Bakgrund: Att snabbt identifiera och behandla sepsis är avgörande för patientens överlevnad. Sjuksköterskor inom akutsjukvården spelar en central roll i identifiering av sepsis då de är den profession som gör den initiala bedömningen och övervakningen av patienterna. Syfte: Syftet med litteraturöversikten var att beskriva faktorer som påverkar sjuksköterskors förutsättningar att identifiera sepsis inom akutsjukvård. Metod: Detta examensarbete är en strukturerad litteraturöversikt med inslag av den metodologi som tillämpas vid systematiska översikter. Litteraturöversikten består av tio vetenskapliga artiklar med kvalitativ och kvantitativ ansats. Sökningar av artiklar gjordes i CINAHL och PubMed och artiklarna var publicerade mellan 2014 och 2024. Resultat: Omfattar de två huvudkategorierna kompetens och organisation med de fyra underkategorierna vikten av utbildning, vikten av erfarenhet, teamsamverkan samt rutiner och resurser. Slutsats: Sjuksköterskorna hade återkommande upplevelser av kunskapsbrist vid identifieringen av tecken på sepsis, något som sjuksköterskorna upplevde skulle kunna förbättras med utbildningsinsatser. Vikten av erfarenhet, samverkan i team och screeningverktyg ansågs stötta sjuksköterskorna i deras bedömningar. Organisatoriska faktorer kunde påverka sjuksköterskorna både positivt och negativt och organisationerna tycks ha svårigheter att tillhandahålla utbildning och träning om sepsis. / Background: Prompt identification and treatment of sepsis is crucial for patient survival. Nurses in emergency care play a central role in the identification of sepsis as they are the profession that performs the initial assessment and monitoring of patients. Aim: The aim of this study was to describe factors that affect nurses' ability to identify sepsis in emergency care. Method: This thesis is a structured literature review that includes elements from the methodology applied in systematic reviews. The literature review consists of ten scientific articles with both qualitative and quantitative approaches. Searches for articles were conducted in CINAHL and PubMed and were published between 2014 and 2024. Results: The result includes the two main categories of competence and organization with the four sub-categories that are importance of education, importance of experience, team collaboration and routines and resources. Conclusions: Nurses have recurring experiences of a lack of knowledge when identifying signs of sepsis, something that the nurses felt could be improved with educational efforts. The importance of experience, teamwork and screening tools were considered to support the nurses in their assessments. Organizational factors could affect nurses both positively and negatively and the organizations seem to have difficulties to provide education and training in sepsis.

Résumé : Le sepsis sévère et le choc septique réfractaire sont d’incidences grandissantes dans la population et restent actuellement un défi de taille avec une mortalité variant de 30 à 70 % à 28 jours malgré l’amélioration du traitement de support. Les corticostéroïdes (CS) sont un traitement d’appoint controversé dans le sepsis sévère et le choc septique réfractaire. Ils modulent entre autre les fonctions des neutrophiles ou polymorphonuclear neutrophils cells (PMN) qui sont des acteurs de 1ère ligne dans la défense immédiate contre le sepsis et les défaillances organiques associées. Résultats : Le sepsis a pour effet de diminuer l’activité phagocytaire, ainsi que la production de radicaux libres oxygénés (ROS) des PMN au jour 1 (J1) et jour 3 (J3). Il augmente l’adhésion qui s’intensifie avec la sévérité de la maladie et persiste jusqu’à J3. Au niveau de la dégranulation, le sepsis augmente la production et la libération de la pentraxine 3 (PTX3). Le sepsis affecte le profil phénotypique des PMN en augmentant l’expression de CD66b et ST2 à J1 et J3. Il accentue également l’expression de CD64. Dans le groupe 2 (G2), ce niveau d’expression diminue à J3. Aucun effet significatif sur le chimiotactisme n’a été observé à J1, ni J3. L’usage de CS in vitro retarde l’apoptose à J1 et J3 dans le groupe 1 (G1), mais ne démontre aucune amélioration significative des fonctions des PMN ou au niveau de leur profil phénotypique. Conclusion : Le sepsis entraîne une immunoparalysie des PMN au niveau de leur migration et des fonctions effectrices. Non seulement cette paralysie augmente avec la sévérité de la maladie, mais elle persiste également après 3 jours suivant l’admission. De faibles doses de CS in vitro et in vivo dans le traitement du choc septique n’ont pas d’effet déterminant sur les PMN dans l’amélioration du pronostic des patients. Davantage de recherches seront nécessaires afin d’approfondir notre compréhension de l’impact d’un traitement aux CS sur les fonctions neutrophiliques dans un contexte septique. Ces derniers permettraient non seulement de mieux cibler leur utilisation dans le but d’arriver à un rapport bénéfique/risque avantageux dans le choc septique, mais aussi pour d’autres maladies inflammatoires. / Abstract : With the increasing rates of severe sepsis and refractory septic shock, there is still a challenge in mortality rates between 30 and 70 % at 28 days despite improved supportive care. Corticosteroids (CS) are a controversial supportive treatment in severe sepsis and refractory septic shock. They modulate the functions of PMN that are players in first line of immediate defence against the sepsis and associated to multiorgan failures. Results : Sepsis leads to a reduced phagocytic activity and ROS production at day 1 (D1) and day 3 (D3). It enhances the adhesion which increases with the severity of sepsis and persists until D3. In terms of degranulation, the sepsis increases the production and release of PTX3. Sepsis affects the phenotypic profile of PMN that increases the expressions of CD66b and ST2 at D1 and D3. It increases the CD64 expression but decreased at D3 in G2. No significant effect on chemotaxis was observed in D1, neither in D3. In G1, use of CS in vitro further delays apoptosis at D1 and D3, but is not showing any improvement in functions of PMN or in phenotypic profile. Conclusions : Sepsis induces an immune paralysis of PMN in their migration and effectives functions. Not only this paralysis increases with the severity of the sepsis, but it also persists after 3 days following the admission. Low doses of CS in vitro and in vivo in the treatment of septic shock have not determinant effect on PMN in improvement of the outcome of patients. More research is needed to learn more about the impacts of CS treatment on PMN functions in sepsis. This would contribute not only to ensure a better target ing of their use in order to achieve an advantageous benefits/risks ratio in septic shock, but also for others inflammatory diseases.

Background: Community acquired pneumonia (CAP) is a high incidence disease resulting in about 260,000 hospital admissions per year in Germany, more than myocardial infarction or stroke. Worldwide, CAP is the most frequent infectious disease with high lethality ranging from 1.2 % in those 20–29 years old to over 10 % in patients older than 70 years, even in industrial nations. CAP poses numerous medical challenges, which the PROGRESS (Pneumonia Research Network on Genetic Resistance and Susceptibility for the Evolution of Severe Sepsis) network aims to tackle: Operationalization of disease severity throughout the course of disease, outcome prediction for hospitalized patients and prediction of transitions from uncomplicated CAP to severe CAP, and finally, to CAP with sepsis and organ failure as a life-threatening condition. It is a major aim of PROGRESS to understand and predict patient heterogeneity regarding outcome in the hospital and to develop novel treatment concepts. Methods: PROGRESS was designed as a clinical, observational, multi-center study of patients with CAP requiring hospitalization. More than 1600 patients selected for low burden of co-morbidities have been enrolled, aiming at a total of 3000. Course of disease, along with therapy, was closely monitored by daily assessments and long-term follow-up. Daily blood samples allow in depth molecular-genetic characterization of patients. We established a well-organized workflow for sample logistics and a comprehensive data management system to collect and manage data from more than 50 study centers in Germany and Austria. Samples are stored in a central biobank and clinical data are stored in a central data base which also integrates all data from molecular assessments. Discussion: With the PROGRESS study, we established a comprehensive data base of high quality clinical and molecular data allowing investigation of pressing research questions regarding CAP. In-depth molecular characterization will contribute to the discovery of disease mechanisms and establishment of diagnostic and predictive biomarkers. A strength of PROGRESS is the focus on younger patients with low burden of co-morbidities, allowing a more direct look at host biology with less confounding. As a resulting limitation, insights from PROGRESS will require validation in representative patient cohorts to assess clinical utility. Trial registration: The PROGRESS study was retrospectively registered on May 24th, 2016 with ClinicalTrials.gov: NCT02782013

Bei der klinischen Beschreibung einer Sepsis sind Symptome vorhanden, die allesamt auf eine endotheliale Beteiligung schließen lassen. Hierzu zählt die Infektion an sich, die Regulation der Gefäßpermeabilität, der Gerinnung, der Interaktion mit zirkulierenden Zellen, des Gefäßtonus und des Sauerstoffverbrauchs. In systematischer Weise werden die Einflüße reaktiver Sauerstoff- und Stickstoffderivate für diese endothelialen Funktionen beschrieben. Beide Molekülgruppen können toxische Wirkungen als unspezifisch im Sinne der Onkose induzieren, die komplex von den jeweiligen Produktionsraten und Umgebungsbedingungen abhängig sind. Es scheint bei einer NO. induzierten Toxizität eine kooperative Wirkung mit reaktiven Sauerstoffderivaten zu geben, wohingegen eine primär durch reaktive Sauerstoffderivate induzierte Toxizität von niedrig dosiertem NO. inhibiert werden kann. Daneben kann der Tod einer Zelle auch als eine teleologisch sinnvolle Form geregelt eintreten. Dieser sogenannte programmierte Zelltod, die Apoptose, scheint durch exogene Zufuhr reaktiver Sauerstoff- oder Stickstoffderivate eher wenig wahrscheinlich. Dagegen scheint die endogene Produktion reaktiver Sauerstoffderivate enger mit proapoptotischen Veränderungen assoziiert zu sein. Die endogene endotheliale Produktion von NO. hat in bisherigen Untersuchungen widersprüchliche Bedeutung für die Apoptose und muß weiteren Untersuchungen vorbehalten bleiben. Ob eine durch Sepsis induzierte endotheliale Apoptose oder Onkose bei Menschen vorliegt wird diskutiert. Unabhängig von der Induktion zum Sterbeprozeß haben reaktive Sauerstoff- und Stickstoffderivate eine signalgebende Funktion in Endothelzellen, die nach exogener Zugabe aber auch durch eine endogene Produktion systematisch zusammengefaßt werden. Zahlreiche Sepsiserreger, oder deren Sekretions-, bzw. Abbauprodukte können primär mit Endothelzellen interagieren. Bereits diese frühen Interaktion gehen mit einer Dysregulation reaktiver Sauerstoff- und Stickstoffderivate einher. Vor allem im Rahmen eines früh auftretenden septischen Schocks wird eine enorm erhöhte Gefäßpermeabilität deutlich. Untersuchungen zur endothelialen Permeabilität legen zumindest in vitro eine Dysregulation reaktiver Sauerstoff- und Stickstoffderivate nahe. Die Regulation des Gefäßtonus ist ganz offensichtlich bei septischen Patienten gestört. Welcher Beitrag hierfür auf eine gestörte Endothelfunktion zurückzuführen ist wurde in zahlreichen tierexperimentellen Modellen untersucht. Endothelzellen sind in der Lage, den Sauerstoffverbrauch ganzer Organe zu regeln und Implikationen für die Pathophysiologie der Sepsis werden diskutiert. Endotheliale Dysfunktionen bei septischen Patienten scheinen aufgrund tierexperimenteller Modellvorstellungen naheliegend, sind aber nur ansatzweise bei Menschen belegt. Es ist unklar, welche endothelialen Funktionsdefizite bei septischen gut definierten Patienten überhaupt sicher zu quantifizieren sind, oder wie lange sie anhalten und sich über die Zeit ändern. Auch ist nicht belegt, ob lösliche Marker ein Funktionsdefizit anzeigen, oder lediglich Ausdruck einer allgemeinen Schädigung eines Organismus sind. Eine Dysbalance der endothelialen Produktion reaktiver Sauerstoff- und Stickstoffderivate liegt allerdings sehr wahrscheinlich vor. / The definition of sepsis includes clinical signs which all are related to endothelial dysfunctions. Infections agents can primarily target endothelial cells. The regulation of vascular permeability and coagulation, the interaction with circulating cells, vasoregulation and oxygen consumption are endothelial dependent. Systematically it is described how reactive oxygen species and reactive nitrogen species act as mediators for these diverse functions. Both reactive oxygen and nitrogen species are well known for their toxic potencies leading to oncosis. Their interaction is very complex. Nitric oxide induced toxic reactions increase in the presence of reactive oxygen species, whereas reactive oxygen species induced toxicity is decreased by low doses of nitric oxide. Apoptosis as opposed to oncosis hardly is induced by exogeneous reactive oxygen or nitrogen species in endothelial cells. However, endogeneous production of reactive oxygen species is more likely to serve proapoptotic functions. Whether patients suffering from sepsis show increased signs of apoptotic endothelium is discussed. Signalling events by low doses of exogeneous reactive oxygen and nitrogen species as well as by endogeneous production in endothelial cells unrelated to death signals are summarized. The known signalling pathways are integrated into specific dysregulated endothelial functions of septic patients. Early interactions of endothelium with infectious agents involve reactive oxygen and nitrogen species. Clinically apparent early signs of septic shock include increased vascular permeability and vasoregulatory disturbance. The involvement of endothelium and reactive oxygen and nitrogen species in these functions is summarized. New data have become available showing that endothelium is able to regulate whole organ oxygen consumption in which reactive oxygen and nitrogen species are involved. These data are discussed. From these in vitro and animal studies it seems evident that endothelial dysfunctions are central features of sepsis. However it remains to be clearly shown that definite endothelial dysfunctions are present and measurable in well defined patient groups, how long these suggested dysfunctions are present or change along the course of septic episodes. The involvement of dysregulated production of reactive oxygen and nitrogen species is most likely.

Das essentielle Spurenelement Selen (Se) wird als Selenocystein (Sec) in sog. Selenoproteine eingebaut. Selenoproteine haben aufgrund von Sec besondere Eigenschaften und eine Reihe von wichtigen Funktionen im Körper. Im Menschen führt starker Se-mangel zu degenerativen Knorpelerkrankungen und stellt einen Risikofaktor für die Entwicklung von Krebs, Entzündungen, kognitiven Verfall, Schlaganfall und Schilddrüsenerkrankungen dar. Hypoxie tritt ebenfalls in einer Vielzahl schwerer Erkrankungen wie Krebs, Sepsis oder Trauma auf. Auf zellulärer Ebene wird die Hypoxieantwort über Transkriptionsfaktoren der HIF-Familie („Hypoxia-Inducible Factor“) vermittelt. Die Leber ist das zentrale Organ des Selenmetabolismus. Hier wird über die Nahrung aufgenommenes Selen in organisches Sec umgewandelt und in Form von Selenoprotein P (SePP) dem Körper zur Verfügung gestellt. Die Hypothese dieser Arbeit war, dass Hypoxie die Selenoproteinbiosynthese beeinflusst. Experimentell induzierte Hypoxie führte in humanen hepatokarzinomen Zellen zu einer verminderten Expression fast aller Selenproteinen bis auf die für Überleben und Abwehr von reaktiven Sauerstoffspezies wichtige Glutathion Peroxidase 4 (GPX4), welche auch unter hypoxischen Bedingungen stabil exprimiert wurde. Diese Umverteilung von Sec, weg von der Biosynthese des sezernierten SePP hin zur intrazellulären GPX4, wurde HIF unabhängig vermittelt. Stattdessen wurden Schlüsselenzyme der Sec-Biosynthese spezifisch herunterreguliert. Mesenchymale Stammzellen (MSC) leben im Körper unter hypoxischen Bedingungen und haben aufgrund Ihrer Plastizität ein großes regeneratives Potential. In diesem Zellmodel führte nicht Hypoxie, sondern Se-Supplementation, zu einer Herunterregulation der Selenoprtoeinbiosynthese. Dieser Effekt dürfte für die Proliferationskapazität der MSC essentiell sein. In dieser Arbeit werden diese Ergebnisse vorgestellt und vor dem Hintergrund einer Studie zu Se-Spiegeln bei Patienten mit Polytrauma diskutiert. / The essential trace element Selenium (Se) is incorporated into proteins, so called selenoproteins, in form of the 21st proteinogenic amino acid selenocysteine (Sec). Due to the unique biochemical characteristics of Sec, selenoproteins fulfill a number of important functions within the body. In humans, a profound Se deficiency predisposes to a degenerative cartilage disease and moderate Se deficiency constitutes a risk factor for a variety of diseases, such as cancer, inflammation, cognitive decline, stroke or thyroid diseases. Hypoxia occurs in a number of severe illnesses, e.g. in cancer, sepsis or trauma. The cellular transcriptional response is mediated via „Hypoxia inducible factors“ (HIF). The liver is the central organ of Se metabolism, where dietary Se is organified to Sec and distributed in form of selenoprotein P (SePP) throughout the body. This thesis tested the hypothesis that hypoxia may directly affect selenoprotein biosynthesis. In human hepatocarcinoma cells, an experimentally-induced hypoxia led to a reduction of almost all selenoproteins analyzed, with the notably exception of Glutathione Peroxidase, type 4 (GPX4). The enzyme GPX4, important for neutralizing lipid hydroperoxides, remained stably expressed under hypoxic conditions. This redistribution of Sec, away from the secreted Se transporter SePP towards the intracellular protective enzyme GPX4, was HIF independent and rather a result down-regulation of key enzymes at the bottleneck of Sec biosynthesis. Mesenchymal stem cells (MSC) survive in the human body in a hypoxic niche. Due to their great plasticity, MSC have a huge regenerative potential. In this cell model, it was not hypoxia, but rather Se supply itself, which led to a coordinated down-regulation of the whole Sec biosynthesis machinery causing diminished selenoprotein biosynthesis. In this thesis these results are presented and discussed in light of a clinical trial on the importance of Se in polytraumatic patients.

Die meisten Lebewesen nutzen zur Abwehr von pathogenen Mikroorganismen u.a. ein weites Spektrum von antimikrobiellen, oft kationischen Peptiden. Etliche dieser natürlichen und künstlichen Peptide sind in der Lage, Bakterienprodukte wie das Lipopolysaccharid (LPS) Gram-negativer Bakterien zu binden. LPS ist als potenter Stimulator des Immunsystems ein bedeutender Faktor bei der Entstehung von Infektion und Entzündung. LPS-bindende kationische Peptide, zu denen auch von der LPS-Bindungssequenz des Limulus-anti-LPS-Faktors (LALF) abgeleiteten Ringpeptide gehören, wirken synergistisch zu den klassischen Antibiotika, ohne jedoch wie diese zu einer vermehrten LPS-Freisetzung zu führen. LALF-Peptide zeigten in bisher veröffentlichten Versuchen vielversprechende Ergebnisse bei der Bindung von LPS und in murinen Sepsismodellen. In der vorliegenden Arbeit wird in Versuchen mit humanen Monozyten und murinen Makrophagen gezeigt, dass neuartige LALF-Peptide eine durch LPS induzierte Ausschüttung des Zytokins TNF-alpha und des vasoaktiv wirksamen Stickstoffoxids wirkungsvoll unterdrücken können. Ferner wird in LPS-Bindungsassays nachgewiesen, dass dies durch eine Blockierung der LPS-Erkennung durch das LPS bindende Protein (LPB) verursacht wird. Die Verwendung von D-Aminosäuren verspricht dabei in ersten in vitro Experimenten eine Optimierung der Peptid-Eigenschaften. Die Entschlüsselung der Wirkmechanismen dieser neuartigen Peptide könnte Auswirkungen auf die Entwicklung neuer therapeutischer Interventionsstrategien bei Infektion und Sepsis haben. / In host defense against pathogenic microorganisms most organisms employ a broad spectrum of antimicrobial, often cationic peptides. Several of these natural or synthetic peptides are able to bind bacterial products like Lipopolysaccharide (LPS) of Gram-negative bacteria. As a potential stimulator of the immune system LPS is an important pathogenetic factor for infection and inflammation. Cationic LPS-binding peptides like cyclic peptides corresponding to the LPS-binding domain of the Limulus-anti-LPS-factor (LALF) have been shown to act synergistic to classic antibiotics. An advantage of these compounds, however, may be their lack of induction of LPS release. In previous studies LALF-peptides have shown promising results for binding LPS, and in murine sepsis models. Here we show in experiments with human monocytes and murine macrophages that novel LALF-derived peptides are able to effectively block the LPS-induces release of the cytokine TNF-alpha and of the vasoactive nitric oxide. In addition it is shown here by employing an LPS-binding assay that this activity is caused by inhibition of LPS-recognition brought about by the LPS binding protein (LBP). In first in vitro experiments the use of D-amino acids looks promising as they improve peptide quality. To further elucidate the mode of action of these novel peptides could lead to the development of new therapeutic strategies against infection and sepsis.

LPS wird von Gram-negativen Bakterien freigesetzt und führt mit Hilfe von LBP zur Ausschüttung proinflammatorischer Zytokine aus Monozyten und Makrophagen. Diese von LPS ausgelöste Kaskade, ist entscheidend an der Entstehung der Sepsis beteiligt. In dieser Arbeit wurde gezeigt, daß die LPS-induzierte Stimulation von Makrophagen durch murines Serum gehemmt werden kann. Außerdem konnte im Rahmen dieser Arbeit im Mausmodell verdeutlicht werden, welche Rolle Lipoproteine und LBP bei dem protektiven Serumeffekt spielen. Von den in Mausseren verschiedener Mausstämme bestimmten Parametern korrelierte der Phospholipidgehalt relativ gut mit dem inhibitorischen Serumeffekt. Eine Depletion von Lipoproteinen aus den Seren führte zu einer starken Reduktion des inhibitorischen Serumpotentials, während die Verwendung von LBP-defizienten Seren keinen Einfluß auf den Serumhemmeffekt hatte. Lipoproteine sehr geringer, geringer und hoher Dichte verursachten in Gegenwart von LBP eine deutliche Reduktion der LPS-Effekte, die gut mit ihrem Phospholipidgehalt korrelierte. In Abwesenheit von Serum und LBP konnten Lipoproteine LPS-Effekte auch bei hohen Phospholipidkonzentrationen kaum noch inhibieren. In nativen murinen Lipoproteinen hoher Dichte und lipoproteindefizientem Serum ließ sich LBP nachweisen. Die Ergebnisse dieser Arbeit zeigen, daß native Lipoproteine sehr geringer, geringer und hoher Dichten als Akzeptoren für LPS dienen können. Ihr inhibitorisches Potential korreliert am besten mit ihrem Phospholipidgehalt. Der Transport von LPS in diese Lipoproteine wird durch LBP katalysiert, was den protektiven Effekt hoher LBP-Konzentrationen erklärt. Weiterhin konnte gezeigt werden, daß LBP nicht der einzige Bestandteil von murinem Serum ist, der LPS in Lipoproteine transferiert. Vermutlich ist bei den, in dieser Arbeit verwendeten Serumkonzentrationen der PLTP-Gehalt ausreichend, diesen LPS-Transfer in Abwesenheit von LBP zu vollziehen. Bei der Interaktion zwischen Lipoproteinen und LPS handelt es sich um einen physiologischen Weg des Organismus, um auf bakterielle Endotoxine zu reagieren und so der Sepsis entgegenzuwirken. Mit genaueren Kenntnissen über diese Interaktion, bei der Lipidtransferproteine wie LBP und PLTP eine entscheidende Rolle spielen, können eventuell in Zukunft Methoden gefunden werden, diese physiologischen Vorgänge des Körpers zu unterstützen, um so eine Sepsis zu therapieren. / LPS released by gram-negative bacteria is bound by LBP and initiates the release of proinflammatory cytokines in makrophages and monocytes. These cytokines are thought to play a central role in the pathophysiology of sepsis. In these studies I was able to show an inhibitory effect of murine serum on the LPS-induced stimulation of macrophages. Furthermore the role of lipoproteins and LBP in this protective effect of serum was investigated. The inhibitory effect of serum from different mouse strains was best correlated to its phospholipid content. Depletion of serum from lipoproteins strongly reduced its LPS-inhibitory potential while depletion of serum from LBP had no effect. Murine VLDL, LDL and HDL were found to be potent inhibitors of LPS-effects in presence of LBP. In abscence of LBP the inhibitory effect was much weaker. LBP could be detected in murine HDL and murine lipoproteindeficient serum. My data shows that HDL, LDL and VLDL can act as acceptors of LPS. Their inhibitory potential is best correlated to their phospholipid content. LBP catalyses transport of LPS into lipoproteins. This could be an explanation for its protective effect in high doses. Furthermore it could be shown that LBP is not the only serum component that transfers LPS into Lipoproteins. Possibly the used serum contained enough PLTP to perform this transfer in absence of LBP. The interaction between Lipoproteins and LPS is a physiological way of the organism to react on endotoxines and inhibit the development of sepsis. PLTP and LBP play major roles in this interaction. Understanding the pathways of LPS-detoxification may help to support the organism s physiological answer and establish new methods to treat sepsis.

Le sepsis est une dérégulation de la réponse de l’hôte à une infection, associé à un dysfonctionnement des organes engageant le pronostic vital du patient. Plus de 30 millions de cas et 5 millions de décès sont estimés par an dans le monde. Le diagnostic du sepsis est basé sur des signes cliniques non spécifiques et la longue procédure d’identification des pathogènes responsables de l’infection. L’objectif de cette étude est de développer et d’évaluer le potentiel de la spectroscopie vibrationnelle appliquée au sérum pour améliorer le diagnostic du sepsis. Les défis inhérents à la nature de l’échantillon et à la technique de même que certains paramètres pré-analytiques ont été évalués pour assurer la qualité des données. Les variations de contenu en eau des échantillons après séchage pouvant affecter la discrimination des données, ont été corrigées en testant différentes méthodes. Enfin, des sérums de patients septicémiques (n=380) collectés avant chirurgie et jusqu’à 3 jours avant et le jour du diagnostic ont été analysés. Les échantillons du groupe contrôle (n=353) collectés suivant la même cinétique, provenant de patients ayant un profil similaire en termes d’âge, de sexe, de procédure chirurgicale subie mais n’ayant pas développé de sepsis et des échantillons (n=180) de patients atteints d’un syndrome de réponse inflammatoire systémique collectés avant chirurgie et le jour du diagnostic ont également été analysés. Les données acquises ont été exploitées par méthodes chimiométriques pour discriminer des zones spectrales reflétant des différences de composition moléculaire avec des sensibilités et spécificités supérieures à 70% malgré l’influence de l’eau résiduelle. / Sepsis is a dysregulated host response to an infection that causes life-threatening organ dysfunction. Each year, over 30 million cases and 5 million deaths are estimated worldwide. Diagnosis of sepsis is based on non-specific clinical signs and time consuming positive identification of the causative pathogen. The objective of this study is to develop and evaluate the potential of vibrational spectroscopy applied to human serum to improve diagnosis of sepsis. Challenges of serum spectroscopy inherent to the sample nature and preparation as well as to the technique have been assessed to determine the most suitable methodological approach. Then, some aspects of the pre-analytical phase have been addressed in order to standardise protocols in sample handling and preparation for spectral acquisitions to ensure quality and reproducibility of spectral data collected. Different methods have been tested to correct water content variations in dried serum, which can impact on data discrimination. Finally, based upon the developed methodology, patient serum samples (n=380) collected before surgery, up to 3 days before sepsis diagnosis, and on the day of sepsis diagnosis have been analysed. Control serum samples (n=353) from age/ sex/ procedure-matched patients who did not go on to develop sepsis have been also analysed over similar timeframes post-surgery as well as samples (n=180) from patients with systemic inflammatory response syndrome. Spectral data acquired have been interrogated by chemometric methods to identify spectral zones reflecting differences in molecular composition allowing discrimination with over 70% of sensitivities and specificities despite water interferences.

Dentre as manifestações clínicas observadas em pacientes sépticos, as disfunções neurológicas são, provavelmente, as de fisiopatologia mais obscura e pobremente explorada, o que consequentemente as torna de difícil entendimento e tratamento médico. Adicionalmente, estudos epidemiológicos indicam que a síndrome séptica é mais frequente e mais letal em pacientes idosos. Nesse contexto, este trabalho objetivou comparar os efeitos da sepse, induzida pelo modelo de ligadura e perfuração cecal, no encéfalo de ratos jovens e idosos por meio da análise da expressão gênica de larga escala (transcriptoma), a fim de averiguar como as alterações no padrão de expressão podem estar relacionadas a disfunções neurológicas. Os resultados deste estudo indicaram a diminuição da expressão dos genes Bcl-3, S100A8 e uridina fosforilase 1, bem como o aumento da expressão de Stefin A3, sendo tais efeitos característicos das manifestações comuns da sepse no sistema nervoso central, independentemente da idade dos animais; por outro lado, a diminuição da expressão do gene da haptoglobina foi observada apenas nos animais idosos com sepse. De forma geral, na comparação entre animais idosos e jovens, os resultados desta pesquisa apontaram que animais idosos apresentam uma quantidade menor de genes modificados pela sepse, o que sugere menor capacidade de ativar mecanismos neuroprotetores / Among the clinical manifestations observed in septic patients, the neurological dysfunctions are probably the most obscure and poorly explored pathophysiology, which consequently makes them difficult to understand and to treat. Additionally, epidemiological studies indicate that septic syndrome is more frequent and more lethal in elderly patients. In this context, this article is aimed at comparing the effects of sepsis, induced by the ligature model and cecal perforation, on the brain of young and elderly rats by means of the analysis of the large scale gene expression (transcriptome), in order to investigate how the changes in this expression may be related to neurological dysfunctions. The results of this study indicated decreased expression of the Bcl-3, S100A8 and uridine phosphorylase 1 genes, as well as increased expression of Stefin A3, these effects being characteristic of the common manifestations of central nervous system sepsis regardless of the age of the animals; on the other hand, decreased haptoglobin gene expression was observed only in the elderly animals with sepsis. In general, in the comparison between old and young animals, the results of this research indicated that elderly animals present a smaller amount of genes modified by sepsis, which suggests a smaller capacity to activate neuroprotective mechanisms

Dentre as manifestações clínicas observadas em pacientes sépticos, as disfunções neurológicas são, provavelmente, as de fisiopatologia mais obscura e pobremente explorada, o que consequentemente as torna de difícil entendimento e tratamento médico. Adicionalmente, estudos epidemiológicos indicam que a síndrome séptica é mais frequente e mais letal em pacientes idosos. Nesse contexto, este trabalho objetivou comparar os efeitos da sepse, induzida pelo modelo de ligadura e perfuração cecal, no encéfalo de ratos jovens e idosos por meio da análise da expressão gênica de larga escala (transcriptoma), a fim de averiguar como as alterações no padrão de expressão podem estar relacionadas a disfunções neurológicas. Os resultados deste estudo indicaram a diminuição da expressão dos genes Bcl-3, S100A8 e uridina fosforilase 1, bem como o aumento da expressão de Stefin A3, sendo tais efeitos característicos das manifestações comuns da sepse no sistema nervoso central, independentemente da idade dos animais; por outro lado, a diminuição da expressão do gene da haptoglobina foi observada apenas nos animais idosos com sepse. De forma geral, na comparação entre animais idosos e jovens, os resultados desta pesquisa apontaram que animais idosos apresentam uma quantidade menor de genes modificados pela sepse, o que sugere menor capacidade de ativar mecanismos neuroprotetores / Among the clinical manifestations observed in septic patients, the neurological dysfunctions are probably the most obscure and poorly explored pathophysiology, which consequently makes them difficult to understand and to treat. Additionally, epidemiological studies indicate that septic syndrome is more frequent and more lethal in elderly patients. In this context, this article is aimed at comparing the effects of sepsis, induced by the ligature model and cecal perforation, on the brain of young and elderly rats by means of the analysis of the large scale gene expression (transcriptome), in order to investigate how the changes in this expression may be related to neurological dysfunctions. The results of this study indicated decreased expression of the Bcl-3, S100A8 and uridine phosphorylase 1 genes, as well as increased expression of Stefin A3, these effects being characteristic of the common manifestations of central nervous system sepsis regardless of the age of the animals; on the other hand, decreased haptoglobin gene expression was observed only in the elderly animals with sepsis. In general, in the comparison between old and young animals, the results of this research indicated that elderly animals present a smaller amount of genes modified by sepsis, which suggests a smaller capacity to activate neuroprotective mechanisms