Clinical and in vitro models identify distinct adaptations enhancing Staphylococcus aureus pathogenesis in human macrophages.

Staphylococcus aureus is a facultative intracellular pathogen of human macrophages, which facilitates chronic infection. The genotypes, pathways, and mutations influencing that phenotype remain incompletely explored. Here, we used two distinct strategies to ascertain S. aureus gene mutations affecting pathogenesis in macrophages. First, we analyzed isolates collected serially from chronic cystic fibrosis (CF) respiratory infections. We found that S. aureus strains evolved greater macrophage invasion capacity during chronic human infection. Bacterial genome-wide association studies (GWAS) identified 127 candidate genes for which mutation was significantly associated with macrophage pathogenesis in vivo. In parallel, we passaged laboratory S. aureus strains in vitro to select for increased infection of human THP-1 derived macrophages, which identified 15 candidate genes by whole-genome sequencing. Functional validation of candidate genes using isogenic transposon mutant knockouts and CRISPR interference (CRISPRi) knockdowns confirmed virulence contributions from 37 of 39 tested genes (95%) implicated by in vivo studies and 7 of 10 genes (70%) ascertained from in vitro selection, with one gene in common to the two strategies. Validated genes included 17 known virulence factors (39%) and 27 newly identified by our study (61%), some encoding functions not previously associated with macrophage pathogenesis. Most genes (80%) positively impacted macrophage invasion when disrupted, consistent with the phenotype readily arising from loss-of-function mutations in vivo. This work reveals genes and mechanisms that contribute to S. aureus infection of macrophages, highlights differences in mutations underlying convergent phenotypes arising from in vivo and in vitro systems, and supports the relevance of S. aureus macrophage pathogenesis during chronic respiratory infection in CF. Additional studies will be needed to illuminate the exact mechanisms by which implicated mutations affect their phenotypes.

Harmonization of clinical practice guidelines for primary prevention and screening: actionable recommendations and resources for primary care.

BACKGROUND: Clinical practice guidelines (CPGs) synthesize high-quality information to support evidence-based clinical practice. In primary care, numerous CPGs must be integrated to address the needs of patients with multiple risks and conditions. The BETTER program aims to improve prevention and screening for cancer and chronic disease in primary care by synthesizing CPGs into integrated, actionable recommendations. We describe the process used to harmonize high-quality cancer and chronic disease prevention and screening (CCDPS) CPGs to update the BETTER program. METHODS: A review of CPG databases, repositories, and grey literature was conducted to identify international and Canadian (national and provincial) CPGs for CCDPS in adults 40-69 years of age across 19 topic areas: cancers, cardiovascular disease, chronic obstructive pulmonary disease, diabetes, hepatitis C, obesity, osteoporosis, depression, and associated risk factors (i.e., diet, physical activity, alcohol, cannabis, drug, tobacco, and vaping/e-cigarette use). CPGs published in English between 2016 and 2021, applicable to adults, and containing CCDPS recommendations were included. Guideline quality was assessed using the Appraisal of Guidelines for Research and Evaluation (AGREE) II tool and a three-step process involving patients, health policy, content experts, primary care providers, and researchers was used to identify and synthesize recommendations. RESULTS: We identified 51 international and Canadian CPGs and 22 guidelines developed by provincial organizations that provided relevant CCDPS recommendations. Clinical recommendations were extracted and reviewed for inclusion using the following criteria: 1) pertinence to primary prevention and screening, 2) relevance to adults ages 40-69, and 3) applicability to diverse primary care settings. Recommendations were synthesized and integrated into the BETTER toolkit alongside resources to support shared decision-making and care paths for the BETTER program. CONCLUSIONS: Comprehensive care requires the ability to address a person's overall health. An approach to identify high-quality clinical guidance to comprehensively address CCDPS is described. The process used to synthesize and harmonize implementable clinical recommendations may be useful to others wanting to integrate evidence across broad content areas to provide comprehensive care. The BETTER toolkit provides resources that clearly and succinctly present a breadth of clinical evidence that providers can use to assist with implementing CCDPS guidance in primary care.

Spectroscopic, biochemical and computational studies of bioactive DNA minor groove binders targeting 5'-WGWWCW-3' motif.

Spectroscopic, biochemical, and computational modelling studies have been used to assess the binding capability of a set of minor groove binding (MGB) ligands against the self-complementary DNA sequences 5'-d(CGCACTAGTGCG)-3' and 5'-d(CGCAGTACTGCG)-3'. The ligands were carefully designed to target the DNA response element, 5'-WGWWCW-3', the binding site for several nuclear receptors. Basic 1D 1H NMR spectra of the DNA samples prepared with three MGB ligands show subtle variations suggestive of how each ligand associates with the double helical structure of both DNA sequences. The variations among the investigated ligands were reflected in the line shape and intensity of 1D 1H and 31P-{1H} NMR spectra. Rapid visual inspection of these 1D NMR spectra proves to be beneficial in providing valuable insights on MGB binding molecules. The NMR results were consistent with the findings from both UV DNA denaturation and molecular modelling studies. Both the NMR spectroscopic and computational analyses indicate that the investigated ligands bind to the minor grooves as antiparallel side-by-side dimers in a head-to-tail fashion. Moreover, comparisons with results from biochemical studies offered valuable insights into the mechanism of action, and antitumor activity of MGBs in relation to their structures, essential pre-requisites for future optimization of MGBs as therapeutic agents.

Contribution of the patient microbiome to surgical site infection and antibiotic prophylaxis failure in spine surgery.

Despite modern antiseptic techniques, surgical site infection (SSI) remains a leading complication of surgery. However, the origins of SSI and the high rates of antimicrobial resistance observed in these infections are poorly understood. Using instrumented spine surgery as a model of clean (class I) skin incision, we prospectively sampled preoperative microbiomes and postoperative SSI isolates in a cohort of 204 patients. Combining multiple forms of genomic analysis, we correlated the identity, anatomic distribution, and antimicrobial resistance profiles of SSI pathogens with those of preoperative strains obtained from the patient skin microbiome. We found that 86% of SSIs, comprising a broad range of bacterial species, originated endogenously from preoperative strains, with no evidence of common source infection among a superset of 1610 patients. Most SSI isolates (59%) were resistant to the prophylactic antibiotic administered during surgery, and their resistance phenotypes correlated with the patient's preoperative resistome (P = 0.0002). These findings indicate the need for SSI prevention strategies tailored to the preoperative microbiome and resistome present in individual patients.

Pharmacological inhibition of RAS overcomes FLT3 inhibitor resistance in FLT3-ITD+ AML through AP-1 and RUNX1.

AML is characterized by mutations in genes associated with growth regulation such as internal tandem duplications (ITD) in the receptor kinase FLT3. Inhibitors targeting FLT3 (FLT3i) are being used to treat patients with FLT3-ITD+ but most relapse and become resistant. To elucidate the resistance mechanism, we compared the gene regulatory networks (GRNs) of leukemic cells from patients before and after relapse, which revealed that the GRNs of drug-responsive patients were altered by rewiring their AP-1-RUNX1 axis. Moreover, FLT3i induces the upregulation of signaling genes, and we show that multiple cytokines, including interleukin-3 (IL-3), can overcome FLT3 inhibition and send cells back into cycle. FLT3i leads to loss of AP-1 and RUNX1 chromatin binding, which is counteracted by IL-3. However, cytokine-mediated drug resistance can be overcome by a pan-RAS inhibitor. We show that cytokines instruct AML growth via the transcriptional regulators AP-1 and RUNX1 and that pan-RAS drugs bypass this barrier.

Gene regulatory network analysis predicts cooperating transcription factor regulons required for FLT3-ITD+ AML growth.

Acute myeloid leukemia (AML) is a heterogeneous disease caused by different mutations. Previously, we showed that each mutational subtype develops its specific gene regulatory network (GRN) with transcription factors interacting within multiple gene modules, many of which are transcription factor genes themselves. Here, we hypothesize that highly connected nodes within such networks comprise crucial regulators of AML maintenance. We test this hypothesis using FLT3-ITD-mutated AML as a model and conduct an shRNA drop-out screen informed by this analysis. We show that AML-specific GRNs predict crucial regulatory modules required for AML growth. Furthermore, our work shows that all modules are highly connected and regulate each other. The careful multi-omic analysis of the role of one (RUNX1) module by shRNA and chemical inhibition shows that this transcription factor and its target genes stabilize the GRN of FLT3-ITD+ AML and that its removal leads to GRN collapse and cell death.

Gene regulatory network analysis predicts cooperating transcription factor regulons required for FLT3-ITD+ AML growth.

AML is a heterogenous disease caused by different mutations. We have previously shown that each mutational sub-type develops its specific gene regulatory network (GRN) with transcription factors interacting with multiple gene modules, many of which are transcription factor genes themselves. Here we hypothesized that highly connected nodes within such networks comprise crucial regulators of AML maintenance. We tested this hypothesis using FLT3-ITD mutated AML as a model and conducted an shRNA drop-out screen informed by this analysis. We show that AML-specific GRNs predict identifying crucial regulatory modules required for AML but not normal cellular growth. Furthermore, our work shows that all modules are highly connected and regulate each other. The careful multi-omic analysis of the role of one (RUNX1) module by shRNA and chemical inhibition shows that this transcription factor and its target genes stabilize the GRN of FLT3-ITD AML and that its removal leads to GRN collapse and cell death.

In Vitro Selection Identifies Staphylococcus aureus Genes Influencing Biofilm Formation.

Staphylococcus aureus generates biofilms during many chronic human infections, which contributes to its growth and persistence in the host. Multiple genes and pathways necessary for S. aureus biofilm production have been identified, but knowledge is incomplete, and little is known about spontaneous mutations that increase biofilm formation as infection progresses. Here, we performed in vitro selection of four S. aureus laboratory strains (ATCC 29213, JE2, N315, and Newman) to identify mutations associated with enhanced biofilm production. Biofilm formation increased in passaged isolates from all strains, exhibiting from 1.2- to 5-fold the capacity of parental lines. Whole-genome sequencing identified nonsynonymous mutations affecting 23 candidate genes and a genomic duplication encompassing sigB. Six candidate genes significantly impacted biofilm formation as isogenic transposon knockouts: three were previously reported to impact S. aureus biofilm formation (icaR, spdC, and codY), while the remaining three (manA, narH, and fruB) were newly implicated by this study. Plasmid-mediated genetic complementation of manA, narH, and fruB transposon mutants corrected biofilm deficiencies, with high-level expression of manA and fruB further enhancing biofilm formation over basal levels. This work recognizes genes not previously identified as contributing to biofilm formation in S. aureus and reveals genetic changes able to augment biofilm production by that organism.

Genome Capture Sequencing Selectively Enriches Bacterial DNA and Enables Genome-Wide Measurement of Intrastrain Genetic Diversity in Human Infections.

Within-host evolution produces genetic diversity in bacterial strains that cause chronic human infections. However, the lack of facile methods to measure bacterial allelic variation in clinical samples has limited understanding of intrastrain diversity's effects on disease. Here, we report a new method termed genome capture sequencing (GenCap-Seq) in which users inexpensively make hybridization probes from genomic DNA or PCR amplicons to selectively enrich and sequence targeted bacterial DNA from clinical samples containing abundant human or nontarget bacterial DNA. GenCap-Seq enables accurate measurement of allele frequencies over targeted regions and is scalable from specific genes to entire genomes, including the strain-specific accessory genome. The method is effective with samples in which target DNA is rare and inhibitory and DNA-degrading substances are abundant, including human sputum and feces. In proof-of-principle experiments, we used GenCap-Seq to investigate the responses of diversified Pseudomonas aeruginosa populations chronically infecting the lungs of people with cystic fibrosis to in vivo antibiotic exposure, and we found that treatment consistently reduced intrastrain genomic diversity. In addition, analysis of gene-level allele frequency changes suggested that some genes without conventional resistance functions may be important for bacterial fitness during in vivo antibiotic exposure. GenCap-Seq's ability to scalably enrich targeted bacterial DNA from complex samples will enable studies on the effects of intrastrain and intraspecies diversity in human infectious disease. IMPORTANCE Genetic diversity evolves in bacterial strains during human infections and could affect disease manifestations and treatment resistance. However, the extent of diversity present in vivo and its changes over time are difficult to measure by conventional methods. We developed a novel approach, GenCap-Seq, to enrich microbial DNA from complex human samples like sputum and feces for genome-wide measurements of bacterial allelic diversity. The approach is inexpensive, scalable to encompass entire targeted genomes, and works in the presence of abundant untargeted nucleic acids and inhibiting substances. We used GenCap-Seq to investigate in vivo responses of diversified bacterial strains to antibiotic treatment. This method will enable new ideas about the effects of intrastrain diversity on human infections to be tested.

Projected estimates of cancer in Canada in 2022.

BACKGROUND: Regular cancer surveillance is crucial for understanding where progress is being made and where more must be done. We sought to provide an overview of the expected burden of cancer in Canada in 2022. METHODS: We obtained data on new cancer incidence from the National Cancer Incidence Reporting System (1984-1991) and Canadian Cancer Registry (1992-2018). Mortality data (1984-2019) were obtained from the Canadian Vital Statistics - Death Database. We projected cancer incidence and mortality counts and rates to 2022 for 22 cancer types by sex and province or territory. Rates were age standardized to the 2011 Canadian standard population. RESULTS: An estimated 233 900 new cancer cases and 85 100 cancer deaths are expected in Canada in 2022. We expect the most commonly diagnosed cancers to be lung overall (30 000), breast in females (28 600) and prostate in males (24 600). We also expect lung cancer to be the leading cause of cancer death, accounting for 24.3% of all cancer deaths, followed by colorectal (11.0%), pancreatic (6.7%) and breast cancers (6.5%). Incidence and mortality rates are generally expected to be higher in the eastern provinces of Canada than the western provinces. INTERPRETATION: Although overall cancer rates are declining, the number of cases and deaths continues to climb, owing to population growth and the aging population. The projected high burden of lung cancer indicates a need for increased tobacco control and improvements in early detection and treatment. Success in breast and colorectal cancer screening and treatment likely account for the continued decline in their burden. The limited progress in early detection and new treatments for pancreatic cancer explains why it is expected to be the third leading cause of cancer death in Canada.

Polyclonality, Shared Strains, and Convergent Evolution in Chronic Cystic Fibrosis Staphylococcus aureus Airway Infection.

Rationale:Staphylococcus aureus is the most common respiratory pathogen isolated from patients with cystic fibrosis (CF) in the United States. Although modes of acquisition and genetic adaptation have been described for Pseudomonas aeruginosa, resulting in improved diagnosis and treatment, these features remain more poorly defined for S. aureus.Objectives: To characterize the molecular epidemiology and genetic adaptation of S. aureus during chronic CF airway infection and in response to antibiotic therapy.Methods: We performed whole-genome sequencing of 1,382 S. aureus isolates collected longitudinally over a mean 2.2 years from 246 children with CF at five U.S. centers between 2008 and 2017. Results were integrated with clinical and demographic data to characterize bacterial population dynamics and identify common genetic targets of in vivo adaptation.Measurements and Main Results: Results showed that 45.5% of patients carried multiple, coexisting S. aureus lineages, often having different antibiotic susceptibility profiles. Adaptation during the course of infection commonly occurred in a set of genes related to persistence and antimicrobial resistance. Individual sequence types demonstrated wide geographic distribution, and we identified limited strain-sharing among children linked by common household or clinical exposures. Unlike P. aeruginosa, S. aureus genetic diversity was unconstrained, with an ongoing flow of new genetic elements into the population of isolates from children with CF.Conclusions: CF airways are frequently coinfected by multiple, genetically distinct S. aureus lineages, indicating that current clinical procedures for sampling isolates and selecting antibiotics are likely inadequate. Strains can be shared by patients in close domestic or clinical contact and can undergo convergent evolution in key persistence and antimicrobial-resistance genes, suggesting novel diagnostic and therapeutic approaches for future study.

Androgen receptor phosphorylation at serine 81 and serine 213 in castrate-resistant prostate cancer.

BACKGROUND: Despite increases in diagnostics and effective treatments, over 300,000 men die from prostate cancer highlighting the need for specific and differentiating biomarkers. AR phosphorylation associates with castrate-resistance, with pARser213 promoting transcriptional activity. We hypothesise that combined pARser81 and pARser213 reduces survival and would benefit from dual-targeting androgen-dependent and Akt-driven disease. METHODS: Immunohistochemistry and immunofluorescence were performed on matched hormone-naive and castrate-resistant prostate cancer samples. TempO-Seq gene profiling was analysed using DESeq2 package. LNCaP-AI cells were stimulated with DHT or EGF. WST-1 assays were performed to determine effects of Enzalutamide and BKM120 on cell viability. RESULTS: Following the development of castrate-resistance, pARser81 expression reduced and pARser213 expression increased. Castrate-resistance pARser81 expression was not associated with survival but high pARser213 expression was associated with reduced survival from relapse. Combined high pARser81 and pARser213 was associated with reduced survival from relapse. pARser81 expression was induced by 10 nM DHT or 10 nM EGF and pARser213 expression was induced by treatment with 10 nM EGF in LNCaP-AI cells. Cell viability was reduced following treatment with 10 nM Enzalutamide and 10 nM BKM120. Eight genes were differentially expressed between hormone-naive and castrate-resistant tumours and twenty-five genes were differentially expressed between castrate-resistant tumours with high and low pARser213 expression. CONCLUSION: Combined pARser81 and pARser213 provides a novel prognostic biomarker for castrate-resistant disease and a potential predictive and therapeutic target for prostate cancer. Further studies will be required to investigate the combined effects of targeting AR and PI3K/AKT signalling.

Cell free DNA from respiratory pathogens is detectable in the blood plasma of Cystic Fibrosis patients.

Diagnostically informative microbial cell-free DNA (cfDNA) can be detected from blood plasma during fulminant infections such as sepsis. However, the potential for DNA from airway pathogens to enter the circulation of cystic fibrosis (CF) patients during chronic infective states has not yet been evaluated. We assessed whether patient blood contained measurable quantities of cfDNA from CF respiratory microorganisms by sequencing plasma from 21 individuals with CF recruited from outpatient clinics and 12 healthy controls. To account for possible contamination with exogenous microbial nucleic acids, statistical significance of microbe-derived read counts from CF patients was determined relative to the healthy control population. In aggregate, relative abundance of microbial cfDNA was nearly an order of magnitude higher in CF patients than in healthy subjects (p = 8.0×10-3). 15 of 21 (71%) CF patients demonstrated cfDNA from one or more relevant organisms. In contrast, none of the healthy subjects evidenced significant microbial cfDNA for any of the organisms examined. Concordance of cfDNA with standard microbiological culture of contemporaneously collected patient sputum was variable. Our findings provide evidence that cfDNA from respiratory pathogens are present in the bloodstream of most CF patients, which could potentially be exploited for the purposes of noninvasive clinical diagnosis.

Genomic Analysis Identifies Novel Pseudomonas aeruginosa Resistance Genes under Selection during Inhaled Aztreonam Therapy In Vivo.

Inhaled aztreonam is increasingly used for chronic Pseudomonas aeruginosa suppression in patients with cystic fibrosis (CF), but the potential for that organism to evolve aztreonam resistance remains incompletely explored. Here, we performed genomic analysis of clonally related pre- and posttreatment CF clinical isolate pairs to identify genes that are under positive selection during aztreonam therapy in vivo We identified 16 frequently mutated genes associated with aztreonam resistance, the most prevalent being ftsI and ampC, and 13 of which increased aztreonam resistance when introduced as single gene transposon mutants. Several previously implicated aztreonam resistance genes were found to be under positive selection in clinical isolates even in the absence of inhaled aztreonam exposure, indicating that other selective pressures in the cystic fibrosis airway can promote aztreonam resistance. Given its potential to confer plasmid-mediated resistance, we further characterized mutant ampC alleles and performed artificial evolution of ampC for maximal activity against aztreonam. We found that naturally occurring ampC mutants conferred variably increased resistance to aztreonam (2- to 64-fold) and other ß-lactam agents but that its maximal evolutionary capacity for hydrolyzing aztreonam was considerably higher (512- to 1,024-fold increases) and was achieved while maintaining or increasing resistance to other drugs. These studies implicate novel chromosomal aztreonam resistance determinants while highlighting that different mutations are favored during selection in vivo and in vitro, show that ampC has a high maximal potential to hydrolyze aztreonam, and provide an approach to disambiguate mutations promoting specific resistance phenotypes from those more generally increasing bacterial fitness in vivo.

Higher Sun Exposure is Associated With Lower Risk of Pediatric Inflammatory Bowel Disease: A Matched Case-control Study.

OBJECTIVES: The incidence of pediatric inflammatory bowel disease (IBD) is increasing worldwide. Ecological studies show higher incidence in regions at higher latitude or lower ambient ultraviolet radiation; individual-level associations with sun exposure have not been assessed. METHODS: We recruited children (0-17 years) with IBD from 2 large hospitals in Melbourne, Australia. Control participants were recruited from the day surgery unit of one of the same hospitals. Questionnaires provided data on demographics, past sun exposure, the likelihood of sunburn (skin sensitivity) or tanning following sun exposure, use of sun protection, physical activity, and parental smoking and education. Grandparent ancestry was used to determine participant ethnicity. Cases and controls were matched on age and sex. We used conditional logistic regression to test the association between being an IBD case and past sun exposure at different ages, adjusted for a range of other factors. RESULTS: After matching, n = 99 cases and n = 396 controls were included in the analysis. In multivariable analysis, for each 10 min increment in leisure-time sun exposure in summer or winter there was a linear 6% reduction in the odds of having IBD (P = 0.002). Results were similar in sensitivity analyses including only the most recently diagnosed cases, only Caucasian cases and controls, only those with symptom onset within the year before study entry, or additionally adjusted for age or physical activity. CONCLUSIONS: Higher sun exposure in the previous summer or winter was associated with a reduced risk of having IBD. There are plausible pathways that could mediate this effect.

Maximizing research impacts on cancer prevention: An integrated knowledge translation approach used by the Canadian Population Attributable Risk of Cancer (ComPARe) study.

With a strong focus on end user, or knowledge user, engagement throughout the study, an integrated knowledge translation approach (iKT) is expected to enhance the quality, relevance and reach of research findings. From its initiation, the Canadian Population Attributable Risk of Cancer (ComPARe) study combined the expertise of the knowledge producers (cancer prevention researchers) and select knowledge users in an iKT approach. We describe in detail our iKT approach, including governance, outputs and early reflections. In our model, knowledge users were integrated as members of the research team or members of a KT Advisory Committee. The integrated knowledge users took a lead role on the KT activities for ComPARe, including developing the KT Blueprint, a four phase systematic approach to guide the planning and implementation of KT activities. This approach included planning, knowledge product development, dissemination and evaluation, with advisory committee engagement built in throughout. Our early reflections identified enablers and challenges of an iKT approach for this study. Enablers included co-investigators' commitment and attitude towards iKT, support for iKT from the funding agency, an established partnership early on, understanding of and experience in each other's area of expertise, dedicated funding, clearly delineated roles, advisory committee buy-in and existing tools. Challenges included anticipating all costs, continuity of involvement, competing priorities, relationship management and geographic distance. A future evaluation will determine the effectiveness and impact of the iKT approach and KT Blueprint. In the interim, the approach we describe here can be modeled by others interested in collaborative, action-oriented research.

Applying spatiotemporal models to monitoring data to quantify fish population responses to the Deepwater Horizon oil spill in the Gulf of Mexico.

Quantifying the impacts of disturbances such as oil spills on marine species can be challenging. Natural environmental variability, human responses to the disturbance (e.g., fisheries closures), the complex life histories of the species being monitored, and limited pre-spill data can make detection of effects of oil spills difficult. Using long-term monitoring data from the state of Louisiana (USA), we applied novel spatiotemporal approaches to identify anomalies in species occurrence and catch rates. We included covariates (salinity, temperature, turbidity) to help isolate unusual events. While some species showed evidence of unlikely temporal anomalies in occurrence or catch rates, we found that the majority of the observed anomalies were also before the Deepwater Horizon event. Several species-gear combinations suggested upticks in the spatial variability immediately following the spill, but most species indicated no trend. Across species-gear combinations, there was no clear evidence for synchronous or asynchronous responses in occurrence or catch rates across sites following the spill. Our results are in general agreement to other analyses of monitoring data that detected small impacts, but in contrast to recent results from ecological modeling that showed much larger effects of the oil spill on fish and shellfish.

Variation in incidence of pediatric Crohn's disease in relation to latitude and ambient ultraviolet radiation: a systematic review and analysis.

BACKGROUND: Pediatric Crohn's disease (CD) is a lifelong, debilitating, and costly disease. In previous studies, CD incidence increased with higher geographic latitude in the Northern Hemisphere. This may indicate a role for lower vitamin D status as a risk factor for CD. Analysis of worldwide incidence of pediatric CD has not been previously reported. METHODS: We undertook a systematic review of population-based studies reporting incidence of pediatric CD and published between 2003 and 2013. Included studies had well-defined diagnostic criteria for CD, evidence of high case ascertainment, reported incidence according to age group, and provided a specific location. Average daily ambient ultraviolet radiation (UVR) for each location was derived from satellite data. Negative binomial regression was used to assess the association between pediatric CD incidence and latitude and ambient UVR, adjusting for the study year. RESULTS: Twenty-eight articles provided 39 incidence data points. Incidence of pediatric CD increased with higher latitude, and in association with a greater number of months where the average daily UVR was lower than a previously published threshold of 1.488 kJ/m. Incidence of pediatric CD increased over calendar time. CONCLUSIONS: After applying rigorous quality assessment criteria, and including only population-based studies, there was a modest increase in incidence of pediatric CD with higher latitude and greater number of months with low ambient UVR. Reporting using nonconsistent diagnostic criteria and age groups, with poorly defined geographic locations, makes it difficult to compare data across different studies.

Intensive serial biomarker profiling for the prediction of neutropenic Fever in patients with hematologic malignancies undergoing chemotherapy: a pilot study.

Neutropenic fever (NF) is a life-threatening complication of myelosuppressive chemotherapy in patients with hematologic malignancies and triggers the administration of broad-spectrum antimicrobials. The ability to accurately predict NF would permit initiation of antimicrobials earlier in the course of infection with the goal of decreasing morbid complications and progression to septic shock and death. Changes in the blood level of inflammatory biomarkers may precede the occurrence of NF. To identify potential biomarkers for the prediction of NF, we performed serial measurements of nine biomarkers [C-reactive protein (CRP), protein C, interleukin (IL)-6, IL-8, IL-10, IL-1ß, tumor necrosis factor-α, monocyte chemotactic protein-1, and intercellular adhesion molecule-1] using a multiplex ELISA array platform every 6-8 hours in patients undergoing myelosuppressive chemotherapy for hematologic malignancies. We found that the blood levels of IL-6 and CRP increased significantly 24 to 48 hours prior to the onset of fever. In addition, we showed that frequent biomarker monitoring is feasible using a bedside micro sample test device. The results of this pilot study suggest that serial monitoring of IL-6 and CRP levels using a bedside device may be useful in the prediction of NF. Prospective studies involving a larger cohort of patients to validate this observation are warranted. This trial is registered at ClinicalTrials.gov (NCT01144793).