Magdalena Holter

Dr. Magdalena Holter

orcid

Research Focus & Metrics

Academic Career Length

8Years (2019-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

View All Publications
9 September 2020 in Journal of Nanobiotechnology
Verified
Journal Article
Open access
PDF file
MGMichael M. Gruber
Michael M. Gruber
BHBirgit Hirschmugl
Birgit Hirschmugl
NBNatascha Berger
Natascha Berger
MHMagdalena Holter
Magdalena Holter
SRSnjezana Radulovic
Snjezana Radulovic
Christian WadsackChristian Wadsack
Christian Wadsack
Background: Nanoparticles, which are exposed to biological fluids are rapidly interacting with proteins and other biomolecules forming a corona. In addition to dimension, charge and material the distinct protein corona influences the interplay of nanoparticles with tissue barriers. In this study we were focused on the impact of in situ formed human plasma protein corona on the transfer of 80 nm polystyrene nanoparticles (PS-particles) across the human placenta. To study materno-to fetal PS transfer we used the human ex vivo placental perfusion approach, which represents an intact and physiological tissue barrier. To analyze the protein corona of PS particles we performed shotgun proteomics of isolated nanoparticles before and after tissue exposure. Results: Human plasma incubated with PS-particles of 80 nm and subsequent formed protein corona enhanced the transfer across the human placenta compared to PS-corona formed by bovine serum albumin and dextran which served as a control. Quantitative and qualitative changes of plasma proteins determined the changes in PS transfer across the barrier. Based on the analysis of the PS-proteome two candidate proteins, namely human albumin and immunoglobulin G were tested if these proteins may account for the enhanced PS-transfer across the placenta. Interestingly, the protein corona formed by human albumin significantly induced the transfer of PS-particles across the tissue compared to the formed IgG-corona. Conclusion: In total we demonstrate the PS corona dynamically and significantly evolves upon crossing the human placenta. Thus, the initial composition of PS particles in the maternal circulation is not predictive for their transfer characteristics and performance once beyond the barrier of the placenta. The precise mechanism of these effects remains to be elucidated but highlights the importance of using well designed biological models when testing nanoparticles for biomedical applications.

7 December 2021 in Antioxidants
Verified
Journal Article
Open access
PDF file
HMHarald Mangge
Harald Mangge
Markus HerrmannMarkus Herrmann
Markus Herrmann
AMAndreas Meinitzer
Andreas Meinitzer
SPSabine Pailer
Sabine Pailer
PCPero Curcic
Pero Curcic
FPFlorian Prüller
Florian Prüller
(1) Background: An inefficient immune response accompanied by an overwhelming inflammatory reaction is involved in severe courses of COVID-19. Kynurenine (KYN) has important immune-modulatory functions and may contribute to a failure in controlling SARS-CoV-2. The present study aims to explore biomarkers that hint at a fatal outcome of COVID-19 early on. (2) Methods: We established a cohort of 148 hospitalized COVID-19 patients for this study. Thirty-one patients died due to a severe COVID-19 course, and 117 recovered within 90 days. We built a biobank by collecting left-over material from these patients whenever blood arrived at the central laboratory of our University hospital for analysis of routine markers. The scientific laboratory analysis comprised KYN, Tryptophan (TRP), KYN/TRP ratio, ferritin, interleukin-6 (IL-6), C-reactive protein (CRP), creatinine, N-terminal pro-natriuretic peptide (NTproBNP), troponin T (TnT), fibrinogen, D-Dimer, prothrombin time (PT), activated partial thromboplastin time (aPTT), antithrombin (AT), protein C, protein S, factor XIII, lupus aPTT, angiotensin-2, vitamin D metabolites, and telomeres in all COVID-19 patients. Basic clinical characteristics and anteceding diseases including cardiovascular, oncologic, renal, hypertension, pulmonary, metabolic (diabetes, obesity) were recorded in a database together with the laboratory data. (3) Results: At the time of diagnosis of SARS-CoV-2 infection those patients who deceased within 90 days afterwards due to COVID-19, had a significantly higher age, higher KYN, KYN/TRP ratio, ferritin, creatinine, and NTproBNP values than SARS-CoV-2 patients who survived COVID-19 along the same time span. In a Kaplan-Meier analysis the variables age, KYN, ferritin, D-Dimer, TnT, NTproBNP, and creatinine showed a significant influence on survival time. Gender, however, showed no influence. In a combined Cox regression analysis KYN had the highest hazard ratio (1.188, 95% CI: 1.071–1.319) followed by age (1.041, 95% CI: 1.011–1.073). In a ROC analysis, KYN values above the cut off limit of 4.82 nmol/l (as specified by Youden index) had a sensitivity of 82% (95% CI: 66–95%) and a specificity of 72% (95% CI: 65–82%) to predict COVID-19 related death within 90 days observation time. (4) Conclusions: Kynurenine is a promising blood biomarker to predict an increased risk of mortality in SARS-CoV-2 infected people already at the time of the first positive SARS-CoV-2 verification detected in these persons.

5 May 2020 in Nutrients
Verified
Journal Article
Open access
PDF file
SMSusanne Macher
Susanne Macher
CHCornelia Herster
Cornelia Herster
MHMagdalena Holter
Magdalena Holter
MMMartina Moritz
Martina Moritz
EMEva Maria Matzhold
Eva Maria Matzhold
Karin AmreinKarin Amrein
Karin Amrein
Background: Besides anemia, iron deficiency may cause more subtle symptoms, including the restless legs syndrome (RLS), the chronic fatigue syndrome (CFS) or sleeping disorders. Objective: The aim of this pre-planned secondary analysis of the IronWoMan randomized controlled trial (RCT) was to compare the frequency and severity of symptoms associated with iron deficiency before and after (intravenous or oral) iron supplementation in iron deficient blood donors. Methods/Design: Prospective, randomized, controlled, single-centre trial. (ClinicalTrials.gov: NCT01787526). Setting: Tertiary care center in Graz, Austria. Participants: 176 (138 female and 38 male) whole-blood and platelet apheresis donors aged ≥ 18 and ≤ 65 years with iron deficiency (ferritin ≤ 30ng/mL at the time of blood donation). Interventions: Intravenous iron (1 g ferric carboxymaltose, n = 86) or oral iron supplementation (10 g iron fumarate, 100 capsules, n = 90). Measurements: Clinical symptoms were evaluated by a survey before iron therapy (visit 0, V0) and after 8–12 weeks (visit 1, V1), including questions about symptoms of restless legs syndrome (RLS), chronic fatigue syndrome (CFS), sleeping disorders, quality of life and symptoms like headaches, dyspnoea, dizziness, palpitations, pica and trophic changes in fingernails or hair. Results: We found a significant improvement in the severity of symptoms for RLS, fatigue and sleep quality (p < 0.001). Furthermore, a significant decrease in headaches, dyspnoea, dizziness and palpitations was reported (p < 0.05). There was no difference between the type of iron supplementation (intravenous versus oral) and clinical outcome data. Conclusion: Iron supplementation in iron-deficient blood donors may be an effective strategy to improve symptoms related to iron deficiency and the wellbeing of blood donors.

1 March 2020 in Clinical Nutrition
Verified
Journal Article
Open access
CDCamilla Drexler
Camilla Drexler
SMSusanne Macher
Susanne Macher
ILInes Lindenau
Ines Lindenau
MHMagdalena Holter
Magdalena Holter
MMMartina Moritz
Martina Moritz
Karin AmreinKarin Amrein
Karin Amrein
Frequent blood donation often leads to iron deficiency and even anemia but appropriate strategies for detection and prevention are currently not mandatory. At the Medical University of Graz, we conducted a single-center prospective clinical trial to compare oral and IV iron supplementation in iron deficient blood donors including Austrian regular whole blood and platelet apheresis donors. We aimed to determine the difference of transferrin saturation between the treatment groups 8-12 weeks iron administration besides other parameters of iron status and blood count. 176 healthy male and female blood donors with iron deficiency (ferritin ≤30 ng/mL) were randomized to either a single dose of IV ferric carboxymaltose (1000 mg, n = 86) or oral iron (II)fumarate (100 tablets of 100 mg [10 per week], n = 90). Between 2014 and 2016, 172 donors (137 women) completed the study; 4 in the oral group were lost to follow-up. At follow-up, median (IQR) transferrin saturation and ferritin were significantly higher in the intravenous group (27 [23-35]%, vs 21.0 [16-32]%; p < 0.001 and 105 [75-145] ng/mL vs 25 [17-34] ng/mL; p < 0.001, respectively) while median (IQR) hemoglobin levels were comparable (IV, 13.6 [13.0-14.4] g/dL vs oral, 13.6 [13.0-14.2] g/dL). The frequency of adverse effects was comparable (38% in both groups) and no serious adverse events occurred. A single dose of 1000 mg of intravenous iron is highly effective to counteract iatrogenic iron deficiency in blood donors. Oral iron appears to be an acceptable alternative. The assessment of body iron stores should play a key role in maintaining blood donors' health. This trial was registered at www.clinicaltrials.gov as NCT01787526 on February 8, 2013 and at www.clinicaltrialsregister.eu (EudraCT identifier: 2013-000327-14) on September 24, 2013.

3 February 2020 in JMIR Research Protocols
Verified
Journal Article
Open access
SSSandra Schüssler
Sandra Schüssler
JZJulia Zuschnegg
Julia Zuschnegg
LPLucas PALETTA
Lucas PALETTA
MFMaria Fellner
Maria Fellner
GLGerald Lodron
Gerald Lodron
SRSilvia Russegger
Silvia Russegger
Background: New technologies, like socially assistive robots (SARs), may have the potential to support caregivers at home. Still, the evidence for people with dementia in home care is unclear because a lot of studies are performed in a laboratory or institutional setting, and mainly use robots in prototype stages.Objective: This study aims to explore the effects of the refined, commercially-available, humanoid SAR Pepper combined with a tablet PC–based dementia training program (Coach Pepper) versus an exclusively tablet PC–based dementia training program on psychosocial and physical outcomes of people with dementia living at home, including caregivers and dementia trainers. We hypothesize that Coach Pepper has a more positive effect on the primary outcome motivation (stable or decreased apathy) of people with dementia.Methods: A mixed methods study will be performed, including a randomized controlled, parallel, 2-arm study with a complementary qualitative part. This sample includes 40 PWD living at home and 40 relatives, each complemented with five professional caregivers and dementia trainers. The intervention group will receive Coach Pepper (a SAR connected with a tablet PC–based dementia training program), and the control group will receive exclusively tablet PC–based training without the SAR. The duration of the intervention will be three weeks per household. Data will be collected at baseline and during and after the intervention by standardized questionnaires, sensor data of the robot, and tablet PC, as well as semistructured interviews, focus groups, and observation.Results: To date, no results are available for this study protocol. The study intervention started in May 2019 and will end in Spring 2020.Conclusions: The intervention of this study can be seen as a nonpharmacological intervention, including cognitive and physical training by a robot. This study will help to further refine SAR for the specific needs of people with dementia living at home.International Registered Report Identifier (IRRID): DERR1-10.2196/14927

22 June 2021 in Nutrients
Verified
Journal Article
Open access
PDF file
SZSieglinde Zelzer
Sieglinde Zelzer
FPFlorian Prüller
Florian Prüller
PCPero Curcic
Pero Curcic
ZSZdenka Sloup
Zdenka Sloup
MHMagdalena Holter
Magdalena Holter
HMHarald Mangge
Harald Mangge
(1) Background: Vitamin D, a well-established regulator of calcium and phosphate metabolism, also has immune-modulatory functions. An uncontrolled immune response and cytokine storm are tightly linked to fatal courses of COVID-19. The present retrospective study aimed to inves-tigate vitamin D status markers and vitamin D degradation products in a mixed cohort of 148 hospitalized COVID-19 patients with various clinical courses of COVID-19. (2) Methods: The serum concentrations of 25(OH)D3, 25(OH)D2, 24,25(OH)2D3, and 25,26(OH)2D3 were determined by a validated liquid-chromatography tandem mass-spectrometry method in leftover serum samples from 148 COVID-19 patients that were admitted to the University Hospital of the Medical Uni-versity of Graz between April and November 2020. Anthropometric and clinical data, as well as outcomes were obtained from the laboratory and hospital information systems. (3) Results: From the 148 patients, 34 (23%) died within 30 days after admission. The frequency of fatal outcomes did not differ between males and females. Non-survivors were significantly older than survivors, had higher peak concentrations of IL-6 and CRP, and required mechanical ventilation more frequently. The serum concentrations of all vitamin D metabolites and the vitamin D metabolite ratio (VMR) did not differ significantly between survivors and non-survivors. Additionally, the need for res-piratory support was unrelated to the serum concentrations of 25(OH)D vitamin D and the two vitamin D catabolites, as well as the VMR. (4) Conclusion: The present results do not support a relevant role of vitamin D for the course and outcome of COVID-19.