Erythrocyte reagents for detecting antibodies to species-specific staphylococcal antigens

Antigenic species-specifics (S. aureus and S. epidermidis) erythrocyte diagnosticums have been obtained with the use of different loading methods. The cross reaction of passive hemagglutination with homologous and heterologous sera have demonstrated that conjugation with amidole ensures the maximum effectiveness and species specificity of diagnosticums in comparison with other conjugation methods.     

Erythrocyte reagents in the study of Erysipelothrix antigens

The activity of species-specific and type-specific antigens in various preparations isolated from the bacterial mass of standard strains of Erysipelothrix, and also in bacterial cells was studied by means of prepared erysipeloid erythrocyte antigen (species-specific and with general type- and species-specificity) and antibody (species-specific, with general type- and species-specificity as also with type-specificity only) diagnosticums. It has been demonstrated that the activity of these antigens differs in preparations from different strains, depending on the method of extraction. An efficient method of serotyping of Erysipelothrix, based on agglutination of erythrocyte antibody diagnosticums, was proposed.     

Increased sensitivity of the parapertussis diagnostic agent

The adsorption activity of formolated sheep red blood cells can be increased by their combined treatment with low-frequency ultrasound, tannin and Tween-40. The diagnosticums thus obtained have proved to be highly sensitive and specific and can be recommended for the detection of antibodies to Bordetella parapertussis in the sera of sick children.     

Erythrocyte diagnostic agents for detecting bacterial antigens of the genus Citrobacter

Citrobacter antigenic and antibody erythrocyte diagnosticums, serogroups 1, 2, 3, 4, 5, 6, 7, 8, 11, 12, 13, and 22, have been developed. Tests with the use of these diagnosticums have proved to be highly sensitive and mainly group-specific. The antigen in the cellular form is best detected by means of the passive hemagglutination test and in the molecular form, by means of the neutralization test. The antibody-binding and agglutinating activities of strictly group-specific and cross-reacting O-antigenic determinants differ in their sensitivity to heating and to treatment with phenol. In the study of fecal samples taken from patients the above method for the detection of Citrobacter antigens has been shown to have high resolution.     

Escherichia-erythrocyte diagnostic agents

The conditions of a simple and practicable method for the preparation of effective antigenic nonprotein diagnosticums on the basis of water-phenol extracts of 23 Escherichia species have been developed. The method consists in heating the mixture of erythrocytes and the antigen in a boiling water bath for 60 minutes. The diagnosticums thus obtained are 16-30 times more sensitive in the passive hemagglutination test and 4-6 times more sensitive in the passive hemagglutination inhibition test than diagnosticums prepared with the use of tannin, rivanol, as well as by the common method for the preparation of nonprotein antigens. The minimum concentration of Escherichia cells detected in the passive hemagglutination inhibition test is 0.8-1.2 million cells/ml.     

Comparative study of the sensitivity and specificity of dried and liquid meningococcal erythrocyte diagnostic agents A, C and Y in a controlled trial

The comparative study of the sensitivity and specificity of dried and liquid meningococcal erythrocyte diagnosticums A, C and Y has been carried out in the indirect hemagglutination test with the sera of persons immunized with different doses of dried chemical meningococcal (group A) polysaccharide vaccine and persons receiving placebo under the conditions of a controlled epidemiological trial. The possibility of using, on principle, both liquid (A, C) and dried (A, C, Y) preparations in clinico-epidemiological studies has been established. The continuation of the research work aimed at the improvement of meningococcal diagnosticums and, in particular, at the development of polyvalent preparations seems to be justified.     

Effect of the species origin of erythrocytes and of the methods for their subsequent handling on their electrophoretic mobility in producing diagnostic agents

Changes in electrophoretic motility correlate with the effect produced by different reagents used in the production of erythrocyte reagents. This characteristic may be one of the criteria for the evaluation of the quality of erythrocytes in the development of diagnosticums.     

Characteristics of erythrocyte diagnostic agents studied using optical methods

The quantitative characterization of erythrocyte diagnosticums (ED) has been made by optical methods (light microscopy with the use of an image analyzer, model Magiscan 2, and the opacity spectrum technique). The following parameters of ED have been determined: the average of the major axis (5.25 +/- 0.57 micron for ED from Shigella sonnei and 5.53 +/- 0.50 micron for ED from Shigella flexneri), the ratio of semiaxes (p approximately equal to 3), the major axis length distribution, the refractive index (1.076 +/- 0.002). For controlling the concentration of ED the use of the opacity spectrum technique is recommended.     

Obtaining erythrocyte diagnosticum for the detection of chlamydial antigen

It is shown possible to obtain erythrocyte diagnosticum for detection of chlamydial antigen, whose cell basis consists of a formalinized suspension of ram erythrocytes, sensibilized with hyperimmune antichlamydial sera by means of the amydol. High sensitivity and specificity of the diagnosticum, absolute correlation with the data obtained in the complex examination of patients with the urogenital tract pathology of the chlamydial etiology by other methods were determined in the course of investigation in the indirect hemagglutination test with diagnosticums of scrape specimens from these patients.     

Interaction of erythrocytes with human serum proteins. I. Analysis of the effect of pH and ionic strength of the medium.

The effect of ionic parameters of the medium (pH and ionic strength) on the processes of interaction of tannin-treated erythrocytes and the protein fractions of human serum (macroglobulins, microbulins and albumin) was studied in factorial experiments. Complex effect of these parametres on the processes under investigation and optimum conditions of erythrocyte sensitization were established. Subsequent fixation of antibodies by the erythrocyte diagnostic and their agglutinating activity are manifested in different mannera depending on the conditions of preceding sensitization. Important peculairities were discovered in the mechanism of interaction between the erythrocytes and various serum proteins. The obtained results should be taken into account in the production of erythrocyte antigen and antibody diagnosticums.     

Determination of Shigella antigens in the feces of people, immunized with enteral vaccine prepared from S. flexneri antigen

The dynamic determination of the presence of the specific antigen and its activity in the excreta of humans subjected to enteral immunization with vaccine prepared from S. flexneri antigen was made in the agglutination test and neutralization test with the use of, respectively, antibody and antigenic erythrocyte diagnosticums. In the feces and urine of the vaccinees antibodies occurred less commonly and, as a rule, they were less active than those detected in dysentery patients at the corresponding time from the beginning of the disease. The occurrence of Shigella antigens in the feces of the vaccinees was greater than in their urine at the corresponding time. Similarities and differences in the dynamics of the isolation of Shigella antigen from dysentery patients and from the vaccinees receiving enteral vaccine prepared from S. flexneri antigens were established.     

Development of a latex agglutination method for the diagnosis of Pseudomonas aeruginosa infection

The present investigation has revealed the possibility of using different kinds of monodispersed polystyrene latex, produced in the USSR, as carriers in the process of the preparation of antibody diagnosticums intended for the detection of water-soluble slime antigens of Pseudomonas aeruginosa strains belonging to the most widespread serological types. The optimum conditions for the preparation of latex reagents and for making the latex-agglutination test have been experimentally established. The new diagnosticums+ have been shown to be highly species- and type-specific, which permits making judgment on the presence or absence of slime antigens of P. aeruginosa strains belonging to definite serovars in the clinical material under study. The preparations thus obtained have been found to retain their sensitivity for 16 months (the term of observation).     

Use of erythrocyte diagnostic agents in the universal system of serological reactions

A method of parallel serologic studies of the material for the detection of specific antigen or antibodies is proposed. This method is not inferior to the known systems of serologic tests (passive hemagglutination-antigen neutralization tests, passive hemagglutination--antibody neutralization tests, etc) in sensitivity and economy, but exceeds all of them in informative value. The method has been tested both experimentally and in the epizootic study of plague infection used as a model. A serologic tests with the use of erythrocyte diagnosticums are based on a universal principle, this method may be used for other infections.     

Biological activity of the components of F1-antigen of Yersinia pestis

Components of the capsule antigen (Baker), described early as F17, F18, F43, Flp, which positively reacts with commercial poly- and monoclonal antifractions plague diagnosticums were studied. Differences and their impacts on vaccine bacteria survival within peritoneal macrophages, guinea pigs and protection of white mice after immunization and fast protection against plague were shown. Hemolytic, cytolytic and hemo- and cytoagglutinations activities of lipoprotein (Flp) and capacity of glycoproteins F17 and F43 for induction of hemo- and cytoagglutinations were detected. Similarity of properties of enumerated components and lectins and their role in infection development and immunogenesis are discussed.     

Circulating immune complexes in the diagnosis of Mycoplasma pneumoniae infection

The possibility of detecting M. pneumoniae antigen and antibodies to it, incorporated into immune complexes, in the sera of patients with acute pneumonia by means of erythrocyte diagnosticums was studied, and the immunological characterization of these complexes was made. In patients with mycoplasmal pneumonia M. pneumoniae antigen and specific antibodies, both free and incorporated into immune complexes, were found to circulate in the blood. In children, antigenemia was detected twice as frequently as in adults. Dissociated M. pneumoniae antigens had different molecular weight, their location on the gel chromatogram of the serum being in fractions 7S and 19S. The dissociation of immune complexes permits the detection of M. pneumoniae antigen and antibodies to it in a bound state by means of the passive hemagglutination test, thus increasing the frequency of positive results in the diagnosis of M. pneumoniae infection.     

Inhibition of lipoprotein oxidation by prenylated xanthones derived from mangostin

Oxidative damage is thought to play a critical role in cardiovascular and other chronic diseases. This has led to considerable interest in the antioxidant activity of dietary compounds. Flavonoids have received the most attention and much is known about the structural requirements for antioxidant activity. However, little is known about the antioxidant activity of other plant derived phenolic compounds such as the xanthones. We have previously shown that the prenylated xanthone, mangostin, can inhibit the oxidation of low density lipoprotein. In order to examine the effects of structure modification on antioxidant activity of this class of compound we have prepared a number of derivatives of mangostin and tested antioxidant activity in an isolated LDL and plasma assay. The results of this study show that structural modification of mangostin can have a profound effect on antioxidant activity. Derivatisation of the C-3 and C-6 hydroxyl groups with either methyl, acetate, propane diol or nitrile substantially reduces antioxidant activity. In contrast, derivatisation of C-3 and C-6 with aminoethyl derivatives enhanced antioxidant activity, which may be related to changes in solubility. Cyclisation of the prenyl chains had little influence on antioxidant activity.     

Inhibition of lipoprotein oxidation by prenylated xanthones derived from mangostin

Oxidative damage is thought to play a critical role in cardiovascular and other chronic diseases. This has led to considerable interest in the antioxidant activity of dietary compounds. Flavonoids have received the most attention and much is known about the structural requirements for antioxidant activity. However, little is known about the antioxidant activity of other plant derived phenolic compounds such as the xanthones. We have previously shown that the prenylated xanthone, mangostin, can inhibit the oxidation of low density lipoprotein. In order to examine the effects of structure modification on antioxidant activity of this class of compound we have prepared a number of derivatives of mangostin and tested antioxidant activity in an isolated LDL and plasma assay. The results of this study show that structural modification of mangostin can have a profound effect on antioxidant activity. Derivatisation of the C-3 and C-6 hydroxyl groups with either methyl, acetate, propane diol or nitrile substantially reduces antioxidant activity. In contrast, derivatisation of C-3 and C-6 with aminoethyl derivatives enhanced antioxidant activity, which may be related to changes in solubility. Cyclisation of the prenyl chains had little influence on antioxidant activity.     

Human aging brain disorders: Role of antioxidant enzymes

In order to investigate the role of two free radical detoxificant enzymes in patients with aging brain disorders, superoxide dismutase (SOD) and catalase (CAT) activities have been measured in blood from male and female human patients of different ages with several types of aging brain disorders. When compared with activities in the normal population, we have detected: 1) SOD and CAT activities are decreased in patients with Parkinson disease. 2) SOD activity seems to be normal and CAT activity is decreased in patients with dementia. 3) In the patients with stroke, SOD activity is normal, while CAT activity is decreased. SOD activity was measured in red blood cells using the Minami and Yoshikawa method. CAT activity was measured in hemolysates by the method of Aebi. We can conclude that SOD and CAT activities in patients with Parkinson disease are decreased.     

The control of O6-methylguanine-DNA methyltransferase (MGMT) activity in mammalian cells: a pre-molecular view

Human peripheral blood lymphocytes (PBLs) can have a range of O⁶-methylguanine-DNA methyltransferase (MGMT) activities. PBLs from some individuals may have almost no MGMT activity. Such individuals have most often been subject to malignancy or to immunodeficiency disease. Long-term lymphoblastoid lines (LCLs) prepared from PBLs of normal subjects by Epstein-Barr virus (EBV) transformation have MGMT activities which are in general somewhat higher than the PBLs from which they derive. Such cultures are therefore generally MGMT-positive. Only in rare cases, and generally from patients with low MGMT activity, are freshly obtained lines with very low activity obtained. There is however a 4-fold range of MGMT activity over which multiple lines derived from the same PBL sample can be found. Long-term cultivation can lead to LCLs with low activity as well as to lines of high activity. On rare occasions an MGMT-positive line may, within a few divisions, give a negative line. Some (but not all) MGMT-negative (or very low) lines have been known to gain (some) activity. Chinese hamster ovary (CHO) cell lines are in general very low in MGMT activity. Lines of higher activity can be selected by treatment with mutagenic crosslinking alkylating agents. Chinese hamster lines with high MGMT activity can be obtained by transfection with human DNA from MGMT-positive cells. Lines with significant activity can also be obtained by transfection of CHO cells with human DNA from MGMT-negative (or very low) cells. Resistance to MNNG treatment can be acquired without the acquisition of significant MGMT activity. Crosses of lines of high and low MGMT activity give equivocal results. Hybrids of low × low activity have no activity. Crosses of positive × positive strains give varied results. It has not been possible to identify MGMT-positive hybrids as including one particular chromosome by this type of experiment. There is no evidence for a general adaptive effect on MGMT synthesis greater than the variation within the cell cycle.     

Biological significance of autologous tumor-killing activity and its induction therapy

Conclusion The overall results presented in this review demonstrate that positive ATK activity at the time of surgery predicts a favorable clinical course in patients who have primary localized solid tumor and receive curative operation. The strong correlation of ATK activity with disease-free interval and total survival (a) indicates that ATK activity is a meaningful prognostic indicator and (b) provides evidence for immunological control of tumor growth and metastasis. According to these data, it is unlikely that cancer patients who remain tumor-free after 5 years of follow-up will develop recurrence or die from the disease. Although there is no direct evidence that ATK effector cells play a critical role in regression of tumor and prevention of tumor regrowth, the lack of ATK activity in patients who relapsed and died after surgery may not result from factors related to their poor performance status since no differences have been observed in background factors between ATK-positive and-negative groups. The prognostic value of ATK activity in patients with documented metastatic tumors has not been established yet. In this respect, however, the induction of ATK activity by BRM has positively correlated with prolonged survival time, while such a correlation is not observed with other parameters such as NK cells or LAK cell activity.Based on the possible biological significance of ATK activity, clinical trials have been conducted to determine whether the induction of ATK activity before surgery by administration of BRM could improve the clinical outcome in patients who naturally have no such potential. The preliminary data indicate that the presence of both natural and induced ATK activity is strongly associated with longterm survival. Thus, considerable emphasis should be placed on a strategy that induces ATK activity in vivo. Such an approach may provide a new focus for cancer immunotherapy.