Prevalence and clinical implications of bloodstream infections in intensive care patients with or without burn injury: a retrospective cohort study.

PURPOSE: Severe burn injuries are often accompanied by infections and associated with high morbidity and mortality. This study aimed to compare the prevalence and clinical impact of bacteremia between patients receiving intensive care with and without burns. METHODS: This single-center retrospective cohort study at the University Hospital Vienna, Austria, analyzed blood cultures from intensive care unit (ICU) patients with and without burns (2012-2022) to assess the prevalence of bacteremia, the associated pathogen distribution and the 60-day all-cause mortality. RESULTS: In 1170 ICU patients, 303 with burns and 867 without, the prevalence of bacteremia was similar among patients with at least one blood culture (31/157 [19.7%] versus 44/213 [20.7%], OR [95%CI] = 0.95 [0.57-1.57]). Burn patients exhibited a significantly higher frequency of microbiological sampling (51.5% versus 24.5%, p < 0.001), resulting in a higher overall prevalence of bacteremia (10.2% versus 5.1%, p = 0.002). 16.2% of all identified pathogens were multidrug-resistant (MDR). The 60-day all-cause mortality was higher in patients with MDR pathogens than in patients without bacteremia (41.7% versus 10.6%, p = 0.026). CONCLUSION: Bacteremia prevalence was similar in burn and non-burn patients, with high rates of multidrug-resistant Gram-negative pathogens. The 60-day all-cause mortality was significantly higher in patients with MDR pathogens than in patients without bacteremia.

Tackling Vaccine Hesitancy and Increasing Vaccine Willingness Among Parents of Unvaccinated Children in Austria.

Objectives: In autumn 2021, there was a surge of COVID-19 infections in Austria, and vaccination coverage stagnated at a below-average level compared to the rest of Europe. Surveys showed that both children and adolescents were the main drivers of the rising infection rates and that vaccination numbers were particularly low in this age group. This was due to widespread vaccination skepticism and hesitancy among parents of unvaccinated children and adolescents. Methods: Here, we describe a novel intervention concept that allowed us to efficiently tackle parental vaccine hesitancy. We designed an intervention series that followed a reproducible format based on online face-to-face seminars in groups of a maximum of twenty people. Each seminar included an anonymous online questionnaire for internal quality control. Moreover, we assessed the motives of parental vaccine hesitancy and asked participants to rate subjective vaccine willingness for their children on a scale of zero to ten. Results: Within 8 weeks, more than 580 people participated in the seminar series. We found that concerns about the side effects of the vaccine were the predominant motive of vaccination hesitancy among the study population. Overall, the intervention could successfully increase the median parental vaccination willingness of participants from a score of five to eight. We identified tree hesitancy motives (distrust towards the pharmaceutical industry, the government, or feelings of restriction from personal freedom) that were associated with below-average vaccination willingness and significant lower increase. Conclusion: With this study we analyzed motives driving COVID-19 vaccination hesitancy among parents of unvaccinated children and reasons of parents to restrain their children from getting vaccinated. The intervention method described here, could effectively address individual concerns on a personal level while at the same time reach a large number of people across geographical and language barriers. Thereby we could significantly increase subjective vaccination willingness of the participants. Our approach is easy to apply, highly cost-effective, and can be used to tackle any kind of medical misinformation.

Brown Adipose Tissue Prevalence Is Lower in Obesity but Its Metabolic Activity Is Intact.

Due to its high metabolic activity, brown adipose tissue (BAT) has become a promising target for the development of novel treatment concepts for metabolic disease. Despite several reports of a negative association between the presence of active BAT and obesity, very little is known about the quantitative and qualitative differences of BAT in lean and obese individuals. Systematic studies directly comparing cold-induced BAT activity in leanness and obesity are currently lacking. Here we studied BAT mass and function in 31 lean and 64 obese men and women. After a standardized cooling protocol using a water-perfused vest, 18F-FDG-positron emission tomography/computed tomography scans were performed, and BAT was delineated using lean body-mass adjusted standardized uptake value (SUV) thresholds in anatomic regions with fat radiodensity. Cold-induced thermogenesis (CIT), a functional readout of BAT activity, was quantified by indirect calorimetry. Active BAT was present in a significantly higher proportion of lean than obese individuals (58% vs. 33%, p=0.019). In these participants with active BAT, however, BAT volume and activity did not differ between leanness and obesity. Accordingly, CIT was similar in both weight groups. BAT metrics were not related to adiposity or total fat mass per se. However, in obese participants a strong negative correlation existed between visceral adipose tissue and BAT volume, 18F-FDG uptake and CIT. In summary, despite a significantly lower prevalence of BAT, the metabolic activity and thermogenic capacity of BAT appears to be still intact in obesity and is inversely associated with visceral fat mass.

Active Brown Adipose Tissue is Associated With a Healthier Metabolic Phenotype in Obesity.

Obesity is associated with increasing cardiometabolic morbidity and mortality worldwide. Not everyone with obesity, however, develops metabolic complications. Brown adipose tissue (BAT) has been suggested as a promoter of leanness and metabolic health. To date, little is known about the prevalence and metabolic function of BAT in subjects with severe obesity, a population at high cardiometabolic risk. In this cross-sectional study, we included 40 individuals with WHO class II-III obesity (BMI ≥ 35 kg/m2). Employing a 150-minute personalized cooling protocol and 18F-fluorodeoxyglucose positron emission tomography/computed tomography, cold-activated BAT was detectable in 14 (35%) of the participants. Cold-induced thermogenesis was significantly higher in participants with detectable BAT compared to those without. Notably, individuals with obesity and active BAT had 28.8% lower visceral fat mass despite slightly higher total fat mass compared to those without detectable BAT 18F-FDG uptake. This was accompanied by lower insulin resistance and systemic inflammation and improved NAFLD parameters, all adjusted for age, sex, and percent body fat. Contrary to previous assumptions, we show here that a significant fraction of individuals with severe obesity has active BAT. We found that decreased BAT 18F-FDG uptake was not associated with adiposity per se but with higher visceral fat mass. In summary, active BAT is linked to a healthier metabolic phenotype in obesity.

Characterization of endogenous bile acid composition in individuals with cold-activated brown adipose tissue.

INTRODUCTION: Bile acid signaling has been suggested to promote BAT activity in various experimental models. However, little is known if and how physiologic bile acid metabolism is linked to BAT function in humans. Here we investigated the association between BAT activity and circulating bile acid concentrations in lean and obese individuals. METHODS: BAT 18F-fluorodeoxyglucose uptake was measured after a standardized cooling protocol by positron emission tomography/computed tomography. Cold-induced thermogenesis was assessed by indirect calorimetry. Fasting bile acid concentrations were determined by high performance liquid chromatography-high-resolution mass spectrometry. RESULTS: In a cohort of 24 BAT-negative and 20 BAT-positive individuals matched by age, sex, and body mass index, circulating bile acid levels were similar between groups except for higher ursodeoxycholic acid and a trend towards a lower 12α-OH/non-12α-OH bile acid ratio in lean participants with active BAT compared to those without. Moreover, the 12α-OH/non-12α-OH ratio, a marker of CYP8B1 activity, correlated negatively with BAT volume and activity. CONCLUSION: Fasting concentrations of major bile acids are not associated with cold-induced BAT activity in humans. However, the inverse association between BAT activity and 12α-OH/non-12α-OH ratio may suggest CYP8B1 as a potential new target in BAT function and warrants additional investigation.

Sex differences in brown adipose tissue activity and cold-induced thermogenesis.

INTRODUCTION: Brown adipose tissue (BAT) is suggested to exhibit a sexual dimorphism and thus contributes to the observed sex differences in cardiometabolic risk observed between women and men. Clinical data supporting this hypothesis are however scarce. The aim of this study was to investigate the relationship between BAT activity and sex using positron emission tomography (PET) - the current gold-standard for BAT quantification. METHODS: In this study, we included 95 subjects with a wide BMI range (20-55 kg/m2) aged from 18 to 50 years. Avoiding shivering, participants were cooled with a water-perfused vest to achieve adequate BAT activation. BAT activity was determined by 18F-fluorodeoxyglucose PET/computed tomography (18F-FDG PET/CT). Cold-induced thermogenesis (CIT) was quantified by indirect calorimetry. RESULTS: BAT was present in 44.6% of pre-menopausal women and in 35.9% of men (p = 0.394). CIT was significantly higher in women (p = 0.024). Estradiol levels were positively associated with CIT independent of age, sex, body fat and other sex hormones (b = 0.360, p = 0.016). In women, CIT decreased during the menstrual cycle, with lower levels in the luteal phase similar to median concentrations in men. CONCLUSION: The prevalence of cold-activated BAT is slightly but non-significantly higher in pre-menopausal women than men. CIT is increased in females and independently associated with estradiol, suggesting that sex hormones may play a role in different thermogenic responses between men and women.