Prevalence of serious bacterial infections and management of febrile infants ≤60 days in Swedish Pediatric Emergency Departments

BACKGROUND. The reported prevalence of serious bacterial infections (SBI: urinary tract infection (UTI), bacteremia, and meningitis) among febrile infants ≤60 days of age varies from 8% to 23%. There are indications that the prevalence of infections differs between the sexes. Infants with fever at home but afebrile at the pediatric emergency department (PED) might have a lower risk of SBIs. Furthermore, the management of febrile infants and adherence to guidelines varies among PEDs. There is a paucity of knowledge regarding how physicians decide whether to follow management recommendations. AIM. To describe the age- and sex-specific prevalence of SBIs in infants aged ≤60 days with fever without source (FWS) at four PEDs in Sweden. To evaluate whether there is a difference in the prevalence between infants with reported fever at home who are afebrile at the PED and those who are still febrile. To describe the clinical management and outcomes of febrile infants. To investigate physicians’ decision-making process when managing febrile infants aged ≤60 days and to describe the factors that influenced this decision.METHOD. This thesis is comprised of 2 separate projects. The first is a retrospective cross-sectional study in previously healthy, full-term febrile infants ≤60 days with FWS who presented at 4 PEDs in 2014-2020. The second is a qualitative study with a phenomenographic approach based on focus group discussions with physicians active in 2 of the PEDs. RESULTS. There were included 2237 febrile infants aged ≤60 days with FWS. The prevalence of SBIs was 12.6% (95% CI, 11.0-14.3), of UTI 11.0% (95% CI, 9.5-12.6), of bacteremia 1.5% (95% CI, 1.0-2.2), and of meningitis 0.5% (95% CI, 0.2–0.9). In infants aged ≤28 days, the prevalence of meningitis did not differ (p=1.000) between girls 0.8% (95% CI, 0.1-2.9) and boys 0.9% (95% CI, 0.2-0.2.7). Similarly, there was no difference in the risk of meningitis between infants aged ≤28 days with reported fever at home who were febrile at the PED and those still febrile, with a risk ratio (RR) of 1.05 (95% CI, 0.18–6.23). In infants aged ≤28 days, lumbar puncture (LP) was performed in 13% (95% CI, 11–16), blood culture in 40% (95% CI, 36–40), broad-spectrum antibiotics were administered in 30% (95% CI, 26–34), and 67% (95% CI,63–71) were hospitalized. Of the infants who did not receive antibiotics at the initial approach, 0.3% (95% CI, 0.1–0.8) were diagnosed with meningitis or bacteremia. Three main factors influenced the decision-making process on whether to perform an LP:1) a possible focus of infection that could explain the origin of the fever; 2) questioning whether the temperature at home reported by the parents was a fever, especially if it was ≤38.2°C; and 3) the infant’s general condition and questioning the need for LP in case of well-appearing infants.CONCLUSIONS. The prevalence of meningitis and bacteremia was low in infants aged ≤60 days with FWS. A different meningitis risk estimation is not justified for infants aged ≤28 days with reported fever at home afebrile at the PED. The management of febrile infants aged ≤28 days did not constitute of routine LP, blood culture, antibiotic treatment, and hospitalization but was not associated with increased adverse outcomes. Such management should be investigated further since it could reduce unnecessary investigations, antibiotic treatments, and hospitalizations. The primary factors that influenced physicians to omit performing LP were general appearance, presence of fever, and possible focus of infection

Experimental study of the structural effect on the nanosecond nonlinear optical response of O-doped polycyclic aromatic hydrocarbons (PAHs)

The nonlinear optical response of some O-doped PAHs is systematically investigated in the present work aiming to understand the influence of structural effects on their nonlinear optical response. In that view, the third-order nonlinear optical properties of these PAHs were measured under 4 ns, visible (532 nm) and infrared (1064 nm) laser excitation. The O-doped PAHs were found exhibiting large saturable absorption and negative sign nonlinear refraction under visible excitation, both increasing with the addition of naphtalene units and with the number of O-atoms. Their nonlinear optical response was found to be negligible under infrared excitation. Similar measurements performed on thin films of these PAHs have shown that they maintain their large nonlinear optical response even in solid state, confirming their high potential for opto-electronic and photonic applications

Tailoring colors by O-annulation of polycyclic aromatic hydrocarbons

The synthesis of O-doped polyaromatic hydrocarbons, in which two polycyclic aromatic hydrocarbon subunits are bridged through one or two O atoms, has been achieved. This includes high-yielding ring-closure key steps that, depending on the reaction conditions, yield the formation of either furanyl or pyranopyranyl linkages through intramolecular C-O bond formation. Comprehensive photophysical measurements in solution showed that these molecules feature exceptionally high emission yields and tunable absorption properties throughout the UV-vis spectral region. Electrochemical investigations showed that in all cases the O-annulation increases the electron donor capabilities by raising the HOMO energy level with the LUMO energy level being less affected. Moreover, third-order NLO measurements of solutions or thin films containing the dyes displayed very good second hyperpolarizibility values. Importantly, PMMA films containing the pyranopyranyl derivatives displayed weak linear absorption and NLO absorption compared to the nonlinearity and NLO refraction, respectively, revealing to be exceptional organic materials for photonic devices

Thyroid hormone alterations in critically and non-critically ill patients with SARS-CoV-2 infection

Objective: Following the evolution of COVID-19 pandemic, reports pointed on a high prevalence of thyroiditis-related thyrotoxicosis. Interpretation of thyroid tests during illness, however, is hampered by changes occurring in the context of non-thyroidal illness syndrome (NTIS). In order to elucidate these findings, w e studied thyroid function in carefully selected cohorts of COVID-19 positive and negative patients. Design: Cohort observational study. Methods: We measured TSH, FT4, T3 within 24 h of admission in 196 patients without thyroid disease and/or confounding medications. In this study, 102 patients were SARS-CoV-2 positive; 41 admitted in the ICU, 46 in the ward and 15 outpatients. Controls consisted of 94 SARS-CoV-2 negative patients; 39 in the ICU and 55 in the ward. We designated the thyroid hormone patterns as consistent with NTIS, thyrotoxicosis and hypothyroidism. Results: A NTIS pattern was encountered in 60% of ICU and 36% of ward patients, with similar frequencies between SARS-CoV-2 positive and negative patients (46.0% vs 46.8%, P = NS). A thyrotoxicosis pattern was observed in 14.6% SARS-CoV-2 ICU patients vs 7.7% in ICU negative (P = NS) and, overall in 8.8% of SARS-CoV-2 positive vs 7.4% of neg ative patients. In these patients, thyroglobulin levels were similar to those with normal thyroid function or NTIS. The hypothyroidism pattern was rare. Conclusions: NTIS pattern is common and relates to the severity of disease rather than SARS-CoV-2 infection. A thyrotoxicosis pattern is less frequently observed with similar frequency between patients with and without COVID-19. It is suggested that thyroid hormone monitoring in COVID-19 should not differ from other crit ically ill patients

TREM-1 expression on neutrophils and monocytes of septic patients: relation to the underlying infection and the implicated pathogen

<p>Abstract</p> <p>Background</p> <p>Current knowledge on the exact ligand causing expression of TREM-1 on neutrophils and monocytes is limited. The present study aimed at the role of underlying infection and of the causative pathogen in the expression of TREM-1 in sepsis.</p> <p>Methods</p> <p>Peripheral venous blood was sampled from 125 patients with sepsis and 88 with severe sepsis/septic shock. The causative pathogen was isolated in 91 patients. Patients were suffering from acute pyelonephritis, community-acquired pneumonia (CAP), intra-abdominal infections (IAIs), primary bacteremia and ventilator-associated pneumonia or hospital-acquired pneumonia (VAP/HAP). Blood monocytes and neutrophils were isolated. Flow cytometry was used to estimate the TREM-1 expression from septic patients.</p> <p>Results</p> <p>Within patients bearing intrabdominal infections, expression of TREM-1 was significantly lower on neutrophils and on monocytes at severe sepsis/shock than at sepsis. That was also the case for severe sepsis/shock developed in the field of VAP/HAP. Among patients who suffered infections by Gram-negative community-acquired pathogens or among patients who suffered polymicrobial infections, expression of TREM-1 on monocytes was significantly lower at the stage of severe sepsis/shock than at the stage of sepsis.</p> <p>Conclusions</p> <p>Decrease of the expression of TREM-1 on the membrane of monocytes and neutrophils upon transition from sepsis to severe sepsis/septic shock depends on the underlying type of infection and the causative pathogen.</p

Ανάπτυξη και χαρακτηρισμός ισχυρής πηγής παλμών αττοδευτερολέπτων για πειράματα XUV-pump-XUV-probe

Many scientific areas in technology and basic research (atomic-molecular and solid state physics, chemistry, biology) will derive tremendous benefit from the investigation of the light-matter interaction in temporal scales of the atomic unit of time. Also, real time studies of several fundamental processes in the microscopic scale involve characteristic times of the order of the period of the nuclear and electron motion in molecules or atoms. Few-femtosecond (fsec) (1 fsec=10-15 sec) and attosecond (asec) (1 asec=10-18 sec) temporal resolution is required in order to obtain snapshots of their evolution. Tools for such studies are light pulses with duration in the asec time scale in the extreme ultraviolet regime (XUV). Intense asec pulses will be beneficial for such investigations since they can induce non-linear processes in a target system and hence can be used for ultra-fast dynamics studies in an XUV-pump-XUV-probe configuration. The aim of my thesis is the development and characterization of a table-top XUV asec source with the highest ever reported XUV intensity and the implementation of this source for XUV-pump-XUV-probe studies in the non-linear XUV regime. The work took place in the Attosecond Science and Technology (AST) laboratory in FORTH-IESL.Πολλοί επιστημονικοί τομείς στην τεχνολογία και τη βασική έρευνα (ατομική-μοριακή και στερεάς κατάστασης φυσική, χημεία, βιολογία) θα αποκομίσουν τεράστιο όφελος από τη διερεύνηση της αλληλεπίδρασης φωτός-ύλης σε χρονικές κλίμακες της ατομικής μονάδας του χρόνου. Επίσης, οι μελέτες σε πραγματικό χρόνο αρκετών θεμελιωδών διαδικασιών στη μικροσκοπική κλίμακα περιλαμβάνουν χαρακτηριστικούς χρόνους της τάξης της περιόδου της πυρηνικής κίνησης και της κίνησης ηλεκτρονίων σε μόρια ή άτομα. Για την μελέτη τέτοιων διαδικασιών απαιτείται χρονική ανάλυση λίγων-φεμπτοδευτερολέπτων (fsec) (1 fsec = 10-15 sec) και αττοδευτερολέπτων (asec) (1 asec = 10-18 sec) για να ληφθούν στιγμιότυπα της εξέλιξής τους. Εργαλεία για τέτοιες μελέτες είναι οι παλμοί φωτός με διάρκεια στην κλίμακα χρόνου asec στο ακραίο υπεριώδες (XUV). Οι ισχυροί παλμοί asec θα είναι επωφελείς για τέτοιες έρευνες δεδομένου ότι μπορούν να προκαλέσουν μη γραμμικές διεργασίες σε ένα ατομικό ή μοριακό σύστημα και ως εκ τούτου μπορούν να χρησιμοποιηθούν για μελέτες δυναμικής εξαιρετικά γρήγορης σε μια διαμόρφωση ανιχνευσης με την μέθοδο XUV-pump-XUV probe. Ο στόχος της διατριβής μου είναι η ανάπτυξη και ο χαρακτηρισμός μιας ισχυρής πηγής XUV asec με την υψηλότερη ένταση XUV που έχει αναφερθεί ποτέ και την εφαρμογή αυτής της πηγής για μελέτες ανιχνευτών XUV-pump-XUV στο μη γραμμικό οπτικές διαδικασίες στην περιοχή του XUV. Οι εργασία πραγματοποιήθηκε στο εργαστήριο Attosecond Science and Technology (AST) στο ΙΤΕ-IESL

1. TOWARDS THE REALIZATION OF SPACES CAPABLE OF HOSTING AND AUGMENTING POLITICAL PARTICIPATION

The spaces of electronic democracy are organized and function as two parallel networks that coexist in constant interaction: the urban network, which refers to the city and the digital network, which refers to the cyberspace. Groups of people come together and create subsequently multiple combinations of collective activities. The project investigates the possibilities of creating actual generators of political actions by placing EDSs close to sites of existing public flows and perceiving them as the means of physical and digital convergence. The virtual space, as it is expressed and represented in the internet, augments their tactile, physical entity, while physical space supports the digital interaction, by ensuring the interpersonal contact, a necessary factor for meaningful democratic dialogue. Those two spaces, digital and physical, must coexist in order for the EDSs to be accessible by everyone. Obviously spaces where public dialogue takes place, like squares and markets, already exist in the city net. There are also virtual equivalents like chatting groups or forums on the internet. In the first case the information is just an instance expression of personal speculations and in the second the information is lost in the chaos of networked places. Political reactions on the subjects that are discussed are rare and therefore all those social dynamics go into hibernation. In the digital and physical space of the project the information of the dialogues is recorded, published and provided to the public in order to be manipulated and redefined. The “vima ” is transformed into a hyper-space, a spatial hypertext, accessible to anyone. The word “vima ” is generated from the ancient Greek word “βήμα ” for tribune in the ancient market where Athenians could express their political ideas. As “vima ” we understand the singular entity of a digital or physical node of the networks, while their intermediate space of interaction is the actual “space ” of the EDSs