Immunoenzyme test system with monoclonal antibodies to human IgG4 in the determination of allergen-specific antibodies in pollinosis

ELISA for determination of allergen-specific IgG4 antibodies was developed with the help of monoclonal anti-IgG4 antibodies obtained by classic hybridoma technique. Subclass specificity of antibodies were studied in sera of 108 patients suffering from pollinosis. Antibodies of this isotype were found in the majority of patients with tree pollen allergy but not in patients with grass pollen allergy. The level of IgG4 antibodies correlated with the severity of the disease but not with the intensity of skin tests. Specific hyposensitization resulted in significant increase of IgG4 antibody level in patients with tree pollen allergy. Determination of IgG4 antibodies is proved to be useful to reveal tree pollen allergy and to monitor hyposensitization therapy.     

Immunoenzyme analysis in pneumococcal infection

Complex protein preparations obtained from pneumococci have been used for the serological examination of patients with pneumococcal infection. The proposed system of ELISA permits the detection of positive results in about 70% of cases. The specificity of the method is 95%. Special attention is paid to the determination of the criterion indicating the presence of positive results.     

Immunoenzyme method in the diagnosis of human brucellosis

The optimum conditions for the determination of specific antibodies in the sera of brucellosis patients by means of enzyme immunoassay (EIA) have been selected. The comparative study of the specificity and sensitivity of EIA and other serological tests has demonstrated that EIA has high diagnostic effectiveness in the diagnosis of acute and chronic brucellosis. The presence of direct correlation between the results of EIA and Coombs' test is observed, which is indicative of the capacity of EIA for detecting both complete and incomplete specific antibodies. It should be pointed out that in all cases the titer of specific antibodies in EIA has been found to be 5-16 times higher than in Coombs' test, the passive hemagglutination test, and agglutination test.     

Immunoenzyme analysis using paper disks

Filter paper discs have been used in the enzyme immunoassay (EIA) as solid phase instead of polystyrene plates. The use of paper discs has made it possible to achieve a multiple increase in the sensitivity of sandwich EIA, thus permitting the detection of Yersinia pestis capsular antigen at a concentration of 0.4 ng/ml. Paper discs can be used not only for the sorption of antigen and antibodies, but also for the affinity purification of preparations.     

Immunoenzyme analysis of angiogenin in cow's milk]

Competitive enzyme immunoassay based on polyclonal antibodies can be used for determining the content of angiogenin in milk. These polyclonal antibodies had no cross-reactions with ribonuclease or other milk whey proteins. Milk angiogenin levels in samples taken fvom animals of a separate population varied from 2.09 to 4.85 mg/l. Unlike cow milk productivity, the number of calvings affects the milk angiogenin content.     

Immunoenzyme assay of human cartilaginous proteoglycans and their antibodies

An ELISA has been developed to measure human cartilaginous proteoglycans (PG) and their auto-antibodies. The assay is described step by step: successively the nature of the microtiter wells, the concentration of the PG to be coated, the optimal dilution of the antiserum, the length of various incubations and their respective temperature, are described. Standard curve obtained with purified PG is linear in a logit-log representation. The sensitivity of the assay is 2 ng/tube. Finally, biological fluids-sérum and synovial fluid-show a good parallelism with PG.     

Immunoenzyme analysis of ovarian metastatic antigen-8]

Immunoenzymatic method for the determination of new ovarian-metastatic antigen-8 in human blood serum was worked out. OMA-8 level was studied in blood serum of 40 healthy women, 40 healthy men, 16 neonates, 33 pregnant women, 103 patients with genital tumours. It was found out that OMA-8 level in blood serum of healthy women changed between 2 to 15.4 micrograms/l, in men between 5-17.0 microgramS/l. OMA-8 concentration higher than 15.4 micrograms/ was considered elevated. The elevated OMA-8 level was marked in neonates (100%) and in pregnant (39.3%). High level was discovered in the amniotic fluid.     

Immunoenzyme determination of human granulocyte-macrophage colony-stimulating factor using monoclonal antibodies

A set of seven hybridomas producing monoclonal antibodies (MAbs) to the human recombinant granulocyte-macrophage colony-stimulating factor (GM-CSF) was obtained. The properties of the monoclonal antibodies were characterized, and pairs of MAbs specific to different non-overlapping epitopes of GM-CSF were identified. A sensitive and simple method of two-site ELISA for GM-CSF was developed on the basis of two MAbs. According to this method, one MAb is absorbed onto a microtiter plate and another is labeled with biotin and used for the detection of GM-CSF bound to the first MAb. MAb labeled with biotin, in its turn, was visualized with the streptavidin-horseradish peroxidase conjugate. The sensitivity of this test was no less than 0.5 ng/ml, and a linear dose-response relationship was observed within a concentration interval from 0.5 to 32 ng/ml. No cross-reactivity was found with human tumor necrosis factor-alpha, granulocyte colony-stimulating factor, interleukin-2, or interleukin-3 in this test system.     

Immunoenzyme analysis in a system of serologic evaluation of louse-borne typhus vaccines

The blood sera of persons immunized with different typhus vaccines have been studied in the complement fixation test, the indirect hemagglutination test and the enzyme immunoassay. The data thus obtained indicate that the enzyme immunoassay is highly sensitive and can be universally used for the determination of antibodies to Rickettsia prowazekii after primary and booster immunization with different typhus vaccines. This method detects specific antibodies both at an early period and, which is of particular importance, at a remote period after immunization (3 years later) when complement-binding and hemagglutinating antibodies are absent. This is seemingly indicative of the two-phase character of postvaccinal immunity induced by live typhus vaccine.     

A kinetic analysis of Na-Li countertransport in human red blood cells

We examined the kinetic properties of the interactions between inner and outer cation sites of the Na-Li countertransport system in human red blood cells. Li-stimulated Na efflux [V(Na)] was measured as a function of external Li [(Li)o] and internal Na [(Na)i] contents. At each (Li)o, a Hanes plot of (Na)i/V(Na) vs. (Na)i allowed us to calculate the apparent dissociation constant for internal Na (KiNa) and the maximal rate of Na efflux [Vmax(Na)]. In erythrocytes from 10 different subjects, the Vmax(Na)/KiNa ratios were independent of the external Li concentrations. In other experiments, Na-stimulated Li efflux [V(Li)] was measured as a function of external Na and internal Li contents. In three subjects studied, the Vmax(Li)/KiLi ratios were independent of the external Na concentrations. The data strongly suggest that the countertransport mechanism is consecutive ("ping-pong").     

Assay of phospholipases A(2) and their inhibitors by kinetic analysis in the scooting mode

Several cellular processes are regulated by interfacial catalysis on biomembrane surfaces. Phospholipases A(2) (PLA(2)) are interesting not only as prototypes for interfacial catalysis, but also because they mobilize precursors for the biosynthesis of eicosanoids and platelet activating factor, and these agents ultimately control a wide range of secretory and inflammatory processes. Since PLA(2) carry out their catalytic function at membrane surfaces, the kinetics of these enzymes depends on what the enzyme 'sees' at the interface, and thus the observed rate is profoundly influenced by the organization and dynamics of the lipidwater interface ('quality of the interface'). In this review we elaborate the advantages of monitoring interfacial catalysis in the scooting mode, that is, under the conditions where the enzyme remains bound to vesicles for several thousand catalytic turnover cycles. Such a highly processive catalytic turnover in the scooting mode is useful for a rigorous and quantitative characterization of the kinetics of interfacial catalysis. This analysis is now extended to provide insights into designing strategy for PLA(2) assays and screens for their inhibitors.     

Immunoenzyme analysis of the fertility alpha 2-microglobulin in the blood serum of men and women

It has been found that fertility alpha 2-microglobulin content in male and female serum does not exceed 20 ng/ml and 40 ng/ml, respectively. A high level of fertility alpha 2-microglobulin was found in the serum in early pregnancy, with its concentration decreased by parturition.     

A kinetic analysis of the 5 alpha-reductases from human prostate and liver

A kinetic analysis of the 5 alpha-reductases from human liver and prostate is presented. Human prostatic 5 alpha-reductase follows an ordered sequential mechanism in which NADPH binds first followed by testosterone. The order of release of products is DHT followed by NADP+. The apparent Km of prostatic 5 alpha-reductase for testosterone is 0.0339 +/- 0.006 microM, while the apparent Km for NADPH is 2.52 +/- 0.65 microM. Human liver 5 alpha-reductase also follows a sequential mechanism. The apparent Km of the liver enzyme is 0.110 +/- 0.08 microM; the apparent Km for NADPH is 6.2 +/- 0.6 microM. The fact that both the liver and prostatic 5 alpha-reductases have a sequential kinetic mechanism rules out the possibility that the reduction of testosterone to dihydrotestosterone involves an electron transport system as previously proposed.     

Immunoenzyme analysis with visual demonstration for detecting antibodies to the tick-borne encephalitis virus

Good prospects for the use of enzyme immunoassay (EIA) with the simple visual indication of results have been shown with the detection of specific antibodies to tick-borne encephalitis virus in blood serum used as an example. When compared with such highly sensitive method as radioimmunoassay, visual EIA is inferior in both sensitivity and selectivity, but its special advantage is that it requires no instrument for evaluating the result.     

Immunoenzyme method in the diagnosis of meningococcal infections

The materials on the development and use of the test system, based on the enzyme-linked immunosorbent assay (ELISA) and intended for the detection of specific group A and C meningococcal polysaccharides and type b Haemophilus influenzae polysaccharide in the spinal fluid of patients, are presented. In this work commercial preparations manufactured in the USSR were used, and all parameters of the assay were developed on the basis of these preparations. The study was made on the samples of spinal fluid from 410 patients; of these, 203 had meningococcal infection, 57 had purulent bacterial meningitides and 150 had other diseases (acute respiratory diseases, influenza, etc.). As demonstrated by the results of this study, ELISA proved to be a highly specific and sensitive technique. In the investigation of the spinal fluid samples from the patients with meningococcal infection the use of ELISA with bacteriological techniques increased the number of positive results to 67%; with countercurrent electrophoresis, to 78%; and with bacterioscopy, to 83.8%. ELISA is recommended for practical use as an auxiliary laboratory technique and as a rapid method for the diagnosis of meningococcal infection.     

Immunoenzyme analysis of decomposition of herbicides by soil and wood-rot fungi

The effect of herbicide atrazine was studied on the growth and development of a number of soil and wood decay fungi: white-rot basidiomycetes (Cerrena maxima, Coriolopsis fulvocenerea, and Coriolus hirsutus), thermophilic micromycetes from self-heating grass composts (cellulolytic fungus Penicillium sp. 13 and noncellulolytic ones Humicola lanuginosa spp. 5 and 12), and mesophilic phenol oxidase-producing micromycete Mycelia sterilia INBI 2-26. Detection of atrazine in liquid fungal cultures was performed by using enzyme immunoassay technique. Both stimulation (Humicola lanuginosa 5) and suppression (Humicola lanuginosa 12 and Penicillium sp. 13) of fungal growth with atrazine were observed on solid agar media. Hyphomycete Mycelia sterilia INBI 2-26 was almost insensitive to the presence of atrazine. Neither of thermophilic strains was capable of atrazine consumption in three-week cultivation. In contrast with that, active laccase producers Cerrena maxima, Coriolopsis fulvocenerea, and Coriolus hirsutus consumed up to 50% atrazine in 5-day cultivation in the presence of the xenobiotic and at least 80-90% in 40 days. Mycelia sterilia INBI 2-26, which also forms extracellular laccase, also consumed up to 70% atrazine in 17 days. The degree of atrazine consumption depended on the term of its addition to the fungal culture medium.     

Immunoenzyme analysis for determining class G and M antibodies to HBsAg

A scheme of the purification of hepatitis B virus surface antigen (HBsAg) as applied to the enzyme immunoassay (EIA) for the detection of antibodies to HBsAg is described. An indirect EIA technique for the detection of IgG and IgM antibodies to HBsAg has been developed and the diagnostic assay system based on the use of immunoreagents and solid-phase carriers produced in the USSR has been obtained. The sensitivity of the indirect EIA technique in the detection of IgG antibodies to HBsAg exceeds that of double immunodiffusion in gel used for this purpose 2,500- to 5,000-fold. The study has shown the possibility of using the indirect EIA technique for the detection of antibodies to HBsAg, both free and bound in immune complexes, of detecting antibodies to HBsAg in patients with acute and chronic viral hepatitis B, as well as of simultaneous detection of IgG and IgM antibodies to HBsAg without pseudonegative results.     

Spectroscopic and kinetic analysis of a monoclonal IgG cryoglobulin. Effect of mild reduction on cryoprecipitation.

The precipitation of a monoclonal IgG2 crystalline cryoglobulin (WEB) is shown to be highly dependent on temperature and concentration. Below a critical concentration of 0.6 mg/mL there is no cryoprecipitation. The kinetics of the aggregation exhibits a concentration-dependent lag time. This evidence suggests that a nucleation event is important in the precipitation. Circular dichroism (CD) was used to investigate the conformational properties of the protein. At a low concentration (0.12 or 0.15 mg/mL), no detectable spectral changes in the far- and near-UV range were noted between 40 and 3 degrees C. However, at higher concentrations (1.21 mg/mL), a small and rapid CD change was observed in the 250-280-nm region at 3 degrees C. This indicates an intermolecular interaction that precedes the precipitation. Cryoprecipitation of WEB was also shown to be dependent on maintenance of intact interchain disulfide bonds. Only one or two interchain disulfides need be cleaved to abolish cryocrystallization and to significantly diminish the CD change at 3 degrees C. The evidence is consistent with the formation of an initial intermediate that involves interactions near the disulfide bonds in the hinge region of the cryoimmunoglobulin. In this model, cleavage of these disulfides prevents this interaction and abolishes cryoprecipitation.