490 results on '"Mrazek, J."'
Search Results
452. Defined Pig Microbiota Mixture as Promising Strategy against Salmonellosis in Gnotobiotic Piglets.
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Modrackova N, Horvathova K, Mekadim C, Splichal I, Splichalova A, Amin A, Mrazek J, Vlkova E, and Neuzil-Bunesova V
- Abstract
Probiotics are a potential strategy for salmonellosis control. A defined pig microbiota (DPM) mixture of nine bacterial strains previously exhibited probiotic and anti- Salmonella properties in vitro. Therefore, we evaluated its gut colonization ability and protection effect against S. typhimurium LT2-induced infection in the gnotobiotic piglet model. The DPM mixture successfully colonized the piglet gut and was stable and safe until the end of the experiment. The colon was inhabited by about 9 log CFU g
-1 with a significant representation of bifidobacteria and lactobacilli compared to ileal levels around 7-8 log CFU g-1 . Spore-forming clostridia and bacilli seemed to inhabit the environment only temporarily. The bacterial consortium contributed to the colonization of the gut at an entire length. The amplicon profile analysis supported the cultivation trend with a considerable representation of lactobacilli with bacilli in the ileum and bifidobacteria with clostridia in the colon. Although there was no significant Salmonella -positive elimination, it seems that the administered bacteria conferred the protection of infected piglets because of the slowed delayed infection manifestation without translocations of Salmonella cells to the blood circulation. Due to its colonization stability and potential protective anti- Salmonella traits, the DPM mixture has promising potential in pig production applications. However, advanced immunological tests are needed.- Published
- 2024
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453. Microbiome composition and presence of cultivable commensal groups of Southern Tamanduas (Tamandua tetradactyla) varies with captive conditions.
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Amin A, Mekadim C, Modrackova N, Bolechova P, Mrazek J, and Neuzil-Bunesova V
- Abstract
Southern Tamanduas (Tamandua tetradactyla) belong to the specialized placental myrmecophages. There is not much information about their intestinal microbiome. Moreover, due to their food specialization, it is difficult to create an adequate diet under breeding conditions. Therefore, we used 16S rDNA amplicon sequencing to analyze the fecal microbiome of captive Southern Tamanduas from four locations in the Czech Republic and evaluated the impact of the incoming diet and facility conditions on microbiome composition. Together with the microbiome analysis, we also quantified and identified cultivable commensals. The anteater fecal microbiome was dominated by the phyla Bacillota and Bacteroidota, while Pseudomonadota, Spirochaetota, and Actinobacteriota were less abundant. At the taxonomic family level, Lachnospiraceae, Prevotellaceae, Bacteroidaceae, Oscillospiraceae, Erysipelotrichaceae, Spirochaetaceae, Ruminococcaceae, Leuconostocaceae, and Streptococcaceae were mainly represented in the fecal microbiome of animals from all locations. Interestingly, Lactobacillaceae dominated in the location with a zoo-made diet. These animals also had significantly lower diversity of gut microbiome in comparison with animals from other locations fed mainly with a complete commercial diet. Moreover, captive conditions of analyzed anteater included other factors such as the enrichment of the diet with insect-based products, probiotic interventions, the presence of other animals in the exposure, which can potentially affect the composition of the microbiome and cultivable microbes. In total, 63 bacterial species from beneficial commensal to opportunistic pathogen were isolated and identified using MALDI-TOF MS in the set of more than one thousand selected isolates. Half of the detected species were present in the fecal microbiota of most animals, the rest varied across animals and locations., (© 2024. The Author(s).)
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- 2024
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454. Thiothrix and Sulfurovum genera dominate bacterial mats in Slovak cold sulfur springs.
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Nosalova L, Mekadim C, Mrazek J, and Pristas P
- Abstract
Microbiota of sulfur-rich environments has been extensively studied due to the biotechnological potential of sulfur bacteria, or as a model of ancient life. Cold terrestrial sulfur springs are less studied compared to sulfur-oxidizing microbiota of hydrothermal vents, volcanic environments, or soda lakes. Despite that, several studies suggested that sulfur springs harbor diverse microbial communities because of the unique geochemical conditions of upwelling waters. In this study, the microbiota of five terrestrial sulfur springs was examined using a 16 S rRNA gene sequencing. The clear dominance of the Proteobacteria and Campylobacterota phyla of cold sulfur springs microbiota was observed. Contrary to that, the microbiota of the hot sulfur spring was dominated by the Aquificota and Firmicutes phylum respectively. Sulfur-oxidizing genera constituted a dominant part of the microbial populations with the Thiothrix and Sulfurovum genera identified as the core microbiota of cold sulfur terrestrial springs in Slovakia. Additionally, the study emphasizes that sulfur springs in Slovakia support unique, poorly characterized bacterial communities of sulfur-oxidizing bacteria., (© 2023. BioMed Central Ltd., part of Springer Nature.)
- Published
- 2023
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455. Dysbiosis of skin microbiome and gut microbiome in melanoma progression.
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Mekadim C, Skalnikova HK, Cizkova J, Cizkova V, Palanova A, Horak V, and Mrazek J
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- Animals, Bacteria genetics, Dysbiosis microbiology, Feces microbiology, Fusobacterium, RNA, Ribosomal, 16S genetics, Swine, Tumor Microenvironment, Gastrointestinal Microbiome genetics, Melanoma, Microbiota
- Abstract
Background: The microbiome alterations are associated with cancer growth and may influence the immune system and response to therapy. Particularly, the gut microbiome has been recently shown to modulate response to melanoma immunotherapy. However, the role of the skin microbiome has not been well explored in the skin tumour microenvironment and the link between the gut microbiome and skin microbiome has not been investigated in melanoma progression. Therefore, the aim of the present study was to examine associations between dysbiosis in the skin and gut microbiome and the melanoma growth using MeLiM porcine model of melanoma progression and spontaneous regression., Results: Parallel analysis of cutaneous microbiota and faecal microbiota of the same individuals was performed in 8 to 12 weeks old MeLiM piglets. The bacterial composition of samples was analysed by high throughput sequencing of the V4-V5 region of the 16S rRNA gene. A significant difference in microbiome diversity and richness between melanoma tissue and healthy skin and between the faecal microbiome of MeLiM piglets and control piglets were observed. Both Principal Coordinate Analysis and Non-metric multidimensional scaling revealed dissimilarities between different bacterial communities. Linear discriminant analysis effect size at the genus level determined different potential biomarkers in multiple bacterial communities. Lactobacillus, Clostridium sensu stricto 1 and Corynebacterium 1 were the most discriminately higher genera in the healthy skin microbiome, while Fusobacterium, Trueperella, Staphylococcus, Streptococcus and Bacteroides were discriminately abundant in melanoma tissue microbiome. Bacteroides, Fusobacterium and Escherichia-Shigella were associated with the faecal microbiota of MeLiM piglets. Potential functional pathways analysis based on the KEGG database indicated significant differences in the predicted profile metabolisms between the healthy skin microbiome and melanoma tissue microbiome. The faecal microbiome of MeLiM piglets was enriched by genes related to membrane transports pathways allowing for the increase of intestinal permeability and alteration of the intestinal mucosal barrier., Conclusion: The associations between melanoma progression and dysbiosis in the skin microbiome as well as dysbiosis in the gut microbiome were identified. Results provide promising information for further studies on the local skin and gut microbiome involvement in melanoma progression and may support the development of new therapeutic approaches., (© 2022. The Author(s).)
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- 2022
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456. Identification of filamentous fungi including dermatophytes using MALDI-TOF mass spectrometry.
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Hamal P, Vavrova A, Mrazek J, and Svobodova L
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- Culture Media, Diagnostic Tests, Routine, Fungi genetics, Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization, Arthrodermataceae genetics
- Abstract
Identification of filamentous fungi based on morphological features is the most available approach used in clinical mycology laboratories. However, MALDI-TOF mass spectrometry is currently invaluable for identification of microorganisms because of its rapidity, simplicity, and accuracy. This study aimed to find the optimal way of identifying filamentous fungi using MALDI-TOF MS.The sample comprised 193 isolates of filamentous fungi. The identification started with morphological assessment. Then isolates were identified using MALDI-TOF MS, both directly from culture and following culture in liquid media with extraction. Subsequently, identification of 20 selected isolates was compared by sequencing of the benA gene, ITS1-5,8-ITS2, and D1-D2 LSU regions.Based on morphological criteria, 17 genera of fungi were identified. With MALDI-TOF MS performed directly from culture, nine isolates were identified to the genus level and 184 to the species level, with a total of 75 species being noted. With the MALDI-TOF MS extraction method, 190 isolates were identified to the species level, with 43 species being noted. The rates of agreement between identification using morphology and the MALDI-TOF MS direct method were 58.55% at the genus level and 22.24% at the species level. The rates of agreement between identification using morphology and the MALDI-TOF MS extraction method were 84.97% at the genus level and 46.11% at the species level. Using sequencing, 87.5% agreement was found for identification with the MALDI-TOF MS extraction method, as compared with only 43.75% for the direct method.The results suggest that the optimal approach to identification of filamentous fungi is a combination of morphological features and MALDI-TOF MS using the extraction method., (© 2021. Institute of Microbiology, Academy of Sciences of the Czech Republic, v.v.i.)
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- 2022
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457. Covid-19 antigen testing: better than we know? A test accuracy study.
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Homza M, Zelena H, Janosek J, Tomaskova H, Jezo E, Kloudova A, Mrazek J, Svagera Z, and Prymula R
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- Antigens, Viral, China, Humans, SARS-CoV-2, Sensitivity and Specificity, COVID-19
- Abstract
Background: Antigen testing for SARS-CoV-2 is considered to be less sensitive than the standard reference method - real-time PCR (RT-PCR). It has been suggested that many patients with positive RT-PCR 'missed' by antigen testing might be non-infectious., Methods: In a real-world high-throughput setting for asymptomatic or mildly symptomatic patients, 494 patients were tested using RT-PCR as well as a single lateral flow antigen test (Ecotest, AssureTech, China). Where the results differed, virus viability was evaluated by cell culture. The test parameters were calculated with RT-PCR and RT-PCR adjusted on viability as reference standards., Results: The overall sensitivity of the used antigen test related to the RT-PCR only was 76.2%, specificity was 97.3%. However, 36 out of 39 patients 'missed' by the antigen test contained no viable virus. After adjusting on that, the sensitivity grew to 97.7% and, more importantly for disease control purposes, the negative predictive value reached 99.2%., Conclusions: We propose that viability testing should be always performed when evaluating a new antigen test. A well-chosen and validated antigen test provides excellent results in identifying patients who are shedding viable virus (although some caveats still remain) in the real-world high-throughput setting of asymptomatic or mildly symptomatic individuals.
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- 2021
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458. Performance of Seven SARS-CoV-2 Self-Tests Based on Saliva, Anterior Nasal and Nasopharyngeal Swabs Corrected for Infectiousness in Real-Life Conditions: A Cross-Sectional Test Accuracy Study.
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Homza M, Zelena H, Janosek J, Tomaskova H, Jezo E, Kloudova A, Mrazek J, Murinova V, and Madar R
- Abstract
Many studies reported good performance of nasopharyngeal swab-based antigen tests for detecting SARS-CoV-2-positive individuals; however, studies independently evaluating the quality of antigen tests utilizing anterior nasal swabs or saliva swabs are still rare, although such tests are widely used for mass testing. In our study, sensitivities, specificities and predictive values of seven antigen tests for detection of SARS-CoV-2 (one using nasopharyngeal swabs, two using anterior nasal swabs and four using saliva) were evaluated. In a setting of a high-capacity testing center, nasopharyngeal swabs for quantitative PCR (qPCR) were taken and, at the same time, antigen testing was performed in accordance with manufacturers' instructions for the respective tests. In samples where qPCR and antigen tests yielded different results, virus culture was performed to evaluate the presence of the viable virus. Sensitivities and specificities of individual tests were calculated using both qPCR and qPCR corrected for viability as the reference. In addition, calculations were also performed for data categorized according to the cycle threshold and symptomatic status. The test using nasopharyngeal swabs yielded the best results (sensitivity of 80.6% relative to PCR and 91.2% when corrected for viability) while none of the remaining tests (anterior nasal swab or saliva-based tests) came even close to the WHO criteria for overall sensitivity. Hence, we advise caution when using antigen tests with alternative sampling methods without independent validation.
- Published
- 2021
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459. Five Antigen Tests for SARS-CoV-2: Virus Viability Matters.
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Homza M, Zelena H, Janosek J, Tomaskova H, Jezo E, Kloudova A, Mrazek J, Svagera Z, and Prymula R
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- Adult, COVID-19 diagnosis, COVID-19 Nucleic Acid Testing, False Negative Reactions, Female, Humans, Male, Mass Screening, Middle Aged, Sensitivity and Specificity, Antigens, Viral analysis, COVID-19 immunology, COVID-19 Testing methods, Microbial Viability, SARS-CoV-2 immunology, Serologic Tests methods
- Abstract
Antigen testing for SARS-CoV-2 (AGT) is generally considered inferior to RT-PCR testing in terms of sensitivity. However, little is known about the infectiousness of RT-PCR positive patients who pass undetected by AGT. In a screening setting for mildly symptomatic or asymptomatic patients with high COVID-19 prevalence (30-40%), 1141 patients were tested using one of five AGTs and RT-PCR. Where the results differed, virus viability in the samples was tested on cell culture (CV-1 cells). The test battery included AGTs by JOYSBIO, Assure Tech, SD Biosensor, VivaChek Biotech and NDFOS. Sensitivities of the ATGs compared to RT-PCR ranged from 42% to 76%. The best test yielded a 76% sensitivity, 97% specificity, 92% positive, and 89% negative predictive values, respectively. However, in the best performing ATG tests, almost 90% of samples with "false negative" AGT results contained no viable virus. Corrected on the virus viability, sensitivities grew to 81-97% and, with one exception, the tests yielded high specificities >96%. Performance characteristics of the best test after adjustment were 96% sensitivity, 97% specificity, 92% positive, and 99% negative predictive values (high prevalence population). We, therefore, believe that virus viability should be considered when assessing the AGT performance. Also, our results indicate that a well-performing antigen test could in a high-prevalence setting serve as an excellent tool for identifying patients shedding viable virus. We also propose that the high proportion of RT-PCR-positive samples containing no viable virus in the group of "false negatives" of the antigen test should be further investigated with the aim of possibly preventing needless isolation of such patients.
- Published
- 2021
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460. Obesity-induced alterations in the gut microbiome in female mice fed a high-fat diet are antagonized by dietary supplementation with a novel, wax ester-rich, marine oil.
- Author
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Schots PC, Jansen KM, Mrazek J, Pedersen AM, Olsen RL, and Larsen TS
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- Animals, Anti-Obesity Agents pharmacology, Bacteria classification, Bacteria genetics, Bacteria growth & development, Colon microbiology, Exenatide pharmacology, Feces microbiology, Female, Metagenome, Mice, Mice, Inbred C57BL, Obesity physiopathology, Obesity therapy, Weight Gain, Diet, High-Fat, Dietary Fats, Unsaturated administration & dosage, Dietary Supplements, Gastrointestinal Microbiome, Obesity microbiology, Oils administration & dosage
- Abstract
Dietary supplementation with calanus oil, a novel wax ester-rich marine oil, has been shown to reduce adiposity in high-fat diet (HFD)-induced obese mice. Current evidence suggests that obesity and its comorbidities are intrinsically linked with unfavorable changes in the intestinal microbiome. Thus, in line with its antiobesity effect, we hypothesized that dietary supplementation with calanus oil should counteract the obesity-related deleterious changes in the gut microbiota. Seven-week-old female C57bl/6J mice received an HFD for 12 weeks to induce obesity followed by 8-week supplementation with 2% calanus oil. For comparative reasons, another group of mice was treated with exenatide, an antiobesogenic glucagon-like peptide-1 receptor agonist. Mice fed normal chow diet or nonsupplemented HFD for 20 weeks served as lean and obese controls, respectively. 16S rRNA gene sequencing was performed on fecal samples from the colon. HFD increased the abundance of the Lactococcus and Leuconostoc genera relative to normal chow diet, whereas abundances of Allobaculum and Oscillospira were decreased. Supplementation with calanus oil led to an apparent overrepresentation of Lactobacillus and Streptococcus and underrepresentation of Bilophila. Exenatide prevented the HFD-induced increase in Lactococcus and caused a decrease in the abundance of Streptococcus compared to the HFD group. Thus, HFD altered the gut microbiota composition in an unhealthy direction by increasing the abundance of proinflammatory genera while reducing those considered health-promoting. These obesity-induced changes were antagonized by both calanus oil and exenatide., (Copyright © 2020 The Author(s). Published by Elsevier Inc. All rights reserved.)
- Published
- 2020
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461. Bifidobacterium canis sp. nov., a novel member of the Bifidobacterium pseudolongum phylogenetic group isolated from faeces of a dog ( Canis lupus f. familiaris ).
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Neuzil-Bunesova V, Lugli GA, Modrackova N, Makovska M, Mrazek J, Mekadim C, Musilova S, Svobodova I, Spanek R, Ventura M, and Killer J
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- Aldehyde-Lyases, Animals, Bacterial Typing Techniques, Base Composition, DNA, Bacterial genetics, Feces microbiology, Genes, Bacterial, RNA, Ribosomal, 16S genetics, Sequence Analysis, DNA, Bifidobacterium classification, Dogs microbiology, Phylogeny
- Abstract
A fructose-6-phosphate phosphoketolase-positive strain (GSD1FS
T ) was isolated from a faecal sample of a 3 weeks old German Shepherd dog. The closest related taxa to isolate GSD1FST based on results from the EZBioCloud database were Bifidobacterium animalis subsp. animalis ATCC 25527T , Bifidobacterium animalis subsp. lactis DSM 10140T and Bifidobacterium anseris LMG 30189T , belonging to the Bifidobacterium pseudolongum phylogenetic group. The resulting 16S rRNA gene identities (compared length of 1454 nucleotides) towards these taxa were 97.30, 97.23 and 97.09 %, respectively. The pairwise similarities of strain GSD1FST using argS , atpA , fusA , hsp 60, pyrG , rpsC , thrS and xfp gene fragments to all valid representatives of the B. pseudolongum phylogenetic group were in the concatenated range of 83.08-88.34 %. Phylogenomic analysis based on whole-genome methods such as average nucleotide identity revealed that bifidobacterial strain GSD1FST exhibits close phylogenetic relatedness (88.17 %) to Bifidobacetrium cuniculi LMG 10738T . Genotypic characteristics and phylogenetic analyses based on nine molecular markers, as well as genomic and comparative phenotypic analyses, clearly proved that the evaluated strain should be considered as representing a novel species within the B. pseudolongum phylogenetic group named as Bifidobacterium canis sp. nov. (GSD1FST =DSM 105923T =LMG 30345T =CCM 8806T ).- Published
- 2020
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462. Molecular Epidemiology of Hantaviruses in the Czech Republic.
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Zelena H, Strakova P, Heroldova M, Mrazek J, Kastl T, Zakovska A, Ruzek D, Smetana J, and Rudolf I
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- Animals, Antibodies, Viral, Czech Republic epidemiology, Genes, Viral, Orthohantavirus immunology, Hantavirus Infections immunology, Humans, Immunoglobulin G immunology, Immunoglobulin M immunology, Phylogeny, Orthohantavirus genetics, Hantavirus Infections epidemiology, Hantavirus Infections virology, Molecular Epidemiology
- Abstract
During 2008-2018, we collected samples from rodents and patients throughout the Czech Republic and characterized hantavirus isolates. We detected Dobrava-Belgrade and Puumala orthohantaviruses in patients and Dobrava-Belgrade, Tula, and Seewis orthohantaviruses in rodents. Increased knowledge of eco-epidemiology of hantaviruses will improve awareness among physicians and better outcomes of patients.
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- 2019
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463. Human Vault Nanoparticle Targeted Delivery of Antiretroviral Drugs to Inhibit Human Immunodeficiency Virus Type 1 Infection.
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Fulcher JA, Tamshen K, Wollenberg AL, Kickhoefer VA, Mrazek J, Elliott J, Ibarrondo FJ, Anton PA, Rome LH, Maynard HD, Deming T, and Yang OO
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- Anti-Retroviral Agents chemistry, Cells, Cultured, Cytoplasm metabolism, Drug Liberation, HIV Infections prevention & control, HIV-1, Humans, Leukocytes, Mononuclear metabolism, Leukocytes, Mononuclear virology, Nanoparticles chemistry, Nanoparticles metabolism, Ribonucleoproteins, Anti-Retroviral Agents administration & dosage, Drug Delivery Systems methods, HIV Infections drug therapy, Nanoparticles therapeutic use
- Abstract
"Vaults" are ubiquitously expressed endogenous ribonucleoprotein nanoparticles with potential utility for targeted drug delivery. Here, we show that recombinant human vault nanoparticles are readily engulfed by certain key human peripheral blood mononuclear cells (PBMC), predominately dendritic cells, monocytes/macrophages, and activated T cells. As these cell types are the primary targets for human immunodeficiency virus type 1 (HIV-1) infection, we examined the utility of recombinant human vaults for targeted delivery of antiretroviral drugs. We chemically modified three different antiretroviral drugs, zidovudine, tenofovir, and elvitegravir, for direct conjugation to vaults. Tested in infection assays, drug-conjugated vaults inhibited HIV-1 infection of PBMC with equivalent activity to free drugs, indicating vault delivery and drug release in the cytoplasm of HIV-1-susceptible cells. The ability to deliver functional drugs via vault nanoparticle conjugates suggests their potential utility for targeted drug delivery against HIV-1.
- Published
- 2019
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464. Successful surgical excision of cerebral abscess caused by Fonsecaea monophora in an immunocompetent patient and review of literature.
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Dobias R, Filip M, Vragova K, Dolinska D, Zavodna P, Dujka A, Linzer P, Jurek P, Studena B, Cerna E, Mrazek J, Jaworska P, Kantorova M, Lyskova P, Krejci E, and Hubka V
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- Amphotericin B therapeutic use, Antifungal Agents pharmacology, Antifungal Agents therapeutic use, Ascomycota drug effects, Ascomycota genetics, Brain Abscess diagnostic imaging, Czech Republic, DNA, Ribosomal genetics, Humans, Immunocompetence, Male, Middle Aged, Mycoses diagnostic imaging, Treatment Outcome, Ascomycota isolation & purification, Brain Abscess microbiology, Brain Abscess surgery, Mycoses diagnosis
- Abstract
Cerebral abscesses caused by dark-pigmented Fonsecaea fungi are rare, especially in otherwise healthy individuals. In this case report, we present a 61-year-old man from Moldova, living in the Czech Republic, who had worked as a locksmith on oil platforms in Turkmenistan, Kazakhstan, Sudan, and Iraq since 1999, and was admitted to a neurology ward for a sudden motion disorder of the right leg, dysarthria, and hypomimia. Imaging revealed presence of expansive focus around the left lateral ventricle of the brain and a pronounced peripheral edema. The intracranial infectious focus was excised under intraoperative SonoWand guidance. Tissue samples were histologically positive for dark-pigmented hyphae, suggesting dematiaceous fungi. Therefore, liposomal amphotericin B therapy was initiated immediately. Fonsecaea monophora was provisionally identified using ITS rDNA region sequencing directly from brain tissue. The identification was subsequently confirmed by cultivation and DNA sequencing from culture. The strain exhibited in vitro sensitive to voriconazole (MIC = 0.016 μg/mL) and resistance to amphotericin B (MIC = 4 μg/mL); therefore, the amphotericin B was replaced with voriconazole. Postoperatively, a significant clinical improvement was observed and no additional surgery was required. Based on the literature review, this is the third documented case of cerebral infection due to this pathogen in patients without underlying conditions and the first such case in Europe.
- Published
- 2019
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465. Effect of Selected Stilbenoids on Human Fecal Microbiota.
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Jaimes JD, Jarosova V, Vesely O, Mekadim C, Mrazek J, Marsik P, Killer J, Smejkal K, Kloucek P, and Havlik J
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- Fermentation, Humans, Metagenome, Metagenomics methods, Molecular Structure, Phylogeny, RNA, Ribosomal, 16S genetics, Feces microbiology, Gastrointestinal Microbiome drug effects, Stilbenes pharmacology
- Abstract
Dietary phenolics or polyphenols are mostly metabolized by the human gut microbiota. These metabolites appear to confer the beneficial health effects attributed to phenolics. Microbial composition affects the type of metabolites produced. Reciprocally, phenolics modulate microbial composition. Understanding this relationship could be used to positively impact health by phenolic supplementation and thus create favorable colonic conditions. This study explored the effect of six stilbenoids (batatasin III, oxyresveratrol, piceatannol, pinostilbene, resveratrol, thunalbene) on the gut microbiota composition. Stilbenoids were anaerobically fermented with fecal bacteria from four donors, samples were collected at 0 and 24 h, and effects on the microbiota were assessed by 16S rRNA gene sequencing. Statistical tests identified affected microbes at three taxonomic levels. Observed microbial composition modulation by stilbenoids included a decrease in the Firmicutes to Bacteroidetes ratio, a decrease in the relative abundance of strains from the genus Clostridium , and effects on the family Lachnospiraceae . A frequently observed effect was a further decrease of the relative abundance when compared to the control. An opposite effect to the control was observed for Faecalibacterium prausnitzii , whose relative abundance increased. Observed effects were more frequently attributed to resveratrol and piceatannol, followed by thunalbene and batatasin III.
- Published
- 2019
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466. Solution Structures of Engineered Vault Particles.
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Ding K, Zhang X, Mrazek J, Kickhoefer VA, Lai M, Ng HL, Yang OO, Rome LH, and Zhou ZH
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- Amino Acid Sequence, Animals, Baculoviridae genetics, Baculoviridae metabolism, Binding Sites, Cloning, Molecular, Crystallography, X-Ray, Gene Expression, Genetic Vectors chemistry, Genetic Vectors metabolism, Models, Molecular, Protein Binding, Protein Conformation, alpha-Helical, Protein Conformation, beta-Strand, Protein Interaction Domains and Motifs, Rats, Recombinant Proteins chemistry, Recombinant Proteins genetics, Recombinant Proteins metabolism, Sf9 Cells, Spodoptera, Vault Ribonucleoprotein Particles genetics, Vault Ribonucleoprotein Particles metabolism, gag Gene Products, Human Immunodeficiency Virus genetics, gag Gene Products, Human Immunodeficiency Virus metabolism, Drug Delivery Systems methods, Protein Engineering methods, Vault Ribonucleoprotein Particles chemistry, gag Gene Products, Human Immunodeficiency Virus chemistry
- Abstract
Prior crystal structures of the vault have provided clues of its structural variability but are non-conclusive due to crystal packing. Here, we obtained vaults by engineering at the N terminus of rat major vault protein (MVP) an HIV-1 Gag protein segment and determined their near-atomic resolution (∼4.8 Å) structures in a solution/non-crystalline environment. The barrel-shaped vaults in solution adopt two conformations, 1 and 2, both with D39 symmetry. From the N to C termini, each MVP monomer has three regions: body, shoulder, and cap. While conformation 1 is identical to one of the crystal structures, the shoulder in conformation 2 is translocated longitudinally up to 10 Å, resulting in an outward-projected cap. Our structures clarify the structural discrepancies in the body region in the prior crystallography models. The vault's drug-delivery potential is highlighted by the internal disposition and structural flexibility of its Gag-loaded N-terminal extension at the barrel waist of the engineered vault., (Copyright © 2018 Elsevier Ltd. All rights reserved.)
- Published
- 2018
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467. Structures and stabilization of kinetoplastid-specific split rRNAs revealed by comparing leishmanial and human ribosomes.
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Zhang X, Lai M, Chang W, Yu I, Ding K, Mrazek J, Ng HL, Yang OO, Maslov DA, and Zhou ZH
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- Anti-Bacterial Agents pharmacology, Humans, Molecular Conformation, Nucleic Acid Conformation, Paromomycin pharmacology, Protein Biosynthesis drug effects, RNA, Ribosomal chemistry, RNA, Ribosomal metabolism, Ribosomes chemistry, Ribosomes metabolism, Cryoelectron Microscopy methods, Leishmania donovani metabolism, RNA, Ribosomal ultrastructure, Ribosomes ultrastructure
- Abstract
The recent success in ribosome structure determination by cryoEM has opened the door to defining structural differences between ribosomes of pathogenic organisms and humans and to understand ribosome-targeting antibiotics. Here, by direct electron-counting cryoEM, we have determined the structures of the Leishmania donovani and human ribosomes at 2.9 Å and 3.6 Å, respectively. Our structure of the leishmanial ribosome elucidates the organization of the six fragments of its large subunit rRNA (as opposed to a single 28S rRNA in most eukaryotes, including humans) and reveals atomic details of a unique 20 amino acid extension of the uL13 protein that pins down the ends of three of the rRNA fragments. The structure also fashions many large rRNA expansion segments. Direct comparison of our human and leishmanial ribosome structures at the decoding A-site sheds light on how the bacterial ribosome-targeting drug paromomycin selectively inhibits the eukaryotic L. donovani, but not human, ribosome.
- Published
- 2016
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468. Widefield imaging of upconverting nanoparticles on epifluorescence microscopes adapted for laser illumination with top-hat profile.
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Mrazek J, Pospisilova M, Svozil V, Cadek O, Nesporova K, Sulakova R, Brandejsova M, Vranova J, and Velebny V
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- Cell Line, Tumor, Fluorescent Dyes, Humans, Lighting, Luminescence, Nanoparticles ultrastructure, Lasers, Microscopy, Fluorescence instrumentation, Nanoparticles metabolism
- Abstract
We describe a modification of epifluorescence microscopes that allows quantitative widefield imaging of samples labeled by upconverting nanoparticles (UCNP). A top-hat illumination profile on the sample was achieved with a 980-nm laser diode by using tandem microlens arrays, a moving diffuser and a telescope, which adjusts the top-hat area to the field of view. Illumination homogeneity is a critical factor for imaging of UCNP since the intensity of their luminescence typically scales with the second power of the excitation intensity. Our illuminator is combined with the epifluorescence attachment of the microscope, allowing easy switching between observation of UCNP and traditional fluorescent dyes. Illumination profile homogeneity of about 98% was measured for objectives with magnification from 4× to 100×, and the top-hat profile was also obtained with phase contrast objectives. We demonstrate capability of the illuminator by evaluating in vitro uptake of UCNP encapsulated in oleyl-hyaluronan micelles into breast cancer cells. Micelles bearing the targeting peptide were about an order of magnitude more efficient than nontargeted micelles.
- Published
- 2016
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469. Development of gut inflammation in mice colonized with mucosa-associated bacteria from patients with ulcerative colitis.
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Du Z, Hudcovic T, Mrazek J, Kozakova H, Srutkova D, Schwarzer M, Tlaskalova-Hogenova H, Kostovcik M, and Kverka M
- Abstract
Background: Disturbances in the intestinal microbial community (i.e. dysbiosis) or presence of the microbes with deleterious effects on colonic mucosa has been linked to the pathogenesis of inflammatory bowel diseases. However the role of microbiota in induction and progression of ulcerative colitis (UC) has not yet been fully elucidated., Methods: Three lines of human microbiota-associated (HMA) mice were established by gavage of colon biopsy from three patients with active UC. The shift in microbial community during its transferring from humans to mice was analyzed by next-generation sequencing using Illumina MiSeq sequencer. Spontaneous or dextran sulfate sodium (DSS)-induced colitis and microbiota composition profiling in germ-free mice and HMA mice over 3-4 generations were assessed to decipher the features of the distinctive and crucial events occurring during microbial colonization and animal reproduction., Results: None of the HMA mice developed colitis spontaneously. When treated with DSS, mice in F4 generation of one line of colonized mice (aHMA) developed colitis. Compared to the DSS-resistant earlier generations of aHMA mice, the F4 generation have increased abundance of Clostridium difficile and decrease abundance of C. symbiosum in their cecum contents measured by denaturing gradient gel electrophoresis and DNA sequencing., Conclusion: In our study, mucosa-associated microbes of UC patients were not able to induce spontaneous colitis in gnotobiotic BALB/c mice but they were able to increase the susceptibility to DSS-induced colitis, once the potentially deleterious microbes found a suitable niche.
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- 2015
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470. Variation in honey bee gut microbial diversity affected by ontogenetic stage, age and geographic location.
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Hroncova Z, Havlik J, Killer J, Doskocil I, Tyl J, Kamler M, Titera D, Hakl J, Mrazek J, Bunesova V, and Rada V
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- Animals, Bacteria classification, Bacteria isolation & purification, Bees embryology, Bees growth & development, DNA, Bacterial genetics, Denaturing Gradient Gel Electrophoresis, Ecosystem, Gastrointestinal Tract microbiology, Lactobacillaceae genetics, RNA, Ribosomal, 16S genetics, Real-Time Polymerase Chain Reaction, Bacteria genetics, Bees microbiology, Gastrointestinal Microbiome
- Abstract
Social honey bees, Apis mellifera, host a set of distinct microbiota, which is similar across the continents and various honey bee species. Some of these bacteria, such as lactobacilli, have been linked to immunity and defence against pathogens. Pathogen defence is crucial, particularly in larval stages, as many pathogens affect the brood. However, information on larval microbiota is conflicting. Seven developmental stages and drones were sampled from 3 colonies at each of the 4 geographic locations of A. mellifera carnica, and the samples were maintained separately for analysis. We analysed the variation and abundance of important bacterial groups and taxa in the collected bees. Major bacterial groups were evaluated over the entire life of honey bee individuals, where digestive tracts of same aged bees were sampled in the course of time. The results showed that the microbial tract of 6-day-old 5th instar larvae were nearly equally rich in total microbial counts per total digestive tract weight as foraging bees, showing a high percentage of various lactobacilli (Firmicutes) and Gilliamella apicola (Gammaproteobacteria 1). However, during pupation, microbial counts were significantly reduced but recovered quickly by 6 days post-emergence. Between emergence and day 6, imago reached the highest counts of Firmicutes and Gammaproteobacteria, which then gradually declined with bee age. Redundancy analysis conducted using denaturing gradient gel electrophoresis identified bacterial species that were characteristic of each developmental stage. The results suggest that 3-day 4th instar larvae contain low microbial counts that increase 2-fold by day 6 and then decrease during pupation. Microbial succession of the imago begins soon after emergence. We found that bacterial counts do not show only yearly cycles within a colony, but vary on the individual level. Sampling and pooling adult bees or 6th day larvae may lead to high errors and variability, as both of these stages may be undergoing dynamic succession.
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- 2015
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471. Polyribosomes are molecular 3D nanoprinters that orchestrate the assembly of vault particles.
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Mrazek J, Toso D, Ryazantsev S, Zhang X, Zhou ZH, Fernandez BC, Kickhoefer VA, and Rome LH
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- Amino Acid Sequence, Animals, Cell Line, Molecular Sequence Data, Sequence Homology, Amino Acid, Spodoptera, Tomography, X-Ray Computed, Polyribosomes, Printing, Three-Dimensional
- Abstract
Ribosomes are molecular machines that function in polyribosome complexes to translate genetic information, guide the synthesis of polypeptides, and modulate the folding of nascent proteins. Here, we report a surprising function for polyribosomes as a result of a systematic examination of the assembly of a large ribonucleoprotein complex, the vault particle. Structural and functional evidence points to a model of vault assembly whereby the polyribosome acts like a 3D nanoprinter to direct the ordered translation and assembly of the multi-subunit vault homopolymer, a process which we refer to as polyribosome templating. Structure-based mutagenesis and cell-free in vitro expression studies further demonstrated the critical importance of the polyribosome in vault assembly. Polyribosome templating prevents chaos by ensuring efficiency and order in the production of large homopolymeric protein structures in the crowded cellular environment and might explain the origin of many polyribosome-associated molecular assemblies inside the cell.
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- 2014
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472. Mupirocin-mucin agar for selective enumeration of Bifidobacterium bifidum.
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Pechar R, Rada V, Parafati L, Musilova S, Bunesova V, Vlkova E, Killer J, Mrazek J, Kmet V, and Svejstil R
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- Animals, Bifidobacterium genetics, Bifidobacterium isolation & purification, Culture Media standards, Feces microbiology, Humans, Lactobacillaceae genetics, Lactobacillaceae metabolism, Polymerase Chain Reaction, Probiotics isolation & purification, RNA, Ribosomal, 16S genetics, Agar standards, Bacterial Load methods, Bifidobacterium physiology, Mucins metabolism, Mupirocin metabolism
- Abstract
Bifidobacterium bifidum is a bacterial species exclusively found in the human intestinal tract. This species is becoming increasingly popular as a probiotic organism added to lyophilized products. In this study, porcine mucin was used as the sole carbon source for the selective enumeration of B. bifidum in probiotic food additives. Thirty-six bifidobacterial strains were cultivated in broth with mucin. Only 13 strains of B. bifidum utilized the mucin to produce acids. B. bifidum was selectively enumerated in eight probiotic food supplements using agar (MM agar) containing mupirocin (100 mg/L) and mucin (20 g/L) as the sole carbon source. MM agar was fully selective if the B. bifidum species was presented together with Bifidobacterium animalis subsp. lactis, Bifidobacterium breve, and Bifidobacterium longum subsp. longum species and with lactic acid bacteria (lactobacilli, streptococci). Isolated strains of B. bifidum were identified using biochemical, PCR, MALDI-TOF procedures and 16S rRNA gene sequencing. The novel selective medium was also suitable for the isolation of B. bifidum strains from human fecal samples., (Copyright © 2014 Elsevier B.V. All rights reserved.)
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- 2014
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473. Effect of DNA extraction and sample preservation method on rumen bacterial population.
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Fliegerova K, Tapio I, Bonin A, Mrazek J, Callegari ML, Bani P, Bayat A, Vilkki J, Kopečný J, Shingfield KJ, Boyer F, Coissac E, Taberlet P, and Wallace RJ
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- Animals, Bacteroidetes classification, Bacteroidetes isolation & purification, Cattle, Denaturing Gradient Gel Electrophoresis, Gram-Positive Bacteria classification, Gram-Positive Bacteria isolation & purification, High-Throughput Nucleotide Sequencing, Phylogeny, Real-Time Polymerase Chain Reaction, Bacteroidetes genetics, Cryopreservation, DNA Barcoding, Taxonomic, DNA, Bacterial isolation & purification, Gram-Positive Bacteria genetics, Rumen microbiology, Specimen Handling methods
- Abstract
The comparison of the bacterial profile of intracellular (iDNA) and extracellular DNA (eDNA) isolated from cow rumen content stored under different conditions was conducted. The influence of rumen fluid treatment (cheesecloth squeezed, centrifuged, filtered), storage temperature (RT, -80 °C) and cryoprotectants (PBS-glycerol, ethanol) on quality and quantity parameters of extracted DNA was evaluated by bacterial DGGE analysis, real-time PCR quantification and metabarcoding approach using high-throughput sequencing. Samples clustered according to the type of extracted DNA due to considerable differences between iDNA and eDNA bacterial profiles, while storage temperature and cryoprotectants additives had little effect on sample clustering. The numbers of Firmicutes and Bacteroidetes were lower (P < 0.01) in eDNA samples. The qPCR indicated significantly higher amount of Firmicutes in iDNA sample frozen with glycerol (P < 0.01). Deep sequencing analysis of iDNA samples revealed the prevalence of Bacteroidetes and similarity of samples frozen with and without cryoprotectants, which differed from sample stored with ethanol at room temperature. Centrifugation and consequent filtration of rumen fluid subjected to the eDNA isolation procedure considerably changed the ratio of molecular operational taxonomic units (MOTUs) of Bacteroidetes and Firmicutes. Intracellular DNA extraction using bead-beating method from cheesecloth sieved rumen content mixed with PBS-glycerol and stored at -80 °C was found as the optimal method to study ruminal bacterial profile., (Copyright © 2013 Elsevier Ltd. All rights reserved.)
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- 2014
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474. Altered gut microbiota promotes colitis-associated cancer in IL-1 receptor-associated kinase M-deficient mice.
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Klimesova K, Kverka M, Zakostelska Z, Hudcovic T, Hrncir T, Stepankova R, Rossmann P, Ridl J, Kostovcik M, Mrazek J, Kopecny J, Kobayashi KS, and Tlaskalova-Hogenova H
- Subjects
- Animals, Azoxymethane toxicity, Blotting, Western, Carcinogens toxicity, Colitis chemically induced, Colonic Neoplasms metabolism, Colonic Neoplasms pathology, Cytokines genetics, Cytokines metabolism, Dextran Sulfate toxicity, Female, Flow Cytometry, Male, Mice, Mice, Inbred C57BL, Mice, Knockout, RNA, Messenger genetics, Real-Time Polymerase Chain Reaction, Receptors, Interleukin-1 metabolism, Reverse Transcriptase Polymerase Chain Reaction, Signal Transduction, T-Lymphocytes, Regulatory immunology, T-Lymphocytes, Regulatory metabolism, T-Lymphocytes, Regulatory pathology, Toll-Like Receptors genetics, Toll-Like Receptors metabolism, Colitis complications, Colonic Neoplasms etiology, Gastrointestinal Tract microbiology, Interleukin-1 Receptor-Associated Kinases physiology, Metagenome
- Abstract
Background: Microbial sensing by Toll-like receptors (TLR) and its negative regulation have an important role in the pathogenesis of inflammation-related cancer. In this study, we investigated the role of negative regulation of Toll-like receptors signaling and gut microbiota in the development of colitis-associated cancer in mouse model., Methods: Colitis-associated cancer was induced by azoxymethane and dextran sodium sulfate in wild-type and in interleukin-1 receptor-associated kinase M (IRAK-M)-deficient mice with or without antibiotic (ATB) treatment. Local cytokine production was analyzed by multiplex cytokine assay or enzyme-linked immunosorbent assay, and regulatory T cells were analyzed by flow cytometry. Changes in microbiota composition during tumorigenesis were analyzed by pyrosequencing, and β-glucuronidase activity was measured in intestinal content by fluorescence assay., Results: ATB treatment of wild-type mice reduced the incidence and severity of tumors. Compared with nontreated mice, ATB-treated mice had significantly lower numbers of regulatory T cells in colon, altered gut microbiota composition, and decreased β-glucuronidase activity. However, the β-glucuronidase activity was not as low as in germ-free mice. IRAK-M-deficient mice not only developed invasive tumors, but ATB-induced decrease in β-glucuronidase activity did not rescue them from severe carcinogenesis phenotype. Furthermore, IRAK-M-deficient mice had significantly increased levels of proinflammatory cytokines in the tumor tissue., Conclusions: We conclude that gut microbiota promotes tumorigenesis by increasing the exposure of gut epithelium to carcinogens and that IRAK-M-negative regulation is essential for colon cancer resistance even in conditions of altered microbiota. Therefore, gut microbiota and its metabolic activity could be potential targets for colitis-associated cancer therapy.
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- 2013
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475. Vault nanoparticles engineered with the protein transduction domain, TAT48, enhances cellular uptake.
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Yang J, Srinivasan A, Sun Y, Mrazek J, Shu Z, Kickhoefer VA, and Rome LH
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- Cell Line, Tumor, HeLa Cells, Humans, Nanoparticles ultrastructure, Neoplasms, Experimental pathology, Particle Size, Vault Ribonucleoprotein Particles chemistry, Nanoparticles chemistry, Neoplasms, Experimental metabolism, Protein Engineering methods, Vault Ribonucleoprotein Particles genetics, Vault Ribonucleoprotein Particles pharmacokinetics
- Abstract
Vaults are naturally-occurring ribonucleoprotein particles found in nearly all eukaryotic cells. They were named for their morphological resemblance to the vaulted ceilings of gothic cathedrals. These ubiquitous nanoparticles are quite abundant with 10(4)-10(6) copies found in the cytoplasm depending on cell type. The structural shell of the particle can self-assemble from 78 copies of a single protein, the major vault protein. This finding has allowed vaults to be bioengineered, resulting in a variety of new functions and capabilities directed toward overcoming many limitations posed by current gene and drug delivery systems. In this study, we demonstrate that recombinant vaults, with the addition of a cell penetration peptide, TAT, can be rapidly delivered to cells in vitro with significantly elevated binding and uptake efficiency. This TAT-vault nanoparticle could be a valuable tool for improving the retention and penetration of therapeutic drugs at tumor sites.
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- 2013
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476. Lysate of probiotic Lactobacillus casei DN-114 001 ameliorates colitis by strengthening the gut barrier function and changing the gut microenvironment.
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Zakostelska Z, Kverka M, Klimesova K, Rossmann P, Mrazek J, Kopecny J, Hornova M, Srutkova D, Hudcovic T, Ridl J, and Tlaskalova-Hogenova H
- Subjects
- Acute Disease, Administration, Oral, Animals, Colitis pathology, Colitis physiopathology, Digestive System drug effects, Digestive System physiopathology, Down-Regulation drug effects, Female, Humans, Immunity drug effects, Intestinal Mucosa drug effects, Intestinal Mucosa immunology, Intestinal Mucosa microbiology, Lipopolysaccharides pharmacology, Lymphocyte Count, Macrophage Activation drug effects, Membrane Proteins metabolism, Metagenome drug effects, Mice, Mice, Inbred BALB C, Mice, SCID, NF-kappa B metabolism, Permeability drug effects, Phosphoproteins metabolism, Probiotics administration & dosage, T-Lymphocytes, Regulatory cytology, T-Lymphocytes, Regulatory drug effects, Tumor Necrosis Factor-alpha biosynthesis, Zonula Occludens-1 Protein, Colitis microbiology, Colitis prevention & control, Digestive System microbiology, Lacticaseibacillus casei metabolism, Probiotics pharmacology
- Abstract
Background: Probiotic bacteria can be used for the prevention and treatment of human inflammatory diseases including inflammatory bowel diseases (IBD). However, the nature of active components and exact mechanisms of this beneficial effects have not been fully elucidated. Our aim was to investigate if lysate of probiotic bacterium L. casei DN-114 001 (Lc) could decrease the severity of intestinal inflammation in a murine model of IBD., Methodology/principal Findings: The preventive effect of oral administration of Lc significantly reduces the severity of acute dextran sulfate sodium (DSS) colitis in BALB/c but not in SCID mice. In order to analyze how this beneficial effect interferes with well-known phases of intestinal inflammation pathogenesis in vivo and in vitro, we evaluated intestinal permeability using the FITC-labeled dextran method and analysed tight junction proteins expression by immunofluorescence and PCR. We also measured CD4(+)FoxP3(+) regulatory T cells proportion by FACS analysis, microbiota composition by pyrosequencing, and local cytokine production by ELISA. Lc leads to a significant protection against increased intestinal permeability and barrier dysfunction shown by preserved ZO-1 expression. We found that the Lc treatment increases the numbers of CD4(+)FoxP3(+) regulatory T cells in mesenteric lymph nodes (MLN), decreases production of pro-inflammatory cytokines TNF-α and IFN-γ, and anti-inflammatory IL-10 in Peyer's patches and large intestine, and changes the gut microbiota composition. Moreover, Lc treatment prevents lipopolysaccharide-induced TNF-α expression in RAW 264.7 cell line by down-regulating the NF-κB signaling pathway., Conclusion/significance: Our study provided evidence that even non-living probiotic bacteria can prevent the development of severe forms of intestinal inflammation by strengthening the integrity of intestinal barrier and modulation of gut microenvironment.
- Published
- 2011
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477. Natural superhydrophilicity and photocatalytic properties of sol-gel derived ZnTiO(3)-ilmenite/r-TiO(2) films.
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Krylova G, Brioude A, Ababou-Girard S, Mrazek J, and Spanhel L
- Abstract
The additive free heteronucleation and nanocrystallization of ternary Zn(x)Ti(y)O(z) sols and coatings is presented. A proper adjustment of the Zn/Ti ratio in the sol allows the formation of elaborate superhydrophilic cubic spinel-like Zn(2)TiO(4), c-ZnTiO(3) or h-ZnTiO(3)-ilmentite/r-TiO(2)-rutile films. Their morphology and natural superhydrophilicity can be fine-tuned by the inclusion of 5% silica. This doping step delivers high dye intake capacities and water contact angle values below 3°. XPS analysis indicates that Zn and Si enrichment enables greater surface hydroxylation and thus improved water wetting behaviour. The transparent h-ZnTiO(3)-ilmenite/r-TiO(2) nanocomposite coatings deposited on glass and Si-wafers show a remarkable activity in the photomineralization of fatty-acids.
- Published
- 2010
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478. Expression and processing of a small nucleolar RNA from the Epstein-Barr virus genome.
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Hutzinger R, Feederle R, Mrazek J, Schiefermeier N, Balwierz PJ, Zavolan M, Polacek N, Delecluse HJ, and Hüttenhofer A
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- Animals, B-Lymphocytes virology, Base Sequence, Cell Line, Tumor, Humans, In Situ Hybridization, Fluorescence, Macaca mulatta, Molecular Sequence Data, RNA, Viral genetics, Gene Expression Regulation, Viral, Genome, Viral, Herpesvirus 4, Human genetics, RNA, Small Nucleolar genetics
- Abstract
Small nucleolar RNAs (snoRNAs) are localized within the nucleolus, a sub-nuclear compartment, in which they guide ribosomal or spliceosomal RNA modifications, respectively. Up until now, snoRNAs have only been identified in eukaryal and archaeal genomes, but are notably absent in bacteria. By screening B lymphocytes for expression of non-coding RNAs (ncRNAs) induced by the Epstein-Barr virus (EBV), we here report, for the first time, the identification of a snoRNA gene within a viral genome, designated as v-snoRNA1. This genetic element displays all hallmark sequence motifs of a canonical C/D box snoRNA, namely C/C'- as well as D/D'-boxes. The nucleolar localization of v-snoRNA1 was verified by in situ hybridisation of EBV-infected cells. We also confirmed binding of the three canonical snoRNA proteins, fibrillarin, Nop56 and Nop58, to v-snoRNA1. The C-box motif of v-snoRNA1 was shown to be crucial for the stability of the viral snoRNA; its selective deletion in the viral genome led to a complete down-regulation of v-snoRNA1 expression levels within EBV-infected B cells. We further provide evidence that v-snoRNA1 might serve as a miRNA-like precursor, which is processed into 24 nt sized RNA species, designated as v-snoRNA1(24pp). A potential target site of v-snoRNA1(24pp) was identified within the 3'-UTR of BALF5 mRNA which encodes the viral DNA polymerase. V-snoRNA1 was found to be expressed in all investigated EBV-positive cell lines, including lymphoblastoid cell lines (LCL). Interestingly, induction of the lytic cycle markedly up-regulated expression levels of v-snoRNA1 up to 30-fold. By a computational approach, we identified a v-snoRNA1 homolog in the rhesus lymphocryptovirus genome. This evolutionary conservation suggests an important role of v-snoRNA1 during gamma-herpesvirus infection.
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- 2009
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479. Measurement of the 20 and 90 keV resonances in the 18O(p,alpha)15N reaction via the Trojan horse method.
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La Cognata M, Spitaleri C, Mukhamedzhanov AM, Irgaziev B, Tribble RE, Banu A, Cherubini S, Coc A, Crucillà V, Goldberg VZ, Gulino M, Kiss GG, Lamia L, Mrazek J, Pizzone RG, Puglia SM, Rapisarda GG, Romano S, Sergi ML, Tabacaru G, Trache L, Trzaska W, and Tumino A
- Abstract
The 18O(p,alpha)15N reaction is of primary importance in several astrophysical scenarios, including fluorine nucleosynthesis inside asymptotic giant branch stars as well as oxygen and nitrogen isotopic ratios in meteorite grains. Thus the indirect measurement of the low energy region of the 18O(p,alpha)15N reaction has been performed to reduce the nuclear uncertainty on theoretical predictions. In particular the strength of the 20 and 90 keV resonances has been deduced and the change in the reaction rate evaluated.
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- 2008
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480. Transfer of conjugative elements from rumen and human Firmicutes bacteria to Roseburia inulinivorans.
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Scott KP, Martin JC, Mrazek J, and Flint HJ
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- Animals, DNA Transposable Elements, DNA, Bacterial chemistry, DNA, Ribosomal chemistry, DNA, Ribosomal genetics, Gram-Positive Bacteria isolation & purification, Humans, Molecular Sequence Data, RNA, Ribosomal, 16S genetics, Sequence Analysis, DNA, Conjugation, Genetic, DNA, Bacterial genetics, Gastrointestinal Tract microbiology, Gram-Positive Bacteria genetics, Rumen microbiology
- Abstract
Studies on Firmicutes bacteria from the gut are hampered by a lack of gene transfer systems. Here the human colonic anaerobe Roseburia inulinivorans A2-194 was shown to be a transfer recipient for two conjugative transposons, Tn1545 from Eubacterium cellulosolvens and TnK10 from Clostridium saccharolyticum K10.
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- 2008
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481. Epstein-Barr virus-encoded latent membrane protein 1 (LMP1) induces the expression of the cellular microRNA miR-146a.
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Motsch N, Pfuhl T, Mrazek J, Barth S, and Grässer FA
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- B-Lymphocytes immunology, B-Lymphocytes metabolism, B-Lymphocytes virology, Base Sequence, Burkitt Lymphoma immunology, Burkitt Lymphoma metabolism, Burkitt Lymphoma virology, Cell Line, Cell Line, Transformed, Cell Line, Tumor, Humans, Molecular Sequence Data, NF-kappa B physiology, Virus Latency genetics, Gene Expression Regulation, Viral physiology, Herpesvirus 4, Human physiology, MicroRNAs biosynthesis, MicroRNAs genetics, Viral Matrix Proteins physiology
- Abstract
MicroRNAs (miRNAs) are involved in sequence-specific cleavage, translational repression or deadenylation of specific target mRNAs resulting in post-transcriptional gene silencing. Epstein-Barr Virus (EBV) infection induces cellular non-coding (nc)RNAs e.g., the "vault" RNAs or miRNAs such as miR-21, miR-155 or miR-146a. MiR-146a is upregulated in various tumours and plays a role in innate immunity. We show that the EBV-encoded latent membrane protein 1 (LMP1) induces the expression of miR-146a via NFkappaB. LMP1 activates the miR-146a promoter but not a promoter with a mutation of the NFkappaB-response elements. Conversely, a LMP1-mutant deficient in NFkappaB-activation failed to activate the promoter. The "CAO"-LMP1 variant which has an increased potential to induce NFkappaB also showed a higher ability to activate the miR-146a promoter as compared to standard B95.8-LMP1. Northern blotting revealed high levels of miR-146a and miR-155 in the Burkitt's lymphoma cell line Jijoye which expresses LMP1 while the LMP1-deficient P3HR1 mutant derived from Jijoye expresses less miR-146a or miR-155. Likewise, EBV-latency type I Burkitt's lymphoma cells with low LMP1 levels also contain low levels of either miR-146a or miR-155 while their levels are increased in LMP1-expressing EBV-latency type III BL cells. Expression of LMP1 in P3HR1 cells upregulates miR-146a levels. Neither miR-146a nor miR-155 are detectable in BCBL-1 cells transformed by the Kaposi-Sarcoma Herpes virus (KSHV/HHV8). It is possible that the induction of miR-146a plays a role in the induction or maintenance of EBV latency by modulating innate immune responses to the virus infected host cell.
- Published
- 2007
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482. Collapse of the N=28 shell closure in (42)Si.
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Bastin B, Grévy S, Sohler D, Sorlin O, Dombrádi Z, Achouri NL, Angélique JC, Azaiez F, Baiborodin D, Borcea R, Bourgeois C, Buta A, Bürger A, Chapman R, Dalouzy JC, Dlouhy Z, Drouard A, Elekes Z, Franchoo S, Iacob S, Laurent B, Lazar M, Liang X, Liénard E, Mrazek J, Nalpas L, Negoita F, Orr NA, Penionzhkevich Y, Podolyák Z, Pougheon F, Roussel-Chomaz P, Saint-Laurent MG, Stanoiu M, Stefan I, Nowacki F, and Poves A
- Abstract
The energies of the excited states in very neutron-rich (42)Si and (41,43)P have been measured using in-beam gamma-ray spectroscopy from the fragmentation of secondary beams of (42,44)S at 39A MeV. The low 2(+) energy of (42)Si, 770(19) keV, together with the level schemes of (41,43)P, provides evidence for the disappearance of the Z=14 and N=28 spherical shell closures, which is ascribed mainly to the action of proton-neutron tensor forces. New shell model calculations indicate that (42)Si is best described as a well-deformed oblate rotor.
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- 2007
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483. Predicting gene expression levels from codon biases in alpha-proteobacterial genomes.
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Karlin S, Barnett MJ, Campbell AM, Fisher RF, and Mrazek J
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- Agrobacterium tumefaciens genetics, Agrobacterium tumefaciens metabolism, Alphaproteobacteria metabolism, Base Composition, Brucella melitensis genetics, Brucella melitensis metabolism, Caulobacter crescentus genetics, Caulobacter crescentus metabolism, Citric Acid Cycle genetics, DNA, Bacterial chemistry, DNA, Bacterial genetics, Energy Metabolism genetics, Flagella genetics, Gene Expression, Inactivation, Metabolic genetics, Multigene Family, Nitrogen Fixation genetics, Sinorhizobium meliloti genetics, Sinorhizobium meliloti metabolism, Species Specificity, Alphaproteobacteria genetics, Codon genetics, Genome, Bacterial
- Abstract
Predicted highly expressed (PHX) genes in five currently available high G+C complete alpha-proteobacterial genomes are analyzed. These include: the nitrogen-fixing plant symbionts Sinorhizobium meliloti (SINME) and Mesorhizobium loti (MESLO), the nonpathogenic aquatic bacterium Caulobacter crescentus (CAUCR), the plant pathogen Agrobacterium tumefaciens (AGRTU), and the mammalian pathogen Brucella melitensis (BRUME). Three of these genomes, SINME, AGRTU, and BRUME, contain multiple chromosomes or megaplasmids (>1 Mb length). PHX genes in these genomes are concentrated mainly in the major (largest) chromosome with few PHX genes found in the secondary chromosomes and megaplasmids. Tricarboxylic acid cycle and aerobic respiration genes are strongly PHX in all five genomes, whereas anaerobic pathways of glycolysis and fermentation are mostly not PHX. Only in MESLO (but not SINME) and BRUME are most glycolysis genes PHX. Many flagellar genes are PHX in MESLO and CAUCR, but mostly are not PHX in SINME and AGRTU. The nonmotile BRUME also carries many flagellar genes but these are generally not PHX and all but one are located in the second chromosome. CAUCR stands out among available prokaryotic genomes with 25 PHX TonB-dependent receptors. These are putatively involved in uptake of iron ions and other nonsoluble compounds.
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- 2003
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484. New technology may reveal mechanisms of radiation resistance in Deinococcus radiodurans.
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Mrazek J
- Subjects
- Bacteria genetics, DNA, Bacterial genetics, DNA, Bacterial radiation effects, RNA, Bacterial genetics, RNA, Bacterial radiation effects, RNA, Ribosomal, 5S genetics, RNA, Ribosomal, 5S radiation effects, Bacteria radiation effects, Radiation Tolerance
- Published
- 2002
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485. Amino acid runs in eukaryotic proteomes and disease associations.
- Author
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Karlin S, Brocchieri L, Bergman A, Mrazek J, and Gentles AJ
- Subjects
- Animals, Asparagine chemistry, Glutamine chemistry, Humans, Leucine chemistry, Serine chemistry, Species Specificity, Transcription, Genetic, Arabidopsis genetics, Caenorhabditis elegans genetics, Drosophila melanogaster genetics, Genome, Genome, Human, Saccharomyces cerevisiae genetics
- Abstract
We present a comparative proteome analysis of the five complete eukaryotic genomes (human, Drosophila melanogaster, Caenorhabditis elegans, Saccharomyces cerevisiae, Arabidopsis thaliana), focusing on individual and multiple amino acid runs, charge and hydrophobic runs. We found that human proteins with multiple long runs are often associated with diseases; these include long glutamine runs that induce neurological disorders, various cancers, categories of leukemias (mostly involving chromosomal translocations), and an abundance of Ca(2 +) and K(+) channel proteins. Many human proteins with multiple runs function in development and/or transcription regulation and are Drosophila homeotic homologs. A large number of these proteins are expressed in the nervous system. More than 80% of Drosophila proteins with multiple runs seem to function in transcription regulation. The most frequent amino acid runs in Drosophila sequences occur for glutamine, alanine, and serine, whereas human sequences highlight glutamate, proline, and leucine. The most frequent runs in yeast are of serine, glutamine, and acidic residues. Compared with the other eukaryotic proteomes, amino acid runs are significantly more abundant in the fly. This finding might be interpreted in terms of innate differences in DNA-replication processes, repair mechanisms, DNA-modification systems, and mutational biases. There are striking differences in amino acid runs for glutamine, asparagine, and leucine among the five proteomes.
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- 2002
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486. Predicted highly expressed and putative alien genes of Deinococcus radiodurans and implications for resistance to ionizing radiation damage.
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Karlin S and Mrazek J
- Subjects
- Chromosomes, Bacterial genetics, Codon genetics, DNA Damage genetics, DNA Repair genetics, Desiccation, Endopeptidases metabolism, Escherichia coli enzymology, Escherichia coli genetics, Genetic Code genetics, Molecular Chaperones metabolism, Multigene Family genetics, Physical Chromosome Mapping, Radiation, Ionizing, Thermus enzymology, Thermus metabolism, Ultraviolet Rays, DNA Damage radiation effects, Genes, Bacterial genetics, Radiation Tolerance genetics, Thermus genetics, Thermus radiation effects
- Abstract
Predicted highly expressed (PHX) and putative alien genes determined by codon usages are characterized in the genome of Deinococcus radiodurans (strain R1). Deinococcus radiodurans (DEIRA) can survive very high doses of ionizing radiation that are lethal to virtually all other organisms. It has been argued that DEIRA is endowed with enhanced repair systems that provide protection and stability. However, predicted expression levels of DNA repair proteins with the exception of RecA tend to be low and do not distinguish DEIRA from other prokaryotes. In this paper, the capability of DEIRA to resist extreme doses of ionizing and UV radiation is attributed to an unusually high number of PHX chaperone/degradation, protease, and detoxification genes. Explicitly, compared with all current complete prokaryotic genomes, DEIRA contains the greatest number of PHX detoxification and protease proteins. Other sources of environmental protection against severe conditions of UV radiation, desiccation, and thermal effects for DEIRA are the several S-layer (surface structure) PHX proteins. The top PHX gene of DEIRA is the multifunctional tricarboxylic acid (TCA) gene aconitase, which, apart from its role in respiration, also alerts the cell to oxidative damage.
- Published
- 2001
- Full Text
- View/download PDF
487. [Real and ideal self-concept of cardiovascular patients (author's transl)].
- Author
-
Mrazek J, Rittner V, Hoppe R, and Baedke D
- Subjects
- Adult, Aged, Educational Status, Female, Humans, Male, Middle Aged, Myocardial Infarction psychology, Personality Inventory, Reality Testing, Cardiovascular Diseases psychology, Self Concept
- Published
- 1979
488. [Subjective perception of myocardial infarct and its causes].
- Author
-
Mrazek J, Rittner V, Seer P, and Weidemann H
- Subjects
- Adaptation, Psychological, Humans, Male, Middle Aged, Risk, Attitude to Health, Life Style, Myocardial Infarction psychology
- Published
- 1983
489. [Coronary risk factors and their relation to psychosocial factors in females with myocardial infarct].
- Author
-
Meyer K, Weidemann H, Kokott HJ, Mrazek J, and Rittner V
- Subjects
- Adult, Aged, Contraceptives, Oral adverse effects, Female, Humans, Hyperlipoproteinemias complications, Middle Aged, Risk Factors, Sex Factors, Smoking adverse effects, Coronary Disease psychology, Life Style, Myocardial Infarction psychology, Stress, Psychological complications
- Abstract
Unlabelled: 237 female patients aged 31-76 years with documented first myocardial infarction were examined on an average of 3 month after the acute event. Risk factors of coronary heart disease, sociobiological and psychosocial variables were assessed via standardized questionnaire. Risk factors were correlated with social characteristics, somatic and psychosocial variables., Results: 1. Hyperlipoproteinemia is correlated with risk factors of nutrition (hypercholesterinemia resp. hypertriglyceridemia, obesity). 2. The analysis of smoking habits reveals a positive correlation with social characteristics (e.g. professional status) and also with the amount of experienced stress. 3. The use of oral contraceptives corresponded with young age of fertile women and also with professional status. Furthermore a correlation with a positive working attitude and smoking behavior was found.
- Published
- 1988
- Full Text
- View/download PDF
490. [Severe chorea gravidarum cured by corticotropin, reserpine and chlorpromazine].
- Author
-
DUBANSKY B, MRAZEK J, and HEKELOVA J
- Subjects
- Female, Humans, Pregnancy, Adrenocorticotropic Hormone therapy, Chlorpromazine therapy, Chorea, Chorea Gravidarum, Pregnancy Complications, Reserpine therapy
- Published
- 1960
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