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Biomedical subjects

M Brůcková

Publications and source records attributed to M Brůcková.

At least 19 recordsLinked to original sources

Long-term analysis of the resistance development in HIV-1 positive patients treated with protease and reverse transcriptase inhibitors: correlation of the genotype and disease progression.

In this study, 27 HIV-1-positive patients on long-term highly active antiretroviral therapy (HAART) in the Czech Republic were followed for a period of up to 7 years. Variability of the HIV-1 protease (PR) sequence common in the Czech Republic was observed. Under the pressure of inhibitors of protease (PRIs) and reverse transcriptase (RTIs) mutations in PR were detected. Development of resistance to PRIs was followed by a decrease in CD4 count and increase in viral load. The dynamics of viral load closely corresponded to the accumulation of specific primary mutations in PR and RT. Out of 27 patients 18 developed resistance to PRIs and the prolonged therapy led to the accumulation of a higher number of amino acid changes associated with the resistance and, consequently, cross-resistance to several PRIs was observed. These multi-resistant variants of HIV-1 with mutations in PR could not be inhibited sufficiently with PRIs that are currently available in clinical practice. Efficient yet temporary suppression of viral replication was achieved by a lopinavir (LPV) treatment.

Amino Acid Substitution↗

Seroprevalence of HHV 8 antibodies among the general population and HIV positive persons in the Czech Republic.

BACKGROUND: The seroprevalence rates of herpesvirus 8 (HHV 8) antibodies were determined for the general Czech population and HIV-positive individuals. OBJECTIVES: Six hundred and sixty six serum samples from the general Czech population and 129 serum samples from HIV-positive persons were tested for the presence of antibodies to the HHV 8 lytic and latent antigens. STUDY DESIGN: HHV 8 antibodies were detected by the indirect immunofluorescence test. RESULTS: In the general Czech population, only 2.4 and 0.3% of the serum samples tested positive for antibodies against the lytic and latent HHV 8 antigens, respectively. As many as 34.9 and 10.9% HIV positive individuals had antibodies to the HHV 8 antigens, respectively. Only three of them have developed Kaposi's sarcoma (KS) to date. At the time of KS diagnosis, the three patients had antibodies to both HHV 8 antigens. HIV-positive homo/bisexuals were at significantly higher risk of acquiring HHV 8 infection compared with HIV-positive heterosexuals. The increase in HHV 8 seroprevalence was associated with progression of the HIV infection from stage A to stage B. No correlation was found between the HHV 8 seroprevalence and CD 4+T-lymphocytes counts or the HIV viral load. CONCLUSIONS: Among the general Czech population, the HHV 8 seroprevalence is as low as in the West European countries. The mean HHV 8 seroprevalence rate in HIV-positive individuals was 34.9% and was comparable with those reported in other low seroprevalence countries.

Acquired Immunodeficiency Syndrome↗

High prevalence of HIV risk-behavior and the identification of predictors for sharing injecting materials among young drug users in Prague, Czech Republic.

This study is one of the first studies in the Czech Republic evaluating the extent of the HIV epidemic among drug users. Interview data on demographics, drug use, sexual practices, and HIV knowledge and risk perception were obtained from study participants and a saliva sample was obtained for an HIV antibody test. Although the HIV infection rate is low (0.2%), the prevalence of high risk behaviors, such as sharing injecting equipment and unsafe sexual practices, indicate a potential for rapid HIV spread in this high risk population. Preventive measures need to be targeted toward drug users, especially those of younger age and women.

AIDS Serodiagnosis↗

Human immunodeficiency virus 1 strains resistant to nucleoside inhibitors of reverse transcriptase in isolates from the Czech Republic as monitored by line probe assay and nucleotide sequencing.

The genetic resistance to nucleoside inhibitors of the reverse transcriptase (RT) of human immunodeficiency virus I (HIV-1) isolates in the Czech Republic was examined by a line probe assay (LiPA) and nucleotide sequencing. The results of LiPA analysis of 294 blood specimens obtained from 156 patients revealed a high incidence of mutations in the RT gene related to resistance to various drugs (67.3%) in various combinations. Mutations in RT gene (M41L, K70R and T215Y/F) conferring the resistance to zidovudine (ZDV) were most frequent (62.6%), that (M184V) responsible for the resistance to lamivudine (3TC) was less frequent (33.7%), while those linked to the resistance to dideoxyinosine (ddl) and dideoxyinosine together with dideoxycytidine (ddl/ddC) were rather rare (6.5% and 5.1%, respectively). LiPA gave a high rate of uninterpretable results due to codon hybridization failure, especially in HIV-1 isolates of non-B subtype. Thirty-two specimens were analyzed also by direct sequencing of a part of RT gene. The results obtained by LiPA and the sequencing were highly concordant for codons successfully analyzed by both methods, but the sequencing provided information also about the codons that could not be analyzed by LiPA. A high prevalence of resistant strains in the Czech Republic and their heterogeneity justifies a regular HIV-1 resistance testing. LiPA turned out as a fast, powerful and most reliable tool for such a purpose. However, due to an increasing diversity of HIV-1 strains circulating in the Czech Republic, LiPA cannot replace the nucleotide sequence analysis.

Base Sequence↗

[Indicators of progression of HIV infection and their application to therapy].

The authors evaluated in a group of 217 HIV positive patients the mutual relationship of the number of CD4+T lymphocytes and the level of the viral load of HIV RNA. Using correlation analysis evidence was provided of a not very marked negative correlation of the two indicators. As it was assumed that the relationship of the two parameters is influenced by the applied therapeutic procedures which reduce in particular the viral load, the two parameters were evaluated in relation to treatment. The closest relationship of the two investigated parameters was found in the group treated by monotherapy with zidovudine, followed by the group treated with a combination of two preparations (two nucleoside inhibitors of reverse transcriptase). In the group treated by three preparations (two nucleoside inhibitors of reverse transcriptase and a protease inhibitor) the relationship of the two parameters was least close. Investigation of the level of the viral load of HIV RNA and number of CD4+T lymphocytes is of major importance for the introduction of antiretrovirus treatment and selection of a suitable combination of antiretrovirus preparations. It makes it also possible to follow up the effectiveness of this treatment.

CD4 Lymphocyte Count↗

[Detection of HIV virus antibodies in saliva].

The authors evaluate the use of saliva as alternative biological material for detection of HIV antibodies. If collected properly and when using the appropriate ELISA methods, HIV antibodies can be assessed in saliva with considerable sensitivity and specificity. Testing in saliva eliminates many disadvantages found when assessing HIV antibodies in serum. It does not require trained staff for blood sampling, collection and processing of saliva reduces the risk of professional infection to a minimum and can be carried out also under field conditions. A great advantage is the easy and unpretentious transport of collected samples to the laboratory, even long distance transport at extreme temperatures (transport medium in the testing kit Omni-SAL ensures great stability of the sample as well as proper collection of the sample). Alternative testing in saliva is useful in particular for epidemiological surveillance and for screening of HIV antibodies in population groups with a high risk of infections such as drug users and commercial works where it is often very difficult to obtain blood samples for examination.

Enzyme-Linked Immunosorbent Assay↗

Mycobacterial infections in patients with AIDS in a low HIV prevalence area.

The Czech Republic is characterized here as both a low HIV prevalence area (1.64 registered positivity per 10(5) population and 45 AIDS patients notified in the 1986-93 period) and a low tuberculosis prevalence area (mortality rate 0.8, incidence of bacillary pulmonary cases 11.3 per 10(5) population and risk of infection 0.04 in 1990). From 1986 to 1993 a total of 10 cases of mycobacterial infections complicating AIDS or ARC disease were registered in the Czech Republic in 9 male patients aged from 29 to 55, 8 homosexuals, and one woman aged 48. Classical pulmonary tuberculosis caused by M. tuberculosis was diagnosed in one male patient and was controlled by antituberculosis chemotherapy. The remaining mycobacterial infections were caused by the following opportunistic mycobacterial pathogens. (a) M. avium in five individuals, four of them died of a disseminated disease; (b) M. kansasii--in two patients, one died of a disseminated infection; (c) M. xenopi--involved in a fatal generalized CMV, and cryptococcal and mycobacterial infection; (d) M. fortuitum caused a generalized disease in a case of exhaustive multifocal encephalopathy. Authors conclude that under conditions of low prevalence of both HIV and tuberculosis infection the risk to AIDS patients of contracting classical tuberculosis is low. A relatively frequent occurrence of non-tuberculosis mycobacterial disease in AIDS patients afflicted with the impaired immunity is explained by transmission of opportunistic mycobacteria from the environment.

AIDS-Related Complex↗

Detection of serum antibodies in tuberculosis patients.

Sera of 14 bacteriological confirmed pulmonary tuberculosis and 16 non-tuberculotic or healthy controls were sampled in Ignace Deen University Hospital in Conakry, Quinea. Samples were examined for IgG and IgM antibodies by means of enzyme-linked immunosorbent assay (ELISA) using sonicated M. bovis BCG and M. avium antigens and were tested for antibodies to HIV-1/HIV-2 as well. Median of IgG antibody titres to M. bovis BCG antigen was 1:445 and differed significantly from that of the control group (1:149). The median of IgM antibody titres was 1:79.1 and did not differ statistically from that of control group (1:69.3) as well as the antibody titres against M. avium antigen in the IgG and IgM classes for both analyzed serum groups. Seven of tested TB patients sera were positive for antibodies against HIV-1. The median of IgG antibody titres against M. bovis BCG antigen was 1:442 not differing significantly from values of remaining TB patients as well as the IgM antibody titre (1:109).

Adult↗

Characteristic features of HIV/AIDS in the Czech Republic.

First laboratory proved HIV infections in the Czech Republic were diagnosed in a homosexual couple in autumn of 1985. Total number of detected HIV+ cases reached 143 persons by the end of 1992 (132 men and 11 women), of that 31 cases were classified as fully blown AIDS (21 already died). Out of these 143 HIV+ cases, 93 (65.0%) are represented by homo/bisexuals, 10 (7.0%) by heterosexuals, 16 (11.2%) by haemophiliacs, 14 (9.8%) by blood recipients, 1 (0.7%) by IVDU and 9 (6.3%) by unknown transmission category. Approx. 2.1 mil. of tests have been done as routine screening of donated blood. Only 5 cases (0.0002%) of HIV positivity have been found in this group. All HIV positive blood recipients (30 cases) were infected before the mandatory HIV testing of blood supply has been introduced in 1987 (14 out of 16 HIV+ haemophiliacs were infected by imported clotting products). The twins born in 1990 to mother infected by contaminated blood in 1984, were declared at the age of 30 months as HIV free, with all laboratory tests (serology, virus cultivation, PCR) negative. The cummulative infection rate of HIV antibody in 1986-1992 reached 13.8 per million inhabitants. It may be concluded that slow steady increase in the number of reported HIV/AIDS cases has been registered during the whole follow-up period. The authors are aware that relatively low prevalence of HIV infection in the Czech Republic may change dramatically in consequences of recent deep social, political and economical changes in the country.

Acquired Immunodeficiency Syndrome↗

Bacterially expressed core and envelope proteins of human immunodeficiency virus type-1 (HIV-1): comparative evaluation in detection of type-specific antibodies.

Recombinant proteins derived from immunodominant conserved domains of HIV-1 env and gag genes were synthesized in E. coli. An immunoblot system using total cell lysates was employed for the analysis of recombinant bacterial clones. Together 427 serum samples obtained from asymptomatic anti-HIV seropositive individuals, AIDS patients, healthy donors and persons suffering from various conditions were comparatively evaluated for the presence of HIV-1 antibodies using recombinant peptides and commercially available western blot (WB) and ELISA assays. The recombinant antigen product of plasmid pEX41 was found to be superior, with respect to sensitivity and specificity, to the viral gp41 which represents a diagnostically important constituent of the WB.

AIDS Serodiagnosis↗

Virus neutralizing antibodies at different stages of the HIV disease: increased levels after azidothymidine treatment.

Specific HIV-1 neutralizing activity was measured in single serum samples obtained from 52 individuals suffering from different stage of HIV disease, as well as in serum samples collected during a four years follow up of other 13 HIV-1 seropositive persons, from whose seven developed AIDS. Three of these persons were treated with azidothymidine. In the former group of single serum specimens, the specific neutralizing antibody positivity rate was 81 per cent in symptomless persons, 92 per cent in patients with ARC and 43 per cent in patients with AIDS. From 13 HIV-1 infected individuals, prospectively investigated from 1986 to 1990, six remained asymptomatic and no significant fluctuation of specific virus neutralizing antibody levels was noted. During this time period, remaining seven patients developed AIDS. In the sera of AIDS patients, specific neutralizing activity was either not detected or its titres were rather low before the appearance of clinical disease. Three AIDS patients were administered azidothymidine. Specific neutralizing antibody titres increased significantly one month after the beginning of azidothymidine administration and persisted at relatively high levels over several months of follow up.

AIDS-Related Complex↗

[Microbiological diagnosis of infection with the human immunodeficiency virus].

The author describes and evaluates different approaches in laboratory diagnosis of HIV infection and AIDS. Serological detection of anti-HIV antibodies provides despite some limitations very good diagnostic opportunities. ELISA screening tests supplemented by confirming tests, in particular the Western blot, ensure maximum accuracy of the obtained results. Evidence of the viral antigen in serum is used as a diagnostic criterium only in special instances and serves rather for monitoring of the state of HIV infected subjects than screening for new cases of infection. Cultivation of the virus from clinical material is difficult but in some instances, e.g. in neonates and young children it is the only evidence of HIV infection. Recently for diagnostic purposes molecular biological methods are used, in particular amplification of proviral DNA by a polymerase chain reaction. Their application is, however, so far restricted to research departments because they are technically and economically pretentious.

AIDS Serodiagnosis↗

[Dynamics of the antibody response and p24 antigenemia in HIV-1 infected individuals in Czechoslovakia].

In a group of 83 anti HIV-1 positive subjects the antibody response against different structural viral proteins was investigated concurrently with assessment of p 24 antigenaemia. Disappearance of antibodies against the capsidal antigen p 24 was recorded in 12% of 42 patients with ARC and AIDS. On the other hand, these antibodies persisted in all 41 asymptomatic infections throughout the three-year investigation period. Disappearance of antibodies against p 17 antigen was proved in 41% of the patients and in 22 subjects without clinical symptoms. The authors found a rising trend of antigenaemia p 24 in the course of HIV infection. The free p 24 antigen was detected in 62% patients with AIDS and only in 10% asymptomatic infections. The investigation confirmed the importance of investigations of the antibody response and p 24 antigenaemia in the prognosis of development of HIV infection and in monitoring of the effect of therapy.

AIDS-Related Complex↗

[Detection of HIV infection using the immunofluorescence test].

The author examined, using the immunofluorescence test, 107 ant HIV positive sera and 114 sera with false reactions in the ELISA test. He proved a high sensitivity and specificity of the immunofluorescence test in the detection of anti-HIV antibodies, comparable with Western-blot's technique and he established the value of the immunofluorescence test for the identification of the virus antigen on isolation of the virus from HIV infected patients.

AIDS Serodiagnosis↗

[Cultivation of HIV-1 virus on mononuclear peripheral blood cells of HIV-1 seropositive individuals].

Using the method of co-cultivation with phytohaemagglutinin-stimulated lymphocytes from healthy donors, the author isolated the HIV-1 virus from peripheral mononuclear blood cells of three patients with the AIDS symptomatology and one patient with the ARC symptomatology. The presence of the virus in infected cells was proved by detection of the viral antigen p 24 in enzymatic immunoassays and in the immunofluorescence test. Three of the isolated strains were adapted to sensitive continual tissue cultures, where the isolates caused chronic infection of the cells associated with the development of a cytopathic effect. In the investigated patients no relationship was proved between viraemia and antigenaemia. The author discusses the importance of virus cultivation for laboratory diagnosis, epidemiology and research of HIV infection and AIDS.

AIDS-Related Complex↗

[Childhood AIDS].

The authors emphasize the present importance of AIDS in children and explain the causes of the rising trend of this syndrome in the child population. They summarize the most important epidemiological characteristics of AIDS in children, its pathogenetic differences and the ensuing clinical symptoms. Attention is drawn to the pitfalls of microbiological diagnosis of child infections caused by HIV, and the authors discuss principles, possibilities and perspectives of causal treatment of this syndrome in children. Finally they summarize contemporary experience and knowledge regarding immunization of children infected with the human immunodeficiency virus.

Acquired Immunodeficiency Syndrome↗

Prospective study of pharyngitis: clinical diagnosis and microbiological profile.

A prospective study of pharyngitis was carried out in the general population of twenty-two thousand in a small country town, over a period of ten weeks in the fall of 1984. It has been confirmed that, as in the past clinical diagnosis "streptococcal" and "nonstreptococcal" pharyngitis without microbiological examination is still highly inaccurate. From the clinical and microbiological parameters, the incidence in the period of follow-up was calculated as 7.2 and 12.0 cases per 100 population per year for streptococcal and nonstreptococcal pharyngitis, respectively. These data document the health importance of this disease which is frequently underestimated. The M (by M or OF antigens) typability accounted for 62% of group A strains isolated, the prevailing types being M 1 and M 12. Comparison of M and OF typability of field strains immediately after isolation and three weeks later proved the superiority of an early typing. The accurate identification of prevailing types is essential for the prospect of streptococcal vaccine. In streptococcal pharyngitis cases treated with penicillin, the increase of antistreptolysin O and antideoxyribonuclease B titres was recorded in very few instances during a three week period after the onset of the disease. The examination of patients with nonstreptococcal pharyngitis aimed at detecting the role of some viruses or of M. pneumoniae proved that the etiology by these agents was practically nil in the cases concerned at this particular period of time. This finding suggests focusing interest on a possible role of other pathogens. The morbidity rates of pharyngitis, and the clinical as well as the microbiological data resulting from the study make it urgent to pay further attention to this infection and to attempt to elucidate the missing points in the etiology and diagnosis of this disease which belongs to the bacterial infections most frequently seen in man in economically developed countries.

Antibodies, Bacterial↗