Uta Dahmen

Prof. Uta Dahmen

University Hospital Jena

Research Focus & Metrics

Academic Career Length

30Years (1997-Present)

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

Representative Publications

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19 September 2014 in Biomechanics and Modeling in Mechanobiology
Verified
Journal Article
Closed access
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TRTim Ricken
Tim Ricken
DWD. Werner
D. Werner
Hermann-Georg HolzhütterHermann-Georg Holzhütter
Hermann-Georg Holzhütter
Matthias KönigMatthias König
Matthias König
Uta DahmenUta Dahmen
Uta Dahmen
ODO. Dirsch
O. Dirsch

27 June 2013 in Cell Death & Disease
Verified
Journal Article
Open access
PDF file
HFH Fang
H Fang
ALA Liu
A Liu
Uta DahmenUta Dahmen
Uta Dahmen
ODO Dirsch
O Dirsch
The anti-malaria drug chloroquine is well known as autophagy inhibitor. Chloroquine has also been used as anti-inflammatory drugs to treat inflammatory diseases. We hypothesized that chloroquine could have a dual effect in liver ischemia/reperfusion (I/R) injury: chloroquine on the one hand could protect the liver against I/R injury via inhibition of inflammatory response, but on the other hand could aggravate liver I/R injury through inhibition of autophagy. Rats (n=6 per group) were pre-treated with chloroquine (60 mg/kg, i.p.) 1 h before warm ischemia, and they were continuously subjected to a daily chloroquine injection for up to 2 days. Rats were killed 0.5, 6, 24 and 48 h after reperfusion. At the early phase (i.e., 0–6 h after reperfusion), chloroquine treatment ameliorated liver I/R injury, as indicated by lower serum aminotransferase levels, lower hepatic inflammatory cytokines and fewer histopathologic changes. In contrast, chloroquine worsened liver injury at the late phase of reperfusion (i.e., 24–48 h after reperfusion). The mechanism of protective action of chloroquine appeared to involve its ability to modulate mitogen-activated protein kinase activation, reduce high-mobility group box 1 release and inflammatory cytokines production, whereas chloroquine worsened liver injury via inhibition of autophagy and induction of hepatic apoptosis at the late phase. In conclusion, chloroquine prevents ischemic liver damage at the early phase, but aggravates liver damage at the late phase in liver I/R injury. This dual role of chloroquine should be considered when using chloroquine as an inhibitor of inflammation or autophagy in I/R injury.

1 June 2016 in Computers in Biology and Medicine
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Journal Article
Closed access
LSLars Schwen
Lars Schwen
AHAndré Homeyer
André Homeyer
MSMichael Schwier
Michael Schwier
Uta DahmenUta Dahmen
Uta Dahmen
ODOlaf Dirsch
Olaf Dirsch
ASAndrea Schenk
Andrea Schenk

Verified
Journal Article
Open access
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FXFengming Xu
Fengming Xu
CHChuanfeng Hua
Chuanfeng Hua
HTHans-Michael Tautenhahn
Hans-Michael Tautenhahn
ODOlaf Dirsch
Olaf Dirsch
Uta DahmenUta Dahmen
Uta Dahmen
Age is one of the key risk factors to develop malignant diseases leading to a high incidence of hepatic tumors in the elderly population. The only curative treatment for hepatic tumors is surgical removal, which initiates liver regeneration. However, liver regeneration is impaired with aging, leading to an increased surgical risk for the elderly patient. Due to the increased risk, those patients are potentially excluded from curative surgery. Aging impairs autophagy via lipofuscin accumulation and inhibition of autophagosome formation. Autophagy is a recycling mechanism for eukaryotic cells to maintain homeostasis. Its principal function is to degrade endogenous bio-macromolecules for recycling cellular substances. A number of recent studies have shown that the reduced regenerative capacity of the aged remnant liver can be restored by promoting autophagy. Autophagy can be activated via multiple mTOR-dependent and mTOR-independent pathways. However, inducing autophagy through the mTOR-dependent pathway alone severely impairs liver regeneration. In contrast, recent observations suggest that inducing autophagy via mTOR-independent pathways might be promising in promoting liver regeneration. Conclusion: Activation of autophagy via an mTOR-independent autophagy inducer is a potential therapy for promoting liver regeneration, especially in the elderly patients at risk.

9 May 2018 in BMC Medical Education
Verified
Journal Article
Open access
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DGDiana Grasreiner
Diana Grasreiner
Uta DahmenUta Dahmen
Uta Dahmen
USUtz Settmacher
Utz Settmacher
Given the expected increase in those entering retirement, the number of practising physicians is predicted to decrease. Conversely, the number of physicians needed is set to increase, due to higher demands resulting from the increasing average age of the German population. This may cause a deficit in the availability and accessibility of medical care for the population in Germany, as well as in other countries. As such, there needs to be a specific focus on the next generation of physicians. Will they fill the gap in those medical specialties where it is most needed? This study aims to investigate (a) preferences for medical specialties over time and (b) the reasoning behind these preferences among students. Over three subsequent years, all medical students from the Jena Faculty of Medicine were repeatedly invited to participate in an online survey. The questionnaire consisted of three parts to explore the students’ (1) preferred postgraduate specialty, (2) the reasons for their decision and (3) socio-demographic data. Data analysis was performed using Fisher’s exact tests and logistic regression analysis. The number of students completing the questionnaire in a given year ranged from 180 to 320, resulting in a total number of 720 completed questionnaires. Between 40 and 50% of the students preferred internal medicine as postgraduate specialty. About 25% of the students were interested in a surgical specialty. Diagnostics and psychiatric medical fields were preferred by about 10% of all students for each field in each year of the survey. A large percentage (about 18%) of the students remained undecided. The factors influencing the students’ specialty preferences were most frequently reconciliation of work and family life, career goals as well as predicted workload. The factors depended on the preferred medical specialty. The influencing factors should be taken into account for recruiting prospective residents. Doing so could increase the chance to attract the number of physicians needed to ensure adequate medical care in the field of interest, according to the growing health needs of the population.

13 April 2012 in PLOS ONE
Verified
Journal Article
Open access
PDF file
ALAnding Liu
Anding Liu
HFHaoshu Fang
Haoshu Fang
ODOlaf Dirsch
Olaf Dirsch
HJHao Jin
Hao Jin
Uta DahmenUta Dahmen
Uta Dahmen
High mobility group box 1 (HMGB1) is a nuclear transcription factor. Once HMGB1 is released by damaged cells or activated immune cells, it acts as danger molecule and triggers the inflammatory signaling cascade. Currently, evidence is accumulating that posttranslational modifications such as oxidation may modulate the pro-inflammatory potential of danger signals. We hypothesized that oxidation of HMGB1 may reduce its pro-inflammatory potential and could take place during prolonged ischemia and upon reperfusion. Liver grafts were cold preserved for 24 h and flushed with saline in hourly intervals to collect the effluent. Liver grafts, cold-preserved for 6 h, were transplanted into syngeneic recipients to obtain serum and liver samples 24 h after initiation of reperfusion. Addition of the effluent to a macrophage culture induced the synthesis of tumor necrosis factor-alpha (TNF-α) and interleukin (IL)-6. The stimulatory activity of graft effluent was reduced after depletion of HMGB1 via immunoprecipitation. Oxidation of the effluent HMGB1 using H2O2 attenuated its stimulatory activity as well. Liver transplantation of cold preserved grafts caused HMGB1 translocation and release as determined by immunohistochemistry and ELISA-assay, respectively. Using Western blot with non-reducing conditions revealed the presence of oxidized HMGB1 in liver samples obtained after 12 h and in effluent samples after 16 h of cold preservation as well as in liver and serum samples obtained 24 h after reperfusion. These observations confirm that post-translational oxidation of HMGB1 attenuates its pro-inflammatory activity. Oxidation of HMGB1 as induced during prolonged ischemia and by reoxygenation during reperfusion in vivo might also attenuate its pro-inflammatory activity. Our findings also call for future studies to investigate the mechanism of the inhibitory effect of oxidized HMGB1 on the pro-inflammatory potential.