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Biomedical subjects

K Burian

Publications and source records attributed to K Burian.

At least 19 recordsLinked to original sources
PubMed2006

A soluble factor(s) released by MRC-5 cells early and late after human cytomegalovirus infection induces maturation of monocyte-derived dendritic cells.

A human cytomegalovirus (HCMV) strain passaged 10 times on MRC-5 human fibroblast cells failed to express immediate early (IE) antigens in immature dendritic cells (iDCs) after infection. However, both the early and the late HCMV conditioning medium, harvested from MRC-5 cells at 24 h or 7-9 days after infection, respectively, induced a higher ratio of DCs expressing maturation markers (CD40, CD83, CD86 and HLA-DR) on the surface of the cells. HCMV conditioning medium, ultracentrifuged to remove virus particles, exhibited a similarly enhanced expression of DC maturation markers. DCs treated with HCMV conditioning medium harvested late after infection increased the percentages of autologous CD4+ and CD8+ cells of seropositive donors to produce IFN-gamma and stimulated HCMV-specific lymphoproliferative responses. The early HCMC conditioning medium was also able to induce the functional maturation of DCs, as demonstrated by supplementing this medium with a Chlamydia pneumoniae antigen.

B7-2 Antigen↗
PubMed2004

The interactions between human dendritic cells and microbes; possible clinical applications of dendritic cells.

The dendritic cells comprise several subsets that induce and regulate the immune responses against foreign and self-antigens, and that can therefore function as initiators of protective immunity and inducers of central or peripheral tolerance. The different subpopulations of dendritic cells interact with and also influence other cell populations of the immune system, such as T and B lymphocytes and natural killer cells. The factors that determine the given dendritic cell functions depend on the state of maturation and the local microenvironment. The interactions between dendritic cells and microorganisms are rather complex, but progress in the past few years has shed light on several aspects of these interactions. This review lays emphasis on the interactions between human dendritic cells, important components of the intima of arterial specimens at areas predisposed to atherosclerotic lesions, and Chlamydia pneumoniae and cytomegalovirus, the human pathogens most strongly implicated in the development of atherosclerosis. In addition, several examples of the potential clinical applications of dendritic cells are described.

Arteriosclerosis↗
PubMed2001

Independent and joint effects of antibodies to human heat-shock protein 60 and Chlamydia pneumoniae infection in the development of coronary atherosclerosis.

BACKGROUND: Studies have suggested that the prevalence of antibodies against heat-shock proteins (HSPs), Chlamydia pneumoniae (CPN), and cytomegalovirus (CMV) is associated with coronary artery disease (CAD), but the independent or joint effects of human (h) HSP60 antibodies and these pathogens in patients have not been fully elucidated. METHODS AND RESULTS: A total of 405 subjects (276 patients with CAD and 129 control individuals) were tested for serum antibodies to hHSP60, CPN, and CMV immediate-early-1 (IE1) antigens. Patients were also assessed for serum cholesterol, triglyceride levels, and smoking habit. Significantly elevated levels of antibodies to hHSP60 and CPN but not to CMV-IE1 antigens were documented in CAD patients. Multiple logistic regression analysis and subanalyses of selected subjects showed that these associations were independent of age, sex, smoking, and serum lipid levels. Antibodies to hHSP60 and CPN did not correlate quantitatively; however, the relative risk of disease development was substantially increased in subjects with high antibody levels to both hHSP60 and CPN:, reaching an odds ratio of 82.0 (95% CI 10.6 to 625.0). CONCLUSIONS: High levels of antibodies to hHSP60 and CPN: are independent risk factors for coronary atherosclerosis, but their simultaneous presence substantially increases the risk for disease development.

Adult↗
PubMed2001

Chlamydia pneumoniae exacerbates aortic inflammatory foci caused by murine cytomegalovirus infection in normocholesterolemic mice.

Inflammatory foci induced by murine cytomegalovirus infection in normocholesterolemic mice were present temporarily in the aortic wall, but some of these foci developed into advanced lesions that persisted late after infection. The early foci induced by virus infection were significantly exacerbated following a single inoculation with Chlamydia pneumoniae.

Animals↗
PubMed2001

Chlamydia pneumoniae in atherosclerotic middle cerebral artery.

BACKGROUND AND PURPOSE: Atherosclerotic middle cerebral arteries are frequent sites of thrombosis, leading to stroke. Previous studies have suggested a role for Chlamydia pneumoniae in the pathogenesis of atherosclerosis. However, the presence of this pathogen in atherosclerotic middle cerebral arteries has heretofore not been documented. In the present study, we analyzed atheromatous plaques from middle cerebral arteries for the presence of C pneumoniae. METHODS: Atherosclerotic middle cerebral arteries from 15 cadavers who died of natural causes and corresponding nonatherosclerotic arteries from 4 otherwise healthy trauma victims were examined. Assays for C pneumoniae DNA were carried out by nested polymerase chain reaction (nPCR) specific for the C pneumoniae ompA gene. The presence of the bacterium was assessed by transmission electron microscopy. RESULTS: Five of the 15 atherosclerotic arterial samples and none of the control tissues were positive for C pneumoniae by nPCR. Particles similar in morphology and size to C pneumoniae elementary bodies were detected by transmission electron microscopy in 4 of the 5 nPCR-positive atherosclerotic samples. CONCLUSIONS: The demonstration of C pneumoniae in atherosclerotic middle cerebral arteries is consistent with the hypothesis that this bacterium is involved in acute and chronic cerebrovascular diseases.

Adult↗
PubMed2000

Cytotoxic T lymphocyte (CTL) responses to human cytomegalovirus pp65, IE1-Exon4, gB, pp150, and pp28 in healthy individuals: reevaluation of prevalence of IE1-specific CTLs.

The prevalence of human cytomegalovirus (HCMV) pp65-, pp150-, IE1-exon4-, gB- and pp28-specific cytotoxic T lymphocyte (CTL) responses was compared among 34 healthy individuals, grouped by neutralizing antibody titers. Moderately and highly seropositive donors showed predominantly pp65- and IE1-exon4-specific CTL responses (92% and 76% of the donors, respectively), with similar precursor frequencies in the 2 donors tested. In addition, highly seropositive and a few moderately seropositive donors showed CTL responses to gB and pp150 (33% and 30% of the donors, respectively). No individual recognized pp28 as a target in the CTL assay. Phenotypic analysis revealed a mixed effector population of CD4+ and CD8+ (1 donor) or only CD8+ cells for pp65-specific effectors (2 donors). IE1-exon4- and pp150-specific effectors were CD8+ (2 donors and 1 donor, respectively), whereas gB-specific CTLs were CD4+ (1 donor). These data may help to design a cellular immunity-based vaccine effective against HCMV diseases.

Adult↗
PubMed1994

The Vienna Cochlear Implant in patients with obliteration of the cochlea.

Twelve deaf patients with obliterated or ossified cochleas received the extracochlear version of the Vienna Cochlear Implant. Four patients, 1 of them a child, developed open speech comprehension. Obliteration of the cochlea could not always be predicted by conventional tomography of the temporal bone. Short duration of deafness, wide dynamic range, and good ability of time resolution (small temporal difference limen [TDL]) are predictors for good postoperative results. Obliteration or ossification of the cochlea per se is no contraindication to cochlear implantation.

Adult↗
PubMed1992

[Current status of electrostimulation of auditory nerve fibers with cochlear implants].

Under the observance of a few selection criteria electrostimulation of the cochlea nerve with cochlea implants is a suitable method to supply totally deafs with a hearing ability and in about the half of the patients even with speech understanding. The technology of the Vienna Cochlea Implant, selection criteria, surgical technique as well as the rehabilitation procedure and the results are discussed.

Adult↗
PubMed1991

[Management of cochlear implants in children--methods and results].

Selection criteria, basic principles of auditory training, development of an auditory test battery for children and results of 15 children between 4 and 14 years are presented and discussed. To summarize, results range from acoustic attention to tones and sounds and recognition of environmental sounds to the use of supra-segmental and segmental features of speech. Some children are able to recognize words and phrases from a closed list. One of the children has postlingual deafness and has had also a very short duration of deafness before implantation. This child shows better results than the pre and perilingually deaf children. Because of the fact that the patient group is small and there are also many intervening variables like age, duration of deafness and use of two different test instruments, it is difficult to find a relationship between the results and all other variables. The auditory test battery for children, which consists of seven subtests, measuring acoustic orientation and auditory speech perception on different linguistic levels, is much more suitable for the evaluation of auditory performance for this age group than the auditory test battery for adults (Eisenwort and Burian 1988).

Adolescent↗
PubMed1991

First behind the ear-wearable speech processor for the Vienna cochlear prosthesis. A preliminary report.

A behind the ear-wearable speech processor for the Vienna cochlear prosthesis has been designed. In a comparative study 6 patients used the new device for 1 week and were then tested. The results from the auditory test battery and a speech tracking were about the same, only the perception of speech from an open list was better when the patients used the conventional processor. It is possible to reduce the size of a speech processor substantially by modifying the speech-processing strategy without major decrease of the performance. More patients have to be tested after using the device for a longer time.

Adult↗
PubMed1990

[The cochlear implant and its psychosocial effects in 36 patients].

In a study on 36 cochlear implant patients questionnaires answered pre- and postsurgically were analyzed. One year after implantation patients demonstrated significant changes on some of the test items. Although results show that the patients accept their device, some of their wishes and hopes remain unsatisfied.

Adolescent↗
PubMed1989

[Experiences with the Vienna auditory prosthesis].

Open set speech comprehension can be achieved by intra- and extracochlear stimulation using an analog broadband signal. There is a tendency that intracochlear provided patients achieve better scores for open set speech comprehension than extracochlear implanted patients. Four prelingually deaf children acquired awareness of tones and sounds and some of them are able to use suprasegmental cues. After reimplantation, speech comprehension scores remain stable. For three patients scores even improve. Controls of the pure-tone audiograms demonstrate that extracochlear implants do not destroy residual hearing.

Adult↗
PubMed1989

[Prognostic indications within the scope of the selection of cochlear implant patients].

The common selection criteria for cochlear implant patients do not allow any prognostic indication on the final result. On the other hand, some postoperative data (threshold, TDL, dynamic range, duration of deafness) corresponds clearly with the results, some of them also correspond with the preoperative data. Preoperative TDL, dynamic range as well as duration of deafness can therefore be used as suitable prognostic indicators.

Auditory Threshold↗
PubMed1988

[Rehabilitation of cochlear implant patients].

Pre- and post-surgical treatment of cochlear implant patients is discussed. Before surgery training of lipreading ability, auditory training with conventional hearing aids and counselling should be offered. After surgery the main focus lies on auditory training with the cochlear implant; communication training in a group and counselling should be offered too.

Cochlear Implants↗