Chemerin in Participants with or without Insulin Resistance and Diabetes.

Chemerin is a chemokine/adipokine, regulating inflammation, adipogenesis and energy metabolism whose activity depends on successive proteolytic cleavages at its C-terminus. Chemerin levels and processing are correlated with insulin resistance. We hypothesized that chemerin processing would be higher in individuals with type 2 diabetes (T2D) and in those who are insulin resistant (IR). This hypothesis was tested by characterizing different chemerin forms by specific ELISA in the plasma of 18 participants with T2D and 116 without T2D who also had their insulin resistance measured by steady-state plasma glucose (SSPG) concentration during an insulin suppression test. This approach enabled us to analyze the association of chemerin levels with a direct measure of insulin resistance (SSPG concentration). Participants were divided into groups based on their degree of insulin resistance using SSPG concentration tertiles: insulin sensitive (IS, SSPG ≤ 91 mg/dL), intermediate IR (IM, SSPG 92-199 mg/dL), and IR (SSPG ≥ 200 mg/dL). Levels of different chemerin forms were highest in patients with T2D, second highest in individuals without T2D who were IR, and lowest in persons without T2D who were IM or IS. In the whole group, chemerin levels positively correlated with both degree of insulin resistance (SSPG concentration) and adiposity (BMI). Participants with T2D and those without T2D who were IR had the most proteolytic processing of chemerin, resulting in higher levels of both cleaved and degraded chemerin. This suggests that increased inflammation in individuals who have T2D or are IR causes more chemerin processing.

Primed inflammatory response by fibroblast subset is necessary for proper oral and cutaneous wound healing.

Fibroblasts are ubiquitous mesenchymal cells that exhibit considerable molecular and functional heterogeneity. Besides maintaining stromal integrity, oral fibroblast subsets are thought to play an important role in host-microbe interaction during injury repair, which is not well explored in vivo. Here, we characterize a subset of fibroblast lineage labeled by paired-related homeobox-1 promoter activity (Prx1Cre+ ) in oral mucosa and skin and demonstrate these fibroblasts readily respond to microbial products to facilitate the normal wound healing process. Using a reporter mouse model, we determined that Prx1Cre+ fibroblasts had significantly higher expression of toll-like receptors 2 and 4 compared to other fibroblast populations. In addition, Prx1 immunopositive cells exhibited heightened activation of inflammatory transcription factor NF-κB during the early wound healing process. At the cytokine level, CXCL1 and CCL2 were significantly upregulated by Prx1Cre+ fibroblasts at baseline and upon LPS stimulation. Importantly, lineage-specific knockout to prevent NF-κB activation in Prx1Cre+ fibroblasts drastically impaired both oral and skin wound healing processes, which was linked to reduced macrophage infiltration, failure to resolve inflammation, and clearance of bacteria. Together, our data implicate a pro-healing role of Prx1-lineage fibroblasts by facilitating early macrophage recruitment and bacterial clearance.

Utilizing directed evolution to interrogate and optimize CRISPR/Cas guide RNA scaffolds.

CRISPR-based editing has revolutionized genome engineering despite the observation that many DNA sequences remain challenging to target. Unproductive interactions formed between the single guide RNA's (sgRNA) Cas9-binding scaffold domain and DNA-binding antisense domain are often responsible for such limited editing resolution. To bypass this limitation, we develop a functional SELEX (systematic evolution of ligands by exponential enrichment) approach, termed BLADE (binding and ligand activated directed evolution), to identify numerous, diverse sgRNA variants that bind Streptococcus pyogenes Cas9 and support DNA cleavage. These variants demonstrate surprising malleability in sgRNA sequence. We also observe that particular variants partner more effectively with specific DNA-binding antisense domains, yielding combinations with enhanced editing efficiencies at various target sites. Using molecular evolution, CRISPR-based systems could be created to efficiently edit even challenging DNA sequences making the genome more tractable to engineering. This selection approach will be valuable for generating sgRNAs with a range of useful activities.

Using network analyses to characterise Australian and Canadian frequent attenders to the emergency department.

OBJECTIVE: To explore and compare the characteristics of frequent attenders to the ED at an Australian and a Canadian tertiary hospitals by utilising a network analysis approach. METHODS: We conducted a retrospective population-based study using administrative data over the 2018 and 2019 calendar years. Participants were from a tertiary hospital in Melbourne, Australia, and Toronto, Canada. Frequent attenders were defined as patients with four or more visits in 12 months. Characteristics of younger (18-39 years), middle-aged (40-69 years) and older (70 years and older) frequent attenders were described using descriptive statistics and network analyses. RESULTS: Younger frequent attenders were characterised by mental illness and substance use, while older frequent attenders had high rates of physical (including chronic) diseases. Middle-aged frequent attenders were characterised by a combination of mental and physical illnesses. These findings were observed at both hospitals. Across all age groups, the network analyses between the Melbourne and Toronto hospitals were different. Among older frequent attender visits, more diagnoses were associated with high triage acuity at the Toronto hospital than at the Melbourne hospital. Some associations were similar at both sites, for example, the negative correlation between high triage acuity and joint pain. CONCLUSION: Younger, middle-aged and older frequent attenders have distinct characteristics, made readily apparent by using network analyses. Future interventions to reduce ED visits should consider the heterogeneity of frequent attenders who have needs specific to their age, presenting problems and jurisdiction.

Prediction of Intraparenchymal Hemorrhage Progression and Neurologic Outcome in Traumatic Brain Injury Patients Using Radiomics Score and Clinical Parameters.

(1) Background: Radiomics analysis of spontaneous intracerebral hemorrhages on computed tomography (CT) images has been proven effective in predicting hematoma expansion and poor neurologic outcome. In contrast, there is limited evidence on its predictive abilities for traumatic intraparenchymal hemorrhage (IPH). (2) Methods: A retrospective analysis of 107 traumatic IPH patients was conducted. Among them, 45 patients (42.1%) showed hemorrhagic progression of contusion (HPC) and 51 patients (47.7%) had poor neurological outcome. The IPH on the initial CT was manually segmented for radiomics analysis. After feature extraction, selection and repeatability evaluation, several machine learning algorithms were used to derive radiomics scores (R-scores) for the prediction of HPC and poor neurologic outcome. (3) Results: The AUCs for R-scores alone to predict HPC and poor neurologic outcome were 0.76 and 0.81, respectively. Clinical parameters were used to build comparison models. For HPC prediction, variables including age, multiple IPH, subdural hemorrhage, Injury Severity Score (ISS), international normalized ratio (INR) and IPH volume taken together yielded an AUC of 0.74, which was significantly (p = 0.022) increased to 0.83 after incorporation of the R-score in a combined model. For poor neurologic outcome prediction, clinical variables of age, Glasgow Coma Scale, ISS, INR and IPH volume showed high predictability with an AUC of 0.92, and further incorporation of the R-score did not improve the AUC. (4) Conclusion: The results suggest that radiomics analysis of IPH lesions on initial CT images has the potential to predict HPC and poor neurologic outcome in traumatic IPH patients. The clinical and R-score combined model further improves the performance of HPC prediction.

Usage of image registration and three-dimensional visualization tools on serial computed tomography for the analysis of patients with traumatic intraparenchymal hemorrhages.

The aim of this study was to apply registration and three-dimensional (3D) display tools to assess the evolution of intraparenchymal hemorrhage (IPH) in patients with traumatic brain injury (TBI). We identified 109 TBI patients who had two computed tomography (CT) scans within 4 days retrospectively. The IPH was manually outlined. The registration was performed in 39 lesions from 29 patients with lesion volume < 1.5 cm on both baseline and follow-up CT. The center of mass (COM) of each lesion was calculated, and the distance between baseline and follow-up CT was used to evaluate the registration effect. The mean distances of COM before registration in the XYZ, XY, and YZ coordinates were 20.5 ± 10.2 mm, 17.8 ± 9.4 mm, and 15.9 ± 9.4 mm, respectively, which decreased significantly (p < 0.001) to 7.9 ± 4.9, 7.8 ± 5.0, and 6.1 ± 4.1 mm after registration. A 3D short video displaying the rendering view of all lesions in 34 randomly selected patients from baseline and follow-up scans were presented side-by-side for comparison. The detection rate of new IPH lesions increased in 3D videos (100%) as compared with axial CT slices (78.6-92.9%). A very high interrater agreement (k = 0.856) on perceiving IPH lesion progression upon viewing 3D video was noted, and the absolute volume increase was significantly higher (p < 0.001) for progressive lesions (median 7.36 cc) over non-progressive lesions (median 0.01 cc). Compared to patients with spontaneous hemorrhagic stroke, evaluation of multiple small traumatic hemorrhages in TBI is more challenging. The applied image analysis and visualization methods may provide helpful tools for comparing changes between serial CT scans.

Prenatal exposure to ambient air multi-pollutants significantly impairs intrauterine fetal development trajectory.

BACKGROUND: Impaired in utero fetal growth trajectory may have long term health consequences of the newborns and increase risk of adulthood metabolic diseases. Prenatal exposure to air pollution has been linked to fetal development restriction; however, the impact of exposure to ambient air pollutants on the entire course of intrauterine fetal development has not been comprehensively investigated. METHODS: During 2015-2018, two cohorts of mother-infant dyads (N = 678 and 227) were recruited in Shanghai China, from which three categories of data were systematically collected: (1) daily exposure to six air pollutants during pregnancy, (2) fetal biometry in the 2nd (gestational week 24, [GW24]) and 3rd trimester (GW36), and (3) neonatal outcomes at birth. We investigated the impact of prenatal exposure to air pollutant mixture on the trajectory of fetal development during the course of gestation, adjusting for a broad set of potential confounds. RESULTS: Prenatal exposure to PM2.5, PM10, SO2 and O3 significantly reduced fetal biometry at GW24, where SO2 had the most potent effect. For every 10 µg/m3 increment increase of daily SO2 exposure during the 1st trimester shortened femur length by 2.20 mm (p = 6.7E-21) translating to 5.3% reduction from the average of the study cohort. Prenatal air pollution exposure also decreased fetal biometry at GW36 with attenuated effect size. Comparing to the lowest exposed quartile, fetus in the highest exposed quartile had 6.3% (p = 3.5E-5) and 2.1% (p = 2.4E-3) lower estimated intrauterine weight in GW24 and GW36, respectively; however, no difference in birth weight was observed, indicating a rapid catch-up growth in the 3rd trimester. CONCLUSIONS: To our knowledge, for the first time, we demonstrated the impact of prenatal exposure to ambient air pollutants on the course of intrauterine fetal development. The altered growth trajectory and rapid catch-up growth in associated with high prenatal exposure may lead to long-term predisposition for adulthood metabolic disorders.