Digestibility of resistant starch containing preparations using two in vitro models

BACKGROUND: Resistant starch (RS) is known for potential health benefits in the human colon. To investigate these positive effects it is important to be able to predict the amount, and the structure of starch reaching the large intestine. AIM OF THE STUDY: The aim of this study was to compare two different in vitro models simulating the digestibility of two RS containing preparations. METHODS: The substrates, high amylose maize (HAM) containing RS type 2, and retrograded long chain tapioca maltodextrins (RTmd) containing RS type 3 were in vitro digested using a batch and a dynamic model, respectively. Both preparations were characterized before and after digestion by using X-Ray and DSC, and by measuring their total starch, RS and protein contents. RESULTS: Using both digestion models, 60-61 g/100 g of RTmd turned out to be indigestible, which is very well in accordance with 59 g/100 g found in vivo after feeding RTmd to ileostomy patients. In contrast, dynamic and batch in vitro digestion experiments using HAM as a substrate led to 58 g/100 g and 66 g/100 g RS recovery. The degradability of HAM is more affected by differences in experimental parameters compared to RTmd. The main variations between the two in vitro digestion methods are the enzyme preparations used, incubation times and mechanical stress exerted on the substrate. However, for both preparations dynamically digested fractions led to lower amounts of analytically RS and a lower crystallinity. CONCLUSIONS: The two in vitro digestion methods used attacked the starch molecules differently, which influenced starch digestibility of HAM but not of RTmd

Pan-cancer analysis of whole genomes

Cancer is driven by genetic change, and the advent of massively parallel sequencing has enabled systematic documentation of this variation at the whole-genome scale(1-3). Here we report the integrative analysis of 2,658 whole-cancer genomes and their matching normal tissues across 38 tumour types from the Pan-Cancer Analysis of Whole Genomes (PCAWG) Consortium of the International Cancer Genome Consortium (ICGC) and The Cancer Genome Atlas (TCGA). We describe the generation of the PCAWG resource, facilitated by international data sharing using compute clouds. On average, cancer genomes contained 4-5 driver mutations when combining coding and non-coding genomic elements; however, in around 5% of cases no drivers were identified, suggesting that cancer driver discovery is not yet complete. Chromothripsis, in which many clustered structural variants arise in a single catastrophic event, is frequently an early event in tumour evolution; in acral melanoma, for example, these events precede most somatic point mutations and affect several cancer-associated genes simultaneously. Cancers with abnormal telomere maintenance often originate from tissues with low replicative activity and show several mechanisms of preventing telomere attrition to critical levels. Common and rare germline variants affect patterns of somatic mutation, including point mutations, structural variants and somatic retrotransposition. A collection of papers from the PCAWG Consortium describes non-coding mutations that drive cancer beyond those in the TERT promoter(4); identifies new signatures of mutational processes that cause base substitutions, small insertions and deletions and structural variation(5,6); analyses timings and patterns of tumour evolution(7); describes the diverse transcriptional consequences of somatic mutation on splicing, expression levels, fusion genes and promoter activity(8,9); and evaluates a range of more-specialized features of cancer genomes(8,10-18).Peer reviewe

THE RELATIONSHIP BETWEEN SMOKING AND MICROVASCULAR COMPLICATIONS IN THE EURODIAB IDDM COMPLICATIONS STUDY

OBJECTIVE: To examine the relationship between smoking and both glycemic control and microvascular complications in patients with insulin-dependent diabetes mellitus (IDDM). RESEARCH DESIGN AND METHODS: This was a prevalence survey of 3,250 men and women aged 15-60 years with IDDM from 31 diabetes centers in 16 European countries. Participants completed a questionnaire, had retinal photographs taken, and performed a 24-h urine collection. HbA1c, frequency of hypoglycemic and ketoacidotic episodes, urinary albumin excretion rates, and retinopathy were compared by smoking category. RESULTS: The prevalence of smoking was 35% in men and 29% in women. Current smokers had poorer glycemic control and, among men, were more likely to have had a ketoacidotic episode than were those who never smoked. Ex-smokers had equivalent glycemic control and marginally more hypoglycemic episodes did than those who never smoked. Current smokers had a higher prevalence of microalbuminuria and total retinopathy than did those who never smoked. Ex-smokers had a higher prevalence of macroalbuminuria and proliferative retinopathy than did those who never smoked, but both had a similar prevalence of microalbuminuria. Adjustment for either current or long-term glycemic control could not fully account for these differences. CONCLUSIONS: Smoking is associated with poorer glycemic control and an increased prevalence of microvascular complications compared with not smoking. Ex-smokers can achieve glycemic control equivalent to and have a prevalence of early complications similar to that of those who never smoked. We suggest that poorer glycemic control can account for some of the increased risk of complications in smokers, and that quitting smoking would be effective in reducing the incidence of complications. Urgent action is required to reduce the high smoking rates in people with IDDM

BLOOD-PRESSURE, RETINOPATHY AND URINARY ALBUMIN EXCRETION IN IDDM - THE EURODIAB IDDM COMPLICATIONS STUDY

Several studies have shown an association between blood pressure and nephropathy, but few have been large enough to examine whether, or how, this relation is influenced by retinopathy. We have therefore examined the independent relations of blood pressure to urinary albumin excretion and retinopathy in a cross-sectional observational study of over 3000 insulin-dependent diabetic patients (the EURODIAB IDDM Complications Study). The relation of blood pressure to urinary albumin excretion differed strikingly between patients with (46%) and without (54%) retinopathy. In those with retinopathy, mean urinary albumin excretion rate was normal (<20 mu g/min) below median diastolic pressure (75 mmHg) and increased steeply (p < 0.001) with blood pressure above this level. However, in patients without retinopathy, mean albumin excretion rate was normal across the range of diastolic pressure. This finding could not be explained by differences in glycaemic control or duration of diabetes between patients with and without retinopathy. These data identify a subgroup of patients whose high risk of nephropathy may reflect abnormal renal vulnerability to mildly raised blood pressure. Retinopathy is a close correlate of this vulnerability. Detection of even mild retinopathy, together with raised blood pressure, may be important in assessing nephropathy risk

Fibrinogen and von Willebrand factor in IDDM: Relationships to lipid vascular risk factors, blood pressure, glycaemic control and urinary albumin excretion rate: The EURODIAB IDDM complications study

Abstract: The interrelationships between fibrinogen, von Willebrand factor, a marker of vascular endothelial cell damage, and serum lipids were explored in well-characterised subjects with insulin-dependent diabetes mellitus. The 2091 subjects were enrolled into a cross-sectional, clinic-based study of complications, from 16 European countries: the EURODIAB IDDM Complications study. The anticipated significant relationships between both plasma fibrinogen and plasma von Willebrand factor concentrations and age and glycaemic control, and between fibrinogen and body mass index, were noted. Fibrinogen, adjusted for age and glycated haemoglobin concentration, was also related to smoking habits and was higher in the quartiles with highest systolic and diastolic blood pressures. There was a clustering of vascular risk factors, with a positive relationship between plasma fibrinogen and serum triglyceride concentrations in both genders and between fibrinogen and total cholesterol in males. An inverse relationship between fibrinogen and high density lipoprotein cholesterol was also apparent in males. A prominent feature was a positive relationship between both fibrinogen and von Willebrand factor and albumin excretion rate (p < 0.001 and p < 0.003 respectively) in those with retinopathy but not in these without this complication. In view of previous observations on blood pressure and albuminuria in these subjects the findings are consistent with the hypothesis that microalbuminuria and increased plasma von Willebrand factor are due to endothelial cell perturbation in response to mildly raised blood pressure in subjects with retinopathy. Fibrinogen may also contribute to microvascular disease and its relationships to lipid vascular risk factors suggest a possible pathogenic role in arterial disease in diabetes

Fibrinogen and von Willebrand factor in IDDM: Relationships to lipid vascular risk factors, blood pressure, glycaemic control and urinary albumin excretion rate: The EURODIAB IDDM complications study

The interrelationships between fibrinogen, von Willebrand factor, a marker of vascular endothelial cell damage, and serum lipids were explored in well-characterised subjects with insulin-dependent diabetes mellitus. The 2091 subjects were enrolled into a cross-sectional, clinic-based study of complications, from 16 European countries: the EURODIAB IDDM Complications study. The anticipated significant relationships between both plasma fibrinogen and plasma von Willebrand factor concentrations and age and glycaemic control, and between fibrinogen and body mass index, were noted. Fibrinogen, adjusted for age and glycated haemoglobin concentration, was also related to smoking habits and was higher in the quartiles with highest systolic and diastolic blood pressures. There was a clustering of vascular risk factors, with a positive relationship between plasma fibrinogen and serum triglyceride concentrations in both genders and between fibrinogen and total cholesterol in males. An inverse relationship between fibrinogen and high density lipoprotein cholesterol was also apparent in males. A prominent feature was a positive relationship between both fibrinogen and von Willebrand factor and albumin excretion rate (p < 0.001 and p < 0.003 respectively) in those with retinopathy but not in these without this complication. In view of previous observations on blood pressure and albuminuria in these subjects the findings are consistent with the hypothesis that microalbuminuria and increased plasma von Willebrand factor are due to endothelial cell perturbation in response to mildly raised blood pressure in subjects with retinopathy. Fibrinogen may also contribute to microvascular disease and its relationships to lipid vascular risk factors suggest a possible pathogenic role in arterial disease in diabetes