[Risk factors and etiological structure of children's cross-allergic reactions to food products]. / Faktory riska i étiologicheskaia struktura perekrestnykh allergicheskikh reaktsii na pishchevye produkty u detei.

Authors of article have recently analyzed the frequency of prevalence and risk factors of cross-reactivity to foodstuffs among 239 children of Abakan in the age of from 6 months till 15 years with skin, respiratory and combined manifestation of atopy. It was proved that risk factors of development of cross-reactivity to food among children of the first years of life are hereditary predisposition to allergic diseases (77.8%) and early introductions of supplemental feeding (44%). Among children older then 7 years pollen sensitization (62%) which preceded the development of cross allergic reactions between separate foodstuffs reaches up to 73.7%, between pollen and foodstuff up to 79% and between epidermal and food up to 10.1%.

[An immunoenzyme method for determining IgA antibodies to lipopolysaccharide in secretions in the diagnosis of shigellosis]. / Immunofermentnyi metod opredeleniia v sekretakh IgA-antitel k lipopolisakharidu v diagnostike shigelleza.

IgA antibodies to S. sonnei and S. flexneri lipopolysaccharides (LPS) in secretions, as well as Escherichia coli LPS in coprofiltrates of children with acute diarrhea, were determined with the use of enzyme immunoassay (EIA). In adult patients with dysentery serum and salivary anti-LPS antibodies were assayed. The results of EIA showed that children aged up to 18 months had an elevated level of LPS of the causative agent in their coprofiltrates. The specificity of this assay permitted its use for finding out the agent of acute enteric infection. In adults, the levels of salivary anti-LPS antibodies in dysentery patients and in healthy persons significantly differed, which might also be regarded as a sign of Shigella infection. No significant difference in the levels of IgG antibodies to LPS in the saliva of sick and healthy persons was registered. IgA antibodies were found to be active mainly against common determinants of S. sonnei and S. flexneri LPS and thus not suitable for the differentiation of the causative agents of dysentery. For this purpose, the levels of serum IgG antibodies to LPS of different Shigella species should be determined.

[The determination in saliva of IgA antibodies to Shigella ribosomes for the diagnosis of dysentery]. / Opredelenie v sliune IgA-antitel k ribosomam shigell dlia diagnostiki dizenterii.

The levels of antiribosomal antibodies to Shigella ribosomes in serum and saliva samples from 38 dysentery patients (15 S. sonnei cases and 23 S. flexneri cases), 14 patients with salmonellosis and 136 healthy adults were determined in ELISA with ribosomes from S. sonnei R-mutant used as solid-phase antigen. High levels of "normal" antiribosomal IgA, IgG and IgM antibodies were revealed in the sera of healthy persons while the level of salivary IgA antibodies was very low. In dysentery infection no increase in the levels of serum IgG and IgM antibodies and only a slight increase in the level of IgA antibodies were revealed. Local immune response was manifested by the early (on days 2-4 from the onset of infection) and significant augmentation (12- to 16-fold) of salivary antiribosomal IgA antibodies. An increase in the level of these antibodies was registered in 95-100% of dysentery patients but not in patients with salmonellosis, which made it possible to recommend the method for diagnosing shigellosis. Immune response to Shigella ribosomal antigens, in contrast to the response induced by Shigella O-antigen, is almost exclusively local.

[Tolerogenic effect of ovalbumin digestion products forming in the gastrointestinal tract of rats]. / Tolerogennyi éffekt produktov perevarivaniia oval'bumina, obrazuiushchikhsia v zheludochno-kishechnom trakte krys.

The authors studied the tolerogenic effect of ovalbumin digestion products absorbed into the blood from the gastrointestinal tract of rats and injected intravenously into mice 24 hours before immunization of these animals with native protein. The preparation is a fraction with a molecular mass of no less than 6,000 daltons obtained by gel filtration of blood serum of ovalbumin fed rats on a column with Sephadex G-25. The titer of antibodies to ovalbumin determined by the passive hemagglutination test reduced on the 14th and 20th days after parenteral immunization with native ovalbumin.

[A comparison of the sorption capability and standardization of plates of different shapes for immunoenzyme analysis]. / Sravnenie sorbtsionnoi sposobnosti i standardnosti planshetov raznykh form dlia immunofermentnogo analiza.

The sorption characteristics of ELISA plates manufactured by the Moscow and Leningrad plants and by some foreign firms are compared. Sorption activities and standard specifications of the plates for chemically heterogeneous antigens like ovalbumin or Shigella sonnei lipopolysaccharides and for complex antigens like Mycobacterium tuberculosis or S. sonnei ribosomal fractions have been examined. Sorption activities of the plates varied in tests with different antigens. The sorption activity and the standard specifications of the plates manufactured in Leningrad have been found in fact the same as of the foreign plates with all the antigens examined, whereas the Moscow plates have been inferior to both.

[Stimulation of the secretory IgA system in monkeys by parenteral immunization with a ribosomal Sonne dysentery vaccine]. / Stimuliatsiia sekretornoi IgA-sistemy obez'ian pri parenteral'noi immunizatsii ribosomal'noi dizenteriinoi vaktsinoi Zonne.

The experiment was made on 16 monkeys (rhesus macaques). Only 1 out of 12 monkeys immunized with S. sonnei ribosomal vaccine and all 4 control monkeys fell ill as the result of oral challenge with S. sonnei virulent strain. The immunized monkeys stopped excreting Shigellae earlier than the control monkeys. Antibody to lipopolysaccharide (LPS) in the serum and saliva of the monkeys were studied in the enzyme immunoassay with monospecific antibodies to human IgA, IgG and IgM. A single injection of the ribosomal vaccine in a dose of 600 micrograms was shown to lead to a considerable increase in the levels of IgA, IgG and IgM antibodies to LPS in saliva. In parenteral immunization with the ribosomal vaccine the stimulation of secretory IgA system is similar to that resulting from oral challenge with Shigella virulent strain introduced in a dose of 50 X 10(9) microbial cells. No difference in the response of monkeys to primary and booster immunization was noted.

Parenteral immunization with Shigella ribosomal vaccine elicits local IgA response and primes for mucosal memory.

The parenteral Shigella ribosomal vaccine (SRV), which previously was shown to protect guinea pigs and monkeys, has been compared with lypopolysaccharide (LPS) for its ability to induce a systemic and a local immune response. Injection of SRV caused a significant rise of the serum O antibodies of different classes and the appearance of IgA O antibodies in tears of guinea pigs and saliva and bile of monkeys. In guinea pigs, the local IgA response to parenteral SRV was much more intensive than that to feeding of high doses of LPS, while in monkeys it was nearly as high as that to challenge with a high dose of live pathogen. These data provide an immunological basis for the protective effect of SRV and are in disagreement with the widely accepted view of the inefficiency of parenteral antigens in stimulating mucosal immunity. The results are interpreted from the viewpoint of the role of ribosomes as a delivery system for the Shigella O antigen which provides high potency of SRV in stimulating local lymphoid tissue and makes it a good vaccine candidate.

[Tolerance induction by the peroral administration of protein antigens]. / Induktsiia tolerantnosti peroral'nym vvedeniem belkovykh antigenov.

The possibility of inducing systemic tolerance in animals by feeding them with ovalbumin and human serum was studied on mice, rats and rabbits. Antibodies to ovalbumin, human serum albumin and immunoglobulins (IgG, IgA, IgM) were determined by the passive hemagglutination test in the sera of the test and control animals after the second immunization made through a parenteral route. Tolerance to all the antigens under study was obtained in mice and rats, while in rabbits such feeding was found to produce the priming effect. The degree of tolerance was the greater, the more was the dose of the antigen and the longer was the period of feeding. Different proteins showed varying tolerogenic activity; the same degree of tolerance in mice was obtained by feeding them with IgG in a dose of 0.3-0.5 mg and with ovalbumin or human serum albumin in a dose of 6-12 mg (per gram of body weight). Tolerance was determined on day 3 after the course of feeding was over; in 3 weeks tolerance essentially decreased, and in 1.5-2 months it was replaced by normal reactiveness. Tolerance induced by the oral administration of antigens proved to be immunologically specific.