Dietary exposure to polyaromatic hydrocarbons of the Hong Kong population.

Polyaromatic hydrocarbons (PAHs) are ubiquitous in the environment and food. The Joint FAO/WHO Expert Committee on Food Additives concluded 13 individual PAHs are carcinogenic and genotoxic in vitro and in vivo. Food is recognized as the main source of exposure to PAHs for adult non-smokers, which contributed to more than 90% of total exposure. In this study, 300 food samples were collected in Hong Kong, analysed the levels of 16 European Union priority PAHs, the dietary exposure to these PAHs by the local adult population from these food items, and the associated health risk. The most predominant detectable PAH was chrysene (CHR) (14.4%), followed by benzo[c]fluorene (11.2%), benzo[a]anthracene (BaA) (10.6%) and benzo[b]fluoranthene (BbFA) (7.8%). The dietary exposures for average consumers of benzo[a]pyrene (BaP) and PAH4 (sum of BaP, CHR, BaA and BbFA) were 0.13-0.90 and 1.4-4.2 ng/kg bw/day respectively for lower and upper bound approaches. Cereal and its products contributed more than 50% to BaP and PAH4 for average consumers in a lower-bound approach. The margin of exposure (MOE) approach was used to assess the health risks of consumers. The calculated MOE values for both BaP and PAH4 of the average and high consumers (90th percentile) were >50,000, indicating a low concern for the health of the Hong Kong population.

Increased intracranial pressure in a patient with Congenital Heart Defect and Ectodermal Dysplasia (CHDED): Extension of phenotype and review of literature.

Congenital heart defect (CHD) is a birth defect that affects the structure of the heart. Although CHD is often multifactorial, it can also be inherited as part of a Mendelian disorder such as in congenital heart defect and ectodermal dysplasia (CHDED). This disorder is caused by de novo variants in PRKD1. Here, we describe a patient with a novel de novo variant of PRKD1 with phenotypic features consistent with CHDED. Previously unreported features were noted including high intracranial pressure (ICP), partial anomalous pulmonary venous return (PAPVR), and bifid uvula. We suggest that these features may be associated with CHDED.

Alternative to Body Surface Area as a Solution to Correct Systematic Bias in Pediatric Echocardiography z Scores.

BACKGROUND: Z scores are the method of choice to report dimensions in pediatric echocardiography. Z scores based on body surface area (BSA) have been shown to cause systematic biases in overweight and obese children. Using aortic valve (AoV) diameters as a paradigm, the aims of this study were to assess the magnitude of z score underestimation in children with increased body mass index z score (BMI-z) and to determine if a predicting model with height and weight as independent predictors would minimise this bias. METHODS: In this multicentre, retrospective, cross-sectional study, 15,006 normal echocardiograms in healthy children 1-18 years old were analyzed. Residual associations with body size were assessed for previously published z score. BSA-based and alternate prediction models based on height and weight were developed and validated in separate training and validation samples. RESULTS: Existing BSA-based z scores incompletely adjusted for weight, BSA, and BMI-z and led to an underestimation of > 0.8 z score units in subjects with higher BMI-z compared with lean subjects. BSA-based models led to overestimation of predicted AoV diameters with increasing weight or BMI-z. Models using height and weight as independent predictors improved adjustment with body size, including in children with higher BMI-z. CONCLUSIONS: BSA-based models result in underestimation of z scores in patients with high BMI-z. Prediction models using height and weight as independent predictors minimise residual associations with body size and generate well fitted predicted values that could apply to all children, including those with low or high BMI-z.

Long COVID-19: A Primer for Cardiovascular Health Professionals, on Behalf of the CCS Rapid Response Team.

It is now widely recognized that COVID-19 illness can be associated with significant intermediate and potentially longer-term physical limitations. The term, "long COVID-19" is used to define any patient with persistent symptoms after acute COVID-19 infection (ie, after 4 weeks). It is postulated that cardiac injury might be linked to symptoms that persist after resolution of acute infection, as part of this syndrome. The Canadian Cardiovascular Society Rapid Response Team has generated this document to provide guidance to health care providers on the optimal management of patients with suspected cardiac complications of long COVID-19.

Preparing for CBME: How often are faculty observing residents?

BACKGROUND: The Royal College of Physicians and Surgeons of Canada officially launched 'Competence by Design' in July 2017, moving from time-based to outcomes-based training. Transitioning to competency-based medical education (CBME) necessitates change in resident assessment. A greater frequency of resident observation will likely be required to adequately assess whether entrustable professional activities have been achieved. PURPOSE: Characterize faculty and resident experiences of direct observation in a single paediatric residency program, pre-CBME implementation. Qualitatively describe participants' perceived barriers and incentives to participating in direct observation. METHODS: Surveys were sent to paediatric residents and faculty asking for demographics, the frequency of resident observation during an average 4-week rotation, perceived ideal frequency of observation, and factors influencing observation frequency. Descriptive data were analyzed. Institutional research ethics board approval was received. RESULTS: The response rate was 54% (34/68 faculty and 16/25 residents). When asked the MAXIMUM frequency FACULTY observed a resident take a history, perform a physical examination, or deliver a plan, the median faculty reply was 1, 2, and 3, for outpatient settings and 0, 1, and 2, for inpatient settings. The median RESIDENT reply was 2, 4, and 10 for outpatient settings and 1, 2, and 20 for inpatient settings. When asked the MINIMUM frequency for each domain, the median FACULTY and RESIDENT reply was 0, except for delivering a plan in the inpatient setting. Faculty reported observing seniors delivering the plan more frequently than junior residents. Faculty and resident median replies for how frequently residents should be observed for each domain were the same, three to four, three to four, and five to six times. Four per cent of faculty reported regularly scheduling observations, and 77% of residents regularly ask to be observed. The most common barriers to observation were too many patients to see and both faculty and residents were seeing patients at the same time. Most faculty and resident responders felt that observation frequency could be improved if scheduled at the start of the rotation; faculty were provided a better tool for assessment; and if residents asked to be observed. CONCLUSIONS: This study provides baseline data on how infrequent faculty observation is occurring and at a frequency lower than what faculty and residents feel is necessary. The time needed for observation competes with clinical service demands, but better scheduling strategies and assessment tools may help.

Systematic design and comparison of expanded carrier screening panels.

PurposeThe recent growth in pan-ethnic expanded carrier screening (ECS) has raised questions about how such panels might be designed and evaluated systematically. Design principles for ECS panels might improve clinical detection of at-risk couples and facilitate objective discussions of panel choice.MethodsGuided by medical-society statements, we propose a method for the design of ECS panels that aims to maximize the aggregate and per-disease sensitivity and specificity across a range of Mendelian disorders considered serious by a systematic classification scheme. We evaluated this method retrospectively using results from 474,644 de-identified carrier screens. We then constructed several idealized panels to highlight strengths and limitations of different ECS methodologies.ResultsBased on modeled fetal risks for "severe" and "profound" diseases, a commercially available ECS panel (Counsyl) is expected to detect 183 affected conceptuses per 100,000 US births. A screen's sensitivity is greatly impacted by two factors: (i) the methodology used (e.g., full-exon sequencing finds more affected conceptuses than targeted genotyping) and (ii) the detection rate of the screen for diseases with high prevalence and complex molecular genetics (e.g., fragile X syndrome).ConclusionThe described approaches enable principled, quantitative evaluation of which diseases and methodologies are appropriate for pan-ethnic expanded carrier screening.

Clinical Utility of Expanded Carrier Screening: Reproductive Behaviors of At-Risk Couples.

Expanded carrier screening (ECS) analyzes dozens or hundreds of recessive genes to determine reproductive risk. Data on the clinical utility of screening conditions beyond professional guidelines are scarce. Individuals underwent ECS for up to 110 genes. Five-hundred thirty-seven at-risk couples (ARC), those in which both partners carry the same recessive disease, were invited to participate in a retrospective IRB-approved survey of their reproductive decision making after receiving ECS results. Sixty-four eligible ARC completed the survey. Of 45 respondents screened preconceptionally, 62% (n = 28) planned IVF with PGD or prenatal diagnosis (PNDx) in future pregnancies. Twenty-nine percent (n = 13) were not planning to alter reproductive decisions. The remaining 9% (n = 4) of responses were unclear. Of 19 pregnant respondents, 42% (n = 8) elected PNDx, 11% (n = 2) planned amniocentesis but miscarried, and 47% (n = 9) considered the condition insufficiently severe to warrant invasive testing. Of the 8 pregnancies that underwent PNDx, 5 were unaffected and 3 were affected. Two of 3 affected pregnancies were terminated. Disease severity was found to have significant association (p = 0.000145) with changes in decision making, whereas guideline status of diseases, controlled for severity, was not (p = 0.284). Most ARC altered reproductive planning, demonstrating the clinical utility of ECS. Severity of conditions factored into decision making.

Canadian Cardiovascular Society/Canadian Pediatric Cardiology Association Position Statement on Pulse Oximetry Screening in Newborns to Enhance Detection of Critical Congenital Heart Disease.

Congenital heart disease is the most common congenital malformation and approximately 3 in 1000 newborns have critical congenital heart disease (CCHD). Timely diagnosis affects morbidity, mortality, and disability, and newborn pulse oximetry screening has been studied to enhance detection of CCHD. In this position statement we present an evaluation of the literature for pulse oximetry screening. Current detection strategies including prenatal ultrasound examination and newborn physical examination are limited by low diagnostic sensitivity. Pulse oximetry screening is safe, noninvasive, easy to perform, and widely available with a high specificity (99.9%) and moderately high sensitivity (76.5%). When an abnormal saturation is obtained, the likelihood of having CCHD is 5.5 times greater than when a normal result is obtained. The use of pulse oximetry combined with current strategies has shown sensitivities of up to 92% for detecting CCHD. False positive results can be minimized by screening after 24 hours, and testing the right hand and either foot might further increase sensitivity. Newborns with abnormal screening results should undergo a comprehensive assessment and echocardiography performed if a cardiac cause cannot be excluded. Screening has been studied to be cost neutral to cost effective. We recommend that pulse oximetry screening should be routinely performed in all healthy newborns to enhance the detection of CCHD in Canada.

Pulse oximetry screening in newborns to enhance detection of critical congenital heart disease.

Pulse oximetry screening is safe, noninvasive, easy to perform and proven to enhance detection of critical congenital heart disease in newborns. However, this test has yet to be adopted as routine practice in Canada. The present practice point highlights essential details and recommendations for screening, which research has shown to be highly specific, with low false-positive rates. Optimal screening for critical congenital heart disease should include prenatal ultrasound, physical examination and pulse oximetry screening. Screening should be performed between 24 hours and 36 hours postbirth, using the infant's right hand and either foot to minimize false-positive results. Newborns with abnormal results should undergo a thorough evaluation by the most responsible health care provider. When a cardiac diagnosis cannot be excluded, referral to a paediatric cardiologist for consultation and echocardiogram is advised.

Trends in pediatric cardiology referrals, testing, and satisfaction at a Canadian tertiary centre.

Anecdotal and European evidence suggests that outpatient pediatric referrals and their diagnostic testing burden are increasing. We sought to characterize new pediatric cardiology referrals, testing performed, outcomes, and patient satisfaction in a Canadian academic hospital and how these had changed over time. Clinical data were extracted from new outpatient consultations to the IWK Children's Heart Centre between August 1, 2011 and August 17, 2012 and compared with similar local data collected in July-February 2002 using χ(2) testing. Predictors of significant differences were sought using regression analysis. Satisfaction data were collected from a validated patient questionnaire, and 620 new outpatients were evaluated. Organic disease was more likely in younger patients (odds ratio [OR], 2.7; 95% confidence interval [CI], 1.8-4.0) or in patients referred by pediatricians (OR, 2.3; 95% CI, 1.6-3.3). Odds of echocardiography being performed were significantly increased if patients were younger than 1 year (OR, 2.0; 95% CI, 1.3-3.0), were seen at outreach clinics (OR, 1.7; 95% CI, 1.2-2.3), or were referred by pediatricians (OR, 3.7; 95% CI, 2.6-5.3). Cardiologists differed significantly in ordering echocardiograms for referred patients (P = 0.002). The patients referred in the current era have significantly less organic disease than did those in 2002 (27% vs 37%; P = 0.007), but they underwent significantly more echocardiography (58% vs 38%; P < 0.001) and Holter monitoring (12% vs 4%; P = 0.001). Satisfaction results were high and unrelated to diagnostic testing. Pediatric cardiology referrals in Maritime Canada have increased in volume, consistent with changes seen at other centres. This, coupled with changing cardiac investigations, has increased testing burden. Individual cardiologists affected the odds of echocardiography being ordered. Satisfaction with services was high, with no predictors identified.

Electrocardiogram interpretation by Canadian general paediatricians: Examining practice, accuracy and confidence.

BACKGROUND: Paediatric electrocardiograms (ECGs) are ordered and interpreted by general paediatricians; however, no previous studies have evaluated the accuracy of their ECG interpretations. OBJECTIVE: To determine general paediatricians' practice and opinions regarding ECG use, accuracy of their interpretation of paediatric ECGs, and the relationship between accuracy and self-perceived confidence. METHODS: In the present cross-sectional study, Canadian general paediatricians were asked to complete a questionnaire and interpret 18 paediatric ECGs. The questionnaire assessed characteristics of ECG use, self-perceived confidence and opinions regarding ECG use in general paediatric practice. For the ECGs provided, respondents were asked whether the ECG was normal or abnormal, what abnormality the ECG demonstrated and how confident they were in this interpretation. RESULTS: ECG interpretation was performed by 124 general paediatricians. General paediatricians frequently use ECGs in their practice and regard this investigation as useful in patient assessment. The mean (± SD) accuracy of identifying ECGs as normal or abnormal, and identifying the specific abnormality was 80±12% and 56±20%, respectively. The sensitivity and specificity of identifying abnormal ECGs were 80% (95% CI 78% to 82%) and 79% (95% CI 75% to 83%), respectively. Correct ECG interpretation for isolated rhythm disturbances (73%) was significantly better than for abnormalities in axis (25%), chamber hypertrophy (41%) and ECG intervals (49%) (P<0.001). Overall confidence in ECG interpretation correlated with and was the only significant predictor of interpretation accuracy (r=0.396, P<0.001). CONCLUSION: General paediatricians were adept at detecting abnormal ECGs, but were less able to identify the abnormalities. Further education in ECG interpretation may be important for this population.

HISTORIQUE: Ce sont des pédiatres généralistes qui demandent et interprètent les électrocardiogrammes (ECG) en pédiatrie, mais aucune étude n'a porté sur l'exactitude de leur interprétation. OBJECTIF: Déterminer la pratique et les avis des pédiatres généralistes en matière d'utilisation des ECG et de l'exactitude des ECG en pédiatrie et établir le lien entre la précision et l'autoperception de la confiance. MÉTHODOLOGIE: Dans la présente étude transversale, les pédiatres généralistes canadiens ont été invités à remplir un questionnaire et à interpréter 18 ECG en pédiatrie. Le questionnaire visait à évaluer les caractéristiques liées à l'utilisation des ECG, l'autoperception de la confiance et les avis relatifs à l'utilisation des ECG en pédiatrie générale. Les répondants étaient invités à préciser si les ECG four-nis étaient normaux ou anormaux, les anomalies démontrées et leur confiance quant à leur interprétation. RÉSULTATS: Cent vingt-quatre pédiatres généralistes ont interprété les ECG. Les pédiatres généralistes utilisent souvent les ECG dans leur pratique et les considèrent comme utiles dans l'évaluation des patients. L'exactitude moyenne dans l'identification des ECG comme normaux ou anormaux et dans la détermination de l'anomalie précise correspondait à 80±12 % et à 56±20 %, respectivement. La sensibilité et la spécificité de l'identification des ECG anormaux s'établissaient à 80 % (95 % IC 78 % à 82 %) et à 79 % (95 % IC 75 % à 83 %), respectivement. La bonne interprétation des ECG révélant des troubles isolés du rythme cardiaque (73 %) était considérablement plus élevée que celle des anomalies de l'axe (25 %), de l'hypertrophie ventriculaire (41 %) et des intervalles d'ECG (49 %) (P<0,001). Dans l'ensemble, la confiance à l'égard de l'interprétation des ECG était corrélée avec l'exactitude des interprétations et en était le seul prédicteur important (r=0,396, P<0,001). CONCLUSION: Les pédiatres généralistes décelaient bien les ECG anormaux, mais réussissaient moins bien à déterminer les anomalies exactes. Il serait peut-être important de leur fournir un perfectionnement dans l'interprétation des ECG.

Inverse relationship between LDL cholesterol and PCSK9 plasma levels in dyslipidemic cynomolgus monkeys: effects of LDL lowering by ezetimibe in the absence of statins.

OBJECTIVES: To assess the lipid-lowering efficacy of ezetimibe in dyslipidemic cynomolgus monkeys comparing two dosing methods, and to evaluate PCSK9 plasma levels during dyslipidemia induction by feeding a high-fat/high-cholesterol diet (HFD), ezetimibe (Zetia(®), Ezetrol(®)) treatment, ezetimibe washout, and HFD washout. METHODS AND RESULTS: Twenty dyslipidemic cynomolgus monkeys on HFD for seven months (LDL cholesterol 100-400 mg/dL) were randomized into two groups and treated with ezetimibe for two weeks, either by oral gavage or by using food treats. The lipid-lowering effects of ezetimibe were identical between the two groups. After treatment, mean LDL cholesterol was decreased by 58% (174-72 mg/dL), total cholesterol by 42% (241-138 mg/dL), and PCSK9 levels were increased by 137% (147-314 ng/mL). PCSK9 levels on regular diet before and after HFD were also inversely correlated to LDL cholesterol. CONCLUSIONS: In a cynomolgus dyslipidemia model, PCSK9 levels are inversely correlated with LDL cholesterol in the absence of statin treatment, regardless whether lipid changes are modulated by diet or ezetimibe treatment.

The study of antiarrhythmic medications in infancy (SAMIS): a multicenter, randomized controlled trial comparing the efficacy and safety of digoxin versus propranolol for prophylaxis of supraventricular tachycardia in infants.

BACKGROUND: Supraventricular tachycardia (SVT) is one of the most common conditions requiring emergent cardiac care in children, yet its management has never been subjected to a randomized controlled clinical trial. The purpose of this study was to compare the efficacy and safety of the 2 most commonly used medications for antiarrhythmic prophylaxis of SVT in infants: digoxin and propranolol. METHODS AND RESULTS: This was a randomized, double-blind, multicenter study of infants <4 months with SVT (atrioventricular reciprocating tachycardia or atrioventricular nodal reentrant tachycardia), excluding Wolff-Parkinson-White, comparing digoxin with propranolol. The primary end point was recurrence of SVT requiring medical intervention. Time to recurrence and adverse events were secondary outcomes. Sixty-one patients completed the study, 27 randomized to digoxin and 34 to propranolol. SVT recurred in 19% of patients on digoxin and 31% of patients on propranolol (P=0.25). No first recurrence occurred after 110 days of treatment. The 6-month recurrence-free status was 79% for patients on digoxin and 67% for patients on propranolol (P=0.34), and there were no first recurrences in either group between 6 and 12 months. There were no deaths and no serious adverse events related to study medication. CONCLUSIONS: There was no difference in SVT recurrence in infants treated with digoxin versus propranolol. The current standard practice may be treating infants longer than required and indicates the need for a placebo-controlled trial. Clinical Trial Registration Information- http://clinicaltrials.gov; NCT-00390546.

A genome-wide siRNA screen to identify modulators of insulin sensitivity and gluconeogenesis.

BACKGROUND: Hepatic insulin resistance impairs insulin's ability to suppress hepatic glucose production (HGP) and contributes to the development of type 2 diabetes (T2D). Although the interests to discover novel genes that modulate insulin sensitivity and HGP are high, it remains challenging to have a human cell based system to identify novel genes. METHODOLOGY/PRINCIPAL FINDINGS: To identify genes that modulate hepatic insulin signaling and HGP, we generated a human cell line stably expressing beta-lactamase under the control of the human glucose-6-phosphatase (G6PC) promoter (AH-G6PC cells). Both beta-lactamase activity and endogenous G6PC mRNA were increased in AH-G6PC cells by a combination of dexamethasone and pCPT-cAMP, and reduced by insulin. A 4-gene High-Throughput-Genomics assay was developed to concomitantly measure G6PC and pyruvate-dehydrogenase-kinase-4 (PDK4) mRNA levels. Using this assay, we screened an siRNA library containing pooled siRNA targeting 6650 druggable genes and identified 614 hits that lowered G6PC expression without increasing PDK4 mRNA levels. Pathway analysis indicated that siRNA-mediated knockdown (KD) of genes known to positively or negatively affect insulin signaling increased or decreased G6PC mRNA expression, respectively, thus validating our screening platform. A subset of 270 primary screen hits was selected and 149 hits were confirmed by target gene KD by pooled siRNA and 7 single siRNA for each gene to reduce G6PC expression in 4-gene HTG assay. Subsequently, pooled siRNA KD of 113 genes decreased PEPCK and/or PGC1alpha mRNA expression thereby demonstrating their role in regulating key gluconeogenic genes in addition to G6PC. Last, KD of 61 of the above 113 genes potentiated insulin-stimulated Akt phosphorylation, suggesting that they suppress gluconeogenic gene by enhancing insulin signaling. CONCLUSIONS/SIGNIFICANCE: These results support the proposition that the proteins encoded by the genes identified in our cell-based druggable genome siRNA screen hold the potential to serve as novel pharmacological targets for the treatment of T2D.

Novel transcriptome profiling analyses demonstrate that selective peroxisome proliferator-activated receptor γ (PPARγ) modulators display attenuated and selective gene regulatory activity in comparison with PPARγ full agonists.

Selective peroxisome proliferator-activated receptor γ (PPARγ) modulators (SPPARγMs) have been actively pursued as the next generation of insulin-sensitizing antidiabetic drugs, because the currently marketed PPARγ full agonists, pioglitazone and rosiglitazone, have been reported to produce serious adverse effects among patients with type 2 diabetes mellitus. We conducted extensive transcriptome profiling studies to characterize and to contrast the activities of 70 SPPARγMs and seven PPARγ full agonists. In both 3T3-L1 adipocytes and adipose tissue from db/db mice, the SPPARγMs generated attenuated and selective gene-regulatory responses, in comparison with full agonists. More importantly, SPPARγMs regulated the expression of antidiabetic efficacy-associated genes to a greater extent than that of adverse effect-associated genes, whereas PPARγ full agonists regulated both gene sets proportionally. Such SPPARγM selectivity demonstrates that PPARγ ligand regulation of gene expression can be fine-tuned, and not just turned on and off, to achieve precise control of complex cellular and physiological functions. It also provides a potential molecular basis for the superior therapeutic window previously observed with SPPARγMs versus full agonists. On the basis of our profiling results, we introduce two novel, gene expression-based scores, the γ activation index and the selectivity index, to aid in the detection and characterization of novel SPPARγMs. These studies provide new insights into the gene-regulatory activity of SPPARγMs as well as novel quantitative indices to facilitate the identification of PPARγ ligands with robust insulin-sensitizing activity and improved tolerance among patients with type 2 diabetes, compared with presently available PPARγ agonist drugs.

Quantifying apoprotein synthesis in rodents: coupling LC-MS/MS analyses with the administration of labeled water.

Stable isotope tracer studies of apoprotein flux in rodent models present difficulties as they require working with small volumes of plasma. We demonstrate the ability to measure apoprotein flux by administering either (2)H- or (18)O-labeled water to mice and then subjecting samples to LC-MS/MS analyses; we were able to simultaneously determine the labeling of several proteolytic peptides representing multiple apoproteins. Consistent with relative differences reported in the literature regarding apoprotein flux in humans, we found that the fractional synthetic rate of apoB is greater than apoA1 in mice. In addition, the method is suitable for quantifying acute changes in protein flux: we observed a stimulation of apoB production in mice following an intravenous injection of Intralipid and a decrease in apoB production in mice treated with an inhibitor of microsomal triglyceride transfer protein. In summary, we demonstrate a high-throughput method for studying apoprotein kinetics in rodent models. Although notable differences exist between lipoprotein profiles that are observed in rodents and humans, we expect that the method reported here has merit in studies of dyslipidemia as i) rodent models can be used to probe target engagement in cases where one aims to modulate apoprotein production and ii) the approach should be adaptable to studies in humans.

Demonstration of diet-induced decoupling of fatty acid and cholesterol synthesis by combining gene expression array and 2H2O quantification.

The liver is a crossroad for metabolism of lipid and carbohydrates, with acetyl-CoA serving as an important metabolic intermediate and a precursor for fatty acid and cholesterol biosynthesis pathways. A better understanding of the regulation of these pathways requires an experimental approach that provides both quantitative metabolic flux measurements and mechanistic insight. Under conditions of high carbohydrate availability, excess carbon is converted into free fatty acids and triglyceride for storage, but it is not clear how excessive carbohydrate availability affects cholesterol biosynthesis. To address this, C57BL/6J mice were fed either a low-fat, high-carbohydrate diet or a high-fat, carbohydrate-free diet. At the end of the dietary intervention, the two groups received (2)H(2)O to trace de novo fatty acid and cholesterol synthesis, and livers were collected for gene expression analysis. Expression of lipid and glucose metabolism genes was determined using a custom-designed pathway focused PCR-based gene expression array. The expression analysis showed downregulation of cholesterol biosynthesis genes and upregulation of fatty acid synthesis genes in mice receiving the high-carbohydrate diet compared with the carbohydrate-free diet. In support of these findings, (2)H(2)O tracer data showed that fatty acid synthesis was increased 10-fold and cholesterol synthesis was reduced by 1.6-fold in mice fed the respective diets. In conclusion, by applying gene expression analysis and tracer methodology, we show that fatty acid and cholesterol synthesis are differentially regulated when the carbohydrate intake in mice is altered.

Attenuation of Slc27a5 gene expression followed by LC-MS measurement of bile acid reconjugation using metabolomics and a stable isotope tracer strategy.

The purpose of this study was to evaluate the use of high resolution LC-MS together with metabolomics and D(4)-cholic acid (D(4)-CA) as a metabolic tracer to measure the metabolism and reconjugation of bile acids (BAs) in vitro and in vivo. Metabolic tracers are very important because they allow for the direct detection (substrate-to-product) of small and significant biological perturbations that may not be apparent when monitoring "static" endogenous levels of particular metabolites. Slc27a5, also known as fatty acid transport protein 5 (FATP5), is the hepatic BA-CoA ligase involved in reconjugating BAs during enterohepatic BA recycling. Using Slc27a5-cKD mice, silencing of ∼90% gene expression was achieved followed by reduction in the reconjugation of D(4)-CA to D(4)-taurocholic acid (D(4)-TCA), as well as other conjugated BA metabolites in plasma (p = 0.0031). The method described allowed a rapid measure of many D(4) and endogenous BA. Analysis of bile resulted in the detection of 39 BA metabolites from a 13 min analytical run. Finally, the utilization of a novel high resolution mass spectrometry method in combination with metabolomics and a stable isotope metabolic tracer allowed for the detection of targeted and untargeted BAs following silencing of the Slc27a5 gene in primary hepatocytes and in mice.

Cost-effectiveness of an early assessment service for young people with early psychosis in Hong Kong.

OBJECTIVE: The Early Assessment Service for Young People with Early Psychosis (EASY) was developed in Hong Kong in 2001 to provide a comprehensive and integrated approach for early detection and intervention for young people suffering from first episode psychosis. The present study examined the cost-effectiveness of the service over a period of 24 months compared to standard care. METHOD: This is a historical control study. Sixty-five patients who presented to the EASY service in 2001 with first episode psychosis were individually matched (on age, sex and diagnosis) with 65 patients who received standard psychiatric care in a precursor service (pre-EASY) between 1999 and 2000. A retrospective cost-effectiveness analysis was conducted over a period of 24 months. The overall average cost of service utilization per patient and the effects on hospitalization rate were compared using bootstrapping analysis. Cost per point improvement in Positive and Negative Syndrome Scale (PANSS) was also computed with sensitivity analysis. Only direct costs were analysed in the current study. RESULTS: There was no significant difference in service utilization between the EASY and pre-EASY standard care groups. The cost-effectiveness acceptability curve, which was used to explore uncertainty in estimates of cost and effects, suggested that there was a probability of at least 94% that the EASY model was more cost-effective than the pre-EASY service in reducing psychiatric inpatient admissions. EASY patients also showed superior results in average cost per unit improvement in PANSS. CONCLUSIONS: EASY is likely to be more cost-effective in improving outcomes, particularly in reducing hospitalization and improving clinical symptoms among young people with first episode psychosis. This study provides a perspective from the east Asian region, and supports further development of similar services, particularly in the local setting. However, further studies with a longer follow up period and larger sample size are required to verify these findings.