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Biomedical subjects

R Khaitov

Publications and source records attributed to R Khaitov.

6 recordsLinked to original sources

Prevalence of skin test reactions to natural rubber latex in hospital personnel in Russia and eastern Europe.

BACKGROUND: Allergic reactions to natural rubber latex have increased during the past 10 years, especially in many health care workers (HCWs) who have high exposure to latex allergens. The prevalence of skin test reactions to natural rubber latex in Russia, the Commonwealth of Independent States (CIS), and eastern Europe is unknown. OBJECTIVE: The purpose of this study was to determine the prevalence of skin test reactivity to natural rubber latex in a population of HCWs exposed to latex. METHODS: Nine hundred one HCWs regularly exposed to latex were evaluated using an allergy history questionnaire. Subjects were tested for latex allergy by titrated skin prick test with a biologically standardized latex extract. The diagnosis of latex allergy was defined by the presence of clinical symptoms when exposed to latex along with a positive skin prick test to latex. RESULTS: Forty-nine (5.4%) HCWs were skin test-positive to latex. Seventeen (1.9%) HCWs were classified as latex-allergic based upon positive skin tests to latex associated with allergy symptoms with exposure. Seven of 901 HCWs had experienced anaphylactic reactions to latex. The most frequently reported symptom related to latex exposure was contact urticaria. CONCLUSIONS: The prevalence of latex allergy among HCWs in Russia, the CIS, and adjacent eastern European countries is considerably less than reported in HCWs exposed to latex in western Europe and the United States. The low prevalence of latex allergy in Russia and the CIS suggests that lessened exposure to natural latex powdered gloves may diminish the prevalence of latex sensitization in HCWs in Russia and the CIS.

Adolescent↗

Prevalence of childhood asthma, rhinitis and eczema in Scandinavia and Eastern Europe.

There is evidence that the prevalence of allergies and asthma differs between populations in western and eastern Europe. This study investigated the prevalence of wheezing, rhinitis and eczema among schoolchildren in urban and rural areas of Scandinavia and the formerly socialist countries of Eastern Europe. A total of 79,000 children from two age groups (13-14 yrs and 6-7 yrs) in 18 study centres responded to a questionnaire within the International Study of Asthma and Allergy in Children (ISAAC). The 12 month period prevalence of symptoms of asthma, allergic rhinoconjunctivitis and atopic eczema was calculated. The prevalence of wheezing among the 13-14 yr old children was 11.2-19.7% in Finland and Sweden, 7.6-8.5% in Estonia, Latvia and Poland and 2.6-5.9% in Albania, Romania, Russia, Georgia and Uzbekistan (except Samarkand). The prevalence of itching eyes and flexural dermatitis varied in a similar manner between the three regions. The regional differences were less pronounced among the 6-7 yr old children in the seven participating centres. The highest prevalence of rhinitis was recorded in April-July in Scandinavia and during the winter months in the other countries. The prevalence of atopy-related disorders was higher in Scandinavia than in Estonia, Latvia and Poland, which in turn had a higher prevalence than five other countries of eastern Europe with a culture less similar to western Europe. This supports the hypothesis that "Western life style" is associated with a high prevalence of childhood allergy.

Adolescent↗

CD4-derived peptide and sulfated polysaccharides have similar mechanisms of anti-HIV activity based on electrostatic interactions with positively charged gp120 fragments.

The mechanism of antiviral activity of the CD4-derived peptide 75-99 was compared with that of sulfated polysaccharides. A set of peptides representing all the high positive charge density regions of gp120 and gp41 was used to determine whether electrostatic interactions occur between these negatively charged agents and positively charged HIV envelope fragments. Synthetic peptide AZ2, amino acids 75-99 from V1 CD4, KIEDSDTYIC(Acm)-EVEDQKEEVQLLVFG, and dextran sulfate 500,000 (DS 500) were used as inhibitory agents of antibody binding in ELISA using: (1) anti-peptide rabbit antibodies; (2) sera from HIV infected persons. Peptide AZ2 and DS were both shown to block antibody binding to peptide (301-323) from the principal neutralizing domain (PND) and peptide (495-516) from the gp120 C-terminus. The blocking concns were 1-2 micrograms/ml for DS and 125-250 micrograms/ml for AZ2. The ELISA system based on rabbit anti-peptide antibodies was less sensitive than that based on positive human sera. Chemical modification of lysine epsilon-amino groups of these peptides resulted in complete failure to bind either DS or AZ2. A correlation was found between the inhibitory activities of a number of sulfated polysaccharides in a syncytium formation assay and in peptide ELISA. The mechanism of direct interactions of specific regions of gp120 with the CDR3-like region of CD4 is proposed.

Amino Acid Sequence↗

Epitope mapping of the low-molecular-mass subunits of reverse transcriptase in human immunodeficiency virus type 1 by monoclonal antibodies.

With the aid of monoclonal antibodies to the reverse transcriptase (RT) of human immunodeficiency virus type 1 (HIV-1), low-molecular-mass subunits (p29, p32, and p40) were identified in HIV-1 RT purified from HIV (HTLV-IIIB) virions by isoelectric focusing. Epitope mapping with synthetic polypeptides from various regions of the pol gene suggests that the low-molecular-mass subunits result from N-terminal cleavage of the p51 subunit. The subunits could be separated only by SDS-polyacrylamide gel electrophoresis and detected by immunoblotting. They could not be separated on chromatographic columns, suggesting that the subunits are complexed or conformationally arranged in such a way that their separation on the basis of molecular mass is not possible. The molecular mass of the active enzyme eluted from a chromatographic column (Sephacryl S-300) loaded with a mixture of the subunits was estimated to be 100 kDa.

Animals↗

Immunoreactivity of cultured pancreatic islet cells with monoclonal antibody ICA-1.

The aim of the present study was to characterize the expression of the pancreatic beta cell antigen family with molecular masses of 64 to 69 kDa [p(64-69)]. This antigen family was detected by immunoreactivity with biotinylated monoclonal antibody (Mab) ICA-1, and Mab against insulin. The molecular masses of the antigens affinity-purified from islet cell lysates by ICA-1 were 64, 67, and 69 kDa. Detailed analysis of p(64-69) expression was carried out on cultured islet cells reassociated into clusters of islet-like structures. Cell-fluorescence image processing by computerized image analysis, combined with transmission and scanning electron microscopy, of cells labelled with Mab ICA-1 and immunogold revealed the localization of the 64-65 kDa antigen family on the beta cell surface and its grouping on microvilli and near areas of fusion of the insulin-containing beta granules with the plasma membrane. In view of the effect of ICA-1 on insulin release and its localization on the beta cell surface in immunoreactions it is proposed that the p(64-69) antigen family is involved in insulin secretion.

Animals↗