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1.  Longitudinal association between serum urate and subclinical atherosclerosis: the Coronary Artery Risk Development in Young Adults (CARDIA) study 
Journal of internal medicine  2013;274(6):10.1111/joim.12120.
The aim of the present study was to determine whether serum urate (sUA) concentration is positively associated with subclinical atherosclerosis, independent of body mass index (BMI), among generally healthy adults.
Design and setting
The CARDIA study followed 5115 black and white individuals aged 18–30 years in 1985–1986 (year 0). Subclinical atherosclerosis comprised coronary artery calcified plaque (CAC; years 15, 20 and 25) and maximum common carotid intima–media thickness (IMT; year 20). sUA (years 0, 10, 15 and 20) was modelled as gender-specific quartiles that were pooled. Discrete-time hazard regressions and generalized linear regressions were used for analyses.
Mean sUA concentration was lower in women than in men, and increased with age. Adjusting for demographic and lifestyle factors, the highest versus lowest quartile of sUA at year 0 was associated with a 44% [95% confidence interval (CI) 20%, 73%] greater risk of CAC progression from year 15 to 25 (Ptrend < 0.001), which was attenuated by adjustment for BMI at year 0 (Ptrend = 0.45). A stronger association was found between sUA at year 15 and CAC progression at year 20 or 25 (hazard ratio 2.07, 95% CI 1.66, 2.58 for the highest versus lowest sUA quartile Ptrend < 0.001), which was attenuated but remained significant with additional adjustment for BMI at year 15 (Ptrend = 0.01). A greater increment in sUA concentration from year 0 to year 15, independent of change in BMI, was related to a higher risk of CAC progression (Ptrend < 0.001). Similar associations were found between sUA and IMT, but only in men.
sUA may be an early biomarker for subclinical atherosclerosis in young adults; starting in early middle age, sUA predicts subclinical atherosclerosis independently of BMI.
PMCID: PMC3825786  PMID: 23952533
calcified plaque; intima–media thickness; subclinical atherosclerosis; urate; uric acid
2.  Implementation of Alternative Test Strategies for the Safety Assessment of Engineered Nanomaterials 
Journal of internal medicine  2013;274(6):561-577.
Nanotechnology introduces a new field that requires novel approaches and methods for hazard and risk assessment. For an appropriate scientific platform for safety assessment, nanoscale properties and functions of engineered nanomaterials (ENMs), including how the physicochemical properties of the materials related to mechanisms of injury at the nano-bio interface, must be considered. Moreover, this rapidly advancing new field requires novel test strategies that allow multiple toxicants to be screened in robust, mechanism-based assays in which the bulk of the investigation can be carried out at the cellular and biomolecular level whilst maintaining limited animal use and is based on the contribution of toxicological pathways to the pathophysiology of disease. First, a predictive toxicological approach for the safety assessment of ENMs will be discussed against the background of a ‘21st-century vision’ for using alternative test strategies (ATSs) to perform toxicological assessment of large numbers of untested chemicals, thereby reducing a backlog that could otherwise become a problem for nanotechnology. An ATS is defined here as an alternative/reduction alternative to traditional animal testing. Secondly, the approach of selecting pathways of toxicity to screen for the pulmonary hazard potential of carbon nanotubes and metal oxides will be discussed, as well as how to use these pathways to perform high-content or high-throughput testing and how the data can be used for hazard ranking, risk assessment, regulatory decision-making and ‘safer-by-design’ strategies. Finally, the utility and disadvantages of this predictive toxicological approach to ENM safety assessment, and how it can assist the 21st- century vision, will be addressed
PMCID: PMC4096910  PMID: 23879741
alternative test strategies; nanomaterials; predictive toxicology; safety assessment
3.  Amyloid-ß-directed immunotherapy for Alzheimer's disease 
Journal of Internal Medicine  2014;275(3):284-295.
Lannfelt L, Relkin NR, Siemers ER (Uppsala University, Uppsala, Sweden; Weill Cornell Medical College, New York, NY; and Eli Lilly and Co., Indianapolis, IN, USA). Amyloid-ß-directed immunotherapy for Alzheimer’s disease. (Key Symposium). J Intern Med 2014; 275: 284–295.
Current treatment options for Alzheimer's disease (AD) are limited to medications that reduce dementia symptoms. Given the rapidly ageing populations in most areas of the world, new therapeutic interventions for AD are urgently needed. In recent years, a number of drug candidates targeting the amyloid-ß (Aß) peptide have advanced into clinical trials; however, most have failed because of safety issues or lack of efficacy. The Aß peptide is central to the pathogenesis, and immunotherapy against Aß has attracted considerable interest. It offers the possibility to reach the target with highly specific drugs. Active immunization and passive immunization have been the most widely studied approaches to immunotherapy of AD. A favourable aspect of active immunization is the capacity for a small number of vaccinations to generate a prolonged antibody response. A potential disadvantage is the variability in the antibody response across patients. The potential advantages of passive immunotherapy include the reproducible delivery of a known amount of therapeutic antibodies to the patient and rapid clearance of those antibodies if side effects develop. A disadvantage is the requirement for repeated infusions of antibodies over time. After more than a decade of research, anti-amyloid immunotherapy remains one of the most promising emerging strategies for developing disease-modifying treatments for AD. In this review, we examine the presently ongoing Aß-directed immunotherapies that have passed clinical development Phase IIa.
PMCID: PMC4238820  PMID: 24605809
Alzheimer's disease; amyloid-beta; clinical trials; immunotherapy
4.  Recent advances towards tuberculosis control: vaccines and biomarkers 
Journal of Internal Medicine  2014;275(5):467-480.
Weiner 3rd J, Kaufmann SHE (Max Planck Institute for Infection Biology, Berlin, Germany). Recent advances towards tuberculosis control: vaccines and biomarkers. (Review). J Intern Med 2014; 275: 467–480.
Of all infectious diseases, tuberculosis (TB) remains one of the most important causes of morbidity and mortality. Recent advances in understanding the biology of Mycobacterium tuberculosis (Mtb) infection and the immune response of the infected host have led to the development of several new vaccines, a number of which are already undergoing clinical trials. These include pre-exposure prime vaccines, which could replace bacille Calmette–Guérin (BCG), and pre-exposure booster vaccines given in addition to BCG. Infants are the target population of these two types of vaccines. In addition, several postexposure vaccines given during adolescence or adult life, in addition to BCG as a priming vaccine during infancy, are undergoing clinical testing. Therapeutic vaccines are currently being assessed for their potential to cure active TB as an adjunct to chemotherapy. BCG replacement vaccines are viable recombinant BCG or double-deletion mutants of Mtb. All booster vaccines are composed of one or several antigens, either expressed by viral vectors or formulated with adjuvants. Therapeutic vaccines are killed mycobacterial preparations. Finally, multivariate biomarkers and biosignatures are being generated from high-throughput data with the aim of providing better diagnostic tools to specifically determine TB progression. Here, we provide a technical overview of these recent developments as well of the relevant computational approaches and highlight the obstacles that still need to be overcome.
PMCID: PMC4238842  PMID: 24635488
bacille Calmette–Guérin; biomarker; biosignature; tuberculosis; vaccine
5.  Lessons from post-genome-wide association studies: functional analysis of cancer predisposition loci 
Journal of internal medicine  2013;274(5):414-424.
In the last few years, genome-wide association studies (GWASs) have identified hundreds of predisposition loci for several types of human cancers. Recent progress has been made in determining the underlying mechanisms through which different single-nucleotide polymorphisms (SNPs) affect predisposition to cancer. Although there has been much debate about the clinical utility of GWASs, less attention has been paid to how GWASs and post-GWASs functional analysis have contributed to understanding the aetiology of cancer. Most common variants associated with cancer risk are localized in non-protein-coding regions highlighting transcriptional regulation as a common theme in the mechanism of cancer predisposition. Here, we outline strategies to functionally dissect predisposition loci and discuss their limitations as well as challenges for future studies.
PMCID: PMC3801430  PMID: 24127939
cancer predisposition; eQTL; GWAS; SNPs; transcription
6.  Low blood pressure, antihypertensive treatment, and physical and mental health status in patients with arterial disease. The SMART-Study 
Journal of internal medicine  2013;274(3):10.1111/joim.12069.
To investigate the independent effects of antihypertensive treatment and blood pressure (BP) levels on physical and mental health status in patients with arterial disease.
Cross-sectional analyses within the Secondary Manifestations of ARTerial disease (SMART) study, a single centre cohort study.
Hospitalized care.
5,877 patients (mean age 57) with symptomatic and asymptomatic arterial disease who underwent a standardized vascular screening.
Main outcome measure
Self-rated physical and mental health assessed with the Short Form (SF)-36.
In the total population, antihypertensive drug use and increased intensity of antihypertensive treatment was associated with poorer health status independent of important confounders including BP levels; adjusted mean differences (95%CI) in physical and mental health between 0 and ≥3 antihypertensives were -1.2 (-2.1, -0.3) and -3.5 (-4.4; -2.6). Furthermore, lower systolic and lower diastolic BP levels were related to poorer physical and mental health status independently of antihypertensive treatment. Mean differences (95%CI) in physical and mental health status per SD decrease in systolic BP were -0.56 (-0.84; -0.27) and -0.32 (-0.61; -0.03), and per SD decrease in diastolic BP -0.50 (-0.78; -0.23) and -0.08 (-0.36; 0.20). The association between low BP and poor health status was particularly present in patients with coronary artery disease.
In a population of patients with asymptomatic and symptomatic arterial disease, antihypertensive treatment and lower BP levels are independently associated with poorer self-rated physical and mental health. These results might indicate that there are different underlying mechanisms explaining these independent associations.
PMCID: PMC3750200  PMID: 23527863
antihypertensive treatment; blood pressure; physical health; mental health; cardiovascular disease
7.  Effects of individual and combined dietary weight loss and exercise interventions in postmenopausal women on adiponectin and leptin levels 
Journal of internal medicine  2013;274(2):163-175.
Excess body weight and a sedentary lifestyle are associated with the development of several diseases, including cardiovascular disease, diabetes, and cancer in women. One proposed mechanism linking obesity to chronic diseases is an alteration in adipose-derived adiponectin and leptin levels. We investigated the effects of 12-month reduced calorie, weight loss and exercise interventions on adiponectin and leptin concentrations.
Overweight/obese postmenopausal women (n=439) were randomized as follows: 1) a reduced calorie, weight loss diet (diet; N=118); 2) moderate-to-vigorous intensity aerobic exercise (exercise; N=117); 3) a combination of a reduced calorie, weight loss diet and moderate-to-vigorous intensity aerobic exercise (diet+exercise; N=117); or 4) control (N=87). The reduced calorie diet had a 10% weight loss goal. The exercise intervention consisted of 45 minutes of moderate-to-vigorous aerobic activity 5 days/week. Adiponectin and leptin levels were measured at baseline and after 12 months of intervention using a radioimmunoassay.
Adiponectin increased by 9.5 % in the diet group and 6.6 % in the diet+exercise group (both p≤0.0001 vs. control). Compared with controls, leptin decreased with all interventions (diet+exercise, −40.1%, p<0.0001; diet, −27.1%, p<0.0001; exercise, −12.7%, p=0.005). The results were not influenced by the baseline body mass index (BMI). The degree of weight loss was inversely associated with concentrations of adiponectin (diet, p-trend=0.0002; diet+exercise, p-trend=0.0005) and directly associated with leptin (diet, p-trend<0.0001; diet+exercise, p-trend<0.0001).
Weight loss through diet or diet+exercise increased adiponectin concentrations. Leptin concentrations decreased in all of the intervention groups, but the greatest reduction occurred with diet+exercise. Weight loss and exercise exerted some beneficial effects on chronic diseases via effects on adiponectin and leptin.
PMCID: PMC3738194  PMID: 23432360
adiponectin; leptin; randomized controlled trial; diet and exercise intervention
8.  Breast cancer as a systemic disease: a view of metastasis 
Journal of internal medicine  2013;274(2):113-126.
Breast cancer is now the most frequently diagnosed cancer and leading cause of cancer death in women worldwide. Strategies targeting the primary tumour have markedly improved, but systemic treatments to prevent metastasis are less effective; metastatic disease remains the underlying cause of death in the majority of breast cancer patients who sucumb to their disease. The long latency period between initial treatment and eventual recurrence in some patients suggests that a tumour may both alter and respond to the host systemic environment in order to facilitate and sustain disease progression. Results from studies in animal models suggest that specific subtypes of breast cancer may direct metastasis through recruitment and activation of haematopoietic cells. In this review we focus on data implicating breast cancer as a systemic disease.
PMCID: PMC3711134  PMID: 23844915
breast cancer; disseminated tumour cells; metastasis; tumour dormancy; tumour microenvironment; systemic instigation
10.  GFR estimating equations, CKD prevalence and the public health 
Journal of internal medicine  2010;267(4):354-356.
PMCID: PMC4088319  PMID: 20433581
11.  Manganese toxicity in the CNS: the glutamine/glutamate-γ-aminobutyric acid cycle 
Journal of internal medicine  2013;273(5):466-477.
Manganese (Mn) is an essential trace element that is required for maintaining proper function and regulation of numerous biochemical and cellular reactions. Despite its essentiality, at excessive levels Mn is toxic to the CNS. Increased accumulation of Mn in specific brain regions, such as the substantia nigra, globus pallidus and striatum, triggers neurotoxicity resulting in a neurological brain disorder, termed manganism. Mn has been also implicated in the pathophysiology of several other neurodegenerative diseases. Its toxicity is associated with disruption of the glutamine (Gln)/glutamate (Glu)-γ-aminobutyric acid (GABA) cycle (GGC) between astrocytes and neurons, thus leading to changes in Glu-ergic and/or GABAergic transmission and Gln metabolism. Here we discuss the common mechanisms underlying Mn-induced neurotoxicity and their relationship to CNS pathology and GGC impairment.
PMCID: PMC3633698  PMID: 23360507
γ-aminobutyric acid (GABA); astrocytes; glutamate (Glu); glutamine (Gln); manganese; neurodegeneration; neurotransmission
12.  Environmental stress, ageing and glial cell senescence: a novel mechanistic link to Parkinson’s disease? 
Journal of internal medicine  2013;273(5):429-436.
Exposure to environmental toxins is associated with a variety of age-related diseases including cancer and neurodegeneration. For example, in Parkinson’s disease (PD), chronic environmental exposure to certain toxins has been linked to the age-related development of neuropathology. Neuronal damage is believed to involve the induction of neuroinflammatory events as a consequence of glial cell activation. Cellular senescence is a potent anti-cancer mechanism that occurs in a number of proliferative cell types and causes the arrest of proliferation of cells at risk of malignant transformation following exposure to potentially oncogenic stimuli. With age, senescent cells accumulate and express a senescence-associated secretory phenotype (SASP; i.e. the robust secretion of many inflammatory cytokines, growth factors and proteases). Whereas cell senescence in peripheral tissues has been causally linked to a number of age-related pathologies, little is known about the induction of cellular senescence and the SASP in the brain. Based on recently reported findings, we propose that environmental stressors associated with PD may act in part by eliciting senescence and the SASP within non-neuronal glial cells in the ageing brain, thus contributing to the characteristic decline in neuronal integrity that occurs in this disorder.
PMCID: PMC3633085  PMID: 23600398
13.  Synaptic dysfunction in human immunodeficiency virus type-1-positive subjects: inflammation or impaired neuronal plasticity? 
Journal of internal medicine  2013;273(5):454-465.
Many people infected with the human immunodeficiency virus type-1 (HIV) exhibit mild or severe neurological problems, termed HIV-associated neurocognitive disorder (HAND), even when receiving antiretroviral therapy. Thus, novel adjunctive therapies must be developed to overcome the neurotoxic effect of HIV. New therapies require a better understanding of the molecular and cellular mechanisms of HIV-induced neurotoxicity and the risk factors that, besides inflammation and T cell depletion and drugs of abuse, render the central nervous system (CNS) a target of HIV-induced neurotoxicity. HIV appears to impair neuronal plasticity, which refers to the innate ability of the CNS to respond to injury and promote recovery of function. The availability of brain-derived neurotrophic factor (BDNF), a potent neurotrophic factor that is present in abundance in the adult brain, is essential for neuronal plasticity. BDNF acts through a receptor system composed of Trk and p75NTR. Here we present experimental evidence that some of the clinical features of HIV-mediated neurological impairment could result from altered BDNF/TrkB/p75NTR regulation and function.
PMCID: PMC3633109  PMID: 23600400
apoptosis; drug abuse; gp120; neuroAIDS; p75NTR; proBDNF
14.  The genetics of ischaemic stroke 
Journal of internal medicine  2010;267(2):139-155.
In this review, we discuss the genetic factors in both the aetiology and treatment of ischaemic stroke. We discuss candidate gene association studies, family linkage studies and the more recent whole genome association studies and whole genome expression studies. We also briefly discuss genetic testing for stroke risk and genetic analysis of treatment complications.
PMCID: PMC4003485  PMID: 20175863
15.  Systems Cancer Medicine: Towards Realization of Predictive, Preventive, Personalized, and Participatory (P4) Medicine 
Journal of internal medicine  2012;271(2):111-121.
A grand challenge impeding optimal treatment outcomes for cancer patients arises from the complex nature of the disease: the cellular heterogeneity, the myriad of dysfunctional molecular and genetic networks as results of genetic (somatic) and environmental perturbations. Systems biology, with its holistic approach to understanding fundamental principles in biology, and the empowering technologies in genomics, proteomics, single-cell analysis, microfluidics, and computational strategies, enables a comprehensive approach to medicine, which strives to unveil the pathogenic mechanisms of diseases, identify disease biomarkers and begin thinking about new strategies for drug target discovery. The integration of multi-dimensional high throughput “omics” measurements from tumor tissues and corresponding blood specimens, together with new systems strategies for diagnostics, enables the identification of cancer biomarkers that will enable presymptomatic diagnosis, stratification of disease, assessment of disease progression, evaluation of patient response to therapy, and the identification of reoccurrences. While some aspects of systems medicine are being adopted in clinical oncology practice through companion molecular diagnostics for personalized therapy, the mounting influx of global quantitative data from both wellness and diseases, is shaping up a transformational paradigm in medicine we termed predictive, preventive, personalized, and participatory (P4) medicine, which requires new strategies, both scientific and organizational, to enable bringing this revolution in medicine to patients and to the healthcare system. P4 medicine will have a profound impact on society—transforming the healthcare system, turning around the ever escalating costs of healthcare, digitizing the practice of medicine and creating enormous economic opportunities for those organizations and nations that embrace this revolution
PMCID: PMC3978383  PMID: 22142401
Systems medicine; cancer complexity; quantized cell populations; blood biomarkers; molecular diagnostics; P4 medicine
16.  An MRI-based index to measure the severity of Alzheimer’s disease-like structural pattern in subjects with mild cognitive impairment 
Journal of internal medicine  2013;273(4):396-409.
Structural magnetic resonance imaging (MRI) is sensitive to neurodegeneration and can be used to estimate the risk of converting to Alzheimer’s disease (AD) in individuals with mild cognitive impairment (MCI). Brain changes in AD and prodromal AD involve a pattern of widespread atrophy. The use of multivariate analysis algorithms could enable the development of diagnostic tools based on structural MRI data. In this study we investigated the possibility of combining multiple MRI features in the form of a severity index.
We used baseline MRI scans from two large multicentre cohorts (AddNeuroMed and ADNI). Based on volumetric and cortical thickness measures at baseline with AD cases and healthy control (CTL) subjects as training sets, we generated an MRI-based severity index using the method of orthogonal projection to latent structures (OPLS). The severity index tends to be close to 1 for AD patients and 0 for CTL subjects. Values above 0.5 indicate a more AD-like pattern. The index was then estimated for subjects with MCI, and the accuracy of classification was investigated.
Based on the data at follow-up, 173 subjects converted to AD, of whom 112 (64.7%) were classified as AD-like and 61 (35.3%) as CTL-like.
We found that joint evaluation of multiple brain regions provided accurate discrimination between progressive and stable MCI, with better performance than hippocampal volume alone, or a limited set of features. A major challenge is still to determine optimal cut-off points for such parameters and to compare their relative reliability.
PMCID: PMC3605230  PMID: 23278858
AD; MCI; MRI; multivariate analysis; progression to AD; sensitivity; specificity
17.  Mutations in LPL, APOC2, APOA5, GPIHBP1 and LMF1 in patients with severe hypertriglyceridaemia 
Journal of internal medicine  2012;272(2):185-196.
The severe forms of hypertriglyceridaemia (HTG) are caused by mutations in genes that lead to loss of function of lipoprotein lipase (LPL). In most patients with severe HTG (TG >10 mmol/L) it is a challenge to define the underlying cause. We investigated the molecular basis of severe HTG in patients referred to the Lipid Clinic at the Academic Medical Center Amsterdam.
The coding regions of LPL, APOC2, APOA5 and two novel genes, lipase maturation factor 1 (LMF1) and GPI-anchored HDL-binding protein 1 (GPIHBP1), were sequenced in 86 patients with type 1 and type 5 HTG and 327 controls.
In 46 patients (54%) rare DNA sequence variants were identified, comprising variants in LPL (n=19), APOC2 (n=1), APOA5 (n=2), GPIHBP1 (n=3) and LMF1 (n=8). In 22 patients (26%) only common variants in LPL (p.Asp36Asn, p.Asn318Ser and p.Ser474Ter) and APOA5 (p.Ser19Trp) could be identified, whereas no mutations were found in 18 patients (21%). In vitro validation revealed that the mutations in LMF1 were not associated with compromised LPL function. Consistent with this, five of the eight LMF1 variants were also found in controls and therefore cannot account for the observed phenotype.
The prevalence of mutations in LPL was 34% and mostly restricted to patients with type 1 HTG. Mutations in GPIHBP1 (n=3), APOC2 (n=1) and APOA5 (n=2) were rare but the associated clinical phenotype was severe. Routine sequencing of candidate genes in severe HTG has improved our understanding of the molecular basis of this phenotype associated with acute pancreatitis, and may help to guide future individualized therapeutic strategies.
PMCID: PMC3940136  PMID: 22239554
triglycerides; lipoprotein lipase; APOC2; APOA5; LMF1; GPIHBP1
18.  GPIHBP1 and the intravascular processing of triglyceride-rich lipoproteins 
Journal of internal medicine  2012;272(6):528-540.
Lipoprotein lipase (LPL) is produced by parenchymal cells, mainly adipocytes and myocytes, but its role in hydrolyzing triglycerides in plasma lipoproteins occurs at the capillary lumen. For decades, the mechanism by which LPL reached its site of action in capillaries was unclear, but this mystery was recently solved. GPIHBP1, a GPI-anchored protein of capillary endothelial cells, picks up LPL from the interstitial spaces and shuttles it across endothelial cells to the capillary lumen. When GPIHBP1 is absent, LPL is mislocalized to the interstitial spaces, leading to severe hypertriglyceridemia. Some cases of hypertriglyceridemia in humans are caused by GPIHBP1 mutations that interfere with GPIHBP1's ability to bind LPL, and some are caused by LPL mutations that impair LPL's ability to bind to GPIHBP1. This review will cover recent progress in understanding GPIHBP1's role in health and disease and will discuss some remaining mysteries surrounding the processing of triglyceride-rich lipoproteins.
PMCID: PMC3940157  PMID: 23020258
hypertriglyceridemia; chylomicronemia; GPIHBP1; lipoprotein lipase; endothelial cells; lymphocyte antigen 6 proteins
19.  Relationship between vitamin D status and left ventricular geometry in a healthy population: results from the Baltimore Longitudinal Study of Aging 
Journal of internal medicine  2012;273(3):253-262.
The effects of vitamin D on the heart have been studied in patients with cardiac disease, but not in healthy persons. We investigated the relation between vitamin D status and left ventricular (LV) structure and function in community-dwelling subjects without heart disease.
The relationship between concentrations of 25-hydroxyvitamin D [25(OH)D], a marker of vitamin D reserve, and LV transthoracic echocardiography measures was analysed in 711 participants in the Baltimore Longitudinal Study of Aging who were without cardiac disease.
Mean 25(OH)D in the study population was 32.3±11.4 ng/mL; only 15.5% of subjects had moderate or severe vitamin D deficiency [25(OH)D <20 ng/mL]. Adjusting for age, body mass index, cardiovascular disease risk factors, physical activity, calcium and parathyroid hormone, 25(OH)D was positively correlated with LV thickness (β 0.095, SE 0.039, P<0.05) and LV mass index (β 7.5, SE 2.6, P<0.01). A significant non-linear relation between 25(OH)D and LV concentric remodelling was observed. LV remodelling was more likely in participants with 25(OH)D levels <30 ng/mL [odds ratio (OR) 1.24; 95% confidence interval (CI) 0.83–1.85] or ≥38 ng/mL (OR 1.73; 95% CI 1.13–2.65), compared with those with 30–37 ng/mL 25(OH)D. Consistently, LV relative wall thickness was significantly lower (P for trend=0.05), and LV diastolic internal diameter index (P for trend<0.05) and end-diastolic volume index (P for trend<0.05) were significantly higher in subjects with 30–37 ng/mL 25(OH)D compared to the rest of the study population. There was a significant interaction between 25(OH)D and hypertension on the risk of LV hypertrophy (P<0.05).
In a population-based sample of predominantly vitamin D-sufficient subjects without heart disease, LV geometry was most favourable at intermediate 25(OH)D concentrations.
PMCID: PMC3568460  PMID: 23061475
heart; left ventricular mass; left ventricular remodeling; population; vitamin D
20.  New Insights into Osteoporosis: The Bone-Fat Connection 
Journal of internal medicine  2012;272(4):317-329.
Osteoporosis and obesity are chronic disorders that are increasing in prevalence. The pathophysiology of these diseases is multifactorial and includes genetic, environmental and hormonal determinants. Long considered as distinct disorders that rarely are found in the same individual, emerging evidence from basic and clinical studies support an important interaction between adipose tissue and the skeleton. Adiposity can influence bone remodeling through three possible mechanisms including secretion of cytokines that directly target bone, adipokines that influence the central nervous system thereby changing sympathetic impulses to bone, and paracrine influences on adjacent skeletal cells. This review will focus on our current understanding of bone-fat interactions and the clinical implications of recent studies linking obesity to osteoporosis.
PMCID: PMC3634716  PMID: 22702419
21.  Genetic polymorphisms for estimating risk of atrial fibrillation: a literature-based meta-analysis 
Journal of internal medicine  2012;272(6):573-582.
Genome-wide association studies have recently identified genetic polymorphisms associated with common, etiologically complex diseases, for which direct-to-consumer genetic testing with provision of absolute genetic risk estimates is marketed by commercial companies. Polymorphisms associated with atrial fibrillation (AF) have shown relatively large risk estimates but the robustness of such estimates across populations and study designs has not been studied.
A systematic literature review with meta-analysis and assessment of between-study heterogeneity was performed for single nucleotide polymorphisms (SNPs) in the six genetic regions associated with AF in genome-wide or candidate gene studies.
Data from 18 samples of European ancestry (n=12,100 cases; 115,702 controls) were identified for the SNP on chromosome 4q25 (rs220733), 16 samples (n=12,694 cases; 132,602 controls) for the SNP on 16q22 (rs2106261) and 4 samples (n=5,272 cases; 59,725 controls) for the SNP in KCNH2 (rs1805123). Only the discovery studies were identified for SNPs on 1q21 and in GJA5 and IL6R, why no meta-analyses were performed for those SNPs. In overall random-effects meta-analyses, association with AF was observed for both SNPs from genome-wide studies on 4q25 (OR 1.67, 95% CI=1.50–1.86, p=2×10−21) and 16q22 (OR 1.21, 95% CI=1.13–1.29, p=1×10−8), but not the SNP in KCNH2 from candidate gene studies (p=0.15). There was substantial effect heterogeneity across case-control and cross-sectional studies for both polymorphisms (I2=0.50–0.78, p<0.05), but not across prospective cohort studies (I2=0.39, p=0.15). Both polymorphisms were robustly associated with AF for each study design individually (p<0.05).
In meta-analyses including up to 150,000 individuals, polymorphisms in two genetic regions were robustly associated with AF across all study designs but with substantial context-dependency of risk estimates.
PMCID: PMC3763745  PMID: 22690879
atrial fibrillation; genetics; genome-wide; prediction; SNP; meta-analysis
22.  Cellular Origins of Beta Cell Regeneration: a Legacy view of Historical Controversies 
Journal of internal medicine  2009;266(4):325-338.
Beta cell regeneration represents a major goal of therapy for diabetes. Unraveling the origin of beta cells during pancreatic regeneration could help restore a functional beta cell mass in diabetes patients. This scientific question has represented a longstanding interest still intensively investigated today. This review focuses on pioneering observations and subsequent theories made hundred years ago and describes how technical innovation helped resolve some, but not all, of the controversies generated by these early investigators. At the end of the nineteenth century, complete pancreatectomy demonstrated the crucial physiological role of the pancreas and its link to diabetes. Pancreatic injury models, including pancreatectomy and ductal ligation, allowed investigators to describe islet function and to assess the regenerative capacity of the pancreas. Three main theories were proposed to explain the origins of newly formed islets: 1) transdifferentiation of acinar cells into islets, 2) islet neogenesis, a process reminiscent of islet formation during embryonic development, and 3) replication of preexisting islet cells. Despite considerable technical innovation in the last fifty years, the origin of new adult beta cells remains highly controversial and the same three theories are still debated today.
PMCID: PMC3762574  PMID: 19765178
Regeneration; Diabetes; Islets; β-cells; Beta-cells; transdifferentiation; Neogenesis; Replication
23.  Utility of Genome-Wide Association Study findings: prostate cancer as a translational research paradigm 
Journal of internal medicine  2012;271(4):344-352.
Genomewide Association Studies (GWAS) have identified thousands of consistently replicated associations between genetic markers and complex disease risk, including cancers. Alone, these markers have limited utility in risk prediction; however, when several of these markers are used in combination, the predictive performance appears to be similar to currently many available clinical predictors. Despite this, there are divergent views regarding the clinical validity and utility of these genetic markers in risk prediction. There are valid concerns, thus providing a direction for new lines of research. Herein, we outline the debate, and use the example of prostate cancer to highlight emerging evidence from studies that aim to address potential concerns. We also describe a translational framework which could be used to guide the development of a new generation of comprehensive research studies aimed at capitalizing on these exciting new discoveries.
PMCID: PMC3753782  PMID: 22272820
cancer; gene polymorphism; molecular medicine; risk factors
24.  Prostate cancer risk in men with prostate and breast cancer family history: results from the REDUCE study (R1) 
Journal of internal medicine  2012;272(1):85-92.
To what degree the associations between PCa risk and family history of prostate cancer (PCa) and/or breast cancer (BCa) are attributable to screening biases is unclear. We examined these questions within the REDUCE study, where biopsies were largely independent of prostate specific antigen (PSA) minimizing screening biases.
Data were from REDUCE, which tested dutasteride 0.5 mg daily for PCa risk reduction in men with PSA 2.5–10.0 ng mL−1 and a negative pre- study biopsy. Among men undergoing at least one on-study biopsy with complete data (n = 6415; 78.1%), the association between family history and PCa risk was tested using multivariate logistic regression adjusting for clinicodemographic characteristics.
A family history of PCa alone was associated with increased PCa diagnosis (OR: 1.47, 95%CI: 1.22–1.77). In North America, PCa family history was not related to PCa diagnosis (OR: 1.02, 95%CI: 0.731.44), whereas outside North America, PCa family history was significantly related to diagnosis (OR: 1.72, 95%CI: 1.38–2.15) (P-interaction = 0.01). A family history of both PCa and BCa (OR: 2.54, 95%CI: 1.72–3.75) but not BCa alone (OR: 1.04, 95%CI: 0.84–1.29) was associated with increased PCa risk versus no family history and irrespective of geographical region.
In REDUCE, PCa family history was significantly related to PCa diagnosis, although only for men outside North America. The presence of both PCa and BCa family history significantly increased risk versus PCa family history alone, irrespective of geographical region. Ultimately, our observations may support the need for changes in how we address family history in terms of both risk of PCa diagnosis and general risk stratification.
PMCID: PMC3576469  PMID: 22211699
breast cancer; family history; prostate cancer; REDUCE
25.  Emerging Peptide Nanomedicine to Regenerate Tissues and Organs 
Journal of internal medicine  2010;267(1):71-88.
Peptide nanostructures containing bioactive signals offer exciting novel therapies of broad potential impact in regenerative medicine. These nanostructures can be designed through self-assembly strategies and supramolecular chemistry, and have the potential to combine bioactivity for multiple targets with biocompatibility. It is also possible to multiplex their functions by using them to deliver proteins, nucleic acids, drugs, and cells. In this review, we illustrate progress made in this new field by our group and others using peptide-based nanotechnology. Specifically, we highlight the use of self-assembling peptide amphiphiles towards applications in the regeneration of the central nervous system, vasculature and hard tissue along with the transplant of islets and the controlled release of nitric oxide to prevent neointimal hyperplasia. Also, we discuss other self-assembling oligopeptide technology and the progress made with these materials towards the development of potential therapies.
PMCID: PMC3676424  PMID: 20059645

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