Robert E. Feldmann

Alterations in Rat Brain Proteins after Desflurane Anesthesia

BackgroundVolatile anesthetics disappear from an organism after the end of anesthesia. Whether changes of protein expression persist in the brain for a longer period is not known. This study investigates the question of whether the expression of proteins is altered in the rat brain after the end of desflurane anesthesia. MethodsThree groups (n = 12 each) of rats were anesthetized with 5.7% desflurane in air for 3 h. Brains were removed directly after anesthesia, 24 h after anesthesia, or 72 h after anesthesia. Two additional groups (n = 12 each) served as naive conscious controls, in which the brains were removed without previous anesthesia 3 or 72 h after the start of the experiment. Cytosolic proteins were isolated. A proteome-wide study was performed, based on two-dimensional gel electrophoresis and mass spectrometry. ResultsCompared with conscious controls, significant (P < 0.05) increase/decrease was found: 3 h of anesthesia, 5/2 proteins; 24 h after anesthesia, 13/1 proteins; 72 h after anesthesia, 6/4 proteins. The overall changes in protein expression as quantified by the induction factor ranged from −1.67 (decrease to 60%) to 1.79 (increase by 79%) compared with the controls (100%). Some of these regulated proteins play a role in vesicle transport and metabolism. ConclusionDesflurane anesthesia produces changes in cytosolic protein expression up to 72 h after anesthesia in the rat brain, indicating yet unknown persisting effects.

Comprehensive proteome expression profiling of undifferentiated versus differentiated neural stem cells from adult rat hippocampus.

Adult neural stem cells can be isolated from various regions of the rat brain and seem to have multilineage differentiation potential. In this study, we investigated the hypothesis that global protein expression of adult neural stem cells isolated from rat hippocampus is changed during in vitro differentiation. After 2 days of differentiation, we separated total protein extracts by two-dimensional gel electrophoresis and used mass spectrometry and gel-matching for identification. We detected a differential expression in 367 regulated protein spots, of which 128 could be identified. Regulated proteins included participants in transcription and DNA metabolism; signal transduction and Ca2+-signaling; MAP kinase pathways; cytoskeletal rearrangement; regulation of cell cycle, proliferation, and survival; protein biosynthesis, folding, and degradation; and glycine and glutamate metabolic pathways. These results suggest a massive reorganization of the stem cell proteomic profile upon differentiation and indicate potential cellular targets mediating the differentiation of neural stem cells.

The proteome of neural stem cells from adult rat hippocampus

BackgroundHippocampal neural stem cells (HNSC) play an important role in cerebral plasticity in the adult brain and may contribute to tissue repair in neurological disease. To describe their biological potential with regard to plasticity, proliferation, or differentiation, it is important to know the cellular composition of their proteins, subsumed by the term proteome.ResultsHere, we present for the first time a proteomic database for HNSC isolated from the brains of adult rats and cultured for 10 weeks. Cytosolic proteins were extracted and subjected to two-dimensional gel electrophoresis followed by protein identification through mass spectrometry, database search, and gel matching. We could map about 1141 ± 209 (N = 5) protein spots for each gel, of which 266 could be identified. We could group the identified proteins into several functional categories including metabolism, protein folding, energy metabolism and cellular respiration, as well as cytoskeleton, Ca2+ signaling pathways, cell cycle regulation, proteasome and protein degradation. We also found proteins belonging to detoxification, neurotransmitter metabolism, intracellular signaling pathways, and regulation of DNA transcription and RNA processing.ConclusionsThe HNSC proteome database is a useful inventory which will allow to specify changes in the cellular protein expression pattern due to specific activated or suppressed pathways during differentiation or proliferation of neural stem cells. Several proteins could be identified in the HNSC proteome which are related to differentiation and plasticity, indicating activated functional pathways. Moreover, we found a protein for which no expression has been described in brain cells before.

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

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 effects of sevoflurane anesthesia on rat brain proteins : A proteomic time-course analysis

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 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.

Volatile anesthetics evoke prolonged changes in the proteome of the left ventricule myocardium: defining a molecular basis of cardioprotection?

Background:  Volatile anesthetics can alter cardiac gene and protein expression. Of those underlying molecular changes in gene and protein expression in the myocardium after exposure to volatile anesthetics that have been identified, some of them have been related to cardioprotection.

Protein expression differs between neural progenitor cells from the adult rat brain subventricular zone and olfactory bulb

BackgroundNeural progenitor cells can be isolated from various regions of the adult mammalian brain, including the forebrain structures of the subventricular zone and the olfactory bulb. Currently it is unknown whether functional differences in these progenitor cell populations can already be found on the molecular level. Therefore, we compared protein expression profiles between progenitor cells isolated from the subventricular zone and the olfactory bulb using a proteomic approach based on two-dimensional gel electrophoresis and mass spectrometry. The subventricular zone and the olfactory bulb are connected by the Rostral Migratory Stream (RMS), in which glial fibrillary acidic protein (GFAP)-positive cells guide neuroblasts. Recent literature suggested that these GFAP-positive cells possess neurogenic potential themselves. In the current study, we therefore compared the cultured neurospheres for the fraction of GFAP-positive cells and their morphology of over a prolonged period of time.ResultsWe found significant differences in the protein expression patterns between subventricular zone and olfactory bulb neural progenitor cells. Of the differentially expressed protein spots, 105 were exclusively expressed in the subventricular zone, 23 showed a lower expression and 51 a higher expression in the olfactory bulb. The proteomic data showed that more proteins are differentially expressed in olfactory bulb progenitors with regard to proteins involved in differentiation and microenvironmental integration, as compared to the subventricular zone progenitors. Compared to 94% of all progenitors of the subventricular zone expressed GFAP, nearly none in the olfactory bulb cultures expressed GFAP. Both GFAP-positive subpopulations differed also in morphology, with the olfactory bulb cells showing more branching. No differences in growth characteristics such as doubling time, and passage lengths could be found over 26 consecutive passages in the two cultures.ConclusionIn this study, we describe differences in protein expression of neural progenitor populations isolated from two forebrain regions, the subventricular zone and the olfactory bulb. These subpopulations can be characterized by differential expression of marker proteins. We isolated fractions of progenitor cells with GFAP expression from both regions, but the GFAP-positive cells differed in number and morphology. Whereas in vitro growth characteristics of neural progenitors are preserved in both regions, our proteomic and immunohistochemical data suggest that progenitor cells from the two regions differ in morphology and functionality, but not in their proliferative capacity.

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

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 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.

Ultrasound-Guided Stellate Ganglion Blocks Combined with Pharmacological and Occupational Therapy in Complex Regional Pain Syndrome (CRPS): A Pilot Case Series Ad Interim

OBJECTIVE This preliminary and retrospective pilot case series examines a treatment concept consisting of ultrasound-guided stellate ganglion blocks (SGBs) combined with pharmacological and occupational therapy in patients with complex regional pain syndrome (CRPS) of the hand. Efficacy of combined treatment concepts and safety of ultrasound-guided SGB have not been sufficiently investigated yet. METHODS A total number of 156 blocks were evaluated in 16 patients with CRPS in a retrospective analysis. All patients received pharmacotherapy and a standard regimen of occupational therapy offered simultaneously to the SGBs. Changes in both spontaneous and evoked pain levels were assessed by numerical pain rating score before and after the last blockade of a series. Side effects were documented. RESULTS The overall mean pain reduction was 63.2% regarding spontaneous and 45.3% regarding evoked pain. Mild complications, such as hoarseness or dysphagia, occurred in 13.5% of the blocks (21 SGBs). Serious complications, such as plexus paresis or accidental puncture of vessels or other structures, did not occur. Time between symptom onset and start of treatment did not affect the extent of pain reduction. CONCLUSIONS The combination of ultrasound-guided SGB and simultaneous pharmacological and occupational therapy showed encouraging treatment results under conditions of this pilot case series. Assessment of efficacy of this combined treatment concept and safety of ultrasound-guided SGB require further prospective clinical studies with larger number of participants.

Comprehensive Curriculum for Phantom-Based Training of Ultrasound-Guided Intercostal Nerve and Stellate Ganglion Blocks

OBJECTIVE Ultrasound (US)-guided pain procedures become increasingly important due to their numerous advantages. Solid proficiency is necessary, however, to minimize complications and guarantee adequate performance. To enable beginners to learn the relevant skills in the technique of US-guided stellate ganglion (SGB) and intercostal nerve block (ICB), a training curriculum was developed and tested using self-made phantoms. DESIGN The curriculum comprised an introduction to the didactics of US, SGB, and ICB, a demonstration of the techniques by an expert user, as well as hands-on training of needle guidance using a gel pad and two phantoms. SUBJECTS Three groups of participants with different levels of expertise with US-guided procedures took part in the curriculum: 12 medical students with no prior experience, 12 anesthesiologists with some experience, and five senior anesthesiologists who already applied these techniques on a regular basis. METHODS Participants evaluated the curriculum via questionnaire, and their performance of time until adequate puncture, attempts required for adequate puncture, number of corrections, and unintentional punctures was assessed. RESULTS The medical students significantly increased their speed during both nerve blocks and reduced the number of attempts and corrections necessary to perform adequate ICB. The anesthesiologists with some experience also increased their speed in both blocks. The participants rated the curriculum as good to very good. CONCLUSIONS The combination of theoretical teaching, expert demonstration, and hands-on training on phantoms proved useful in acquiring skills needed for US-guided procedures such as SGB and ICB, and can potentially improve graduate and post-graduate medical education.