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1.
Front Immunol ; 14: 1170759, 2023.
Article En | MEDLINE | ID: mdl-37180152

Background: Recent data on immune evasion of new SARS-CoV-2 variants raise concerns about the efficacy of antibody-based COVID-19 therapies. Therefore, in this study the in-vitro neutralization capacity against SARS-CoV-2 variant B.1 and the Omicron subvariants BA.1, BA.2 and BA.5 of sera from convalescent individuals with and without boost by vaccination was assessed. Methods and findings: The study included 313 serum samples from 155 individuals with a history of SARS-CoV-2 infection, divided into subgroups without (n=25) and with SARS-CoV-2 vaccination (n=130). We measured anti-SARS-CoV-2 antibody concentrations by serological assays (anti-SARS-CoV-2-QuantiVac-ELISA (IgG) and Elecsys Anti-SARS-CoV-2 S) and neutralizing titers against B.1, BA.1, BA.2 and BA.5 in a pseudovirus neutralization assay. Sera of the majority of unvaccinated convalescents did not effectively neutralize Omicron sublineages BA.1, BA.2 and BA.5 (51.7%, 24.1% and 51.7%, resp.). In contrast, 99.3% of the sera of superimmunized individuals (vaccinated convalescents) neutralized the Omicron subvariants BA.1 and BA.5 and 99.6% neutralized BA.2. Neutralizing titers against B.1, BA.1, BA.2 and BA.5 were significantly higher in vaccinated compared to unvaccinated convalescents (p<0.0001) with 52.7-, 210.7-, 141.3- and 105.4-fold higher geometric mean of 50% neutralizing titers (NT50) in vaccinated compared to unvaccinated convalescents. 91.4% of the superimmunized individuals showed neutralization of BA.1, 97.2% of BA.2 and 91.5% of BA.5 with a titer ≥ 640. The increase in neutralizing titers was already achieved by one vaccination dose. Neutralizing titers were highest in the first 3 months after the last immunization event. Concentrations of anti-S antibodies in the anti-SARS-CoV-2-QuantiVac-ELISA (IgG) and Elecsys Anti-SARS-CoV-2 S assays predicted neutralization capacity against B.1 and Omicron subvariants BA.1, BA.2 and BA.5. Conclusions: These findings confirm substantial immune evasion of the Omicron sublineages, which can be overcome by vaccination of convalescents. This informs strategies for choosing of plasma donors in COVID-19 convalescent plasma programs that shall select specifically vaccinated convalescents with very high titers of anti-S antibodies.


COVID-19 , SARS-CoV-2 , Humans , COVID-19 Vaccines , COVID-19/prevention & control , COVID-19 Serotherapy , Vaccination , Antibodies, Viral , Immunoglobulin G
2.
BMJ Open ; 13(4): e071277, 2023 04 27.
Article En | MEDLINE | ID: mdl-37105693

INTRODUCTION: COVID-19 convalescent plasma (CCP) is a possible treatment option for COVID-19. A comprehensive number of clinical trials on CCP efficacy have already been conducted. However, many aspects of CCP treatment still require investigations: in particular (1) Optimisation of the CCP product, (2) Identification of the patient population in need and most likely to benefit from this treatment approach, (3) Timing of administration and (4) CCP efficacy across viral variants in vivo. We aimed to test whether high-titre CCP, administered early, is efficacious in preventing hospitalisation or death in high-risk patients. METHODS AND ANALYSIS: COVIC-19 is a multicentre, randomised, open-label, adaptive superiority phase III trial comparing CCP with very high neutralising antibody titre administered within 7 days of symptom onset plus standard of care versus standard of care alone. We will enrol patients in two cohorts of vulnerable patients [(1) elderly 70+ years, or younger with comorbidities; (2) immunocompromised patients]. Up to 1020 participants will be enrolled in each cohort (at least 340 with a sample size re-estimation after reaching 102 patients). The primary endpoint is the proportion of participants with (1) Hospitalisation due to progressive COVID-19, or (2) Who died by day 28 after randomisation. Principal analysis will follow the intention-to-treat principle. ETHICS AND DISSEMINATION: Ethical approval has been granted by the University of Ulm ethics committee (#41/22) (lead ethics committee for Germany), Comité de protection des personnes Sud-Est I (CPP Sud-Est I) (#2022-A01307-36) (ethics committee for France), and ErasmusMC ethics committee (#MEC-2022-0365) (ethics committee for the Netherlands). Signed informed consent will be obtained from all included patients. The findings will be published in peer-reviewed journals and presented at relevant stakeholder conferences and meetings. TRIAL REGISTRATION: Clinical Trials.gov (NCT05271929), EudraCT (2021-006621-22).


COVID-19 , Humans , Aged , COVID-19/therapy , SARS-CoV-2 , COVID-19 Serotherapy , Hospitalization , Immunization, Passive/methods , Treatment Outcome , Randomized Controlled Trials as Topic , Multicenter Studies as Topic
3.
Hamostaseologie ; 43(1): 67-74, 2023 Feb.
Article En | MEDLINE | ID: mdl-36807822

COVID-19 convalescent plasma (CCP) has been explored as one of the treatment options for COVID-19. Results of many cohort studies and clinical trials have been recently published. At first glance, the results of the CCP studies appear to be inconsistent. However, it became clear that CCP is not beneficial if CCP with low anti-SARS-CoV-2 antibody concentrations is used, if it is administered late in advanced disease stages, and to patients who already mounted an antibody response against SARS-CoV-2 at the time of CCP transfusion. On the other hand, CCP may prevent progression to severe COVID-19 when very high-titer CCP is given early in vulnerable patients. Immune escape of new variants is a challenge for passive immunotherapy. While new variants of concern developed resistance to most clinically used monoclonal antibodies very rapidly, immune plasma from individuals immunized by both a natural SARS-CoV-2 infection and SARS-CoV-2 vaccination retained neutralizing activity against variants. This review briefly summarizes the evidence on CCP treatment to date and identifies further research needs. Ongoing research on passive immunotherapy is not only relevant for improving care for vulnerable patients in the ongoing SARS-CoV-2 pandemic, but even more as a model for passive immunotherapy in case of future pandemics with a newly evolving pathogen. Compared to other drugs, which must be newly developed in a pandemic (e.g., monoclonal antibodies, antiviral drugs), convalescent plasma is rapidly available, inexpensive to produce, and can be adaptive to viral evolution by selection of contemporary convalescent donors.


COVID-19 , Humans , SARS-CoV-2/physiology , COVID-19 Vaccines , COVID-19 Serotherapy , Antibodies, Monoclonal
4.
Philos Trans R Soc Lond B Biol Sci ; 377(1847): 20210042, 2022 03 28.
Article En | MEDLINE | ID: mdl-35125007

Here we report on a new Early Cretaceous eutherian represented by a partial skeleton from the Jiufotang Formation at Sihedang site, Lingyuan City, Liaoning Province that fills a crucial gap between the earliest eutherians from the Yixian Formation and later Cretaceous eutherians. The new specimen reveals, to our knowledge for the first time in eutherians, that the Meckelian cartilage was ossified but reduced in size, confirming a complete detachment of the middle ear from the lower jaw. Seven hyoid elements, including paired stylohyals, epihyals and thyrohyals and the single basihyal are preserved. For the inner ear the ossified primary lamina, base of the secondary lamina, ossified cochlear ganglion and secondary crus commune are present and the cochlear canal is coiled through 360°. In addition, plesiomorphic features of the dentition include weak conules, lack of pre- and post-cingula and less expanded protocones on the upper molars and height differential between the trigonid and talonid, a large protoconid and a small paraconid on the lower molars. The new taxon displays an alternating pattern of tooth replacement with P3 being the last upper premolar to erupt similar to the basal eutherian Juramaia. Parsimony analysis places the new taxon with Montanalestes, Sinodelphys and Ambolestes as a sister group to other eutherians. This article is part of the theme issue 'The impact of Chinese palaeontology on evolutionary research'.


Eutheria , Fossils , Animals , Biota , Mammals , Phylogeny
5.
J Mamm Evol ; 28(4): 1083-1143, 2021.
Article En | MEDLINE | ID: mdl-34924738

Taeniolabis taoensis is an iconic multituberculate mammal of early Paleocene (Puercan 3) age from the Western Interior of North America. Here we report the discovery of significant new skull material (one nearly complete cranium, two partial crania, one nearly complete dentary) of T. taoensis in phosphatic concretions from the Corral Bluffs study area, Denver Formation (Danian portion), Denver Basin, Colorado. The new skull material provides the first record of the species from the Denver Basin, where the lowest in situ specimen occurs in river channel deposits ~730,000 years after the Cretaceous-Paleogene boundary, roughly coincident with the first appearance of legumes in the basin. The new material, in combination with several previously described and undescribed specimens from the Nacimiento Formation of the San Juan Basin, New Mexico, is the subject of detailed anatomical study, aided by micro-computed tomography. Our analyses reveal many previously unknown aspects of skull anatomy. Several regions (e.g., anterior portions of premaxilla, orbit, cranial roof, occiput) preserved in the Corral Bluffs specimens allow considerable revision of previous reconstructions of the external cranial morphology of T. taoensis. Similarly, anatomical details of the ascending process of the dentary are altered in light of the new material. Although details of internal cranial anatomy (e.g., nasal and endocranial cavities) are difficult to discern in the available specimens, we provide, based on UCMP 98083 and DMNH.EPV 95284, the best evidence to date for inner ear structure in a taeniolabidoid multituberculate. The cochlear canal of T. taoensis is elongate and gently curved and the vestibule is enlarged, although to a lesser degree than in Lambdopsalis.

6.
Nature ; 590(7845): 224-226, 2021 02.
Article En | MEDLINE | ID: mdl-33505000
7.
Nature ; 581(7809): 421-427, 2020 05.
Article En | MEDLINE | ID: mdl-32461642

The fossil record of mammaliaforms (mammals and their closest relatives) of the Mesozoic era from the southern supercontinent Gondwana is far less extensive than that from its northern counterpart, Laurasia1,2. Among Mesozoic mammaliaforms, Gondwanatheria is one of the most poorly known clades, previously represented by only a single cranium and isolated jaws and teeth1-5. As a result, the anatomy, palaeobiology and phylogenetic relationships of gondwanatherians remain unclear. Here we report the discovery of an articulated and very well-preserved skeleton of a gondwanatherian of the latest age (72.1-66 million years ago) of the Cretaceous period from Madagascar that we assign to a new genus and species, Adalatherium hui. To our knowledge, the specimen is the most complete skeleton of a Gondwanan Mesozoic mammaliaform that has been found, and includes the only postcranial material and ascending ramus of the dentary known for any gondwanatherian. A phylogenetic analysis including the new taxon recovers Gondwanatheria as the sister group to Multituberculata. The skeleton, which represents one of the largest of the Gondwanan Mesozoic mammaliaforms, is particularly notable for exhibiting many unique features in combination with features that are convergent on those of therian mammals. This uniqueness is consistent with a lineage history for A. hui of isolation on Madagascar for more than 20 million years.


Fossils , Islands , Mammals/anatomy & histology , Mammals/classification , Phylogeny , Skeleton/anatomy & histology , Animals , Dentition , Madagascar , Skull/anatomy & histology
8.
Science ; 365(6450): 222-223, 2019 07 19.
Article En | MEDLINE | ID: mdl-31320523
9.
Front Neuroanat ; 12: 32, 2018.
Article En | MEDLINE | ID: mdl-29867373

The degree to which molecular and morphological loss of function occurs synchronously during the vestigialization of traits is not well understood. The mammalian vomeronasal system, a sense critical for mediating many social and reproductive behaviors, is highly conserved across mammals. New World Leaf-nosed bats (Phyllostomidae) are under strong selection to maintain a functional vomeronasal system such that most phyllostomids possess a distinct vomeronasal organ and an intact TRPC2, a gene encoding a protein primarily involved in vomeronasal sensory neuron signal transduction. Recent genetic evidence, however, shows that TRPC2 is a pseudogene in some Caribbean nectarivorous phyllostomids. The loss-of-function mutations suggest the sensory neural tissue of the vomeronasal organ is absent in these species despite strong selection on this gene in its mainland relatives, but the anatomy was unknown in most Caribbean nectarivorous phyllostomids until this study. We used diffusible iodine-based contrast-enhanced computed tomography (diceCT) to test whether the vomeronasal and main olfactory anatomy of several phyllostomid species matched genetic evidence of function, providing insight into whether loss of a structure is linked to pseudogenization of a molecular component of the system. The vomeronasal organ is indeed rudimentary or absent in species with a disrupted TRPC2 gene. Caribbean nectar-feeders also exhibit derived olfactory turbinal morphology and a large olfactory recess that differs from closely related bats that have an intact vomeronasal organ, which may hint that the main olfactory system may compensate for loss. We emphasize non-invasive diceCT is capable of detecting the vomeronasal organ, providing a feasible approach for quantifying mammalian chemosensory anatomy across species.

10.
Nature ; 558(7708): 32-33, 2018 06.
Article En | MEDLINE | ID: mdl-29872180
11.
Nature ; 515(7528): 512-7, 2014 Nov 27.
Article En | MEDLINE | ID: mdl-25383528

Previously known only from isolated teeth and lower jaw fragments recovered from the Cretaceous and Palaeogene of the Southern Hemisphere, the Gondwanatheria constitute the most poorly known of all major mammaliaform radiations. Here we report the discovery of the first skull material of a gondwanatherian, a complete and well-preserved cranium from Upper Cretaceous strata in Madagascar that we assign to a new genus and species. Phylogenetic analysis strongly supports its placement within Gondwanatheria, which are recognized as monophyletic and closely related to multituberculates, an evolutionarily successful clade of Mesozoic mammals known almost exclusively from the Northern Hemisphere. The new taxon is the largest known mammaliaform from the Mesozoic of Gondwana. Its craniofacial anatomy reveals that it was herbivorous, large-eyed and agile, with well-developed high-frequency hearing and a keen sense of smell. The cranium exhibits a mosaic of primitive and derived features, the disparity of which is extreme and probably reflective of a long evolutionary history in geographic isolation.


Fossils , Mammals , Phylogeny , Skull/anatomy & histology , Animals , Herbivory , Mosaicism , Species Specificity , Tooth/anatomy & histology
12.
J Food Sci ; 79(6): M1175-80, 2014 Jun.
Article En | MEDLINE | ID: mdl-24917424

UNLABELLED: This study evaluated the genetic similarity and prevalence of the stx1, stx2, eae, and ehxA genes in Escherichia coli isolated from pasteurized cow milk. Eighty-seven E. coli isolates from pasteurized cow milk from 22 dairies located in northwestern Paraná state, Brazil, were analyzed. Genetic similarity was evaluated using enterobacterial repetitive intergenic consensus sequence polymerase chain reaction (ERIC-PCR) and repetitive extragenic palindromic sequence PCR (REP-PCR). E. coli isolates were also analyzed by PCR to investigate the presence of the stx1, stx2, eae, and ehxA genes. ERIC-PCR and REP-PCR clustered 87 bacterial isolates in 76 and 81 genomic profiles, respectively. Both techniques revealed high genetic diversity among the E. coli isolates, confirming the possibility of their use in epidemiological studies. The stx1, stx2, eae, and ehxA virulence genes were not detected in E. coli isolates, indicating a low prevalence of Shiga toxin-producing E. coli in milk produced in the region studied. PRACTICAL APPLICATION: Knowledge about the presence of diarrheagenic Escherichia coli in pasteurized milk is important developing and implementing control measures in milk and dairy production.


Escherichia coli/genetics , Food Microbiology , Genes, Bacterial , Genetic Variation , Milk/microbiology , Shiga Toxin/genetics , Virulence Factors/genetics , Adhesins, Bacterial/genetics , Animals , Brazil , Cattle , Escherichia coli/isolation & purification , Escherichia coli/pathogenicity , Escherichia coli Infections/microbiology , Escherichia coli Infections/prevention & control , Escherichia coli Proteins/genetics , Female , Humans , Pasteurization , Polymerase Chain Reaction/methods , Shiga-Toxigenic Escherichia coli/genetics , Shiga-Toxigenic Escherichia coli/isolation & purification , Shiga-Toxigenic Escherichia coli/pathogenicity , Virulence
13.
Ann Thorac Surg ; 96(5): 1567-73, 2013 Nov.
Article En | MEDLINE | ID: mdl-24011623

BACKGROUND: The Ross procedure is an established option for aortic valve replacement in young patients. It does, however, involve implantation of a valved conduit in the pulmonary position and dissection in the right ventricular (RV) myocardium with the possibility of RV impairment. Aortic valve reconstruction (AVr) may avoid the drawbacks of this method. METHODS: To assess ventricular performance, 2-dimensional (2D) echocardiography and longitudinal strain analysis were performed in 19 patients after a Ross procedure and 19 patients after AVr and compared with 19 age-matched healthy controls. RESULTS: Left ventricular (LV) volumes were significantly increased in both patient groups compared with controls (p < 0.05). Right ventricular (RV) volumes were significantly elevated in the Ross group compared with the AVr group (p < 0.05) and controls (p < 0.01). Peak longitudinal LV strain was significantly reduced in the Ross group (-14.8% ± 4.7%) compared with the AVr group (-18.8% ± 2.5%; p = 0.003) and healthy controls (-20.2% ± 3.9%; p = 0.001). Peak longitudinal RV strain was also significantly reduced in the Ross group (-21.8% ± 4.8%) compared with the AVr group (-25.1% ± 2.5%; p = 0.02) and healthy controls (-26.5% ± 3.2%; p = 0.003). Reduced RV strain was associated with increased pressure gradients of the pulmonary substitute (r = 0.48; p = 0.04) but not with follow-up time, RV volumes, or RV ejection fraction (EF). CONCLUSIONS: Elevation of LV volumes can still be noticed in patients years after the Ross operation or AVr. Increased RV volumes and a reduced RV longitudinal strain are found after the Ross operation, indicating persistent systolic RV dysfunction even in patients with mild RV pressure overload.


Aortic Valve/surgery , Heart Valve Prosthesis Implantation/methods , Heart Ventricles/diagnostic imaging , Ventricular Function , Adolescent , Adult , Cardiac Surgical Procedures/methods , Child , Female , Humans , Male , Middle Aged , Ultrasonography , Young Adult
14.
J Vasc Surg ; 53(6): 1528-33, 2011 Jun.
Article En | MEDLINE | ID: mdl-21609796

OBJECTIVES: To report incidence, indication, and timing of reinterventions after thoracic endovascular aortic repair (TEVAR) and identify subgroups most prone to reinterventions. METHODS: Between January 1997 and March 2010, a total of 264 patients received TEVAR in our institution. During follow-up, 58 patients (39 men, median age 63 years, range 28-87 years) required a total of 68 reinterventions, which represent the study population of this retrospective, single center analysis. The mean follow-up of all 264 patients was 31.2 months (range 0-141 months). RESULTS: The overall reintervention rate was 22%: 1-, 3-, and 5-year free reintervention rates were 82% ± 3%, 74% ± 3%, and 70% ± 4%, respectively. Indications for reintervention were predominately endoleaks (41%) and progression of the underlying aortic disease (29%). Reinterventions were performed by endovascular means in 44%, by open repair in 35% (including 11 conversions), and by hybrid procedures in 21%. Multiple logistic regression analysis revealed patients with chronic expanding aortic dissections (odds ratio [OR]: 2.35), hybrid aortic procedures (OR: 2.11), and connective tissue diseases (OR: 7.54) at an increased risk for reintervention. The necessity for reintervention did not influence survival in this cohort (log-rank test P = .1706). CONCLUSIONS: TEVAR is associated with a relevant reintervention rate, predominately caused by endoleaks and progression of the aortic pathology. Patients with chronic expanding aortic dissections, hybrid aortic procedures, and connective tissue diseases are at an increased risk for reintervention and should therefore undergo close follow-up.


Aortic Diseases/surgery , Blood Vessel Prosthesis Implantation , Adult , Aged , Aged, 80 and over , Aorta, Thoracic/surgery , Aortic Aneurysm, Thoracic/surgery , Female , Humans , Incidence , Male , Middle Aged , Reoperation , Retrospective Studies
15.
Circ Res ; 100(1): 140-6, 2007 Jan 05.
Article En | MEDLINE | ID: mdl-17170366

In patients with unstable angina, plaque rupture and coronary microembolization (ME) can precede complete coronary artery occlusion and impending infarction. ME-induced microinfarcts initiate an inflammatory reaction with increased tumor necrosis factor-alpha (TNF-alpha) expression, resulting in progressive contractile dysfunction. However, TNF-alpha is not only a negative inotrope but can also protect the myocardium against infarction. In anesthetized pigs, we studied whether ME protects against infarction when TNF-alpha expression is increased. ME (group1; n=7) was induced by intracoronary infusion of microspheres (42 microm; 3000 per mL/min inflow). Controls (group 2; n=8) received saline. Groups 3 and 4 (n=4 each) were pretreated with ovine TNF-alpha antibodies (25 mg/kg body weight) 30 minutes before ME or placebo, respectively. Ischemia (90 minutes) was induced 6 hours after ME when TNF-alpha was increased (66+/-21 pg/g wet weight; mean+/-SEM) or after placebo (TNF-alpha, 21+/-10 pg/g; P<0.05). Infarct size (percentage area at risk) was determined after 2 hours of reperfusion (triphenyl tetrazolium chloride staining). ME decreased systolic wall thickening progressively over 6 hours (group 1 versus group 2, 65+/-4% versus 90+/-1%; percentage of baseline; P<0.05). TNF-alpha antibodies attenuated the progressive decrease in systolic wall thickening following ME (group 3, 77+/-5% of baseline; P<0.05 versus group 1) with no effect in controls (group 4; 90+/-8% of baseline). With ME, infarct size was decreased to 18+/-4% versus 33+/-4% in group 2 (P<0.05). The infarct size reduction was abolished by TNF-alpha antibodies (group 3 versus group 4, 29+/-3% versus 35+/-5%). In ME, TNF-alpha is responsible for both progressive contractile dysfunction and delayed protection against infarction.


Cardiotonic Agents/metabolism , Coronary Disease/physiopathology , Embolism/physiopathology , Myocardial Contraction , Myocardial Infarction/prevention & control , Tumor Necrosis Factor-alpha/metabolism , Animals , Antibodies/pharmacology , Coronary Disease/etiology , Coronary Disease/metabolism , Embolism/etiology , Embolism/metabolism , Heart/drug effects , Heart/physiopathology , Microspheres , Myocardial Infarction/etiology , Myocardial Infarction/pathology , Myocardial Reperfusion Injury/complications , Myocardium/metabolism , Myocardium/pathology , Swine , Swine, Miniature , Systole , Time Factors , Tumor Necrosis Factor-alpha/immunology
16.
Article De | MEDLINE | ID: mdl-15985776

BACKGROUND: Patients with M. Crohn or colitis ulcerosa live with a chronic disease. Pharmaceuticals used in convention-al medicine have been proven to be effective but can have strong side-effects. Thus, it is no surprise that affected patients are very interested in complementary and alternative medicine (CAM). OBJECTIVE: The aim of our survey was to investigate the use and the application of CAM by patients with M. Crohn and colitis ulcerosa in Switzerland. PATIENTS AND METHODS: Out-patients of the gastroenterological centre at the University Hospital Bern and of two gastroenterological private practices in a medium-sized city completed a self-administered questionnaire on CAM. Demographic variables, disease-related data, use of different approaches of complementary medicine, attitudes towards and the use of CAM were asked for. RESULTS: Out of 204 mailed questionnaires 71% (144) could be evaluated, 44% from patients of the University Hospital, 56% from patients of the gastroenterological private practices. CAM was used by 47% of the patients. The most commonly used methods of CAM were: homeopathy, traditional Chinese medicine and acupuncture. 67% of the patients benefitted by CAM in the long run, whereas 10.5% suffered a relapse of their disease during CAM therapies. The main reason for the patients to apply to CAM was to complement conventional treatment. CONCLUSION: Our survey points out that the studied out-patients have a strong interest in CAM. It is therefore important that clinical research in the various unconventional therapies will be further promoted.


Colitis, Ulcerative/therapy , Complementary Therapies , Crohn Disease/therapy , Gastroenterology , Humans , Surveys and Questionnaires , Switzerland
17.
Free Radic Biol Med ; 36(6): 765-73, 2004 Mar 15.
Article En | MEDLINE | ID: mdl-14990355

The mitochondrial electron transport chain (ETC) is the most important source of reactive oxygen species (ROS) in mammalian cells. To assess its relevance to the endogenous generation of oxidative DNA damage in the nucleus, we have compared the background (steady-state) levels of oxidative DNA base modifications sensitive to the repair glycosylase Fpg (mostly 7,8-dihydro-8-oxoguanine) in wild-type HeLa cells and HeLa rho0 cells. The latter are depleted of mitochondrial DNA and therefore are unable to produce ROS in the ETC. Although the levels of ROS measured by flow cytometry and redox-sensitive probes in rho0 cells were only 10-15% those of wild-type cells, steady-state levels of oxidative DNA base modifications were the same as in wild-type cells. Mitochondrial generation of ROS was then stimulated in HeLa wild-type cells using inhibitors interfering with the ETC. Although mitochondrial ROS production was raised up to 6-fold, none of the substances nor their combinations induced additional oxidative base modifications in the nuclear DNA. This was also true for glutathione-depleted cells. The results indicate that the contribution of mitochondria to the endogenously generated background levels of oxidative damage in the nuclear DNA is negligible.


Cell Nucleus/metabolism , DNA Damage , DNA/metabolism , Guanosine/analogs & derivatives , Mitochondria/metabolism , Reactive Oxygen Species/metabolism , Animals , Carbonyl Cyanide m-Chlorophenyl Hydrazone/metabolism , Carbonyl Cyanide m-Chlorophenyl Hydrazone/pharmacology , Cells/chemistry , Cells/metabolism , DNA Damage/drug effects , DNA-Formamidopyrimidine Glycosylase/metabolism , Electron Transport , Escherichia coli Proteins/metabolism , Flow Cytometry , Guanosine/chemistry , Guanosine/metabolism , HeLa Cells , Humans , Macrolides/metabolism , Macrolides/pharmacology , Nucleotides/chemistry , Nucleotides/metabolism , Oxidation-Reduction
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