A new study reveals that the majority of macrophages in established
atherosclerotic lesions are derived from local proliferation, rather than from
the influx of blood-borne monocytes. While the factors driving proliferation
remain to be understood, the findings suggest that targeting macrophage
proliferation could represent a new therapeutic opportunity in established
International medical students, those attending medical school outside of their country of citizenship, account for a growing proportion of medical undergraduates worldwide. This study aimed to establish the fairness, predictive validity and acceptability of Multiple Mini Interview (MMI) in an internationally diverse student population.
This was an explanatory sequential, mixed methods study. All students in First Year Medicine, National University of Ireland Galway 2012 were eligible to sit a previously validated 10 station MMI. Quantitative data comprised: demographics, selection tool scores and First Year Assessment scores. Qualitative data comprised separate focus groups with MMI Assessors, EU and Non-EU students.
109 students participated (45% of class). Of this 41.3% (n = 45) were Non-EU and 35.8% (n = 39) did not have English as first language. Age, gender and socioeconomic class did not impact on MMI scores. Non-EU students and those for whom English was not a first language achieved significantly lower scores on MMI than their EU and English speaking counterparts (difference in mean 11.9% and 12.2% respectively, P<0.001). MMI score was associated with English language proficiency (IELTS) (r = 0.5, P<0.01). Correlations emerged between First Year results and IELTS (r = 0.44; p = 0.006; n = 38) and EU school exit exam (r = 0.52; p<0.001; n = 56). MMI predicted EU student OSCE performance (r = 0.27; p = 0.03; n = 64). In the analysis of focus group data two overarching themes emerged: Authenticity and Cultural Awareness. MMI was considered a highly authentic assessment that offered a deeper understanding of the applicant than traditional tools, with an immediate relevance to clinical practice. Cultural specificity of some stations and English language proficiency were seen to disadvantage international students. Recommendations included cultural awareness training for MMI assessors, designing and piloting culturally neutral stations, lengthening station duration and providing high quality advance information to candidates.
MMI is a welcome addition to assessment armamentarium for selection, particularly with regard to stakeholder acceptability. Understanding the mediating and moderating influences for differences in performance of international candidates is essential to ensure that MMI complies with the metrics of good assessment practice and principles of both distributive and procedural justice for all applicants, irrespective of nationality and cultural background.
Electronic supplementary material
The online version of this article (doi:10.1186/s12909-014-0267-0) contains supplementary material, which is available to authorized users.
Multiple mini interview; Selection; International students; Mixed methods; Culture; Language; Recommendations; Stakeholder views
Wilms tumor (WT) blastema retains gene expression profiles characteristic of the multipotent nephron progenitor pool, or cap mesenchyme (CM), in the developing kidney. As a result, WT blastema and the CM are believed to represent contextual analogues of one another. Sine oculis homeobox 2 (SIX2) is a transcription factor expressed specifically in the CM, provides a critical mechanism for CM self-renewal, and remains persistently active in WT blastema, although its purpose in this childhood malignancy remains unclear. We hypothesized that SIX2, analogous to its function in development, confers a survival pathway to blastema, the putative WT stem cell. To test its functional significance in WT biology, wild-type SIX2 was overexpressed in the human WT cell line, WiT49. After validating this model, SIX2 effects on anchorage-independent growth, proliferation, invasiveness, canonical WNT pathway signaling, and gene expression of specific WNT pathway participants were evaluated. Relative to controls, WiT49 cells overexpressing SIX2 showed significantly enhanced anchorage-independent growth and early-passage proliferation representing surrogates of cell survival. Interestingly, overexpression of SIX2 generally repressed TCF/LEF-dependent canonical WNT signaling, which activates and coordinates both differentiation and stem pathways, but significantly heightened canonical WNT signaling through the survivin promoter, a mechanism that exclusively maintains the stem state. In summary, when overexpressed in a human WT cell line, SIX2 enhances cell survival and appears to shift the balance in WNT/β-catenin signaling away from a differentiation path and toward a stem cell survival path.
Patient reported outcome measures (PROMs) are used to evaluate lifestyle interventions but little is known about differences between patients returning valid and invalid responses, or of potential for bias in evaluations. We aimed to examine the characteristics of patients who returned valid responses to lifestyle questionnaires compared to those whose responses were invalid for evaluating lifestyle change.
We conducted a secondary data analysis from the SPHERE Study, a trial of an intervention to improve outcomes for patients with coronary heart disease in primary care. Postal questionnaires were used to assess physical activity (Godin) and diet (DINE) among study participants at baseline and 18 month follow-up. Three binary response variables were generated for analysis: (1) valid Godin score; (2) valid DINE Fibre score; and (3) valid DINE Total Fat score. Multivariate analysis comprised generalised estimating equation regression to examine the association of patients’ characteristics with their return of valid responses at both timepoints.
Overall, 92.1% of participants (832/903) returned questionnaires at both baseline and 18 months. Relatively fewer valid Godin scores were returned by those who left school aged <15 years (36.5%) than aged 18 and over (50.5%), manual workers (39.5%) than non-manual (49.5%) and those with an elevated cholesterol (>5 mmol) (34.7%) than those with a lower cholesterol (44.4%) but multivariate analysis identified that only school leaving age (p = 0.047) was of statistical significance.
Relatively fewer valid DINE scores were returned by manual than non-manual workers (fibre: 80.8% v 86.8%; fat: 71.2% v 80.0%), smokers (fibre: 72.6% v 84.7%; fat: 67.5% v 76.9%), patients with diabetes (fibre: 75.9% v 82.9%; fat: 66.9% v 75.8%) and those with cholesterol >5 mmol (fat: 68.2% v 76.2%) but multivariate analysis showed statistical significance only for smoking (fibre: p = 0.013; fat: p = 0.045), diabetes (fibre: p = 0.039; fat: p = 0.047), and cholesterol (fat: p = 0.039).
Our findings illustrate the importance of detailed reporting of research methods, with clear information about response rates, respondents and valid outcome data. Outcome measures which are relevant to a study population should be chosen carefully. The impact of methods of outcome measurement and valid response rates in evaluating healthcare requires further study.
PROMs; Lifestyle; Self report questionnaires; Diet; Physical activity; Research methods
Sleep is an essential component of good physical and mental health. Previous studies have reported that poor quality sleep is associated with an increased risk of hypertension and cardiovascular disease. Hypertension is the most common and important risk factor for cardiovascular disease, and even modest reductions in blood pressure can result in significant reductions in the risk of stroke and myocardial infarction. In this trial, we will determine the efficacy of an online sleep intervention in improving blood pressure, in participants with hypertension and poor sleep quality.
Trial design: Randomized-controlled, two-group, parallel, blinded, single-center, Phase II trial of 134 participants. Population and recruitment: Primary prevention population of participants with hypertension (systolic blood pressure, 130 to 160 mm Hg; diastolic blood pressure, <110 mm Hg) and poor sleep quality in a community setting. Intervention: Multicomponent online sleep intervention consisting of sleep information, sleep hygiene education, and cognitive behavioral therapy. Comparator: Standardized cardiovascular risk factor and lifestyle-education session (usual care). Primary outcome: Change in mean 24-hour ambulatory systolic blood pressure between baseline and 8-week follow-up. Hypertension has been selected as the primary outcome measure because of its robust association with both poor sleep quality and cardiovascular disease. Statistical analyses: Intention-to-treat analysis by using a linear mixed model.
ClinicalTrials.gov: NCT01809821, registered March 8, 2013.
Sleep; Hypertension; Cardiovascular disease
Given evolving imaging technologies, we noted significant variation in the diagnostic evaluation of pediatric choledochal cysts (CDC). To streamline the diagnostic approach to CDC, and minimize associated expenses, we compared typing accuracy and costs of ultrasound (US), intraoperative cholangiography (IOC), and magnetic resonance cholangiopancreatography (MRCP).
Records of 30 consecutive pediatric CDC patients were reviewed. Blinded to all clinical data, two pediatric radiologists reviewed all US, MRCPs, and IOCs to type CDCs according to the Todani classification. When compared with pathologic findings, the concordance between and accuracy of each diagnostic test were determined. Inflation-adjusted procedure charges and collections for imaging modalities were analyzed.
Mean typing accuracy overlapped for US, IOC, and MRCP. Inter-rater reliability was 87 % for US (κ = 0.77), 80 % for IOC (κ = 0.62), and 60 % for MRCP (κ = 0.37). MRCP procedure charges ($1204.69) and collections ($420.85) exceeded IOC and US combined ($264.80 charges, p = 0.0002; $93.40 collections, p = 0.0021).
Our data support the use of US alone in the diagnosis of pediatric CDC when no intrahepatic biliary ductal dilatation is visualized. However, when dilated intrahepatic ducts are encountered on US, MRCP should be utilized to distinguish a type I from a type IV CDC, which may alter the operative approach.
Choledochal cyst; Intraoperative cholangiogram; Ultrasound; Magnetic resonance cholangiopancreatography; Cost minimization
The NOG protein is a secretory antagonist of bone morphogenetic proteins (BMPs). Nog−/− mouse embryos demonstrate proximal esophageal atresia (EA) and distal tracheoesophageal fistula (TEF) compatible with the most common configuration of EA/TEF observed in humans. Four microdeletions that span the NOG locus at 17q22 have been described in human patients having EA/ TEF. We investigated the incidence of point mutations in the coding region of the NOG gene in human EA/TEF.
DNA was collected from 50 patients previously treated for EA/TEF. PCR was used to amplify the coding region of NOG. To detect single nucleotide polymorphisms (SNPs), amplicons were subjected to temperature gradient capillary electrophoresis (TGCE). Candidate SNPs were directly sequenced.
TGCE analysis revealed a SNP in the coding region of NOG in 1 of 50 patients (2%). DNA sequencing revealed a synonymous SNP at position 468 (C–T) of the NOG coding region.
SNPs in the coding region of the NOG gene are identified infrequently in human cases of EA/TEF. Further investigation of SNPs in the promoter region of NOG is warranted, as is the effect of synonymous SNPs on NOG mRNA stability.
Esophageal atresia; Tracheoesophageal fistula; NOG; Noggin
Regular physical activity is known to help prevent and treat numerous non-communicable diseases. Smartphone applications (apps) have been shown to increase physical activity in primary care but little is known regarding the views of patients using such technology or how such technology may change behaviour.
To explore patients’ views and experiences of using smartphones to promote physical activity in primary care.
Design and setting
This qualitative study was embedded within the SMART MOVE randomised controlled trial, which used an app (Accupedo-Pro Pedometer) to promote physical activity in three primary care centres in the west of Ireland.
Taped and transcribed semi-structured interviews with a purposeful sample of 12 participants formed the basis of the investigation. Framework analysis was used to analyse the data.
Four themes emerged from the analysis: transforming relationships with exercise; persuasive technology tools; usability; and the cascade effect. The app appeared to facilitate a sequential and synergistic process of positive change, which occurred in the relationship between the participants and their exercise behaviour; the study has termed this the ‘Know-Check-Move’ effect. Usability challenges included increased battery consumption and adjusting to carrying the smartphone on their person. There was also evidence of a cascade effect involving the families and communities of participants.
Notwithstanding technological challenges, an app has the potential to positively transform, in a unique way, participants’ relationships with exercise. Such interventions can also have an associated cascade effect within their wider families and communities.
exercise; health behaviour; primary health care; qualitative research; smartphone; technology
Internet-delivered psychological interventions among people with chronic pain have the potential to overcome environmental and economic barriers to the provision of evidence-based psychological treatment in the Irish health service context. While the use of internet-delivered cognitive–behavioural therapy programmes has been consistently shown to have small-to-moderate effects in the management of chronic pain, there is a paucity in the research regarding the effectiveness of an internet-delivered Acceptance and Commitment Therapy (ACT) programme among people with chronic pain. The current study will compare the clinical-effectiveness and cost-effectiveness of an online ACT intervention with a waitlist control condition in terms of the management of pain-related functional interference among people with chronic pain.
Methods and analysis
Participants with non-malignant pain that persists for at least 3 months will be randomised to one of two study conditions. The experimental group will undergo an eight-session internet-delivered ACT programme over an 8-week period. The control group will be a waiting list group and will be offered the ACT intervention after the 3-month follow-up period. Participants will be assessed preintervention, postintervention and at a 3-month follow-up. The primary outcome will be pain-related functional interference. Secondary outcomes will include: pain intensity, depression, global impression of change, acceptance of chronic pain and quality of life. A qualitative evaluation of the perspectives of the participants regarding the ACT intervention will be completed after the trial.
Ethics and dissemination
The study will be performed in agreement with the Declaration of Helsinki and is approved by the National University of Ireland Galway Research Ethics Committee (12/05/05). The results of the trial will be published according to the CONSORT statement and will be presented at conferences and reported in peer-reviewed journals.
Trial registration number
Previous studies have shown that mice with defects in cellular cholesterol efflux show hematopoietic stem cell (HSPC) and myeloid proliferation, contributing to atherogenesis. We hypothesized that the combination of hypercholesterolemia and defective cholesterol efflux would promote HSPC expansion and leukocytosis more prominently than either alone.
We crossed Ldlr−/− with Apoa1−/− mice and found that compared to Ldlr−/− mice, Ldlr−/−/Apoa1+/− mice, with similar LDL cholesterol levels but reduced HDL cholesterol (HDL-C) levels, had expansion of HSPCs, monocytosis and neutrophilia. Ex vivo studies showed that HSPCs expressed high levels of Ldlr, Scarb1 (Srb1), and Lrp1 and were able to take up both native and oxidized LDL. Native LDL directly stimulated HSPC proliferation, while co-incubation with reconstituted HDL attenuated this effect. We also assessed the impact of HDL-C levels on monocytes in children with familial hypercholesterolemia (FH) (n=49) and found that subjects with the lowest level of HDL-C, had increased monocyte counts compared to the mid and higher HDL-C levels. Overall, HDL-C was inversely correlated with the monocyte count. These data suggest that in mice, a balance of cholesterol uptake and efflux mechanisms may be one factor in driving HSPC proliferation and monocytosis. Higher monocyte counts in children with FH and low HDL cholesterol suggest a similar pattern in humans.
Hematopoietic stem cells; atherosclerosis; hypercholesterolemia; HDL-C; apoA1
Infusions of apoA-I, mimetic peptides or HDL remain a promising approach to treatment of atherosclerotic coronary disease. However, rapid clearance leads to a requirement for repeated administration of large amounts of material and limits effective plasma concentrations.
Since pegylation of purified proteins is commonly used as a method to increase their half-life in the circulation, we determined whether pegylation of apoA-I or HDL would increase its plasma half-life and in turn its anti-atherogenic potential.
Methods and Results
Initial pegylation attempts using lipid-poor apoA-I showed a marked tendency to form multi-pegylated (PEG) species with reduced ability to promote cholesterol efflux from macrophage foam cells. However, pegylation of human holo-HDL or reconstituted phospholipid/apoA-I particles (rHDL) led to selective N-terminal mono-pegylation of apoA-I with full preservation of cholesterol efflux activity. The plasma clearance of PEG-rHDL was estimated following injection into hypercholesterolemic Apoe−/− mice; the half-life of pegylated apoA-I following injection of PEG-rHDL was increased about 7-fold compared to apoA-I in non-pegylated rHDL. Compared to non-pegylated rHDL, infusion of PEG-rHDL (40 mg/kg) into hypercholesterolemic Apoe−/− mice led to more pronounced suppression of bone marrow myeloid progenitor cell proliferation and monocytosis, as well as reduced atherosclerosis and a stable plaque phenotype.
We describe a novel method for effective mono-pegylation of apoA-I in HDL particles, in which lipid binding appears to protect against pegylation of key functional residues. Pegylation of apoA-I in rHDL markedly increases its plasma half-life and enhances anti-atherogenic properties in vivo.
HDL; apoA-I; atherosclerosis; hematopoiesis; cholesterol
Hepatoblastomas often require neoadjuvant chemotherapy to facilitate partial hepatectomy, which necessitates freedom of tumor borders from the confluence of hepatic veins (COHV), portal vein bifurcation (PVB), and retrohepatic inferior vena cava (IVC). This study aimed to clarify the effect of incremental neoadjuvant cycles on the AHEP0731 protocol criteria of hepatoblastoma resectability.
Hepatoblastoma responses to neoadjuvant chemotherapy were analyzed among patients (n=23) treated at two children’s hospitals between 1996 and 2010. Using digital imaging data, ellipsoid and point-based models were created to measure tumor volume regression and respective distances from tumor borders nearest to the COHV, PVB, and IVC.
Hepatoblastoma volumes regressed with incremental neoadjuvant chemotherapy cycles (p<0.001). Although tumor borders regressed away from the COHV (p=0.008), on average only 1.1mm was gained. No change from tumor borders to the PVB was detected (p=0.102). Distances from tumor borders to the IVC remained stable at one hospital (p=0.612), but increased only 0.15mm every 10 days of therapy at the other (p=0.002). Neoadjuvant chemotherapy induced slightly more tumors to meet the threshold vascular margin of 1cm (baseline to completion): COHV, 11 (47.8%) to 17 (73.9%; p=0.058); PVB, 11 (47.8%) to 15 (65.2%; p=0.157); IVC, 4 (17.4%) to 10 (43.5%; p=0.034). No differences were detected in demographic or disease-specific characteristics between patients who did or did not achieve this 1cm margin after conclusion of chemotherapy.
Hepatoblastoma volumes regress significantly with increasing neoadjuvant chemotherapy cycles. However, tumors often remain anchored to the major hepatic vasculature, showing marginal improvement in resectability criteria.
hepatoblastoma; AHEP0731; neoadjuvant chemotherapy; tumor volume; tumor regression
Plasma HDL levels are inversely correlated with atherosclerosis. Although it is widely assumed that this is due to the ability of HDL to promote cholesterol efflux from macrophage foam cells, direct experimental support for this hypothesis is lacking.
To assess the role of macrophage cholesterol efflux pathways in atherogenesis.
Methods and Results
We developed MAC-ABCDKO mice with efficient deletion of the ATP Binding Cassette Transporters A1 and G1 (ABCA1 and ABCG1) in macrophages but not in hematopoietic stem or progenitor populations. MAC-ABCDKO bone marrow (BM) was transplanted into Ldlr-/- recipients. On the chow diet, these mice had similar plasma cholesterol and blood monocyte levels but increased atherosclerosis compared to controls. On the Western type diet (WTD), MAC-ABCDKO BM transplanted Ldlr-/- mice had disproportionate atherosclerosis, considering they also had lower VLDL/LDL cholesterol levels than controls. ABCA1/G1 deficient macrophages in lesions showed increased inflammatory gene expression. Unexpectedly, WTD-fed MAC-ABCDKO BM transplanted Ldlr-/- mice displayed monocytosis and neutrophilia in the absence of HSPC proliferation. Mechanistic studies revealed increased expression of M-CSF and G-CSF in splenic macrophage foam cells, driving BM monocyte and neutrophil production.
These studies 1) show that macrophage deficiency of ABCA1/G1 is pro-atherogenic likely by promoting plaque inflammation and 2) uncover a novel positive feedback loop in which cholesterol-laden splenic macrophages signal BM progenitors to produce monocytes, with suppression by macrophage cholesterol efflux pathways.
Atherosclerosis; high-density-lipoprotein; inflammation; macrophages; monocytes
Nonalcoholic fatty liver disease is the most common chronic liver disorder in developed countries. Its pathogenesis is poorly understood, and therapeutic options are limited. Here we show that SIRT7, an NAD+-dependent H3K18Ac deacetylase, functions at chromatin to suppress ER stress and prevents the development of fatty liver disease. SIRT7 is induced upon ER stress and is stabilized at the promoters of ribosomal proteins through its interaction with the transcription factor Myc to silence gene expression and to relieve ER stress. SIRT7 deficient mice develop chronic hepatosteatosis resembling human fatty liver disease. Myc inactivation or pharmacological suppression of ER stress alleviates fatty liver caused by SIRT7 deficiency. Importantly, SIRT7 suppresses ER stress and reverts the fatty liver disease in diet-induced obese mice. Our study identifies SIRT7 as a cofactor of Myc for transcriptional repression and delineates a druggable regulatory branch of the ER stress response that prevents and reverts fatty liver disease.
Diabetes is a major risk factor for atherosclerosis. Although atherosclerosis is initiated by deposition of cholesterol-rich lipoproteins in the artery wall, the entry of inflammatory leukocytes into lesions fuels disease progression and impairs resolution. We show that diabetic mice have increased numbers of circulating neutrophils and Ly6-Chi monocytes, reflecting hyperglycemia-induced proliferation and expansion of bone marrow myeloid progenitors and release of monocytes into the circulation. Increased neutrophil production of S100A8/A9, via an interaction with the receptor for advanced glycation end products on common myeloid progenitor cells, leads to enhanced myelopoiesis. Treatment of hyperglycemia reduces monocytosis, entry of monocytes into atherosclerotic lesions and promotes regression. In patients with type I diabetes plasma S100A8/A9 levels correlate with leukocyte counts and coronary artery disease. Thus, hyperglycemia drives myelopoiesis and thus promotes atherogenesis in diabetes.
Adults undergoing oncologic resections at low-volume centers experience increased perioperative morbidity and mortality. The volume-outcome effect has not been extensively studied in pediatric oncologic resections.
To clarify volume-outcome effects in pediatric oncologic resections, we analyzed resection of renal malignancies in children less than 15 y of age. We conducted a cross-sectional analysis of hospital discharges included in the health care utilization project kids’ inpatient database from 1997 to 2009, examining in-hospital operative complications, length of stay (LOS), and inflation-adjusted hospital charges. Hospital volume was expressed as low (n = 1–2), medium (n = 3–4), and high (n > 4) annual volume of resections.
One thousand five hundred thirty-eight patients underwent renal malignancy resection. Of these, 527 patients had resection in low-, 422 in medium-, and 589 in high-volume hospitals. Relative to low-volume hospitals, those resected in medium-volume hospitals had an odds ratio of 0.62 (95% confidence interval 0.39–0.99, P = 0.046) for operative complication and those in high-volume hospitals had an odds ratio of 1.02 (95% confidence interval 0.63–1.65, P = 0.95). There was no detectable association with LOS (P = 0.113) or inflation-adjusted charges (P = 0.331).
The number of complications, total charges, and LOS attributable to resection of a childhood renal malignancy did not differ among high-, medium-, or low-operative volume hospitals, although oncologic outcomes could not be determined because of the limited nature of this administrative database.
Wilms’ tumor; Volume-outcome effects
Increased neutrophil and monocyte counts are often associated with an increased risk of atherosclerosis, but their relationship to insulin sensitivity is unknown.
To investigate the contribution of forkhead transcription factors (FoxO) in myeloid cells to neutrophil and monocyte counts, atherosclerosis, and systemic insulin sensitivity.
Methods and Results
Genetic ablation of the three genes encoding FoxO isoforms 1, 3a, and 4, in myeloid cells resulted in an expansion of the granulocyte/monocyte progenitor compartment, and was associated with increased atherosclerotic lesion formation in Ldl receptor knockout mice. In vivo and ex vivo studies indicate that FoxO ablation in myeloid cells increased generation of reactive oxygen species. Accordingly, treatment with the antioxidant N-acetyl-L-cysteine reversed the phenotype, normalizing atherosclerosis.
Our data indicate that myeloid cell proliferation and oxidative stress can be modulated via the FoxO branch of insulin receptor signaling, highlighting a heretofore-unknown link between insulin sensitivity and leukocytosis that can affect the predisposition to atherosclerosis.
Atherosclerosis; neutrophils; macrophages; insulin resistance; oxidative stress; antioxidant enzymes; stem cell
The Yes-associated-protein-1 (YAP1) is a novel, direct regulator of stem cell genes both in development and cancer. FAT4 is an upstream regulator that induces YAP1 cytosolic sequestering by phosphorylation (p-Ser 127) and therefore inhibits YAP1-dependent cellular proliferation. We hypothesized that loss of FAT4 signaling would result in expansion of the nephron progenitor population in kidney development and that YAP1 subcellular localization would be dysregulated in Wilms tumor (WT), an embryonal malignancy that retains gene expression profiles and histologic features reminiscent of the embryonic kidney.
Fetal kidneys from Fat4−/− mice were harvested at e18.5 and markers of nephron progenitors were investigated using immunohistochemical analysis. To examine YAP1 subcellular localization in WT, a primary WT cell line (VUWT30) was analyzed by immunofluorescence. Forty WT specimens evenly distributed between favorable and unfavorable histology (n = 20 each), and treatment failure or success (n = 20 each) was analyzed for total and phosphorylated YAP1 using immunohistochemistry and Western blot.
Fat4−/− mouse fetal kidneys exhibit nuclear YAP1 with increased proliferation and expansion of nephron progenitor cells. In contrast to kidney development, subcellular localization of YAP1 is dysregulated in WT, with a preponderance of nuclear p-YAP1. By Western blot, median p-YAP1 quantity was 5.2-fold greater in unfavorable histology WT (P = 0.05).
Fetal kidneys in Fat4−/− mice exhibit a phenotype reminiscent of nephrogenic rests, a WT precursor lesion. In WT, YAP1 subcellular localization is dysregulated and p-YAP1 accumulation is a novel biomarker of unfavorable histology.
anaplasia; biomarker; nephrogenic rests; Wilms tumor; YAP1
Wilms tumor (WT) is the most common childhood kidney cancer and retains gene expression profiles reminiscent of the embryonic kidney. We have shown previously that CITED1, a transcriptional regulator that labels the self-renewing, multipotent nephron progenitor population of the developing kidney, is robustly expressed across all major WT disease and patient characteristics. In this malignant context, CITED1 becomes enriched in the nucleus, which deviates from its cytosolic predominance in embryonic nephron progenitors. We designed the current studies to test the functional and mechanistic effects of differential CITED1 subcellular localization on WT behavior. To mimic its subcellular distribution observed in clinical WT specimens, CITED1 was misexpressed ectopically in the human WT cell line, WiT49, as either a wild-type (predominantly cytosolic) or a mutant, but transcriptionally active, protein (two point mutations in its nuclear export signal, CITED1ΔNES; nuclear-enriched). In vitro analyses showed that CITED1ΔNES enhanced WiT49 proliferation and colony formation in soft agar relative to wild-type CITED1 and empty vector controls. The nuclear-enriched CITED1ΔNES cell line showed the greatest tumor volumes after xenotransplantation into immunodeficient mice (n=15 animals per cell line). To elucidate CITED1 gene targets in this model, microarray profiling showed that wildtype CITED1 foremost upregulated LGR5 (stem cell marker), repressed CDH6 (early marker of epithelial commitment of nephron progenitors), and altered expression of specific WNT pathway participants. In summary, forced nuclear enrichment of CITED1 in a human WT cell line appears to enhance tumorigenicity, whereas ectopic cytosolic expression confers stem-like properties and an embryonic phenotype, analogous to the developmental context.
CITED1; Wilms tumor; WNT; WiT49; cancer stem cell
Obesity and type 2 diabetes are now recognized as chronic pro-inflammatory diseases. In the last decade, the role of the macrophage in particular has become increasingly implicated in their pathogenesis. Abundant literature now establishes that monocytes get recruited to peripheral tissues (i.e., pancreas, liver, and adipose tissue) to become resident macrophages and contribute to local inflammation, development of insulin resistance, or even pancreatic dysfunction. Furthermore, an accumulation of evidence has established an important role for macrophage polarization in the development of metabolic diseases. The general view in obesity is that there is an imbalance in the ratio of M1/M2 macrophages, with M1 “pro-inflammatory” macrophages being enhanced compared with M2 “anti-inflammatory” macrophages being down-regulated, leading to chronic inflammation and the propagation of metabolic dysfunction. However, there is emerging evidence revealing a more complex scenario with the spectrum of macrophage states exceeding well beyond the M1/M2 binary classification and confused further by human and animal models exhibiting different macrophage profiles. In this review, we will discuss the recent findings regarding macrophage polarization in obesity and type 2 diabetes.
macrophage; inflammation; obesity; type 2 diabetes; M1/M2; polarization
Atherosclerotic cardiovascular disease is a chronic inflammatory disease of the blood vessels that can lead to myocardial infarction or stroke. The major cell in the atherosclerotic lesion, the macrophage, is thought to be an important contributor to the production of inflammatory mediators that exacerbate this disease. Macrophages are generally derived from circulating monocytes, which are in turn produced by hematopoietic stem and multipotential progenitor cells (HSPCs) in the bone marrow and other medullary organs. Recent studies suggest that disruption in cholesterol homeostasis or prolonged exposure to a hypercholesterolemic environment can influence HSPCs to over-produce monocytes, resulting in monocytosis. These monocytes may carry a pre-programed ability to become M1-like macrophages once they enter the atherosclerotic lesion. Future studies may help to differentiate the role of such pre-programing versus responses to local environmental cues in determining M1, M2, or other macrophage phenotypes in atherosclerotic lesions.
atherosclerosis; hematopoiesis; cholesterol efflux; monocytes; macrophages; HDL
Ric-8A (resistance to inhibitors of cholinesterase 8A) and Ric-8B are guanine nucleotide exchange factors that enhance different heterotrimeric guanine nucleotide–binding protein (G protein) signaling pathways by unknown mechanisms. Because transgenic disruption of Ric-8A or Ric-8B in mice caused early embryonic lethality, we derived viable Ric-8A– or Ric-8B–deleted embryonic stem (ES) cell lines from blastocysts of these mice. We observed pleiotropic G protein signaling defects in Ric-8A−/− ES cells, which resulted from reduced steady-state amounts of Gαi, Gαq, and Gα13 proteins to <5% of those of wild-type cells. The amounts of Gαs and total Gβ protein were partially reduced in Ric-8A−/− cells compared to those in wild-type cells, and only the amount of Gαs was reduced substantially in Ric-8B−/− cells. The abundances of mRNAs encoding the G protein α subunits were largely unchanged by loss of Ric-8A or Ric-8B. The plasma membrane residence of G proteins persisted in the absence of Ric-8 but was markedly reduced compared to that in wild-type cells. Endogenous Gαi and Gαq were efficiently translated in Ric-8A−/− cells but integrated into endomembranes poorly; however, the reduced amounts of G protein α subunits that reached the membrane still bound to nascent Gβγ. Finally, Gαi, Gαq, and Gβ1 proteins exhibited accelerated rates of degradation in Ric-8A−/− cells compared to those in wild-type cells. Together, these data suggest that Ric-8 proteins are molecular chaperones required for the initial association of nascent Gα subunits with cellular membranes.
The overuse of antimicrobials is recognized as the main selective pressure driving the emergence and spread of antimicrobial resistance in human bacterial pathogens. Urinary tract infections (UTIs) are among the most common infections presented in primary care and empirical antimicrobial treatment is currently recommended. Previous research has identified that a substantial proportion of Irish general practitioners (GPs) prescribe antimicrobials for UTIs that are not in accordance with the Guidelines for Antimicrobial Prescribing in Primary Care in Ireland. The aim of this trial is to design, implement and evaluate the effectiveness of a complex intervention on GP antimicrobial prescribing and adult (18 years of age and over) patients’ antimicrobial consumption when presenting with a suspected UTI.
The Supporting the Improvement and Management of Prescribing for urinary tract infections (SIMPle) study is a three-armed intervention with practice-level randomization. Adult patients presenting with suspected UTIs in primary care will be included in the study.
The intervention integrates components for both GPs and patients. For GPs the intervention includes interactive workshops, audit and feedback reports and automated electronic prompts summarizing recommended first-line antimicrobial treatment and, for one intervention arm, a recommendation to consider delayed antimicrobial treatment. For patients, multimedia applications and information leaflets are included. Thirty practices will be recruited to the study; laboratory data indicate that 2,038 patients will be prescribed an antimicrobial in the study. The primary outcome is a change in prescribing of first-line antimicrobials for UTIs in accordance with the Guidelines for Antimicrobial Prescribing in Primary Care in Ireland. The study will take place over 15 months with a six-month intervention period. Data will be collected through a remote electronic anonymized data-extraction system, a text-messaging system and GP and patient interviews and surveys. The intervention will be strengthened by the implementation of a social marketing framework and an economic evaluation.
This intervention is registered at ClinicalTrials.gov, ID
Antimicrobial; Intervention; Prescribing; Primary care; Social marketing; Urinary tract infection
We report the complex case of a 12-month-old female with stage IV hepatoblastoma accompanied by thrombosis and cavernous transformation of the portal vein. Following neoadjuvant chemotherapy, she underwent right hepatectomy, which was complicated by iatrogenic injury of her left hepatic duct, and subsequently developed a postoperative biloma and chronic biliocutaneous fistula. Concomitant with multiple percutaneous interventions to manage the biloma nonoperatively while the child completed her adjuvant chemotherapy, she progressed to develop chronic malnutrition, jaundice, and failure to thrive. Once therapy was completed and the child was deemed free of disease she underwent exploratory laparotomy with roux-en-Y biliary cyst-enterostomy for definitive management, resulting in resolution of her biliary fistula, jaundice, and marked improvement in her nutritional status. Roux-en-Y biliary cyst-enterostomy is a unique and efficacious management option in the highly selected patient population with chronic biliary leak refractory to minimally invasive management.
hepatoblastoma; biloma; roux-en Y biliary cyst enterostomy
Skin wound repair requires complex and highly coordinated interactions between keratinocytes, fibroblasts and immune cells to restore the epidermal barrier and tissue architecture after acute injury. The cytokine interleukin-22 (IL-22) mediates unidirectional signaling from immune cells to epithelial cells during injury of peripheral tissues such as the liver and colon, where IL-22 causes epithelial cells to produce anti-bacterial proteins, express mucins, and enhance epithelial regeneration. In this study, we use IL-22−/− mice to investigate the in vivo role for IL-22 in acute skin wounding. We find that IL-22−/− mice display major defects in the skin’s dermal compartment after full thickness wounding. We find that IL-22 signaling is active in fibroblasts using in vitro assays with primary fibroblasts and that IL-22 directs extracellular matrix (ECM) gene expression as well as myofibroblast differentiation both in vitro and in vivo. These data define roles of IL-22 beyond epithelial crosstalk, and suggest that IL-22 plays a previously unidentified role in skin repair by mediating interactions between immune cells and fibroblasts.
Interleukin 22; Wound Healing; Fibroblasts; extracellular matrix