy and light forms of bovine kidney gamma-glutamyltransferase, both enzyme forms were determined in some cow body fluids and tissue preparations by enzyme linked immunosorbent assay (ELISA). The mean activity of the light form of gamma-glutamyltransferase in cow sera, new-born calf sera and in cow colostra was 29.2, 612 and 2630 mU/ml respectively. Good correlation was noted between the results obtained by ELISA and by colorimetric method. In supernatants from cow kidney and liver homogenate after incubation at 37 degrees C, a marked increase of the heavy form assayed by ELISA was noted.