Bacterial Sphingolipids Exacerbate Colitis by Inhibiting ILC3-derived IL-22 Production.

BACKGROUND & AIMS: Gut bacterial sphingolipids, primarily produced by Bacteroidetes, have dual roles as bacterial virulence factors and regulators of the host mucosal immune system, including regulatory T cells and invariant natural killer T cells. Patients with inflammatory bowel disease display altered sphingolipids profiles in fecal samples. However, how bacterial sphingolipids modulate mucosal homeostasis and regulate intestinal inflammation remains unclear. METHODS: We used dextran sodium sulfate (DSS)-induced colitis in mice monocolonized with Bacteroides fragilis strains expressing or lacking sphingolipids to assess the influence of bacterial sphingolipids on intestinal inflammation using transcriptional, protein, and cellular analyses. Colonic explant and organoid were used to study the function of bacterial sphingolipids. Host mucosal immune cells and cytokines were profiled and characterized using flow cytometry, enzyme-linked immunosorbent assay, and Western blot, and cytokine function in vivo was investigated by monoclonal antibody injection. RESULTS: B fragilis sphingolipids exacerbated intestinal inflammation. Mice monocolonized with B fragilis lacking sphingolipids exhibited less severe DSS-induced colitis. This amelioration of colitis was associated with increased production of interleukin (IL)-22 by ILC3. Mice colonized with B fragilis lacking sphingolipids following DSS treatment showed enhanced epithelial STAT3 activity, intestinal cell proliferation, and antimicrobial peptide production. Protection against DSS colitis associated with B fragilis lacking sphingolipids was reversed on IL22 blockade. Furthermore, bacterial sphingolipids restricted epithelial IL18 production following DSS treatment and interfered with IL22 production by a subset of ILC3 cells expressing both IL18R and major histocompatibility complex class II. CONCLUSIONS: B fragilis-derived sphingolipids exacerbate mucosal inflammation by impeding epithelial IL18 expression and concomitantly suppressing the production of IL22 by ILC3 cells.

Failure of Israeli pediatric residency curricula to cover child development and special education issues: results of a national survey on levels of knowledge.

BACKGROUND: There is an increasing prevalence of developmental difficulties among Israeli children. We aimed to assess whether pediatricians are equipped to diagnose and manage them. METHODS: We assessed the knowledge of basic child development issues and availability of services and content of special education systems among a randomly selected national sample of residents and senior Israeli pediatricians. This was done via an 70-itemed survey developed especially for this study which consisted of seven main subjects: developmental milestones, global developmental delay, autism spectrum disorder, attention deficit hyperactivity disorder, protocol for referring to a child development institute, availability and facilities of special education systems, and medical conditions associated with developmental delay. RESULTS: A total of 310 pediatricians (an 86 % usable response rate) participated. The total median knowledge score was 32.1 % (IQR 17.8-53.5 %). Knowledge was significantly better among senior pediatricians (p < .001), those working in an office-based setting (p < .001), and those who were parents (p < .001) or had a family history of a developmental condition (p = .003). Most responders (94 %) felt that their resident training in child development was inadequate, and that they do not have sufficient access to resources and guidelines about child development and special education systems (80 %). CONCLUSIONS: The gap in knowledge on topics of child development and special education systems among Israeli pediatricians stems from inadequacies in the current curricula of pediatric residencies. The alarmingly low scores of our survey on these issues call for prompt revamping of the syllabus to include them.

Effectiveness and Safety of High- vs Low-Dose Swallowed Topical Steroids for Maintenance Treatment of Eosinophilic Esophagitis: A Multicenter Observational Study.

BACKGROUND & AIMS: Data evaluating efficacy of different doses of swallowed topical corticosteroids (STC) in the long-term management of eosinophilic esophagitis (EoE) are lacking. We assessed long-term effectiveness and safety of different STC doses for adults with EoE after achievement of histological remission. METHODS: We performed a retrospective multicenter study at five EoE referral centers (US and Switzerland). We analyzed data on 82 patients with EoE in histological remission and ongoing STC treatment with therapeutic adherence of ≥75% (58 males; mean age at diagnosis, 37.2±14.4 years). Patients were followed for a median of 2.2 years (interquartile range [IQR], 1.0-3.8 years). We collected data from 217 follow-up endoscopy visits. The primary endpoint was time to histological relapse. RESULTS: Histological relapse occurred in 67% of patients. Relapse rates were comparable in patients taking low dose (≤0.5 mg per day, n = 58) and high dose STC (>0.5 mg per day, n = 24) with 72 vs 54% (ns). However, histological relapse occurred significantly earlier with low dose STC (1.0 vs 1.8 years, P = .030). There was no difference regarding rates of and time to stricture formation for low vs high dose STC. Esophageal candidiasis was observed in 6% of patients (5% for low dose, 8% for high dose, ns). No dysplasia or mucosal atrophy was detected. CONCLUSION: Histological relapse frequently occurs in EoE despite ongoing STC treatment regardless of STC doses. However, relapse develops later in patients on high dose STC without an increase in side-effects. Doses higher than 0.5 mg/day may be considered for EoE maintenance treatment, but advantage over lower doses appears to be small.

Significant Medical Comorbidities Are Associated With Lower Causality Scores in Patients Presenting With Suspected Drug-Induced Liver Injury.

INTRODUCTION: Drug-induced liver injury (DILI) is a diagnosis of exclusion, and it can be challenging to adjudicate when there are multiple comorbidities and concomitant medications. In this study, we tested the hypothesis that comorbidity burden impacts the causality adjudication in patients with suspected DILI. METHODS: We studied consecutive patients with suspected DILI enrolled in the Drug-Induced Liver Injury Network Prospective Study at 2 centers between 2003 and 2017. The comorbidity burden at presentation was determined using the Charlson Comorbidity Index (CCI). We analyzed the association between significant comorbidity (CCI > 75th percentile) and (i) the adjudication of DILI by expert consensus as definite, highly likely, or probable (high-confidence DILI) and (ii) the Roussel Uclaf Causality Assessment Method (RUCAM) scores. RESULTS: Our cohort consisted of 551 patients who were classified as "no comorbidity" (54%, CCI = 0), "mild comorbidity" (29%, CCI = 1 or 2), and "significant comorbidity" (17%, CCI > 2). The probability of high-confidence DILI was significantly lower in patients with significant comorbidity compared with those with mild or no comorbidities (67% vs 76% vs 87%, respectively, P < 0.001). The mean RUCAM scores decreased with increasing comorbidity (no comorbidity 6.6 ± 2, mild comorbidity 6 ± 2.4, and significant comorbidity 5.6 ± 2.7, P < 0.001). In the multiple logistic regression, significant comorbidity had an independent inverse relationship with DILI (odds ratio: 0.37, 95% confidence interval: 0.2-0.69, P = 0.001). DISCUSSION: Higher comorbidity burden impacts the causality assessment in patients with suspected DILI. Further studies are needed to investigate the utility of comorbidity burden as a variable in the DILI causality instruments.

Development and Validation of a Model Consisting of Comorbidity Burden to Calculate Risk of Death Within 6 Months for Patients With Suspected Drug-Induced Liver Injury.

BACKGROUND & AIMS: Patients with drug-induced liver injury (DILI) frequently have comorbid conditions, but the effects of non-liver comorbidities on outcomes are not well understood. We investigated the association between comorbidity burden and outcomes of patients with DILI, and developed and validated a model to calculate risk of death within 6 months. METHODS: A multiple logistic regression model identified variables independently associated with death within 6 months of presenting with suspected DILI (6-month mortality) for 306 patients enrolled in the Drug-Induced Liver Injury Network prospective study at Indiana University (discovery cohort). The model was validated using data from 247 patients with suspected DILI enrolled in the same study at the University of North Carolina (validation cohort). Medical comorbidity burden was calculated using the Charlson Comorbidity Index-patients with scores higher than 2 were considered to have significant comorbidities. RESULTS: Six-month mortality was 8.5% in the discovery cohort and 4.5% in the validation cohort. In the discovery cohort, significant comorbidities (odds ratio, 5.4; 95% confidence interval [CI], 2.1-13.8), Model for End-Stage Liver Disease score (odds ratio, 1.11; 95% CI, 1.04-1.17), and serum level of albumin at presentation (odds ratio, 0.39; 95% CI, 0.2-0.76) were independently associated with 6-month mortality. A model based on these 3 variables identified patients who died within 6 months, with c-statistic values of 0.89 (95% CI, 0.86-0.94) in the discovery cohort and 0.91 (95% CI, 0.83-0.99) in the validation cohort. We developed a web-based calculator for use in the clinic to determine risk of death within 6 months for patients with suspected DILI. CONCLUSIONS: We developed and validated a model based on comorbidity burden, Model for End-Stage Liver Disease score, and serum level of albumin that predicts 6-month mortality in patients with suspected DILI.

Human Colorectal Cancer Stage-dependent Global DNA Hypomethylation of Cancer-associated Fibroblasts.

BACKGROUND/AIM: Cancer-associated fibroblasts (CAFs) play an important role in tumor development and progression. The prevailing consensus favors the view that a specific epigenetic signature underpins the stable CAF phenotype. The aim of the present study was to assess global DNA methylation in CAFs during the adenoma-carcinoma sequence in non-familial sporadic human colorectal cancer (CRC). PATIENTS AND METHODS: Immunohistochemical staining of nuclear 5-methylcytosine (5'-meCyt) was performed in matched samples of colonic tumor tissue and normal colonic mucosa excised from six patients with adenomas and four with adenocarcinomas. The staining intensity was expressed semi-quantitatively as the immunohistochemical staining score (ISS). RESULTS: ISS values of human colonic CAFs and adenomatous samples were 14.00±2.2 and 14.08±1.8, respectively, showing no statistically significant difference. In contrast, a marked trend was found towards global DNA hypomethylation in CAFs from adenocarcinomatous specimens compared to matched normal mucosa: ISS: 9.25±2.44 (range=6-11) vs. 16.17±0.75, respectively, p<0.03. CONCLUSION: Final stages of cancer development in CRC are associated with global DNA hypomethylation in stromal CAFs.

Dietary linoleic acid-induced alterations in pro- and anti-nociceptive lipid autacoids: Implications for idiopathic pain syndromes?

BACKGROUND: Chronic idiopathic pain syndromes are major causes of personal suffering, disability, and societal expense. Dietary n-6 linoleic acid has increased markedly in modern industrialized populations over the past century. These high amounts of linoleic acid could hypothetically predispose to physical pain by increasing the production of pro-nociceptive linoleic acid-derived lipid autacoids and by interfering with the production of anti-nociceptive lipid autacoids derived from n-3 fatty acids. Here, we used a rat model to determine the effect of increasing dietary linoleic acid as a controlled variable for 15 weeks on nociceptive lipid autacoids and their precursor n-6 and n-3 fatty acids in tissues associated with idiopathic pain syndromes. RESULTS: Increasing dietary linoleic acid markedly increased the abundance of linoleic acid and its pro-nociceptive derivatives and reduced the abundance of n-3 eicosapentaenoic acid and docosahexaenoic acid and their anti-nociceptive monoepoxide derivatives. Diet-induced changes occurred in a tissue-specific manner, with marked alterations of nociceptive lipid autacoids in both peripheral and central tissues, and the most pronounced changes in their fatty acid precursors in peripheral tissues. CONCLUSIONS: The present findings provide biochemical support for the hypothesis that the high linoleic acid content of modern industrialized diets may create a biochemical susceptibility to develop chronic pain. Dietary linoleic acid lowering should be further investigated as part of an integrative strategy for the prevention and management of idiopathic pain syndromes.

Re-evaluation of the traditional diet-heart hypothesis: analysis of recovered data from Minnesota Coronary Experiment (1968-73).

OBJECTIVE: To examine the traditional diet-heart hypothesis through recovery and analysis of previously unpublished data from the Minnesota Coronary Experiment (MCE) and to put findings in the context of existing diet-heart randomized controlled trials through a systematic review and meta-analysis. DESIGN: The MCE (1968-73) is a double blind randomized controlled trial designed to test whether replacement of saturated fat with vegetable oil rich in linoleic acid reduces coronary heart disease and death by lowering serum cholesterol. Recovered MCE unpublished documents and raw data were analyzed according to hypotheses prespecified by original investigators. Further, a systematic review and meta-analyses of randomized controlled trials that lowered serum cholesterol by providing vegetable oil rich in linoleic acid in place of saturated fat without confounding by concomitant interventions was conducted. SETTING: One nursing home and six state mental hospitals in Minnesota, United States. PARTICIPANTS: Unpublished documents with completed analyses for the randomized cohort of 9423 women and men aged 20-97; longitudinal data on serum cholesterol for the 2355 participants exposed to the study diets for a year or more; 149 completed autopsy files. INTERVENTIONS: Serum cholesterol lowering diet that replaced saturated fat with linoleic acid (from corn oil and corn oil polyunsaturated margarine). Control diet was high in saturated fat from animal fats, common margarines, and shortenings. MAIN OUTCOME MEASURES: Death from all causes; association between changes in serum cholesterol and death; and coronary atherosclerosis and myocardial infarcts detected at autopsy. RESULTS: The intervention group had significant reduction in serum cholesterol compared with controls (mean change from baseline -13.8%v-1.0%; P<0.001). Kaplan Meier graphs showed no mortality benefit for the intervention group in the full randomized cohort or for any prespecified subgroup. There was a 22% higher risk of death for each 30 mg/dL (0.78 mmol/L) reduction in serum cholesterol in covariate adjusted Cox regression models (hazard ratio 1.22, 95% confidence interval 1.14 to 1.32; P<0.001). There was no evidence of benefit in the intervention group for coronary atherosclerosis or myocardial infarcts. Systematic review identified five randomized controlled trials for inclusion (n=10,808). In meta-analyses, these cholesterol lowering interventions showed no evidence of benefit on mortality from coronary heart disease (1.13, 0.83 to 1.54) or all cause mortality (1.07, 0.90 to 1.27). CONCLUSIONS: Available evidence from randomized controlled trials shows that replacement of saturated fat in the diet with linoleic acid effectively lowers serum cholesterol but does not support the hypothesis that this translates to a lower risk of death from coronary heart disease or all causes. Findings from the Minnesota Coronary Experiment add to growing evidence that incomplete publication has contributed to overestimation of the benefits of replacing saturated fat with vegetable oils rich in linoleic acid.

Family as the primary caregiver: palliative care in the Golan Heights.

Palliative care is recognised by the WHO as an essential component of care for the seriously ill. Geographically isolated and historically underserved communities, particularly from ethnic minority groups, face obstacles in obtaining adequate palliative care. This case involves the care of a 26-year-old Druze man suffering from a terminal cancer in his Golan Heights village. Local physicians were able to train the patient's father in a palliative care capacity. In the effort of capacity building, the physician and palliative care team also aided the aggrieved family in the process of coping. Robust support networks, both at state and community levels, facilitated the care provided. In showcasing the role of the national and local safety net in activating and building community resources to address a dearth of palliative care services in disadvantaged regions, this case models a potentially effective community-based approach to palliative care for patients from underserved populations.

Dietary omega-6 fatty acid lowering increases bioavailability of omega-3 polyunsaturated fatty acids in human plasma lipid pools.

BACKGROUND: Dietary linoleic acid (LA, 18:2n-6) lowering in rats reduces n-6 polyunsaturated fatty acid (PUFA) plasma concentrations and increases n-3 PUFA (eicosapentaenoic (EPA) and docosahexaenoic acid (DHA)) concentrations. OBJECTIVE: To evaluate the extent to which 12 weeks of dietary n-6 PUFA lowering, with or without increased dietary n-3 PUFAs, alters unesterified and esterified plasma n-6 and n-3 PUFA concentrations in subjects with chronic headache. DESIGN: Secondary analysis of a randomized trial. Subjects with chronic headache were randomized for 12 weeks to (1) average n-3, low n-6 (L6) diet; or (2) high n-3, low n-6 LA (H3-L6) diet. Esterified and unesterified plasma fatty acids were quantified at baseline (0 weeks) and after 12 weeks on a diet. RESULTS: Compared to baseline, the L6 diet reduced esterified plasma LA and increased esterified n-3 PUFA concentrations (nmol/ml), but did not significantly change plasma arachidonic acid (AA, 20:4n-6) concentration. In addition, unesterified EPA concentration was increased significantly among unesterified fatty acids. The H3-L6 diet decreased esterified LA and AA concentrations, and produced more marked increases in esterified and unesterified n-3 PUFA concentrations. CONCLUSION: Dietary n-6 PUFA lowering for 12 weeks significantly reduces LA and increases n-3 PUFA concentrations in plasma, without altering plasma AA concentration. A concurrent increase in dietary n-3 PUFAs for 12 weeks further increases n-3 PUFA plasma concentrations and reduces AA.

Targeted alteration of dietary n-3 and n-6 fatty acids for the treatment of chronic headaches: a randomized trial.

Omega-3 and n-6 fatty acids are biosynthetic precursors to lipid mediators with antinociceptive and pronociceptive properties. We conducted a randomized, single-blinded, parallel-group clinical trial to assess clinical and biochemical effects of targeted alteration in dietary n-3 and n-6 fatty acids for treatment of chronic headaches. After a 4-week preintervention phase, ambulatory patients with chronic daily headache undergoing usual care were randomized to 1 of 2 intensive, food-based 12-week dietary interventions: a high n-3 plus low n-6 (H3-L6) intervention, or a low n-6 (L6) intervention. Clinical outcomes included the Headache Impact Test (HIT-6, primary clinical outcome), Headache Days per month, and Headache Hours per day. Biochemical outcomes included the erythrocyte n-6 in highly unsaturated fatty acids (HUFA) score (primary biochemical outcome) and bioactive n-3 and n-6 derivatives. Fifty-six of 67 patients completed the intervention. Both groups achieved targeted intakes of n-3 and n-6 fatty acids. In intention-to-treat analysis, the H3-L6 intervention produced significantly greater improvement in the HIT-6 score (-7.5 vs -2.1; P<0.001) and the number of Headache Days per month (-8.8 vs -4.0; P=0.02), compared to the L6 group. The H3-L6 intervention also produced significantly greater reductions in Headache Hours per day (-4.6 vs -1.2; P=0.01) and the n-6 in HUFA score (-21.0 vs -4.0%; P<0.001), and greater increases in antinociceptive n-3 pathway markers 18-hydroxy-eicosapentaenoic acid (+118.4 vs +61.1%; P<0.001) and 17-hydroxy-docosahexaenoic acid (+170.2 vs +27.2; P<0.001). A dietary intervention increasing n-3 and reducing n-6 fatty acids reduced headache pain, altered antinociceptive lipid mediators, and improved quality-of-life in this population.

Use of dietary linoleic acid for secondary prevention of coronary heart disease and death: evaluation of recovered data from the Sydney Diet Heart Study and updated meta-analysis.

OBJECTIVE: To evaluate the effectiveness of replacing dietary saturated fat with omega 6 linoleic acid, for the secondary prevention of coronary heart disease and death. DESIGN: Evaluation of recovered data from the Sydney Diet Heart Study, a single blinded, parallel group, randomized controlled trial conducted in 1966-73; and an updated meta-analysis including these previously missing data. SETTING: Ambulatory, coronary care clinic in Sydney, Australia. PARTICIPANTS: 458 men aged 30-59 years with a recent coronary event. INTERVENTIONS: Replacement of dietary saturated fats (from animal fats, common margarines, and shortenings) with omega 6 linoleic acid (from safflower oil and safflower oil polyunsaturated margarine). Controls received no specific dietary instruction or study foods. All non-dietary aspects were designed to be equivalent in both groups. OUTCOME MEASURES: All cause mortality (primary outcome), cardiovascular mortality, and mortality from coronary heart disease (secondary outcomes). We used an intention to treat, survival analysis approach to compare mortality outcomes by group. RESULTS: The intervention group (n=221) had higher rates of death than controls (n=237) (all cause 17.6% v 11.8%, hazard ratio 1.62 (95% confidence interval 1.00 to 2.64), P=0.05; cardiovascular disease 17.2% v 11.0%, 1.70 (1.03 to 2.80), P=0.04; coronary heart disease 16.3% v 10.1%, 1.74 (1.04 to 2.92), P=0.04). Inclusion of these recovered data in an updated meta-analysis of linoleic acid intervention trials showed non-significant trends toward increased risks of death from coronary heart disease (hazard ratio 1.33 (0.99 to 1.79); P=0.06) and cardiovascular disease (1.27 (0.98 to 1.65); P=0.07). CONCLUSIONS: Advice to substitute polyunsaturated fats for saturated fats is a key component of worldwide dietary guidelines for coronary heart disease risk reduction. However, clinical benefits of the most abundant polyunsaturated fatty acid, omega 6 linoleic acid, have not been established. In this cohort, substituting dietary linoleic acid in place of saturated fats increased the rates of death from all causes, coronary heart disease, and cardiovascular disease. An updated meta-analysis of linoleic acid intervention trials showed no evidence of cardiovascular benefit. These findings could have important implications for worldwide dietary advice to substitute omega 6 linoleic acid, or polyunsaturated fats in general, for saturated fats. TRIAL REGISTRATION: Clinical trials NCT01621087.

Lowering dietary linoleic acid reduces bioactive oxidized linoleic acid metabolites in humans.

Linoleic acid (LA) is the most abundant polyunsaturated fatty acid in human diets, a major component of human tissues, and the direct precursor to the bioactive oxidized LA metabolites (OXLAMs), 9- and 13 hydroxy-octadecadienoic acid (9- and 13-HODE) and 9- and 13-oxo-octadecadienoic acid (9- and 13-oxoODE). These four OXLAMs have been mechanistically linked to pathological conditions ranging from cardiovascular disease to chronic pain. Plasma OXLAMs, which are elevated in Alzheimer's dementia and non-alcoholic steatohepatitis, have been proposed as biomarkers useful for indicating the presence and severity of both conditions. Because mammals lack the enzymatic machinery needed for de novo LA synthesis, the abundance of LA and OXLAMs in mammalian tissues may be modifiable via diet. To examine this issue in humans, we measured circulating LA and OXLAMs before and after a 12-week LA lowering dietary intervention in chronic headache patients. Lowering dietary LA significantly reduced the abundance of plasma OXLAMs, and reduced the LA content of multiple circulating lipid fractions that may serve as precursor pools for endogenous OXLAM synthesis. These results show that lowering dietary LA can reduce the synthesis and/or accumulation of oxidized LA derivatives that have been implicated in a variety of pathological conditions. Future studies evaluating the clinical implications of diet-induced OXLAM reductions are warranted.