Repeated caffeine intake suppresses cerebral grey matter responses to chronic sleep restriction in an A1 adenosine receptor-dependent manner: a double-blind randomized controlled study with PET-MRI.

Evidence has shown that both sleep loss and daily caffeine intake can induce changes in grey matter (GM). Caffeine is frequently used to combat sleepiness and impaired performance caused by insufficient sleep. It is unclear (1) whether daily use of caffeine could prevent or exacerbate the GM alterations induced by 5-day sleep restriction (i.e. chronic sleep restriction, CSR), and (2) whether the potential impact on GM plasticity depends on individual differences in the availability of adenosine receptors, which are involved in mediating effects of caffeine on sleep and waking function. Thirty-six healthy adults participated in this double-blind, randomized, controlled study (age = 28.9 ± 5.2 y/; F:M = 15:21; habitual level of caffeine intake < 450 mg; 29 homozygous C/C allele carriers of rs5751876 of ADORA2A, an A2A adenosine receptor gene variant). Each participant underwent a 9-day laboratory visit consisting of one adaptation day, 2 baseline days (BL), 5-day sleep restriction (5 h time-in-bed), and a recovery day (REC) after an 8-h sleep opportunity. Nineteen participants received 300 mg caffeine in coffee through the 5 days of CSR (CAFF group), while 17 matched participants received decaffeinated coffee (DECAF group). We examined GM changes on the 2nd BL Day, 5th CSR Day, and REC Day using magnetic resonance imaging and voxel-based morphometry. Moreover, we used positron emission tomography with [18F]-CPFPX to quantify the baseline availability of A1 adenosine receptors (A1R) and its relation to the GM plasticity. The results from the voxel-wise multimodal whole-brain analysis on the Jacobian-modulated T1-weighted images controlled for variances of cerebral blood flow indicated a significant interaction effect between caffeine and CSR in four brain regions: (a) right temporal-occipital region, (b) right dorsomedial prefrontal cortex (DmPFC), (c) left dorsolateral prefrontal cortex (DLPFC), and (d) right thalamus. The post-hoc analyses on the signal intensity of these GM clusters indicated that, compared to BL, GM on the CSR day was increased in the DECAF group in all clusters  but decreased in the thalamus, DmPFC, and DLPFC in the CAFF group. Furthermore, lower baseline subcortical A1R availability predicted a larger GM reduction in the CAFF group after CSR of all brain regions except for the thalamus. In conclusion, our data suggest an adaptive GM upregulation after 5-day CSR, while concomitant use of caffeine instead leads to a GM reduction. The lack of consistent association with individual A1R availability may suggest that CSR and caffeine affect thalamic GM plasticity predominantly by a different mechanism. Future studies on the role of adenosine A2A receptors in CSR-induced GM plasticity are warranted.

Intraoperative contrast-enhanced ultrasound has an outcome-relevant impact on surgery of primary and metastatic liver lesions.

PURPOSE: Complete resection of the affected tissue remains the best curative treatment option for liver-derived tumors and colorectal liver metastases. In addition to preoperative cross-sectional imaging, contrast-enhanced intraoperative ultrasound (CE-IOUS) plays a crucial role in the detection and localization of all liver lesions. However, its exact role is unclear. This study was designed to evaluate the clinical and oncological impact of using CE-IOUS in the surgical treatment of these diseases. MATERIALS AND METHODS: Over the three-year study period, 206 patients with primary liver tumors and hepatic metastases were enrolled in this prospective, monocentric study to evaluate the impact of CE-IOUS in liver surgery. Secondary outcomes included comparing the sensitivity and specificity of CE-IOUS with existing preoperative imaging modalities and identifying preoperative parameters that could predict a strategic impact of CE-IOUS. In addition, the oncological significance of CE-IOUS was evaluated using a case-cohort design with a minimum follow-up of 18 months. RESULTS: CE-IOUS findings led to a change in surgical strategy in 34% of cases (n=70/206). The accuracy in cases with a major change could be confirmed histopathologically in 71.4% of cases (n=25/35). The impact could not be predicted using parameters assumed to be clinically relevant. An oncological benefit of a CE-IOUS adapted surgical approach was demonstrated in patients suffering from HCC and colorectal liver metastases. CONCLUSION: CE-IOUS may significantly increase R0 resection rates and should therefore be used routinely as an additional staging method, especially in complex liver surgery.

Early risk factors for conduct problem trajectories from childhood to adolescence: the 2004 Pelotas (BRAZIL) Birth Cohort.

Conduct problems are associated with an increased risk of a wide range of physical, mental, and social problems. However, there is still uncertainty about how early risk factors differentiate different developmental patterns of conduct problems and whether findings replicate across diverse social contexts. We aimed to identify developmental trajectories of conduct problems, and test early risk factors, in the 2004 Pelotas Birth Cohort in Brazil. Conduct problems were measured at ages 4, 6, 11, and 15 years from caregiver reports on the Child Behaviour Checklist (CBCL) and Strengths and Difficulties Questionnaire (SDQ). Conduct problem trajectories were estimated using group-based semi-parametric modeling (n = 3938). Multinomial logistic regression was used to examine associations between early risk factors and conduct problem trajectories. We identified four trajectories: three with elevated conduct problems, including early-onset persistent (n = 150; 3.8%), adolescence-onset (n = 286; 17.3%), and childhood-limited (n = 697; 17.7%), and one with low conduct problems (n = 2805; 71.2%). The three elevated conduct problem trajectories were associated with a wide range of sociodemographic risk factors, prenatal smoking, maternal mental health, harsh parenting, childhood trauma, and child neurodevelopmental risk factors. Early-onset persistent conduct problems were particularly associated with trauma, living without a father figure, and attention difficulties. The four trajectories of conduct problems from ages 4 to 15 years in this Brazilian cohort have similar longitudinal patterns to those identified in high-income countries. The results confirm previous longitudinal research and developmental taxonomic theories on the etiology of conduct problems in a Brazilian sample.

Fiber alignment in 3D collagen networks as a biophysical marker for cell contractility.

Cells cultured in 3D fibrous biopolymer matrices exert traction forces on their environment that induce deformations and remodeling of the fiber network. By measuring these deformations, the traction forces can be reconstructed if the mechanical properties of the matrix and the force-free matrix configuration are known. These requirements limit the applicability of traction force reconstruction in practice. In this study, we test whether force-induced matrix remodeling can instead be used as a proxy for cellular traction forces. We measure the traction forces of hepatic stellate cells and different glioblastoma cell lines and quantify matrix remodeling by measuring the fiber orientation and fiber density around these cells. In agreement with simulated fiber networks, we demonstrate that changes in local fiber orientation and density are directly related to cell forces. By resolving Rho-kinase (ROCK) inhibitor-induced changes of traction forces, fiber alignment, and fiber density in hepatic stellate cells, we show that the method is suitable for drug screening assays. We conclude that differences in local fiber orientation and density, which are easily measurable, can be used as a qualitative proxy for changes in traction forces. The method is available as an open-source Python package with a graphical user interface.

A genetic variation in the adenosine A2A receptor gene contributes to variability in oscillatory alpha power in wake and sleep EEG and A1 adenosine receptor availability in the human brain.

The EEG alpha rhythm (∼ 8-13 Hz) is one of the most salient human brain activity rhythms, modulated by the level of attention and vigilance and related to cerebral energy metabolism. Spectral power in the alpha range in wakefulness and sleep strongly varies among individuals based on genetic predisposition. Knowledge about the underlying genes is scarce, yet small studies indicated that the variant rs5751876 of the gene encoding A2A adenosine receptors (ADORA2A) may contribute to the inter-individual variation. The neuromodulator adenosine is directly linked to energy metabolism as product of adenosine tri-phosphate breakdown and acts as a sleep promoting molecule by activating A1 and A2A adenosine receptors. We performed sleep and positron emission tomography studies in 59 healthy carriers of different rs5751876 alleles, and quantified EEG oscillatory alpha power in wakefulness and sleep, as well as A1 adenosine receptor availability with 18F-CPFPX. Oscillatory alpha power was higher in homozygous C-allele carriers (n = 27, 11 females) compared to heterozygous and homozygous carriers of the T-allele (n(C/T) = 23, n(T/T) = 5, 13 females) (F(18,37) = 2.35, p = 0.014, Wilk's Λ = 0.487). Furthermore, a modulatory effect of ADORA2A genotype on A1 adenosine receptor binding potential was found across all considered brain regions (F(18,40) = 2.62, p = 0.006, Wilk's Λ = 0.459), which remained significant for circumscribed occipital region of calcarine fissures after correction for multiple comparisons. In female participants, a correlation between individual differences in oscillatory alpha power and A1 receptor availability was observed. In conclusion, we confirmed that a genetic variant of ADORA2A affects individual alpha power, while a direct modulatory effect via A1 adenosine receptors in females is suggested.

Effects of electroconvulsive therapy on cerebral A1 adenosine receptor availability: a PET study in patients suffering from treatment-resistant major depressive disorder.

Introduction: Sleep deprivation and electroconvulsive therapy (ECT) effectively ameliorate symptoms in major depressive disorder (MDD). In rodents, both are associated with an enhancement of cerebral adenosine levels, which in turn likely influence adenosinergic receptor expression. The aim of the current study was to investigate cerebral A1 adenosine receptor (A1AR) availability in patients with MDD as a potential mediating factor of antidepressant effects of ECT using [18F]CPFPX and positron emission tomography (PET). Methods: Regional A1AR availability was determined before and after a series of ECT applications (mean number ± SD 10.4 ± 1.2) in 14 subjects (4 males, mean age 49.5 ± 11.8 years). Clinical outcome, measured by neuropsychological testing, and ECT parameters were correlated with changes in A1AR availability. Results: ECT had a strong antidepressive effect (p < 0.01) while on average cerebral A1AR availability remained unaltered between pre-and post-ECT conditions (F = 0.65, p = 0.42, mean difference ± SD 3.93% ± 22.7%). There was no correlation between changes in clinical outcome parameters and regional A1AR availability, although individual patients showed striking bidirectional alterations of up to 30-40% in A1AR availability after ECT. Solely, for the mean seizure quality index of the applied ECTs a significant association with changes in A1AR availability was found (rs = -0.6, p = 0.02). Discussion: In the present study, therapeutically effective ECT treatment did not result in coherent changes of A1AR availability after a series of ECT treatments. These findings do not exclude a potential role for cerebral A1ARs in ECT, but shift attention to rather short-termed and adaptive mechanisms during ECT-related convulsive effects.

Noninvasive Assessment of Arterial Pulse-Pressure Variation During General Anesthesia: Clinical Evaluation of a New High-Fidelity Upper Arm Cuff.

OBJECTIVES: To compare noninvasive pulse-pressure variation (PPV) measurements obtained from a new high-fidelity upper arm cuff using a hydraulic coupling technique to corresponding intraarterial PPV measurements. DESIGN: The authors used prospective multicenter comparison and development studies for the new high-fidelity upper arm cuff. SETTING: The study was performed in the departments of Anesthesiology at the Ludwig-Maximilians-Universität München Hospital, the University Hospital of Bonn, and the RoMed Hospital in Rosenheim (all Germany). PARTICIPANTS: A total of 153 patients were enrolled, undergoing major abdominal surgery or neurosurgery with mechanical ventilation. For the evaluation of PPV, 1,467 paired measurements in 107 patients were available after exclusion due to predefined quality criteria. INTERVENTIONS: Simultaneous measurements of PPV were performed from a reference femoral arterial catheter (PPVref) and the high-fidelity upper arm cuff (PPVcuff). The new device uses a semirigid conical shell. It incorporates a hydraulic sensor pad with a pressure transducer, leading to a tissue pressure-pulse contour with all characteristics of an arterial- pulse contour. MEASUREMENTS AND MAIN RESULTS: The comparative analysis of the included measurements showed that PPVref and PPVcuff were closely correlated (r = 0.92). The mean of the differences between PPVref and PPVcuff was 0.1 ± 2.0%, with 95% limits of agreement between -4.1% and 3.9%. To track absolute changes in PPV >2%, the concordance rate between the 2 methods was 93%. CONCLUSIONS: The new high-fidelity upper arm cuff method provided a clinically reliable estimate of PPV.

Associations between resting state brain activity and A1 adenosine receptor availability in the healthy brain: Effects of acute sleep deprivation.

Introduction: Previous resting-state fMRI (Rs-fMRI) and positron emission tomography (PET) studies have shown that sleep deprivation (SD) affects both spontaneous brain activity and A1 adenosine receptor (A1AR) availability. Nevertheless, the hypothesis that the neuromodulatory adenosinergic system acts as regulator of the individual neuronal activity remains unexplored. Methods: Therefore, fourteen young men underwent Rs-fMRI, A1AR PET scans, and neuropsychological tests after 52 h of SD and after 14 h of recovery sleep. Results: Our findings suggested higher oscillations or regional homogeneity in multiple temporal and visual cortices, whereas decreased oscillations in cerebellum after sleep loss. At the same time, we found that connectivity strengths increased in sensorimotor areas and decreased in subcortical areas and cerebellum. Discussion: Moreover, negative correlations between A1AR availability and rs-fMRI metrics of BOLD activity in the left superior/middle temporal gyrus and left postcentral gyrus of the human brain provide new insights into the molecular basis of neuronal responses induced by high homeostatic sleep pressure.

Divergent Effects of the Nonselective Adenosine Receptor Antagonist Caffeine in Pre-Manifest and Motor-Manifest Huntington's Disease.

There is a controversy about potentially positive or negative effects of caffeine consumption on onset and disease progression of neurodegenerative diseases such as Huntington's Disease (HD). On the molecular level, the psychoactive drug caffeine targets in particular adenosine receptors (AR) as a nonselective antagonist. The aim of this study was to evaluate clinical effects of caffeine consumption in patients suffering from premanifest and motor-manifest HD. Data of the global observational study ENROLL-HD were used, in order to analyze the course of HD regarding symptoms onset, motor, functional, cognitive and psychiatric parameters, using cross-sectional and longitudinal data of up to three years. We split premanifest and manifest participants into two subgroups: consumers of >3 cups of caffeine (coffee, cola or black tea) per day (>375 mL) vs. subjects without caffeine consumption. Data were analyzed using ANCOVA-analyses for cross-sectional and repeated measures analysis of variance for longitudinal parameters in IBM SPSS Statistics V.28. Within n = 21,045 participants, we identified n = 1901 premanifest and n = 4072 manifest HD patients consuming >3 cups of caffeine/day vs. n = 841 premanifest and n = 2243 manifest subjects without consumption. Manifest HD patients consuming >3 cups exhibited a significantly better performance in a series of neuropsychological tests. They also showed at the median a later onset of symptoms (all p < 0.001), and, during follow-up, less motor, functional and cognitive impairments in the majority of tests (all p < 0.050). In contrast, there were no beneficial caffeine-related effects on neuropsychological performance in premanifest HD mutation carriers. They showed even worse cognitive performances in stroop color naming (SCNT) and stroop color reading (SWRT) tests (all p < 0.050) and revealed more anxiety, depression and irritability subscores in comparison to premanifest participants without caffeine consumption. Similarly, higher self-reported anxiety and irritability were observed in genotype negative/control group high dose caffeine drinkers, associated with a slightly better performance in some cognitive tasks (all p < 0.050). The analysis of the impact of caffeine consumption in the largest real-world cohort of HD mutation carriers revealed beneficial effects on neuropsychological performance as well as manifestation and course of disease in manifest HD patients while premanifest HD mutation carrier showed no neuropsychological improvements, but worse cognitive performances in some tasks and exhibited more severe signs of psychiatric impairment. Our data point to state-related psychomotor-stimulant effects of caffeine in HD that might be related to regulatory effects at cerebral adenosine receptors. Further studies are required to validate findings, exclude potential other unknown biasing factors such as physical activity, pharmacological interventions, gender differences or chronic habitual influences and test for dosage related effects.

A simple risk score for mortality including the PCR Ct value upon admission in patients hospitalized due to COVID-19.

PURPOSE: To develop a simple score for the outcomes from COVID-19 that integrates information obtained at the time of admission including the Ct value (cycle threshold) for SARS-CoV-2. METHODS: Patients with COVID-19 hospitalized from February 1st to May 31st 2021 in RoMed hospitals, Germany, were included. Clinical and laboratory parameters upon admission were recorded and patients followed until discharge or death. Logistic regression analysis was used to determine predictors of outcomes. Regression coefficients were used to develop a risk score for death. RESULTS: Of 289 patients (46% female, median age 66 years), 29% underwent high-flow nasal oxygen (HFNO) therapy, 28% were admitted to the Intensive Care Unit (ICU, 51% put on invasive ventilation, IV), and 15% died. Age > 70 years, oxygen saturation ≤ 90%, oxygen supply upon admission, eGFR ≤ 60 ml/min and Ct value ≤ 26 were significant (p < 0.05 each) predictors for death, to which 2, 2, 1, 1 and 2 score points, respectively, could be attributed. Sum scores of ≥ 4 or ≥ 5 points were associated with a sensitivity of 95.0% or 82.5%, and a specificity of 72.5% or 81.7% regarding death. The high predictive value of the score was confirmed using data obtained between December 15th 2020 and January 31st 2021 (n = 215). CONCLUSION: In COVID-19 patients, a simple scoring system based on data available shortly after hospital admission including the Ct value had a high predictive value for death. The score may also be useful to estimate the likelihood for required interventions at an early stage.

Plectin-mediated cytoskeletal crosstalk controls cell tension and cohesion in epithelial sheets.

The coordinated interplay of cytoskeletal networks critically determines tissue biomechanics and structural integrity. Here, we show that plectin, a major intermediate filament-based cytolinker protein, orchestrates cortical cytoskeletal networks in epithelial sheets to support intercellular junctions. By combining CRISPR/Cas9-based gene editing and pharmacological inhibition, we demonstrate that in an F-actin-dependent context, plectin is essential for the formation of the circumferential keratin rim, organization of radial keratin spokes, and desmosomal patterning. In the absence of plectin-mediated cytoskeletal cross-linking, the aberrant keratin-desmosome (DSM)-network feeds back to the actin cytoskeleton, which results in elevated actomyosin contractility. Also, by complementing a predictive mechanical model with Förster resonance energy transfer-based tension sensors, we provide evidence that in the absence of cytoskeletal cross-linking, major intercellular junctions (adherens junctions and DSMs) are under intrinsically generated tensile stress. Defective cytoarchitecture and tensional disequilibrium result in reduced intercellular cohesion, associated with general destabilization of plectin-deficient sheets upon mechanical stress.

Cerebral A1 adenosine receptor availability in female and male participants and its relationship to sleep.

The neuromodulator adenosine and its receptors are mediators of sleep-wake regulation which is known to differ between sexes. We, therefore, investigated sex differences in A1 adenosine receptor (A1AR) availability in healthy human subjects under well-rested conditions using [18F]CPFPX and positron emission tomography (PET). [18F]CPFPX PET scans were acquired in 50 healthy human participants (20 females; mean age ± SD 28.0 ± 5.3 years). Mean binding potential (BPND; Logan's reference tissue model with cerebellum as reference region) and volume of distribution (VT) values were calculated in 12 and 15 grey matter brain regions, respectively. [18F]CPFPX BPND was higher in females compared to males in all investigated brain regions (p < 0.025). The largest differences were found in the pallidum and anterior cingulate cortex, where mean BPND values were higher by 29% in females than in males. In females, sleep efficiency correlated positively and sleep latency negatively with BPND in most brain regions. VT values did not differ between sexes. Sleep efficiency correlated positively with VT in most brain regions in female participants. In conclusion, our analysis gives a first indication for potential sex differences in A1AR availability even under well-rested conditions. A1AR availability as measured by [18F]CPFPX BPND is higher in females compared to males. Considering the involvement of adenosine in sleep-wake control, this finding might partially explain the known sex differences in sleep efficiency and sleep latency.

Patients' treatment limitations as predictive factor for mortality in COVID-19: results from hospitalized patients of a hotspot region for SARS-CoV-2 infections.

BACKGROUND: In hospitalized patients with SARS-CoV-2 infection, outcomes markedly differ between locations, regions and countries. One possible cause for these variations in outcomes could be differences in patient treatment limitations (PTL) in different locations. We thus studied their role as predictor for mortality in a population of hospitalized patients with COVID-19. METHODS: In a region with high incidence of SARS-CoV-2 infection, adult hospitalized patients with PCR-confirmed SARS-CoV-2 infection were prospectively registered and characterized regarding sex, age, vital signs, symptoms, comorbidities (including Charlson comorbidity index (CCI)), transcutaneous pulse oximetry (SpO2) and laboratory values upon admission, as well as ICU-stay including respiratory support, discharge, transfer to another hospital and death. PTL assessed by routine clinical procedures comprised the acceptance of ICU-therapy, orotracheal intubation and/or cardiopulmonary resuscitation. RESULTS: Among 526 patients included (median [quartiles] age 73 [57; 82] years, 47% female), 226 (43%) had at least one treatment limitation. Each limitation was associated with age, dementia and eGFR (p < 0.05 each), that regarding resuscitation additionally with Charlson comorbidity index (CCI) and cardiac disease. Overall mortality was 27% and lower (p < 0.001) in patients without treatment limitation (12%) compared to those with any limitation (47%). In univariate analyses, age and comorbidities (diabetes, cardiac, cerebrovascular, renal, hepatic, malignant disease, dementia), SpO2, hemoglobin, leucocyte numbers, estimated glomerular filtration rate (eGFR), C-reactive protein (CRP), Interleukin-6 and LDH were predictive for death (p < 0.05 each). In multivariate analyses, the presence of any treatment limitation was an independent predictor of death (OR 4.34, 95%-CI 2.10-12.30; p = 0.001), in addition to CCI, eGFR < 55 ml/min, neutrophil number > 5 G/l, CRP > 7 mg/l and SpO2 < 93% (p < 0.05 each). CONCLUSION: In hospitalized patients with SARS-CoV-2, the percentage of patients with treatment limitations was high. PTL were linked to age, comorbidities and eGFR assessed upon admission and strong, independent risk factors for mortality. These findings might be useful for further understanding of COVID-19 mortality and its regional variations. Clinical trial registration ClinicalTrials.gov Identifier: NCT04344171.

Additional Assessment of Fecal Corticosterone Metabolites Improves Visual Rating in the Evaluation of Stress Responses of Laboratory Rats.

Since animal experiments cannot be completely avoided, the pain, suffering, and distress of laboratory animals must be minimized. To this end, a major prerequisite is reliable assessment of pain and distress. Usually, evaluation of animal welfare is done by visual inspection and score sheets. However, relatively little is known about whether standardized, but subjective, score sheets are able to reliably reflect the status of the animals. The current study aimed to compare visual assessment scores and changes in body weight with concentrations of fecal corticosterone metabolites (FCMs) in a neuroscientific experimental setup. Additionally, effects of refinement procedures were investigated. Eight male adult Sprague-Dawley rats underwent several experimental interventions, including electroencephalograph electrode implantation and subsequent recording, positron emission tomography (PET), and sleep deprivation (SD) by motorized activity wheels. Additional 16 rats were either used as controls without any treatment or to evaluate refinement strategies. Stress responses were determined on a daily basis by means of measuring FCMs, body weight, and evaluation of the animals' welfare by standardized score sheets. Surgery provoked a significant elevation of FCM levels for up to five days. Increases in FCMs due to PET procedures or SD in activity wheels were also highly significant, while visual assessment scores did not indicate elevated stress levels and body weights remained constant. Visual assessment scores correlate with neither changes in body weight nor increases in FCM levels. Habituation procedures to activity wheels used for SD had no impact on corticosterone release. Our results revealed that actual score sheets for visual assessment of animal welfare did not mirror physiological stress responses assessed by FCM measurements. Moreover, small changes in body weight did not correlate with FCM concentration either. In conclusion, as visual assessment is a method allowing immediate interventions on suffering animals to alleviate burden, timely stress assessment in experimental rodents via score sheets should be ideally complemented by validated objective measures (e.g., fecal FCM measured by well-established assays for reliable detection of FCMs). This will complete a comprehensive appraisal of the animals' welfare status in a retrospective manner and refine stressor procedures in the long run.

Species Differences in Microsomal Metabolism of Xanthine-Derived A1 Adenosine Receptor Ligands.

Tracer development for positron emission tomography (PET) requires thorough evaluation of pharmacokinetics, metabolism, and dosimetry of candidate radioligands in preclinical animal studies. Since variations in pharmacokinetics and metabolism of a compound occur in different species, careful selection of a suitable model species is mandatory to obtain valid data. This study focuses on species differences in the in vitro metabolism of three xanthine-derived ligands for the A1 adenosine receptor (A1AR), which, in their 18F-labeled form, can be used to image A1AR via PET. In vitro intrinsic clearance and metabolite profiles of 8-cyclopentyl-3-(3-fluoropropyl)-1-propylxanthine (CPFPX), an established A1AR-ligand, and two novel analogs, 8-cyclobutyl-3-(3-fluoropropyl)-1-propylxanthine (CBX) and 3-(3-fluoropropyl)-8-(1-methylcyclobutyl)-1-propylxanthine (MCBX), were determined in liver microsomes from humans and preclinical animal species. Molecular mechanisms leading to significant differences between human and animal metabolite profiles were also examined. The results revealed significant species differences regarding qualitative and quantitative aspects of microsomal metabolism. None of the tested animal species fully matched human microsomal metabolism of the three A1AR ligands. In conclusion, preclinical evaluation of xanthine-derived A1AR ligands should employ at least two animal species, preferably rodent and dog, to predict in vivo behavior in humans. Surprisingly, rhesus macaques appear unsuitable due to large differences in metabolic activity towards the test compounds.

Factors associated with risk behaviors in adolescence: a systematic review

Objective: Understanding the distal (≤ 6 years of age) and proximal (between 6 years of age and early adolescence) factors in adolescent risk behavior is important for preventing and reducing morbidity and mortality in this population. This study sought to investigate the factors associated with the following adolescent risk behaviors: i) aggressiveness and violence, ii) tobacco, alcohol, and illicit substance use, iii) depressive behavior and self-harm (including suicidal ideation and attempts), iv) sexual risk behavior, and v) multiple risk behavior. Methods: A systematic review was conducted to identify longitudinal studies that examined factors associated with adolescent risk behaviors. The PubMed, PsycINFO, and LILACS databases were searched. Results: Of the 249 included studies, 23% reported distal risk factors, while the remaining reported proximal risk factors. Risk factors were related to sociodemographic characteristics (neighborhood, school, and peers), family patterns, and the presence of other adolescent risk behaviors. Conclusion: Distal and proximal factors in adolescent risk behavior that are not exclusively socioeconomic, familial, environmental, or social should be explored more thoroughly.

EuroScore and IL-6 predict the course in ICU after cardiac surgery.

BACKGROUND: Despite modern advances in intensive care medicine and surgical techniques, mortality rates in cardiac surgical patients are still about 3%. Considerable efforts were made to predict morbidity and mortality after cardiac surgery. In this study, we analysed the predictive properties of EuroScore and IL-6 for mortality in ICU, prolonged postoperative mechanical ventilation, and prolonged stay in ICU. METHODS: We enrolled 2972 patients undergoing cardiac surgery. The patients either underwent aortic valve surgery (AV), mitral valve surgery (MV), coronary artery bypass grafting (CABG), and combined operations of aortic valve and coronary artery bypass grafting (AV + CABG) or of mitral and tricuspid valve (MV + TV). Different laboratory and clinical parameters were analysed. RESULTS: EuroScore as well as IL-6 were associated with increased mortality after cardiac surgery. Furthermore, a higher EuroScore and elevated levels of IL-6 were predictors for prolonged mechanical ventilation and a longer stay in ICU. Especially, highly significant elevated IL-6 levels and an increased EuroScore showed a strong association. Statistics suggested superiority when both parameters were combined in a single model. CONCLUSION: Our results suggest that EuroScore and IL-6 are helpful in predicting the course in ICU after cardiac surgery, and therefore, the use of intensive care resources. Especially, the combination of highly elevated levels of IL-6 and EuroScore may prove to be excellent predictors for an unfortunate postoperative course in ICU.

Coffee effectively attenuates impaired attention in ADORA2A C/C-allele carriers during chronic sleep restriction.

Many people consume coffee to attenuate increased sleepiness and impaired vigilance and attention due to insufficient sleep. We investigated in genetically caffeine sensitive men and women whether 'real world' coffee consumption during a simulated busy work week counteracts disabling consequences of chronically restricted sleep. We subjected homozygous C-allele carriers of ADORA2A (gene encoding adenosine A2A receptors) to five nights of only 5 h time-in-bed. We administered regular coffee (n = 12; 200 mg caffeine at breakfast and 100 mg caffeine after lunch) and decaffeinated coffee (n = 14) in double-blind fashion on all days following sleep restriction. At regular intervals four times each day, participants rated their sleepiness and performed the psychomotor vigilance test, the visual search task, and the visuo-spatial and letter n-back tasks. At bedtime, we quantified caffeine and the major caffeine metabolites paraxanthine, theobromine and theophylline in saliva. The two groups did not differ in age, body-mass-index, sex-ratio, chronotype and mood states. Subjective sleepiness increased in both groups across consecutive sleep restriction days and did not differ. By contrast, regular coffee counteracted the impact of repeated sleep loss on sustained and selective attention, as well as executive control when compared to decaffeinated coffee. The coffee also induced initial or transient benefits on different aspects of baseline performance during insufficient sleep. All differences between the groups disappeared after the recovery night and the cessation of coffee administration. The data suggest that 'real world' coffee consumption can efficiently attenuate sleep restriction-induced impairments in vigilance and attention in genetically caffeine sensitive individuals. German Clinical Trial Registry: # DRSK00014379.

Factors associated with risk behaviors in adolescence: a systematic review.

OBJECTIVE: Understanding the distal (≤ 6 years of age) and proximal (between 6 years of age and early adolescence) factors in adolescent risk behavior is important for preventing and reducing morbidity and mortality in this population. This study sought to investigate the factors associated with the following adolescent risk behaviors: i) aggressiveness and violence, ii) tobacco, alcohol, and illicit substance use, iii) depressive behavior and self-harm (including suicidal ideation and attempts), iv) sexual risk behavior, and v) multiple risk behavior. METHODS: A systematic review was conducted to identify longitudinal studies that examined factors associated with adolescent risk behaviors. The PubMed, PsycINFO, and LILACS databases were searched. RESULTS: Of the 249 included studies, 23% reported distal risk factors, while the remaining reported proximal risk factors. Risk factors were related to sociodemographic characteristics (neighborhood, school, and peers), family patterns, and the presence of other adolescent risk behaviors. CONCLUSION: Distal and proximal factors in adolescent risk behavior that are not exclusively socioeconomic, familial, environmental, or social should be explored more thoroughly.

Techno-economic analysis of a new downstream process for the production of astaxanthin from the microalgae Haematococcus pluvialis.

The biotechnological production of the carotenoid astaxanthin is done with the microalgae Haematococcus pluvialis (H. pluvialis). Under nutrient deficiency and light stress, H. pluvialis accumulates astaxanthin intracellularly and forms a resistant cyst cell wall that impedes direct astaxanthin extraction. Therefore, a complex downstream process is required, including centrifugation, mechanical cell wall disruption, drying, and supercritical extraction of astaxanthin with CO2. In this work, an alternative downstream process based on the direct extraction of astaxanthin from the algal broth into ethyl acetate using a centrifugal partition extractor (CPE) was developed. A mechanical cell wall disruption or germination of the cysts was carried out to make astaxanthin accessible to the solvent. Zoospores containing astaxanthin are released when growth conditions are applied to cyst cells, from which astaxanthin can directly be extracted into ethyl acetate. Energy-intensive unit operations such as spray-drying and extraction with supercritical CO2 can be replaced by directly extracting astaxanthin into ethyl acetate. Extraction yields of 85% were reached, and 3.5 g of oleoresin could be extracted from 7.85 g homogenised H. pluvialis biomass using a CPE unit with 244 mL column volume. A techno-economic analysis was done for a hypothetical H. pluvialis production facility with an annual biomass output of 8910 kg. Four downstream scenarios were examined, comparing the novel process of astaxanthin extraction from homogenised cyst cells and germinated zoospores via CPE extraction with the conventional industrial process using in-house or supercritical CO2 extraction via an external service provider. After 10 years of operation, the highest net present value (NPV) was determined for the CPE extraction from germinated zoospores.