Armin Kalenka

Publications of Armin Kalenka

• Image findings of patients with H1N1 virus pneumonia and acute respiratory failure.

  Authors: Thomas Henzler, Mathias Meyer, Armin Kalenka, Markus Alb, Gerald Schmid-Bindert, Sönke Bartling, Joseph U Schoepf, Stefan O Schoenberg, Christian Fink

  Academic radiology. 06/2010; 17(6):681-5.

  The aim of this study was to assess the findings of chest radiography and high-resolution computed tomography in patients requiring intensive care unit treatment for severe H1N1 virus pneumonia. InThe aim of this study was to assess the findings of chest radiography and high-resolution computed tomography in patients requiring intensive care unit treatment for severe H1N1 virus pneumonia. In 2009, 10 patients required treatment in an intensive care unit for confirmed H1N1 pneumonia. All patients underwent chest radiography and high-resolution computed tomography. All 10 patients required mechanical ventilation because of respiratory failure. Nine patients presented with severe acute respiratory distress syndrome, and one patient died. Four patients underwent extracorporeal membrane oxygenation (ECMO) therapy. The results of chest radiography and high-resolution computed tomographic scans of these patients were systematically analyzed. The mean age of all patients was 44.1 +/- 12.3 years. All 10 patients showed abnormal results on chest radiography. The radiographic abnormalities were bilateral and multifocal in 10 patients. The predominant radiographic findings were consolidations (n = 9), ground-glass opacities (n = 8), and reticular opacities (n = 2). The most frequent computed tomographic findings at presentation consisted of bilateral ground-glass opacities (n = 9), pleural effusion (n = 9), areas of consolidation (n = 8), interstitial marking (n = 8), and crazy paving (n = 4). All patients undergoing ECMO therapy showed extensive bilateral ground-glass opacities, multifocal areas of consolidation, and crazy paving. Pleural effusion was present in three of four patients undergoing ECMO therapy. Patients requiring treatment in an intensive care unit for severe H1N1 pneumonia are at high risk for developing acute respiratory distress syndrome and frequently require ECMO therapy.

• Time-dependent alterations of cerebral proteins following short-term normobaric hyperoxia.

  Authors: Jochen Hinkelbein, Robert E Feldmann, Armin Kalenka

  Molecular and cellular biochemistry. 06/2010; 339(1-2):9-21.

  Sufficient oxygenation is indispensable for cognitive performance in mammals. In order to assure adequate oxygenation and to prevent hypoxia in medicine or aviation, different approaches of oxygenSufficient oxygenation is indispensable for cognitive performance in mammals. In order to assure adequate oxygenation and to prevent hypoxia in medicine or aviation, different approaches of oxygen delivery are realized. With regard to hyperoxia, it is well known that it increases the risk of tissue toxicity and inflammation by generating radical oxygen species. However, this impact of hyperoxia on the expression of specific brain proteins has not been evaluated in detail yet. The present study analyzes time-dependent changes in protein expression in rat brain after a short-term exposure to normobaric hyperoxia. Thirty-six Wistar rats were randomly assigned to six different groups, three normobaric hyperoxia (NH) groups or three normobaric normoxia (NN) groups, each consisting of n = 6 animals. NH animals were exposed to 100% oxygen, NN rats to 21% oxygen, each group for 3 h. One group of NH and one group of NN were killed immediately after the 3 h, one group each after 3 days and one group each after 7 days. Rat brains were removed for analysis and whole brain detergent protein lysates were separated via two-dimensional gel electrophoresis followed by subsequent identification of protein expression alterations by peptide mass fingerprinting using mass spectrometry. Also, a functional network mapping and molecular pathway analysis were carried out. Statistical analysis was performed using analysis of variance (ANOVA) with Bonferroni correction using P < 0.01. Physiological parameters of the animals did not differ significantly between the two groups except for partial oxygen pressure (580 vs. 89 mmHg; P < 0.05). The expression of nine proteins was found to be significantly altered (five up-regulated: GOT1, CCT2, TCP1, G6PD, and ALB; four down-regulated: PEBP1, PRDX2, ENO1, and MDH1). IPA generated a network with eight focus proteins associated with pathways in "cell death, cancer, and signalling". Although hyperoxia was normobaric and induced for only 3 h, significant changes in brain protein expression were detectable immediately after the 3 h, after 3 days, as well as after 7 days. This may indicate effects on brain protein expression take place in the rat brain following a relatively short period of hyperoxia.

• Isoflurane anesthesia elicits protein pattern changes in rat hippocampus.

  Authors: Armin Kalenka, Benjamin Gross, Martin H Maurer, Hermann-Josef Thierse, Robert E Feldmann

  Journal of neurosurgical anesthesiology. 04/2010; 22(2):144-54.

  Postoperative cognitive dysfunction (POCD) is a known phenomenon occurring after anesthesia with volatile anesthetics (VA), such as isoflurane. Recent reports suggest that VA interact withPostoperative cognitive dysfunction (POCD) is a known phenomenon occurring after anesthesia with volatile anesthetics (VA), such as isoflurane. Recent reports suggest that VA interact with neurodegenerative disease-associated proteins including compounds with pathogenic relevance in Alzheimer disease (AD) and induce processes that may be linked to AD neuropathology. Unfortunately, our present understanding of the exact anesthetics' molecular mechanisms of action, their side effects on the brain, and their catenation with AD pathology is still limited. The present study analyzes the differential proteome of the hippocampus immediately after and 3 days after a 3-hour 1 minimal alveolar concentration isoflurane anesthesia in rats. Differential 2-dimensional electrophoresis, mass spectrometry, and functional network mapping were used to identify and functionally classify 12 different hippocampal proteins, which were significantly regulated after isoflurane anesthesia (6 up-regulated, 11 down-regulated with P<0.01). Induction of differential expression ranged from 0.05 (25-fold down-regulation) to 4.4 (4.4-fold up-regulation). Ten proteins were regulated immediately after and 7 proteins 3 days after isoflurane exposure. The proteome displays isoflurane-responsive protein candidates, which have also been shown to play a role in AD. They were grouped according to their key biologic activities, which showed that isoflurane affects selected biologic processes including synaptic plasticity, stress response, detoxification, and cytoskeleton in early and late recovery phases after anesthesia. These processes are also affected in AD. Results are discussed in view of AD, the toxicity mechanisms of isoflurane as well as the implications for our present understanding and conduction of clinical anesthesia.

• Proteome and metabolome alterations in heart and liver indicate compromised energy production during sepsis.

  Authors: Jochen Hinkelbein, Armin Kalenka, Charlotte Schubert, Anna Peterka, Robert E Feldmann

  Protein and peptide letters. 01/2010; 17(1):18-31.

  During the course of sepsis, heart and liver dysfunction occurs in 20-30 % of patients. Both septic cardiomyopathy and septic liver dysfunction have a high mortality and the underlying molecularDuring the course of sepsis, heart and liver dysfunction occurs in 20-30 % of patients. Both septic cardiomyopathy and septic liver dysfunction have a high mortality and the underlying molecular pathophysiology remains unclear. The present study investigated changes in both cardiac and liver protein expression after cecal ligature and puncture (CLP) in a model of rat sepsis during a post-induction time course of 12, 24, and 48 hours. After approval by the local institutional review board, 62 male Wistar rats were investigated and assigned to three sham groups (n=16) and three sepsis groups (n=46). Rats of the sepsis groups and control groups were analyzed at specific time points after sepsis induction. Sepsis was induced by CLP and both heart and liver were removed after decapitation and prepared for proteomics. 2D-gel electrophoresis (2D-GE) and mass spectrometry (MS) as well as bioinformatic network pathway analysis (Ingenuity Pathways Analysis, IPA) were used to identify changes in protein expression between septic and non-septic samples. N=27 rats of the sepsis group died (mortality 59 %) and no rat of the sham group died. More than 1,100 proteins could be discriminated with the proteomic method in both organs, of which 12 and 13 proteins were significantly regulated in heart and liver, respectively. 82 % of the cardiac proteins could be associated with mitochondrial function. Both heart and liver proteins were primarily down-regulated in the course of sepsis. IPA associated the sets of differentially regulated proteins with proteins of heart and liver with compromised energy production. Sepsis induced significant alterations in the cardiac and liver proteome at 12, 24, and 48 hours after sepsis induction. Differentially regulated proteins of both organs mainly play a role in energy production. The diverse protein regulation indicates metabolic derangement and severely compromised cellular energy production following sepsis. Here, protein alterations may reflect septic organ dysfunction.

• Anaesthesia and Parkinson's disease: how to manage with new therapies?

  Authors: Armin Kalenka, Anke Schwarz

  Current opinion in anaesthesiology. 05/2009;

  PURPOSE OF REVIEW: Parkinson's disease is the second most prevalent neurodegenerative disease and presents a particular anaesthetic challenge. The clinical features are described in detail, andPURPOSE OF REVIEW: Parkinson's disease is the second most prevalent neurodegenerative disease and presents a particular anaesthetic challenge. The clinical features are described in detail, and recent advances in medical management and neurosurgical treatment options are highlighted. RECENT FINDINGS: Deep brain stimulation (DBS) has experienced a renaissance for selected patients. Potential drug interactions with anaesthetics are described and recommendations are made about suitable anaesthetic techniques, especially for DBS. In addition to the classic DBS in an awake state, stimulation under modified general anaesthesia seems possible in selected patients who are not suitable for awake craniotomy. SUMMARY: DBS is an attractive option for severely disabled patients with Parkinson's disease who pose a particular anaesthetic challenge.

• Alterations in rat serum proteome and metabolome as putative disease markers in sepsis.

  Authors: Jochen Hinkelbein, Robert E Feldmann, Charlotte Schubert, Anna Peterka, Dominik Schelshorn, Martin H Maurer, Armin Kalenka

  The Journal of trauma. 05/2009; 66(4):1065-75.

  OBJECTIVES: Despite a decreased mortality from sepsis, the absolute number of sepsis-related deaths has actually increased during the last years. At present, there are no biological markers availableOBJECTIVES: Despite a decreased mortality from sepsis, the absolute number of sepsis-related deaths has actually increased during the last years. At present, there are no biological markers available that can reliably assist early clinical diagnosis and the prompt initiation of therapy. This study investigated the changes in serum protein expression in a coecal ligature and puncture model of rat sepsis at 12, 24, and 48 hours after the induction of sepsis using differential proteomics. METHODS: Sixty-two male Wistar rats were randomly assigned to a sepsis group (coecal ligature and puncture; n = 46) or a sham group (n = 16). Surviving rats were killed 12 hour (n = 6), 24 hour (n = 9), or 48 hour (n = 4) after operation, and their serum lysates were subjected to two-dimensional gel electrophoresis and peptide mass fingerprinting. A systematic functional network mapping and molecular pathway analysis were performed using Ingenuity Pathways Analysis. RESULTS: Septic mortality was 58.7%, but no rat of the sham group was lost. Per gel, an average of 1,082 +/- 10 spots could be discriminated, of which 40 different protein spots were differentially expressed (p < 0.01). From the total of 40, the number of regulated protein spots was 13 (12 hour group) versus 10 (24 hour group) versus 18 (48 hour group). Ingenuity pathways analysis identified 10 of the differential proteins and allocated them to a pathway of tissue inflammation. CONCLUSIONS: The present study quantitatively detected several proteins differentially expressed in acute sepsis. Since a longer time-period was investigated and compared with previous studies, the results may offer new insights into septic organ dysfunction and altered protein pathways. The horizontal analysis of protein expression arrays and systematic biochemical pathways may represent an important new tool for the clinical assessment of septic conditions and support the development of early sepsis markers.

• Reduction in rat phosphatidylethanolamine binding protein-1 (PEBP1) after chronic corticosterone treatment may be paralleled by cognitive impairment: a first study.

  Authors: Robert E Feldmann, Martin H Maurer, Christian Hunzinger, Sabina Lewicka, Heinrich F Buergers, Armin Kalenka, Jochen Hinkelbein, Jens O Broemme, Guenter H Seidler, Eike Martin, Konstanze Plaschke

  Stress (Amsterdam, Netherlands). 07/2008; 11(2):134-47.

  Chronic stress is associated with hippocampal atrophy and cognitive dysfunction. This study investigates how long-lasting administration of corticosterone as a mimic of experimentally induced stressChronic stress is associated with hippocampal atrophy and cognitive dysfunction. This study investigates how long-lasting administration of corticosterone as a mimic of experimentally induced stress affects psychometric performance and the expression of the phosphatidylethanolamine binding protein (PEBP1) in the adult hippocampus of one-year-old male rats. Psychometric investigations were conducted in rats before and after corticosterone treatment using a holeboard test system. Rats were randomly attributed to 2 groups (n = 7) for daily subcutaneous injection of either 26.8 mg/kg body weight corticosterone or sesame oil (vehicle control). Treatment was continued for 60 days, followed by cognitive retesting in the holeboard system. For protein analysis, the hippocampal proteome was separated by 2D electrophoresis (2DE) followed by image processing, statistical analysis, protein identification via peptide mass fingerprinting and gel matching and subsequent functional network mapping and molecular pathway analysis. Differential expression of PEBP1 was additionally quantified by Western blot analysis. Results show that chronic corticosterone significantly decreased rat hippocampal PEBP1 expression and induced a working and reference memory dysfunction. From this, we derive the preliminary hypothesis that PEBP1 may be a novel molecular mediator influencing cognitive integrity during chronic corticosterone exposure in rat hippocampus.

• Hydrocortisone therapy for patients with septic shock.

  Authors: Charles L Sprung, Djillali Annane, Didier Keh, Rui Moreno, Mervyn Singer, Klaus Freivogel, Yoram G Weiss, Julie Benbenishty, Armin Kalenka, Helmuth Forst, Pierre-Francois Laterre, Konrad Reinhart, Brian H Cuthbertson, Didier Payen, Josef Briegel

  The New England journal of medicine. 02/2008; 358(2):111-24.

  BACKGROUND: Hydrocortisone is widely used in patients with septic shock even though a survival benefit has been reported only in patients who remained hypotensive after fluid and vasopressorBACKGROUND: Hydrocortisone is widely used in patients with septic shock even though a survival benefit has been reported only in patients who remained hypotensive after fluid and vasopressor resuscitation and whose plasma cortisol levels did not rise appropriately after the administration of corticotropin. METHODS: In this multicenter, randomized, double-blind, placebo-controlled trial, we assigned 251 patients to receive 50 mg of intravenous hydrocortisone and 248 patients to receive placebo every 6 hours for 5 days; the dose was then tapered during a 6-day period. At 28 days, the primary outcome was death among patients who did not have a response to a corticotropin test. RESULTS: Of the 499 patients in the study, 233 (46.7%) did not have a response to corticotropin (125 in the hydrocortisone group and 108 in the placebo group). At 28 days, there was no significant difference in mortality between patients in the two study groups who did not have a response to corticotropin (39.2% in the hydrocortisone group and 36.1% in the placebo group, P=0.69) or between those who had a response to corticotropin (28.8% in the hydrocortisone group and 28.7% in the placebo group, P=1.00). At 28 days, 86 of 251 patients in the hydrocortisone group (34.3%) and 78 of 248 patients in the placebo group (31.5%) had died (P=0.51). In the hydrocortisone group, shock was reversed more quickly than in the placebo group. However, there were more episodes of superinfection, including new sepsis and septic shock. CONCLUSIONS: Hydrocortisone did not improve survival or reversal of shock in patients with septic shock, either overall or in patients who did not have a response to corticotropin, although hydrocortisone hastened reversal of shock in patients in whom shock was reversed. (ClinicalTrials.gov number, NCT00147004.)

• Alterations in cerebral metabolomics and proteomic expression during sepsis.

  Authors: Jochen Hinkelbein, Robert E Feldmann, Anna Peterka, Charlotte Schubert, Dominik Schelshorn, Martin H Maurer, Armin Kalenka

  Current neurovascular research. 12/2007; 4(4):280-8.

  The cause of brain dysfunction during sepsis and septic encephalopathy is still under ongoing research. Sepsis induced changes in cerebral protein expression may play a significant role in theThe cause of brain dysfunction during sepsis and septic encephalopathy is still under ongoing research. Sepsis induced changes in cerebral protein expression may play a significant role in the understanding of septic encephalopathy. The aim of the present study was to explore cerebral proteome alterations in septic rats. Fifty-six male Wistar rats were randomly assigned to a sepsis group (coecal ligature and puncture, CLP) or a control group (sham). Surviving rats were killed 24 or 48 hours after surgery and whole-brain lysates were used for two-dimensional gel electrophoresis and subsequent protein identification. Differentially expressed proteins were identified by mass spectrometry. Using the Ingenuity Pathways Analysis (IPA) tool, the relationship and interaction between the identified proteins was analyzed. Mortality was 53 % in septic rats. No rat of the control group was lost. More than 1,100 spots per gel were discriminated of which 29 different proteins were significantly (2-fold, P<0.01) changed: 24 proteins down-regulated after 24 hours; two proteins up-regulated and three down-regulated after 48 hours. IPA identified 11 of 35 differentially regulated proteins allocating them to an existing inflammatory pathway. In the analysis of septic rat brains, multiple differentially expressed proteins associated with metabolism, signaling, and cell stress can be identified via proteome analysis, that may help to understand the development of septic encephalopathy.

• The effects of sevoflurane anesthesia on rat brain proteins: a proteomic time-course analysis.

  Authors: Armin Kalenka, Jochen Hinkelbein, Robert E Feldmann, Wolfgang Kuschinsky, Klaus F Waschke, Martin H Maurer

  Anesthesia and analgesia. 05/2007; 104(5):1129-35, tables of contents.

  BACKGROUND: Recent studies showed changes in cerebral protein expression up to 3 days after desflurane anesthesia in rats. In the present study, we investigated the existence of persisting changes onBACKGROUND: Recent studies showed changes in cerebral protein expression up to 3 days after desflurane anesthesia in rats. In the present study, we investigated the existence of persisting changes on the proteome level after sevoflurane anesthesia that persisted for as long as 28 days after anesthesia. METHODS: Rats were anesthetized by spontaneous inhalation of 2.4% sevoflurane in air for 3 h. Animals (n = 6 for each group) were killed either directly, 72 h, or 28 days after anesthesia. Brains were removed and subjected to global protein expression profiling based on two-dimensional gel electrophoresis and mass spectrometry. Expression factors were compared to results from untreated conscious animals at each time point. Data were statistically analyzed by ANOVA (P < 0.01) and a cut of more than two-fold change in the expression factor. RESULTS: We found 11 protein spots differentially regulated directly after anesthesia. Seventeen proteins were differentially expressed 72 h after the anesthesia. Only one spot was differentially regulated 28 days after anesthesia. The plausible targets of these differentially regulated proteins can be attributed to synaptic vesicle handling and cell-cell communication. CONCLUSIONS: Sevoflurane induced relevant changes in protein expression profiles directly and 72 h after an anesthesia with 1 MAC. Twenty-eight days after the anesthesia, all proteins except one had returned to baseline levels of abundance.

• Local cerebral blood flow is preserved in sepsis.

  Authors: Jochen Hinkelbein, Helmut Schroeck, Anna Peterka, Charlotte Schubert, Wolfgang Kuschinsky, Armin Kalenka

  Current neurovascular research. 02/2007; 4(1):39-47.

  Sepsis is often complicated by encephalopathy, neuroendocrine dysfunction and cardiovascular autonomic failure. The cause of septic brain dysfunction is not fully understood. The aim of the presentSepsis is often complicated by encephalopathy, neuroendocrine dysfunction and cardiovascular autonomic failure. The cause of septic brain dysfunction is not fully understood. The aim of the present study is to explore whether septic brain dysfunction in a common septic model in the rat correlates with abnormalities either of local cerebral blood flow (LCBF) of defined brain areas or of whole brain blood flow (CBF). 45 male Wistar rats (320+/-13 g) were randomly assigned to a sepsis group (31 rats, cecal ligature and puncture, CLP) or a control group (14 rats, sham operation). Of these 45 rats, 16 rats were used for blood analysis; the remaining 29 rats were used for CBF/LCBF measurements. LCBF measurements were performed 24h after initial surgery using quantitative autoradiography with 4-iodo[N-methyl-(14)C]antipyrine, which allows to analyze CBF on a regional/local and global basis. In 42 different brain regions bilateral optical density measurements were performed. Septic rats (vs. control) presented tachycardia (507+/-37 vs. 452+/-44 min(-1), P<0.05), leukocytopenia (2.96+/-2.37 vs. 8.83+/-2.9710(9) x L(-1), P<0.05), hypocapnia (29.3+/-4.6 vs. 36.4+/-3.9 mmHg, P<0.05), and higher serum lactate concentrations (5.7+/-3.9 vs. 2.2+/-2.0 mmol x L(-1), P<0.05). LCBF of all 42 areas, as well as, CBF (116+/-59 vs. 115+/-52 m x 100 g(-1)min(-1), n.s.) did not differ. The results showed that severe sepsis (mortality rate of 43 %) did not induce alterations in mean CBF and LCBF. It is concluded that brain dysfunction is not reflected in changes of CBF during severe sepsis.

• Changes in the serum proteome of patients with sepsis and septic shock.

  Authors: Armin Kalenka, Robert E Feldmann, Kevin Otero, Martin H Maurer, Klaus F Waschke, Fritz Fiedler

  Anesthesia and analgesia. 01/2007; 103(6):1522-6.

  BACKGROUND: Sepsis is still the leading cause of death in the intensive care unit. Our goal was to elucidate potential early differences in serum between survivors (SURV) and non-survivors (NON-SURV)BACKGROUND: Sepsis is still the leading cause of death in the intensive care unit. Our goal was to elucidate potential early differences in serum between survivors (SURV) and non-survivors (NON-SURV) on day 28. METHODS: We applied proteomic technology to serum samples of patients with sepsis and septic shock. Serum samples from 18 patients with sepsis and septic shock were obtained during the first 12 h after diagnosis of septic shock. Patients were grouped into SURV and NON-SURV on day 28. RESULTS: Seven patients survived and 11 patients died. Using proteome analysis, two-dimensional gel electrophoresis detected more than 200 spots per gel. A differential protein expression was discovered between SURV and NON-SURV, whereby protein alterations not yet described in sepsis were revealed. CONCLUSIONS: Our results show that proteomic profiling is a useful approach for detecting protein expression dynamics in septic patients, and may bring us closer to achieving a comprehensive molecular profiling compared with genetic studies alone.

• The heterogeneity of human mesenchymal stem cell preparations--evidence from simultaneous analysis of proteomes and transcriptomes.

  Authors: Wolfgang Wagner, Robert E Feldmann, Anja Seckinger, Martin H Maurer, Frederik Wein, Jonathon Blake, Ulf Krause, Armin Kalenka, Heinrich F Bürgers, Rainer Saffrich, Patrick Wuchter, Wolfgang Kuschinsky, Anthony D Ho

  Experimental hematology. 05/2006; 34(4):536-48.

  OBJECTIVE: Mesenchymal stem cells (MSC) raise high hopes in clinical applications. However, the lack of common standards and a precise definition of MSC preparations remains a major obstacle inOBJECTIVE: Mesenchymal stem cells (MSC) raise high hopes in clinical applications. However, the lack of common standards and a precise definition of MSC preparations remains a major obstacle in research and application of MSC. Whereas surface antigen markers have failed to precisely define this population, a combination of proteomic data and microarray data provides a new dimension for the definition of MSC preparations. METHODS: In our continuing effort to characterize MSC, we have analyzed the differential transcriptome and proteome expression profiles of MSC preparations isolated from human bone marrow under two different expansion media (BM-MSC-M1 and BM-MSC-M2). RESULTS: In proteomics, 136 protein spots were unambiguously identified by MALDI-TOF-MS and corresponding cDNA spots were selected on our "Human Transcriptome cDNA Microarray." Combination of datasets revealed a correlation in differential gene expression and protein expression of BM-MSC-M1 vs BM-MSC-M2. Genes involved in metabolism were more highly expressed in BM-MSC-M1, whereas genes involved in development, morphogenesis, extracellular matrix, and differentiation were more highly expressed in BM-MSC-M2. Interchanging culture conditions for 8 days revealed that differential expression was retained in several genes whereas it was altered in others. CONCLUSION: Our results have provided evidence that homogeneous BM-MSC preparations can reproducibly be isolated under standardized conditions, whereas culture conditions exert a prominent impact on transcriptome, proteome, and cellular organization of BM-MSC.

• Recombinant factor VIIa to treat traumatic bleeding in a children.

  Authors: Armin Kalenka, Elke Münch, Fritz Fiedler

  Paediatric anaesthesia. 12/2005; 15(11):1025-7.

• Stem cell proteomes: a profile of human mesenchymal stem cells derived from umbilical cord blood.

  Authors: Robert E Feldmann, Karen Bieback, Martin H Maurer, Armin Kalenka, Heinrich F Bürgers, Benjamin Gross, Christian Hunzinger, Harald Klüter, Wolfgang Kuschinsky, Hermann Eichler

  Electrophoresis. 08/2005; 26(14):2749-58.

  Multipotent mesenchymal stem cells (MSCs) derived from human umbilical cord blood (UCB) represent promising candidates for the development of future strategies in cellular therapy. To create aMultipotent mesenchymal stem cells (MSCs) derived from human umbilical cord blood (UCB) represent promising candidates for the development of future strategies in cellular therapy. To create a comprehensive protein expression profile for UCB-MSCs, one UCB unit from a full-term delivery was isolated from the unborn placenta, transferred into culture, and their whole-cell protein fraction was subjected to two-dimensional electrophoresis (2-DE). Unambiguous protein identification was achieved with peptide mass fingerprinting matrix-assisted laser desorption/ionization - time of flight - mass spectrometry (MALDI-TOF-MS), peptide sequencing (MALDI LIFT-TOF/TOF MS), as well as gel-matching with previously identified databases. In overall five replicate 2-DE runs, a total of 2037 +/- 437 protein spots were detected of which 205 were identified representing 145 different proteins and 60 isoforms or post-translational modifications. The identified proteins could be grouped into several functional categories, such as metabolism, folding, cytoskeleton, transcription, signal transduction, protein degradation, detoxification, vesicle/protein transport, cell cycle regulation, apoptosis, and calcium homeostasis. The acquired proteome map of nondifferentiated UCB-MSCs is a useful inventory which facilitates the identification of the normal proteomic pattern as well as its changes due to activated or suppressed pathways of cytosolic signal transduction which occur during proliferation, differentiation, or other experimental conditions.

• pO(2) measurements by phosphorescence quenching: characteristics and applications of an automated system.

  Authors: Heinz Kerger, Gesine Groth, Armin Kalenka, Peter Vajkoczy, Amy G Tsai, Marcos Intaglietta

  Microvascular research. 02/2003; 65(1):32-8.

  An automated system for pO(2) analysis based upon phosphorescence quenching was tested. The system was calibrated in vitro with capillary samples of saline and blood. Results were compared to aAn automated system for pO(2) analysis based upon phosphorescence quenching was tested. The system was calibrated in vitro with capillary samples of saline and blood. Results were compared to a conventional measuring procedure wherein pO(2) was calculated off-line by computer fitting of phosphorescence decay signals. PO(2) measurements obtained by the automated system were correlated (r(2) = 0.98) with readings simultaneously generated by a blood gas analyzer, accuracy being highest in the low (0-20 mm Hg) and medium pO(2) ranges (21-70 mm Hg). Measurements in in vivo studies in the hamster skin-fold preparation were similar to previously reported results. The automated system fits the phosphorescence decay data to a single exponential and allows repeated pO(2) measurements in rapid sequence.

• pO2 measurements by phosphorescence quenching: characteristics and applications of an automated system

  Authors: Heinz Kerger, Gesine Groth, Armin Kalenka, Peter Vajkoczy, Amy G Tsai, Marcos Intaglietta

  Microvascular Research.

  An automated system for pO2 analysis based upon phosphorescence quenching was tested. The system was calibrated in vitro with capillary samples of saline and blood. Results were compared to aAn automated system for pO2 analysis based upon phosphorescence quenching was tested. The system was calibrated in vitro with capillary samples of saline and blood. Results were compared to a conventional measuring procedure wherein pO2 was calculated off-line by computer fitting of phosphorescence decay signals. PO2 measurements obtained by the automated system were correlated (r2 = 0.98) with readings simultaneously generated by a blood gas analyzer, accuracy being highest in the low (0–20 mm Hg) and medium pO2 ranges (21–70 mm Hg). Measurements in in vivo studies in the hamster skin-fold preparation were similar to previously reported results. The automated system fits the phosphorescence decay data to a single exponential and allows repeated pO2 measurements in rapid sequence.

• Comparison of statistical approaches for the analysis of proteome expression data of differentiating neural stem cells.

  Authors: Martin H Maurer, Robert E Feldmann, Jens O Brömme, Armin Kalenka

  Journal of proteome research. 4(1):96-100.

  Comparative proteomic studies often use statistical tests included in the software for the analysis of digitized images of two-dimensional electrophoresis gels. As these programs include only limitedComparative proteomic studies often use statistical tests included in the software for the analysis of digitized images of two-dimensional electrophoresis gels. As these programs include only limited capabilities for statistical analysis, many studies do not further describe their statistical approach. To find potential differences produced by different data processing, we compared the results of (1) Student's t-test using a spreadsheet program, (2) the intrinsic algorithms implemented in the Phoretix 2D gel analysis software, and (3) the SAM algorithm originally developed for microarray analysis. We applied the algorithms to proteome data of undifferentiated neural stem cells versus in vitro differentiated neural stem cells. We found (1) 367 spots differentially expressed using Student's t-test, (2) 203 spots using the algorithms in Phoretix 2D, and (3) 119 spots using the algorithms in SAM, respectively, with an overlap of 42 spots detected by all three algorithms. Applying different statistical approaches on the same dataset resulted in divergent set of protein spots labeled as statistically "significant". Currently, there is no agreement on statistical data processing of 2DE datasets, but the statistical tests applied in 2DE studies should be documented. Tools for the statistical analysis of proteome data should be implemented and documented in the existing 2DE software.