Microflora of sputum and autopsy material of patients with COVID-19.

The rapid spread of a new coronavirus infection in the country actualizes the conduct of bacteriological studies of clinical material obtained from the respiratory tract of patients with COVID-19. During the experiments, 230 sputum samples and 260 autopsy lung samples from patients with COVID-19 were analyzed. 946 high-risk strains were isolated and identified by MALDI-ToF mass spectrometry on a Microflex LT instrument (Bruker®). According to the results of bacteriological cultures of sputum, a predominance of gram-positive ones was revealed, amounting to 50.5% (222 strains) of the total number of isolated pathogens. However, falling into this group is manifested by natural representatives of the microflora of the human mucous membranes from the genera Streptococcus, Rothia and Lactobacillus (109 strains in total), which can be manifested by the detection of improper sputum collection, causing contamination by the substance of intense salivation and nasopharyngeal discharge. In turn, the "classic" gram-positive causative agents of pneumonia were detected much less frequently: S. aureus in 5 cases, S. pneumoniae in 6 patients. The causative agents in the order Enterobacterales are represented by 42 strains, among which the most likely species are K.pneumoniae (27 strains). In the group of non-fermenting gram-negative bacteria, A. baumanii (29 strains) prevailed, and P. aeruginosa was also identified in 2 cases. When analyzing the results of a microbiological study of autopsy material (lungs) of patients with COVID-19, significant differences in the qualitative and quantitative composition of the microflora were revealed, compared with sputum. In the group of gram-positive bacteria, 15 strains of the natural microflora of the mucous membranes were identified, while sensitive species dominated among gram-negative pathogens: K. pneumoniae (102 strains), A. baumanii (75 strains), P. aeruginosa (11 strains). Regular microbiological monitoring is essential for antibiotic therapy and prevention of secondary bacterial infection. In the event of a fatal outcome, the results of microbiological analysis of autopsy material can determine the cause of death of the patient.

General characteristics, features of cultivation and antibiotic resistance representatives of mycobacterium fortuitum group representatives (review of literature).

Recently, more and more scientific works have been devoted to non-tuberculous mycobacteria, both by domestic and foreign researchers. One of the main reasons for this is the increase in patients with immunosuppression of various origins, improvement of the quality of laboratory and instrumental diagnostics of mycobacteriosis. This article focuses on the representatives of the M. fortuitum group, as the main pathogens among the group of fast-growing mycobacteria. The data on the modern classification based on the use of molecular genetic studies are indicated. The M. fortuitum group includes: Mycobacterium fortuitum, M. peregrinum, M. senegalense, M. porcinum, M. houstonense, M. neworleansense, M. boenickei, M. conceptionense, M. septicum, M. alvei. According to the new data, mycobacteria were divided into 5 clades (Abscessus-Chelonae, Fortuitum-Vaccae, Terrae, Triviale, Tuberculosis-Simiae), and based on molecular genetic studies, new genera in the Mycobacteriaceae family were isolated: Mycolicibacter spp., Mycolicibacillus spp., Mycolicibacillus spp., Mycobacteroides spp., Mycolicibacterium spp. In accordance with the new classification, representatives of the Mycobacterium fortuitum group belong to the genus Mycolicibacterium. The main epidemiological features of the main sources of the spread of mycobacteria, factors and ways of their transmission are indicated. Due to their wide distribution in the environment, representatives of the M. fortuitum group are capable of causing diseases of the pulmonary and extrapulmonary localization. The distinctive features of pathogenicity factors, due to which the course of the disease is determined, are noted. The article also indicates the main difficulties and features of determining the sensitivity to antimicrobial chemotherapy drugs, provides data on the main features of antibiotic resistance of M.fortuitum group. In preparing the review, literature sources obtained from international and domestic databases were used: Scopus, Web of Science, Springer, RSCI.

[Results of immunoprophylaxis of HIV-infected patients with 13-valent conjugated pneumococcal vaccine].

AIM: To assess changes in the composition of the microflora of the upper respiratory tract and indicators of cellular immunity 1 year after the administration of 13-valent conjugated pneumococcal vaccine (PCV13) in adult HIV-infected patients. MATERIALS AND METHODS: Were recruited 100 participants of both sexes (50% male and 50% female). All patients underwent microbiological and immunological (determination of the level of CD3+, CD3+CD4+, CD3+CD8+, CD19+, CD45RO+ peripheral blood lymphocytes) examinations before vaccine administration and after 12 months. RESULTS: Immunization with PCV13 leads to a statistically significant decrease in the carriage of Streptococcus pneumoniae 1 year after vaccination (p=0.012). After 1 year after the administration of PCV13, the patients showed a statistically significant increase in the total number of T-lymphocytes, T-helpers, and cytotoxic T-lymphocytes in comparison with pre-vaccination levels. A statistically significant increase in the level of CD45RO+ lymphocytes was found 1 year after the administration of PCV13 (p0.0001). S. pneumoniae was found on the mucous membrane of the posterior pharyngeal wall in 16% of the participants, indicating its high prevalence in HIV-infected patients. Also, representatives of enterobacteria and Candida spp. were found in smears. (22 and 15% of participants, respectively). One year after the vaccine administration, pneumococcus was isolated from 5 participants, which is statistically significantly lower than before immunization (p=0.012). After the introduction of PCV13, there is a statistically significant increase in the total number of T-lymphocytes, T-helpers and cytotoxic T-lymphocytes 1 year after immunization. However, there is no statistically significant increase in the B-lymphocyte population. In addition, PCV13 leads to the formation of immunological memory cells in HIV-infected patients. CONCLUSION: Thus, immunoprophylaxis with PCV13 in adult HIV-infected patients leads to a decrease in the carriage of S. pneumoniae, and also promotes the stimulation of the T-cell link of the immune system and stimulates the formation of immunological memory cells.

[Structure of microorganisms isolated from bronhoalveolar lavage from patients in the department of reanimation and intensive therapy.] / Структура микроорганизмов, Ð²Ñ‹Ð´ÐµÐ»ÐµÐ½Ð½Ñ‹Ñ Ð¸Ð· Ð±Ñ€Ð¾Ð½Ñ Ð¾Ð°Ð»ÑŒÐ²ÐµÐ¾Ð»ÑÑ€Ð½Ð¾Ð³Ð¾ лаважа от пациентов отделения реанимации и интенсивной терапии.

The aim of the work was to determine and compare the structure of microorganisms isolated from bronchoalveolar lavage from patients in the ICU of Clinics in 2016 and 2019. This work presents the results of a bacteriological examination of 229 samples from 139 patients for 2016 and 387 samples from 218 patients for 2019. The predominant microorganism in 2016 was Acinetobacter baumanii - 75 (26.2%). Less common were Klebsiella pneumoniae - 55 (19.2%), Pseudomonas aeruginosa - 35 (12.2%), Escherichia coli - 19 (6.6%). In 2019, the prevailing microorganism was K.pneumoniae - 158 (19.1%). As in 2016, A.baumanii - 115 (13.9%) and P. aeruginosa - 57 (6.9%) were most often found, but unlike 2016, in 2019 there was a high incidence of such pathogens as Enterococcus faecalis - 52 (6.3%), Candida albicans - 43 (5.2%), Staphylococcus aureus and Stenotrophomonas maltophilia - 40 (4.8%). One of the features is the presence of polymicrobial associations. In 2016, microorganisms isolated in monoculture predominated (53.4%), while in 2019 the frequency of occurrence of monocultures decreased and amounted to 24.7%. At the same time, a two-component association prevailed (31.5%). Thus, in ICU it is necessary to regularly monitor nosocomial pathogens not only to make the right decision when choosing antimicrobial therapy, but also to identify new potential nosocomial pathogens.

[Mycobacterium abscessus complex representatives in patients with bronchopulmonary pathology: prevalence, peculiarities of cultivation and identification.]

More and more publications appear in the modern literature on the increase in the prevalence of non-tuberculous mycobacteria (NTMs), in particular, representatives of M. chelonae / Mycobacterium abscessus complex (MABSc). The paper presents data on the current classification of M. chelonae / Mycobacterium abscessus complex and its main representatives. The main data on the possible sources and ways of infection of MABSc patients in hospital are presented. The main features of cultivation on various nutrient media and their possible identification using modern methods are also indicated. The main risk factors for the development of mycobacteriosis in patients and the possible clinical picture are described. The prevalence of MABSc representatives in the structure of non-tuberculous mycobacteria isolated from clinical material from 483 patients from the Samara region was assessed for examination for tuberculosis, and the prevalence from 933 patients with cystic fibrosis (CF) from 55 regions of the Russian Federation from 2016 to 2019 was estimated. In total, as a result of the study, 316 NTM strains (65.4%) were isolated and identified in the first group of patients. M.abscessus was isolated and identified 10 strains and 5 strains - M.chelonae, which amounted to 3.2% and 1.6%, respectively, of all NTMs. In general, MABSc representatives were isolated in 3.1% of the examined patients. As a result of a screening study of patients with CF, 14194 microorganism strains from 933 patients were isolated and identified. Altogether M. abscessus was isolated and confirmed from 14 patients of different ages. Thus, the prevalence of MABSc among the examined patients with CF in the Russian Federation was 1.5%.

[The structure of conditionally pathogenic microflora, isolated from the urogenital tract of women with pathological course of pregnancy.]

The structure of the microflora of the urogenital tract of a woman is variable and diverse, changing its qualitative and quantitative composition can affect various physiological processes in the body of a woman, including the course of pregnancy. In this study, the results of cultures of 1415 samples of urine and cervical canal discharge of pregnant women were analyzed. Species identification was carried out by MALDI-ToF mass spectrometry using Microflex LT (Bruker) mass spectrometer. Gram-positive bacteria (69.5%) dominated the structure of the cervical canal microflora, among which Staphylococcus spp prevailed., Enterococcus spp. and Lactobacillus spp. Among gram-negative bacteria most often encountered microorganisms of the order Enterobacteriales, the predominant species among which was E. coli. Also, yeast-like fungi were isolated from the material of the cervical canal, their number was 11% of the total number of crops. Qualitative microbiological composition of urine was represented by gram-positive flora (68.7%), gram-negative flora (30.1%) and Candida fungi (1.2%). There is a significant predominance of coagulase-negative staphylococci (97.3%) over coagulase-positive (2.7%) in the structure of gram-positive microorganisms. The composition of gram-negative flora is mainly represented by bacteria of the order Enterobacteriales (71.4%). The study identified microorganisms that can cause postpartum complications and the development of inflammatory diseases of the newborn, which suggests the need for regular microbiological examination for pregnant women.

[Experience with 13-valent conjugated pneumococcal vaccine in HIV-infected patients].

AIM: Evaluate the effect of PCV13 vaccination on the composition of the microflora of the upper respiratory tract and the immune system in HIV-infected patients. MATERIALS AND METHODS: 100 patients with HIV-infection were included in the study. The patients underwent immunological examination and the collection of biomaterial from the posterior pharyngeal wall for microbiological examination. After obtaining the results of the examinations, PCV13 was intramuscularly administered. 7 days after the introduction of the vaccine, an assessment of adverse events was carried out, after 3 months, microbiological and immunological examinations were repeated. RESULTS: Immediately after the administration of PCV13, 5% of patients felt pain during the administration. Local reactions were reported in 6 patients. One participant showed a rise in temperature to 38.3C over 2 days. Before vaccination, 16 strains of S. pneumoniae were seeded in patients. 3 months after the administration of PCV13, pneumococcus was isolated in 8 patients. 3 months after immunization, the median level of populations and subpopulations of lymphocytes became higher than the pre-vaccination. DISCUSSION: Our results show high risk of pneumococcal infections in HIV-positive patients. A tendency towards a decrease in the level of S. pneumoniae carriage was revealed 3 months after the administration of PCV13. The high level of enterobacteria carriage in HIV-positive patients is noteworthy. There is a pronounced positive effect from the use of PCV13 in HIV-positive patients on cellular factors of the immune system. CONCLUSION: The use of PCV13 is a safe and effective method for the prevention of S. pneumoniae infections.

Clinical releveance of hemorrhagic component of endobronchial inflammation in severe chronic obstructive pulmonary disease exacerbation.

AIM: The study aimed at investigating the relationship between severe exacerbations of chronic obstructive pulmonary disease and hemorrhagic component of endobronchial inflammation. MATERIALS AND METHODS: Clinico-endoscopic characteristics of 118 patients presenting with severe infectious exacerbation of chronic obstructive pulmonary disease, bloody expectorations and endoscopically confirmed hemorrhagic component of endobronchial inflammation have been analyzed. All patients underwent a series (5-6) of bronchoscopic examinations accompanied by collection of bronchoalveolar lavage specimens to reveal the presence of acid-resistant mycobacteria and to determine the bacterial flora. The exclusion criteria were the concomitant pulmonary or extrapulmonary pathologic conditions which could lead to hemorrhagic endobronchial manifestations. The other direction of the study was to investigate a correlation between jugulation of the exacerbation and dynamics of such endobronchial symptoms as mucosal edema and hyperemia, quality of bronchial secretions and hemorrhagic component of endobronchial inflammation. RESULTS: All patients were found to have diffuse endobronchitis of severity grade II (39.83%) or III (60.17%) by Lemoine. The neoplastic and tuberculosis genesis of the hemorrhagic component of endobronchial inflammation and its clinical equivalent, the bloody expectorations, had been ruled out. In 50.85% of cases the hemorrhagic component of endobronchial inflammation could not be accounted for by hemolytic properties of cultured microorganisms. The mucosal edema and hyperemia remained stable during jugulation of the exacerbation. Unlike the improvement of quality of bronchial secretions, faster reversal of the hemorrhagic component of endobronchial inflammation showed statistical significance. CONCLUSION: The hemorrhagic component of endobronchial inflammation can represent a non-obligatory manifestation of severe exacerbation of chronic obstructive pulmonary disease, and its relief is the earliest endobronchial sign of incipient remission from severe COPD exacerbation.

[The laboratory diagnostic in patients with mucoviscidosis: A review.]

The mycobacterioses as a group of diseases conditioned by non-tuberculosis mycobacteria, acquire even greater significance for patients from various risk groups. The patients with cystic fibrosis along with patients with other genetic diseases, consist risk group of infection with non-tuberculosis mycobacteria. The diagnostic of mycobacterioses in patients with cystic fibrosis has a number of peculiarities both at the stage of processing clinical material and the stage of identification of separated microorganisms. The review presents modern data about possibilities of laboratory diagnostic of with regard to characteristics of epidemiology, risk factors, contamination screening, material decontamination, methods of cultivation and identification of non-tuberculosis mycobacteria in patients with cystic fibrosis. The data is presented concerning increasing of morbidity of mycobacterioses up to 6-13% among patients with cystic fibrosis in developed countries. The low level of prevalence of mycobacterioses among patients with cystic fibrosis in the Russian Federation is demonstrated. The risk factors of development of mycobacterioses from point of view of contamination with various microorganisms, particularly with fungi of species Aspergillus are described. The technique of two-stage decontamination of phlegm and possible limitations of its cultivation in automated systems and possibilities of using 1% solution of chlorhexidine and sodium dodecyl sulfate for decontamination are described. Besides standard techniques, a technique of separation of mycobacteria is presented based on inoculation of material on medium for selective separation of Burkholderia cepacia complex. The possibilities of identification of mycobacteria using MALDIToF mass-spectrometry. The review was based on sources from such international and national data bases as Scopus, Web of Science, RINC.

[Analysis of the effectiveness and long-term results of formation of adaptive immunity in the use of various medications and vaccination schemes against pneumococcal infection in patients with chronic obstructive pulmonary disease]. / Analiz otdalennykh rezul'tatov éffektivnosti i formirovaniia adaptivnogo immuniteta pri primenenii raznykh preparatov i skhem vaktsinatsii protiv pnevmokokkovoi infektsii u bol'nykh s khronicheskoi obstruktivnoi bolezn'iu legkikh.

AIM: To assess the long-term clinical results of vaccination with pneumococcal polysaccharide and conjugated polysaccharide vaccines in the separate and sequential use, by determining the optimal vaccination schedule in adult patients with chronic obstructive pulmonary disease (COPD) and to investigate adaptive immunity levels. SUBJECTS AND METHODS: The clinical effects of vaccination were evaluated in patients with COPD within 1 and 4 years after immunization against pneumococcal infection using various schemes, as well as the time course of changes in adaptive immunity indicators was examined. RESULTS: Four years after vaccination, the 13-valent pneumococcal conjugate vaccine (PCV13)/23-valent pneumococcal polysaccharide vaccine (PPV23) group showed a decline in the number of patients with COPD exacerbations by 50% (p<0.001) and reductions in the number of antimicrobial chemotherapy cycles by 47.8% (p<0.001) and in that of hospitalizations by 87.5% (p<0.001). At 1 year after vaccination versus at baseline, the COPD patients vaccinated against pneumococcal disease, regardless of the drug and schedule of vaccination, displayed elevated levels of IgG antibodies to the mixture of capsular polysaccharides included in PPV23 and PCV13. CONCLUSION: It has been indicated that a complex of basic therapy for patients with COPD should include initial vaccination with PCV13, followed by administration of a booster dose of PPV23.

[Choice of optimal vaccination tactics against pneumococcal infection from immunological and clinical standpoints in patients with chronic obstructive pulmonary disease].

AIM: To provide a rationale for choosing the optimal tactics of vaccination against pneumococcal infection in patients with chronic obstructive pulmonary disease (COPD) in the context of evidence-based medicine and on the basis of immunological and clinical data. SUBJECTS AND METHODS: Patients with COPD were examined during a year after vaccination with a 13-valent pneumococcal conjugate (Prevenar-13, PCV13) and a 23-valent pneumococcal polysaccharide (Pnemo-23, PPV23) vaccines. The following vaccination schemes were used: PCV13 monovaccination, PPV23 monovaccination, sequential vaccination with PPV23/PCV13, and sequential vaccination with PCV13/PPV23. RESULTS: Vaccination using all the analyzed schemes in the patients with COPD caused a statistically significant reduction in the frequency of exacerbations, the number of antibiotic cycles, and the number of hospital admissions, as shown by the results of analysis of short-term data. The use of PCV13 was followed by additional effects that were unobserved in the use of PPV23, namely: it promoted the formation of immunological memory to Streptococcus pneumoniae antigens, resulted in the enhanced activity of nonspecific resistance factors, and caused activation of antiviral defense factors. CONCLUSION: If patients with COPD need to be vaccinated against pneumococcal infection, preference should be given to PCV13 monovaccination. Short-term observations have shown that the sequential use of pneumococcal conjugate and polysaccharide vaccines is redundant and gives no additional benefit to patients with COPD. However, the sequential application of both vaccines may have additional advantages in the long term.

[Anogenital warts: a new way of solving the common problem of urology (results of long-term follow-up)].

AIM: To evaluate the effectiveness of combined use of the imiquimod 5% cream and vaccination against human papillomavirus (HPV) using a quadrivalent recombinant vaccine to achieve long-term clinical remission of chronic HPV infection manifested by anogenital warts. MATERIAL AND METHODS: The study comprised 36 patients, including 22 men, aged 26.4+/-4.1 years, who had from 1 to 5 anogenital warts. Participants of the study were vaccinated by quadrivalent recombinant vaccine under a 3-dose scheme 0-2-6 months co-administered with imiquimod 5% cream three times per week up to 16 weeks. The follow-up period was 2 years. RESULTS: Complete disappearance of genital warts within 1 year from baseline was observed in 34 (94.4%) patients. Two patients with anogenital warts after 1 year were treated for 1 year 3 months and 1 year and 4 months with Solcoderm which lead to the complete disappearance of genital warts. There were no recurrences of genital warts during the 2 years of follow-up. CONCLUSION: Vaccination with a recombinant quadrivalent vaccine concurrently with using imiquimod 5% cream results in prolonged clinical remission of chronic HPV infection manifested by anogenital warts in at least 94.4% of the cases (2 year follow-up).

[New ideas on the therapeutic effect of a combination of vaccines against pneumococcal, Haemophilus influenzae type b infection, and influenza in patients with chronic obstructive pulmonary disease].

AIM: To estimate the indicators of the therapeutic effect of combination vaccination against pneumococcal, Haemophilus influenzae type b infection, and influenza in patients with chronic obstructive pulmonary disease (COPD). SUBJECTS AND METHODS: Clinical, bacteriological, and immunological studies, by determining the quality of life (QL), were conducted in COPD patients during a year after combination vaccination against pneumococcal, Haemophilus influenza type b infection, and influenza. RESULTS: One year after the vaccination, there were reductions in the number of COPD exacerbations by 3.7 times, in that of antibiotic therapy cycles by 3.4 times, in the levels of inflammatory mediators of interleukins 2 and 8 and interferon-γ, and in the synthesis of IgG antibodies to Streptococcus pneumoniae, Haemophilus influenzae type b, and influenza virus strains as compared to the baseline values. CONCLUSION: Combination vaccination against bacterial and viral infections substantially improves the major clinical parameters of COPD, positively affecting LQ indicators that generally characterize the therapeutic effect of immunization.

[Effect of complex vaccination against pneumococcal, Haemophilus type b infections and influenza in patients with chronic obstructive pulmonary disease].

AIM: Determination of the effect of complex vaccination with Pneumo-23, Hiberix, Grippol plus on sputum bacterial content 6 months after the vaccination of patients with chronic obstructive pulmonary disease (COPD) compared with unvaccinated patients. MATERIALS AND METHODS: Bacteriological analysis of sputum obtained for 6 months from 80 patients with COPD was carried out. The first group of 31 patients with COPD was immunized simultaneously with Pneumo-23, Hiberix, Grippol plus (mean age--59.25 +/- 1.12). The second group consisted of 49 unvaccinated patients with COPD (mean age--57.16 +/- 0.98). Classical microbiological method was used in the study. RESULTS: 6 months after the complex vaccination a significant decrease to 35.48 +/- 8.59% of vaccinated patients, that expectorate sputum with Streptococcus pneumoniae, compared with 80.65 +/- 7.1% in unvaccinated patients with COPD was observed. CONCLUSION: A combined vaccination against pneumococcal, haemophilus type b infection and influenza carried out with a prophylactic and therapeutic goal is recommended for patients with COPD as a part of the treatment and prophylaxis complex measures.

[Effect of phytosubstances with antioxidant activity on persistence properties of microorganisms].

The in vitro effect of phytosubstances containing flavonoids and phenylpropanoids on the antilysozyme activity of varioous groups of microorganisms, such as staphylococci, bacilli, enterobacteria and nonfermenting bacteria was studied. The second fraction of the pink carbonic acid extract showed high antioxidant activity and most efficiently inhibited the ability of various microorganisms to inactivate the host lysozyme. The selected phytosubstance could be useful in clinical practice as an additional antimicrobial agent in etiotropic therapy or prophylaxis of some infections.

[Monitoring and treatment of severe bronchial ashma in adults: results of national multicenter trial NABAT].

AIM: To study quality of monitoring, features of a course and therapy of severe bronchial asthma (BA) in Russia. MATERIALS AND METHODS: The trial recruited 378 patients with severe bronchial asthma (SBA) in 7 cities of Russia. Each center participating in the study filled in individual case sheets recording demographic, clinical, monitoring, pharmacotherapeutic data. A special focus was on factors influencing the disease course. The chi-square and Mann-Witney criteria were used. RESULTS: It was found that current recommendations of BA patients' management are not used in full. Most of the patients do not receive adequate therapy. Phenotypes of uncontrolled course of severe BA are prevalent. The key role of adequate management of severe BA patients in control of the disease is shown. CONCLUSION: Wider use of updated recommendations on therapy and monitoring of BA with special focus on patients with uncontrolled course of the disease is urgent. Fulfilment of all the components of management of a patient with bronchial asthma recommended by GINA including the patient education and control over the disease triggers contribute much to effective treatment and control over BA.

[Immunological changes in dust-induced lung diseases]. / Immunologicheskie izmeneniia pri pylevoi patologii legkikh.

One hundred and forty five patients with different forms of dust-induced lung disease and 57 controls having no contacts with industrial aerosols were examined. It was ascertained that clinical and functional evidence cannot predict the course of the disease and the development of infectious complications (silicotuberculosis, mechanic bronchitis). Impaired humoral immunity and nonspecific resistance in dust-induced lung disease depend on the type of disease and predispose to infectious complications. Predisposition to occupational lung diseases (pneumoconioses, mechanical bronchitis) is associated with increases in the concentrations of plasma fibronectin and serum IgA and a decrease in serum mucin antigen levels. In chronic mechanical bronchitis, there were lower activities of lysozyme and complement and elevated serum IgM and IgG concentrations. Fibronectin, total IgE and the inflammatory marker the mucin antigen 3EG5 are involved in immunological inflammation in dust-induced lung disease. It is worth of determining the factors of humoral immunity and nonspecific resistance in workers contacting with high concentrations of industrial aerosols and in patients with dust-induced diseases to make a precise assessment of the time course of changes in a pathological process and to define a risk for infectious complications.

Spontaneous luminol-dependent chemiluminescence of thrombocytes increases in hemorrhagic fever with renal syndrome.

Spontaneous luminol-dependent chemiluminescence (CL) of thrombocytes was studied in 12 patients with hemorrhagic fever with renal syndrome (HFRS) caused by Puumala virus. CL in the acute phase of HFRS (median, 61 mV/10 sec; range, 22-91) was higher than that of healthy controls (median, 22 mV/10 sec; range, 18-29; P < 0.01) and patients with acute hepatitis B infection accompanied by thrombocytopenia (median, 33 mV/10 sec; range, 13-45; P < 0.01). CL of thrombocytes in the convalescence phase of HFRS (median, 31 mV/10 sec; range, 12-80) was significantly lower than that during the acute phase (P < 0.01). Neither was there a difference in CL response between HFRS patients with or without thrombocytopenia, but both groups produced a higher CL response than that of the control groups. Both the complement-containing and complement-free sera from acute HFRS patients (final dilutions: range 1:10-1:2560) exhibited no effect on CL response of normal thrombocytes. A possible role of increased oxygen radicals production by thrombocytes in pathogenesis of HFRS is discussed.

On the compact form of linear duplex DNA: globular states of the uniform elastic (persistent) macromolecule.

A theory of collapse of DNA considered as unifilar homopolymer is suggested. The collapse is interpreted as the coil-globule transition. Three reasons of the collapse such as the confinement in a microcavity, the influence of poor low-molecular-weight solvent and the influence of polymeric solvent were studied. The results are summed up by the stage diagrams in variables: DNA length versus the characteristics of the compaction factor (the cavity volume, the energy of attraction of DNA segments in poor low-molecular-weight solvent and the concentration of polymer added). It is shown that a sufficiently long DNA forms the spherical compact particle while the relatively short DNA forms the toroidal one. More delicate features of the tertiary structure are determined by the relative role of the bending stiffness and steric repulsions in preventing further collapse. As the compaction occurs in polymeric solvent almost all added polymer is forced out from the globule. Thus, the internal structure of the compact DNA particle in polymeric solvent is similar to that in the model of microcavity.