The enteric nervous system (ENS) innervates the gastrointestinal (GI) tract and controls central aspects of GI physiology including contractility of the intestinal musculature, glandular secretion and intestinal blood flow. The ENS is composed of neurons that conduct electrical signals and of enteric glial cells (EGCs). EGCs resemble central nervous system (CNS) astrocytes in their morphology and in the expression of shared markers such as the intermediate filament protein glial fibrillary acidic protein (GFAP). They are strategically located at the interface of ENS neurons and their effector cells to modulate intestinal motility, epithelial barrier stability and inflammatory processes. The specific contributions of EGCs to the maintenance of intestinal homeostasis are subject of current research. From a clinical point of view EGC involvement in pathophysiological processes such as intestinal inflammation is highly relevant. Like CNS astrocytes ECGs can acquire a reactive, tissue-protective phenotype in response to intestinal injury. In patients with chronic inflammatory bowel diseases (IBD) such as Crohn's disease and ulcerative colitis, alterations in the EGC network are well known, particularly a differential expression of GFAP, which is a hallmark of reactive gliosis in the CNS. With increasing recognition of the role of EGCs in intestinal health and disease comes the need to study the glial population in its complexity. The overall aim of this thesis was to comprehensively study EGCs with focus on the reactive GFAP-expressing subpopulation under inflammatory conditions in vivo and in vitro. In a first step, a novel in vivo rat model of acute systemic inflammation mimicking sepsis was employed to investigate rapidly occuring responses of EGCs to inflammation. This study revealed that within a short time frame of a few hours, EGCs responded to the inflammation with an upregulation of Gfap gene expression. This inflammation-induced upregulation was confined to the myenteric plexus and varied in intensity along the intestinal rostro-caudal axis. This highly responsive myenteric GFAP-expressing EGC population was further characterized in vivo andin vitro using a transgenic mouse model (hGFAP-eGFP mice). Primary purified murine GFAP-EGC cultures in vitro were established and it was assessed how the transcriptomic and proteomic profiles of these cells change upon inflammatory stimulation. Here, myenteric GFAP-EGCs were found to undergo a shift in gene expression profile that predominantly affects expression of genes associated with inflammatory responses. Further, a secretion of inflammatory mediators was validated on protein level. The GFAP+ subpopulation is hence an active participant in inflammatory pathophysiology. In an acute murine IBD model in vivo, GFAP-EGCs were found to express components of the major histocompatibility complex (MHC) class II in inflamed tissue, which also indicates a crosstalk of EGCs with the innate and the adaptive lamina propria immune system in acute inflammation. Taken together, this work advances our knowledge on EGC (patho-)physiology by identifying and characterizing an EGC subpopulation rapidly responsive to inflammation. This study further provides the transcriptomic profile of this population in vivo and in vitro, which can be used to identify targets for therapeutic intervention. Due to the modulating influence of EGCs on the intestinal microenvironment, the study further underlines the importance of integrating EGCs into in vitro test systems that aim to model intestinal tissues in vitro and presents an outlook on a potential strategy. / Das enterische Nervensystem (ENS) innerviert den gastrointestinalen Trakt und kontrolliert zentrale Aspekte der gastrointetinalen Physiologie, wie die Kontraktilität der intestinalen Muskulatur, Sekretion und den intestinalen Blutfluss. Das ENS setzt sich aus elektrisch leitenden Neuronen und enterischen Gliazellen (EGZ) zusammen. EGZ ähneln Astrozyten des zentralen Nervensystems (ZNS) hinsichtlich ihrer Morphologie und der Expression gemeinsamer Marker wie dem Intermediärfilament Saures Gliafaserprotein (GFAP von engl. glial fibrillary acidic protein). EGZ sind strategisch an der Kontaktstelle zwischen ENS-Neuronen und deren Effektorzellen positioniert, um die intestinale Motilität, die epitheliale Barrierestabilität sowie inflammatorischen Prozesse zu modulieren. Die spezifische Beteiligung der EGZ an der Aufrechterhaltung der Darmhomöostase wird gegenwärtig erforscht. Aus klinischer Sicht ist die Beteiligung von EGZ an pathophysiologischen Prozessen wie der intestinalen Entzündung besonders relevant. Wie ZNS-Astrozyten können EGZ bei intestinalen Schädigungen einen reaktiven, gewebe-protektiven Phänotyp annehmen. Bei Patienten mit chronisch-entzündlichen Darmerkrankungen (IBD, von engl. inflammatory bowel disease) wie Morbus Crohn und Colitis ulcerosa sind Veränderungen im EGZ-Netzwerk bekannt, besonders eine veränderte Expression von GFAP, welches ein prominentes Kennzeichen der reaktiven Gliose im ZNS ist. Nachdem sich die Bedeutung der EGZ im gesunden und kranken Darm zunehmend herausgestellt hat, muss ein stärkerer Fokus auf die Erforschung der glialen Population gelegt werden. Die Zielsetzung dieser Arbeit war die umfassende Untersuchung der EGZ mit Fokus auf die reaktive GFAP-exprimierende Population unter entzündlichen Bedingungen in vivo und in vitro}. In einem ersten Schritt wurde ein neuartiges in vivo-Rattenmodell einer akuten systemischen Entzündung verwendet, um die schnell stattfindenden Veränderungen der EGZ unter entzündlichen Bedingungen zu untersuchen. Diese Studie ergab, dass innerhalb von wenigen Stunden EGZ mit einer Hochregulation der Gfap-Genexpression auf die Entzündung reagieren. Diese entzündungsinduzierte Hochregulation war lokal auf den myenterischen Plexus begrenzt und entlang der rostro-kaudalen Achse des Darms unterschiedlich stark ausgeprägt. Die responsive, GFAP-exprimierende myenterische EGZ-Population wurde daraufhin in vivo und in vitro charakterisiert unter Zuhilfenahme eines transgenen Mausmodells (hGFAP-eGFP-exprimierende Mäuse). Primäre, aufgereinigte GFAP-EGZ-Zellkulturen wurden etabliert und dahingehend untersucht, wie sich das transkriptomische und proteomische Profil der Population unter entzündlichen Bedingungen verändert. Hierbei wurde reproduzierbar eine Verschiebung des transkriptomischen Profils myenterischer GFAP-exprimierender EGZ gefunden. Die davon betroffenen Gene sind vorwiegend mit Immunantworten assoziiert. Weiterhin wurde die Sekretion solcher Immunmediatoren auf Proteinebene validiert. Die GFAP+ Subpopulation ist somit ein aktiver Modulator entzündlicher pathophysiologischer Prozesse. In einem akuten IBD-Mausmodell konnte weiterhin gezeigt werden, dass GFAP-EGZ verstärkt Komponenten des Haupthistokompatibilitätskomplex (MHC) Klasse II im entzündeten Gewebe exprimieren. Dies weist auf eine direkt Interaktion der EGZ mit dem Immunsystem in der Lamina propria hin. Insgesamt konnte mit dieser Arbeit das Wissen über die (Patho-)Physiologie von EGZ erweitert werden, indem eine schnell responsive EGZ-Subpopulation identifizert und charakterisiert wurde. Weiterhin wurde im Rahmen dieser Arbeit das gesamte Transkriptomprofil der GFAP-Subpopulation in vivo und in vitro veröffentlicht, welches für weitere Studien zur Identifikation möglicher therapeutischer Anwendungen genutzt werden kann. Aufgrund des modulierenden Einflusses der EGZ auf die Darmphysiologie betont diese Studie die Notwendigkeit EGZs in in-vitro-Gewebemodelle des Darms zu integrieren und präsentiert einen Ausblick auf eine mögliche Strategie.

In this study, we investigated the role of angiotensinergic neurotransmission at nucleus reticularis ventrolateralis (NRVL), and the subtype of angiotensin receptors involved, during experimental endotoxemia induced by E. coli lipopolysaccharide (LPS). In adult male Sprague-Dawley rats maintained under propofol anesthesia (30 mg/kg/h), paralyzed with pancuronium (2 mg/kg/h) and mechanically ventilated (85-95 stroke/min, 2.5-3 ml/stroke), intravenous administration of LPS (15 or 30 mg/kg) induced an immediate hypotension, followed by a rebound increase and a secondary decrease in systemic arterial pressure (SAP). LPS also reduced the power density of the very low-frequency (0-0.25 Hz) and low-frequency (0.25-0.8 Hz) components of SAP signals (Phase ¢¹), which represented the sympathetic vasomotor tone, followed by an increase (Phase ¢º) and a secondary decrease (Phase ¢»). Pretreatment with microinjection of the selective non-peptide AT1 receptor antagonist, losartan (1.6 nmol), or the selective non-peptide AT2 receptor antagonist, PD-123319 (1.6 nmol), into the bilateral NRVL significantly reduced the survival time after the induction of acute experimental endotoxemia. Both pretreatments shortened the duration of Phase ¢º and Phase ¢» in acute endotoxemia, accelerated the secondary hypotension, and excited the power density of the very low-frequency. We conclude that endogenous angiotensin ¢º at the NRVL may play a crucial role in the maintenance of SAP during acute experimental endotoxemia, possibly via an action on both AT1 and AT2 subtype receptors on the very low-frequency component of SAP spectrum.

Septic shock is one of the most common causes of mortality in intensive care, in spite of antibiotic treatment. Glucocorticoid treatment can be used to blunt an overwhelming immune response in severe inflammation. The varying effects of glucocorticoid treatment in sepsis are poorly understood, with consequences for the clinical guidelines for treatment. Glucocorticoids are potent anti-inflammatory mediators which exert their effects through the glucocorticoid receptor (GR). Deeper understanding about the mechanisms of GR signalling may help to guide and improve glucocorticoid treatment. The aim of this thesis was to analyse GR expression and binding capacity in experimental and human septic shock and severe inflammation with cellular specificity using flow cytometry. In the late phase of a murine sepsis model, we observed decreased GR expression in leukocytes. In a murine model of early endotoxic shock, we observed decreased GR binding capacity in spite of an increased expression, in neutrophils. Glucocorticoid treatment was beneficial only when administered early in both models. Compared to healthy subjects, GR expression was increased in leukocytes from patients during the initial sepsis phase, while GR binding capacity was only increased in lymphocytes and monocytes. In contrast, neutrophils and other leukocyte subsets displayed decreased GR binding capacity. Neutrophil numbers were increased in all patients with sepsis compared to healthy subjects. We also studied patients with burn injury after admission before any infectious event had likely occurred, and on day 7 post admission, when several of the patients had been diagnosed with sepsis. GR expression and binding capacity was increased in leukocytes on admission as compared to healthy subjects, and patients diagnosed with sepsis on day 7 had a further increased GR expression in T lymphocytes. GR binding capacity was decreased in proportion to the extent of the burn injury on day 14 post admission. In conclusion, sepsis and severe inflammation have significant impact on the expression and function of GR, likely to influence the efficiency of glucocorticoid treatment. In addition, glucocorticoid treatment is beneficial only when given early in these models of experimental sepsis.

Intarvaskulinių kateterių infekcija yra viena iš pirminių sepsio šaltinių RITS . Šio darbo tikslas išsiaiškinti slaugytojo vaidmenį kateterinio sepsio profilaktikai. Tyrimo hipotezė: slaugytojų darbo kokybė turi įtakos kateterinio sepsio atsiradimo prevencijai. Tam, kad būtų išsiaiškintas kateterinio sepsio dažnis RITS; nustatos kateterizacijos vietos, kateterio buvimo trukmės ir infuzijos (parenterinės mitybos, kraujo ir jo komponentų) įtaka kateterinio sepsio dažniui buvo tiriami ligoniai, kurie buvo gydomi RITS ne trumpiau trijų dienų ir kuriems buvo atlikta centrinės venos kateterizacija Siekiant išsiaiškinti, kokios RITS slaugytojų žinios CVK priežiūros klausimais, kokie veiksmai daro įtaką jų darbui, kokie jų praktiniai įgūdžiai, buvo atlikta anketinė apklausa. Tyrimo metu Vilniaus universiteto ligoninėje Santariškių klinikos I RITS nustatyta: infekuoto kateterio atvejų – 16,9%; su CVK susijusios bakteremijos atvejų – 8,4%; (kateterinis sepsis nustatytas visais su CVK susijusios bakteremijos atvejais); iš viso su CVK susijusios infekcijos dažnis sudaro 25,3%. CVK buvimo trukmė daro įtaką kateterinės infekcijos atsiradimo dažniui. Kuo trumpesnis CVK buvimo laikotarpis, tuo mažesnė kateterinės infekcijos atsiradimo rizika. Priklausomybės ryšio tarp kateterizacijos vietos ir kateterinės infekcijos dažnių bei tarp infuzijos (parenterinės mitybos, kraujo ir jo komponentų) ir kateterinės infekcijos dažnių nenustatyta. Spėjama, kad tai susiję su naujų technologijų I RITS... [toliau žr. visą tekstą] / Kravčenko Tatjana Role of the norse in prevention of Catheter-Related infections in Intesive Care Unit. Final Master‘s paper on the speciality of Nursing Supervisor: doc. Baublys A. Vilnius University, Faculty of Medicine Institute of Rehabilitation, Sports Medicine and Nursing Central venous catheters (CVCs) are widely used in critically ill patients and is one of the source for sepsis development in Intensive Care Units. The aim of this study was to evaluate the rate of catheter-related sepsis in ICU, the influence of catheter insertion site, insertion procedure, duration and infusion components for the development of sepsis. We investigate the patients with central venous catheters treated more than three days in ICU. We prepared the questionnaire for nurses about CVCs care and their theoretical and practical skills additionally. Research showed, that occurrence of catheter infection in ICU of Vilnius University Hospital Santariskiu Klinikos was 16.9%, the occurrence of bacteremia related to CVCs was 8.4%. Generally the observed rate of CVCs related infection - 25.3%. Analyzing the data we determine, that duration of CVC influence the rate of infection. Shorter duration - less risk for the development of catheter-related infection. No dependence was found between CVCs infection rate and catheter insertion site, infusion components. Supposedly, it associated with the use of new technologies and good organised, qualitative nurse work. The results of the research revealed... [to full text]

Universiẗat, Diss., 2007--Giessen.

Diss. (sammanfattning) Stockholm : Karol. inst., 2003. / Härtill 5 uppsatser.

Diss. (sammanfattning) Uppsala : Univ., 2004. / Härtill 5 uppsatser.

Zugl.: Giessen, Universiẗat, Diss., 2008.

Zugl.: Jena, Univ., Diss., 2006 u.d.T.: Hagel, Stefan: Protein-C- und Antithrombin-III-Aktivität / Hergestellt on demand

Regensburg, Univ., Diss., 2005.