European Biological Variation Study (EuBIVAS): within- and between-subject biological variation estimates of ß-isomerized C-terminal telopeptide of type I collagen (ß-CTX), N-terminal propeptide of type I collagen (PINP), osteocalcin, intact fibroblast growth factor 23 and uncarboxylated-unphosphorylated matrix-Gla protein-a cooperation between the EFLM Working Group on Biological Variation and the International Osteoporosis Foundation-International Federation of Clinical Chemistry Committee on Bone Metabolism.

We have calculated the biological variation (BV) of different bone metabolism biomarkers on a large, well-described cohort of subjects. BV is important to calculate reference change value (or least significant change) which allows evaluating if the difference observed between two consecutive measurements in a patient is biologically significant or not. INTRODUCTION: Within-subject (CVI) and between-subject (CVG) biological variation (BV) estimates are essential in determining both analytical performance specifications (APS) and reference change values (RCV). Previously published estimates of BV for bone metabolism biomarkers are generally not compliant with the most up-to-date quality criteria for BV studies. We calculated the BV and RCV for different bone metabolism markers, namely ß-isomerized C-terminal telopeptide of type I collagen (ß-CTX), N-terminal propeptide of type I collagen (PINP), osteocalcin (OC), intact fibroblast growth factor 23 (iFGF-23), and uncarboxylated-unphosphorylated Matrix-Gla Protein (uCuP-MGP) using samples from the European Biological Variation Study (EuBIVAS). METHODS: In the EuBIVAS, 91 subjects were recruited from six European laboratories. Fasting blood samples were obtained weekly for ten consecutive weeks. The samples were run in duplicate on IDS iSYS or DiaSorin Liaison instruments. The results were subjected to outlier and variance homogeneity analysis before CV-ANOVA was used to obtain the BV estimates. RESULTS: We found no effect of gender upon the CVI estimates. The following CVI estimates with 95% confidence intervals (95% CI) were obtained: ß-CTX 15.1% (14.4-16.0%), PINP 8.8% (8.4-9.3%), OC 8.9% (8.5-9.4%), iFGF23 13.9% (13.2-14.7%), and uCuP-MGP 6.9% (6.1-7.3%). CONCLUSIONS: The EuBIVAS has provided updated BV estimates for bone markers, including iFGF23, which have not been previously published, facilitating the improved follow-up of patients being treated for metabolic bone disease.

Factors associated with glycaemic control in adults with Type 1 diabetes: a registry-based analysis including 7601 individuals from 34 centres in Norway.

AIMS: To use data from the Norwegian Diabetes Registry for Adults and Statistics Norway to assess factors associated with glycaemic control in type 1 diabetes. METHODS: The analyses included all individuals aged ≥18 years who had a type 1 diabetes duration of >2 years and a recorded value in the registry between 2013 and 2015 (n=7601). Predicted mean HbA1c levels for subgroups of participants were assessed using linear regression analysis. RESULTS: Young age (18-25 years), low education levels, smoking, living alone, exercising infrequently, monitoring glucose infrequently, high insulin requirements, low frequency of symptomatic hypoglycaemia, history of ketoacidosis and a BMI <18.5 kg/m2 were associated with a 2-12-mmol/mol (0.2-1.1%) higher HbA1c level. Those with 10-15 years of diabetes duration had 5-mmol/mol (0.5%) higher HbA1c level than those who had a diabetes duration of 2-5 years. Sex, participation (ever) in a diabetes education course, or ever experiencing serious hypoglycaemia were not associated with glycaemic control. CONCLUSIONS: We present representative national data on factors that were associated with glycaemic control. A better understanding and awareness of these factors, together with technological advances in diabetes management, could lead to more personalized management strategies, better glycaemic control and a lower risk of diabetes complications.

Variation in the achievement of HbA1c , blood pressure and LDL cholesterol targets in type 2 diabetes in general practice and characteristics associated with risk factor control.

AIMS: To identify population, general practitioner, and practice characteristics associated with the achievement of HbA1c , blood pressure and LDL cholesterol targets, and to describe variation in the achievement of risk factor control. METHODS: We conducted a cross-sectional survey of 9342 people with type 2 diabetes, 281 general practitioners and 77 general practices in Norway. Missing values (7.4%) were imputed using multiple imputation by chained equations. We used three-level logistic regression with the achievement of HbA1c , blood pressure and LDL cholesterol targets as dependent variables, and factors related to population, general practitioners, and practices as independent variables. RESULTS: Treatment targets were achieved for HbA1c in 64%, blood pressure in 50%, and LDL cholesterol in 52% of people with type 2 diabetes, and 17% met all three targets. There was substantial heterogeneity in target achievement among general practitioners and among practices; the estimated proportion of a GPs diabetes population at target was 55-73% (10-90 percentiles) for HbA1c , 36-63% for blood pressure, and 47-57% for LDL cholesterol targets. The models explained 11%, 5% and 14%, respectively, of the total variation in the achievement of HbA1c , blood pressure and LDL cholesterol targets. Use among general practitioners of a structured diabetes form was associated with 23% higher odds of achieving the HbA1c target (odds ratio 1.23, 95% confidence interval (CI) 1.02-1.47) and 17% higher odds of achieving the LDL cholesterol target (odds ratio 1.17, 95% CI 1.01-1.35). CONCLUSIONS: Clinical diabetes management is difficult, and few people meet all three risk factor control targets. The proportion of people reaching target varied among general practitioners and practices. Several population, general practitioner and practice characteristics only explained a small part of the total variation. The use of a structured diabetes form is recommended.

Low anterior resection syndrome in a Scandinavian population of patients with rectal cancer: a longitudinal follow-up within the QoLiRECT study.

AIM: Low anterior resection syndrome (LARS) is common after low anterior resection. Our aim was to evaluate the prevalence and 'bother' (subjective, symptom-associated distress) of major LARS after 1 and 2 years, identify possible risk factors and relate the bowel function to a reference population. METHOD: The QoLiRECT (Quality of Life in RECTal cancer) study is a Scandinavian prospective multicentre study including 1248 patients with rectal cancer, of whom 552 had an anterior resection. Patient questionnaires were distributed at diagnosis and after 1, 2 and 5 years. Data from the baseline and at 1- and 2-year follow-up were included in this study. RESULTS: The LARS score was calculated for 309 patients at 1 year and 334 patients at 2 years. Prevalence was assessed by a generalized linear mixed effects model. Major LARS was found in 63% at 1 year and 56% at 2 years. Bother was evident in 55% at 1 year, decreasing to 46% at 2 years. Major LARS was most common among younger women (69%). Among younger patients, only marginal improvement was seen over time (63-59%), for older patients there was more improvement (62-52%). In the reference population, the highest prevalence of major LARS-like symptoms was noted in older women (12%). Preoperative radiotherapy, defunctioning stoma and tumour height were found to be associated with major LARS. CONCLUSION: Major LARS is common and possibly persistent over time. Younger patients, especially women, are more affected, and perhaps these patients should be prioritized for early stoma closure to improve the chance of a more normal bowel function.

Population, general practitioner and practice characteristics are associated with screening procedures for microvascular complications in Type 2 diabetes care in Norway.

AIMS: To assess population, general practitioner (GP) and practice characteristics associated with the performance of microvascular screening procedures and to propose strategies to improve Type 2 diabetes care. METHODS: A cross-sectional survey in Norway (281 GPs from 77 practices) identified 8246 people with a Type 2 diabetes duration of 1 year or more. We used multilevel regression models with either the recording of at least two of three recommended screening procedures (albuminuria, monofilament, eye examination) or each procedure separately as dependent variable (yes/no), and characteristics related to the person with diabetes, GP or practice as independent variables. RESULTS: The performance of recommended screening procedures was recorded in the following percentages: albuminuria 31.5%, monofilament 27.5% and eye examination 60.0%. There was substantial heterogeneity between practices, and between GPs within practices for all procedures. Compared with people aged 60-69 years, those aged < 50 years were less likely to have an albuminuria test performed [odds ratio (OR) 0.75, 95% CI 0.61 to 0.93] and eye examination (OR 0.79, 95% CI 0.66 to 0.95). People with macrovascular disease had fewer screening procedures recorded (OR 0.68, 95% CI 0.59 to 0.78). Use of an electronic diabetes form was associated with improved screening  (OR 2.65, 95% CI 1.86 to 3.78). GPs with high workload recorded fewer procedures (OR 0.59, 95% CI 0.39 to 0.90). CONCLUSIONS: Performance of screening procedures was suboptimal overall, and in people who should be prioritized. Performance varied substantially between GPs and practices. The use of a structured diabetes form should be mandatory.

Recurrent attacks of acute hepatic porphyria: major role of the chronic inflammatory response in the liver.

BACKGROUND: Acute intermittent porphyria (AIP) is an inherited disorder of haem metabolism characterized by life-threatening acute neurovisceral attacks due to the induction of hepatic δ-aminolevulinic acid synthase 1 (ALAS1) associated with hydroxymethylbilane synthase (HMBS) deficiency. So far, the treatment of choice is hemin which represses ALAS1. The main issue in the medical care of AIP patients is the occurrence of debilitating recurrent attacks. OBJECTIVE: The aim of this study was to determine whether chronic hemin administration contributes to the recurrence of acute attacks. METHODS: A follow-up study was conducted between 1974 and 2015 and included 602 French AIP patients, of whom 46 had recurrent AIP. Moreover, we studied the hepatic transcriptome, serum proteome, liver macrophage polarization and oxidative and inflammatory profiles of Hmbs-/- mice chronically treated by hemin and extended the investigations to five explanted livers from recurrent AIP patients. RESULTS: The introduction of hemin into the pharmacopeia has coincided with a 4.4-fold increase in the prevalence of chronic patients. Moreover, we showed that both in animal model and in human liver, frequent hemin infusions generate a chronic inflammatory hepatic disease which induces HO1 remotely to hemin treatment and maintains a high ALAS1 level responsible for recurrence. CONCLUSION: Altogether, this study has important impacts on AIP care underlying that hemin needs to be restricted to severe neurovisceral crisis and suggests that alternative treatment targeting the liver such as ALAS1 and HO1 inhibitors, and anti-inflammatory therapies should be considered in patients with recurrent AIP.

Acute hepatic porphyria and cancer risk: a nationwide cohort study.

BACKGROUND: Acute hepatic porphyria (AHP) is considered to be a risk factor for primary liver cancer (PLC), but varying risk estimates have been published. OBJECTIVES: Our aim was to investigate the risk of PLC and other cancers in persons with AHP using a nationwide cohort design. Given that greater numbers of women than men tend to have manifest and more severe AHP, a further aim was to investigate sex differences in this risk. METHODS: The study sample consisted of all Norwegian residents aged 18 years or older during the period 2000-2011. Persons with AHP (n = 251) were identified through the Norwegian Porphyria Centre, and patients with a cancer diagnosis were identified by linkage to the Cancer Registry of Norway. RESULTS: For persons with AHP, the annual incidence rate of PLC was 0.35%. PLC risk was substantially higher for individuals with an AHP diagnosis compared to the reference population [adjusted hazard ratio (aHR) 108, 95% confidence interval (CI) 56-207]. In a meta-analysis of published studies on PLC and AHP, including ours, women had a higher risk than men. In addition, our results suggested that persons with AHP may have increased risks of kidney (aHR 7.4, 95% CI 2.4-23.1) and endometrial cancers (aHR 6.2, 95% CI 2.0-19.3). CONCLUSIONS: Our findings confirmed a substantially higher risk of PLC associated with AHP compared to the general population. In a meta-analysis, the risk was shown to be greater for women than men. The novel findings of a moderate to substantial association between AHP and kidney and endometrial cancers should be investigated further.

Strong and persistent effect on liver fat with a Paleolithic diet during a two-year intervention.

BACKGROUND/OBJECTIVES: Our objective was to investigate changes in liver fat and insulin sensitivity during a 2-year diet intervention. An ad libitum Paleolithic diet (PD) was compared with a conventional low-fat diet (LFD). SUBJECTS/METHODS: Seventy healthy, obese, postmenopausal women were randomized to either a PD or a conventional LFD. Diet intakes were ad libitum. Liver fat was measured with proton magnetic resonance spectroscopy. Insulin sensitivity was evaluated with oral glucose tolerance tests and calculated as homeostasis model assessment-insulin resistance (HOMA-IR)/liver insulin resistance (Liver IR) index for hepatic insulin sensitivity and oral glucose insulin sensitivity (OGIS)/Matsuda for peripheral insulin sensitivity. All measurements were performed at 0, 6 and 24 months. Forty-one women completed the examinations for liver fat and were included. RESULTS: Liver fat decreased after 6 months by 64% (95% confidence interval: 54-74%) in the PD group and by 43% (27-59%) in the LFD group (P<0.01 for difference between groups). After 24 months, liver fat decreased 50% (25-75%) in the PD group and 49% (27-71%) in the LFD group. Weight reduction between baseline and 6 months was correlated to liver fat improvement in the LFD group (rs=0.66, P<0.01) but not in the PD group (rs=0.07, P=0.75). Hepatic insulin sensitivity improved during the first 6 months in the PD group (P<0.001 for Liver IR index and HOMA-IR), but deteriorated between 6 and 24 months without association with liver fat changes. CONCLUSIONS: A PD with ad libitum intake had a significant and persistent effect on liver fat and differed significantly from a conventional LFD at 6 months. This difference may be due to food quality, for example, a higher content of mono- and polyunsaturated fatty acids in the PD. Changes in liver fat did not associate with alterations in insulin sensitivity.

A skin disease, a blood disease or something in between? An exploratory focus group study of patients' experiences with porphyria cutanea tarda.

BACKGROUND: Porphyria cutanea tarda (PCT) is characterized by fragile skin with blistering on sun-exposed areas. Symptoms typically develop in late adulthood and can be triggered by iron overload, alcohol intake, oestrogens and various liver diseases. Treatment consists of phlebotomy to reduce iron, or increasing urinary porphyrin excretion by administering chlorochin. To optimize patient care, health personnel need to understand the subjective experiences of PCT. OBJECTIVES: To explore the experiences of persons with PCT with regard to symptoms, treatment, follow-up and prevention of the disease. METHODS: Interpretive description was used as a qualitative approach. Twenty-one participants attended three focus groups. All participants had experienced PCT symptoms during the last 5 years. RESULTS: Participants' experiences varied from trivializing symptoms and fragile skin to what was described as a desperate situation, with huge blisters, skin falling off and feeling as if one was in a 'horror movie'. For some, itching was very troublesome, preventing sleep and delaying skin healing. In managing PCT a shift in focus from skin to blood was described. PCT was perceived as a chronic and systemic disease causing a range of health problems. Strategies for preventing symptoms ranged from doing nothing to frequent controls and check-ups. CONCLUSIONS: Participants had a systemic perception of PCT, and a tendency to attribute a range of health problems to the condition. This study adds insight into the experiences patients have with PCT.

A Palaeolithic-type diet causes strong tissue-specific effects on ectopic fat deposition in obese postmenopausal women.

OBJECTIVES: Ectopic fat accumulation in liver and skeletal muscle may be an essential link between abdominal obesity, insulin resistance and increased risk of cardiovascular disease after menopause. We hypothesized that a diet containing a relatively high content of protein and unsaturated fat [mainly monounsaturated fatty acids (MUFAs)] but limited carbohydrates and saturated fat would reduce lipid content in liver and muscle and increase insulin sensitivity in postmenopausal women. SUBJECTS: Ten healthy, nonsmoking postmenopausal women with a body mass index (BMI) >27 (28-35) kg m(-2) were included in the study. INTERVENTIONS: Participants were instructed to consume an ad libitum Palaeolithic-type diet intended to provide approximately 30 energy percentage (E%) protein, 40 E% fat (mainly MUFAs) and 30 E% carbohydrate. Intramyocellular lipid (IMCL) levels in calf muscles and liver triglyceride levels were quantified using proton magnetic resonance spectroscopy ((1) H-MRS) before and 5 weeks after dietary intervention. Insulin sensitivity was estimated by homoeostasis model assessment (HOMA) indices and the euglycaemic hyperinsulinaemic clamp technique. RESULTS: Mean energy intake decreased by 25% with a weight loss of 4.5 kg. BMI, waist and hip circumference, waist/hip ratio and abdominal sagittal diameter also decreased significantly, as did diastolic blood pressure (mean -7 mmHg), levels of fasting serum glucose, cholesterol, triglycerides, LDL/HDL cholesterol, apolipoprotein B (ApoB) and apolipoprotein A1 (ApoA1), urinary C-peptide and HOMA indices. Whole-body insulin sensitivity did not change. Liver triglyceride levels decreased by 49%, whereas IMCL levels in skeletal muscle were not significantly altered. CONCLUSIONS: A modified Palaeolithic-type diet has strong and tissue-specific effects on ectopic lipid deposition in postmenopausal women.

Self-monitoring of blood glucose in patients with diabetes who do not use insulin--are guidelines evidence-based?

AIMS: To evaluate if clinical practice guideline recommendations regarding self-monitoring of blood glucose in patients with diabetes not using insulin follow the principles of evidence-based medicine. METHODS: After a search from 1999 to 2011, 18 clinical practice guidelines were included. Recommendations regarding self-monitoring of blood glucose were graded on a scale from one (strongly against self-monitoring) to four (strongly in favour of self-monitoring) and compared with the similarly graded conclusions of systematic reviews that were cited by the clinical practice guidelines. We also investigated how clinical practice guideline characteristics, for example funding sources, and quality of references cited could be related to the guideline recommendations. RESULTS: The clinical practice guidelines cited in total 15 systematic reviews, 14 randomized controlled trials, 33 non-randomized controlled trials papers and 18 clinical practice guidelines or position statements. The clinical practice guideline recommendations had an average grade of 3.4 (range 2.0-4.0). Higher grades were seen for clinical practice guidelines that acknowledged industry funding (mean value 4.0) or were issued by organizations depending on private funding (mean value 3.6 vs. 3.0 for governmental funding). The conclusions of the 15 systematic reviews had a mean grade of 2.2 (range 1.0-3.8). Systematic reviews with low grades were less cited. In total, 21 randomized controlled trials were included in the systematic reviews. Approximately half of these evaluated an educational intervention where the effect of self-monitoring of blood glucose could not be clearly isolated. CONCLUSIONS: Clinical practice guidelines were more in favour of self-monitoring use than the systematic reviews that were cited. The citation practice was non-systematic and industry funding seemingly led to a more positive attitude towards use of self-monitoring of blood glucose.

[Current issues in measurement and reporting of urinary albumin excretion]. / Données actuelles sur le dosage de l'excrétion urinaire de l'albumine.

Urinary excretion of albumin indicates kidney damage and is recognized as a risk factor for progression of kidney disease and cardiovascular disease. The role of urinary albumin measurements has focused attention on the clinical need for accurate and clearly reported results. The National Kidney Disease Education Program and the IFCC convened a conference to assess the current state of preanalytical, analytical, and postanalytical issues affecting urine albumin measurements and to identify areas needing improvement. The chemistry of albumin in urine is incompletely understood. Current guidelines recommend the use of the albumin/creatinine ratio (ACR) as a surrogate for the erro-prone collection of timed urine samples. Although ACR results are affected by patient preparation and time of day of sample collection, neither is standardized. Considerable intermethod differences has been reported for both albumin and creatinine measurement, but trueness is unknown because there are no reference measurement procedures for albumin and no referance materials for either analyte in urine. The recommanded reference intervals for the ACR do not take into account the large intergroup differences in creatinine excretion (e.g., related to differences in age, sex, and ethicity) nor the continuous increase in risk related to albumin excretion. Clinical needs have been identified for standardization of (a) urine collection methodes, (b) urine albumin and creatinine measurements based on a complete reference system, (c) reporting of test results, and (d) reference intervals for the ACR.

[Evaluation of prescription and interpretation of microalbuminuria by general practitioners]. / Evaluation de la prescription et de l'interprétation des dosages de microalbuminurie en médecine générale.

Microalbuminuria is well recognized as an independent marker of early renal failure in patients with diabetes mellitus and hypertension. We describe here the french results of an international study on the use and interpretation of microalbuminuria by general practitioners. A case history based questionnaire upon a type 2 diabetic patient was sent to 600 general practitioners in the Champagne-Ardenne Region to identify their habits in terms of prescription and of results interpretation. The analysis of the results shows a great variability of practices, regarding the procedures of urine collection, the units used, or the decision limits. These discrepancies can lead to inappropriate care of the patient. Even though national recommendations on the use of MA have been made, this study highlights the necessity for general practitioners to refer to concerted and consensual practices.

Systematic review of the biological variation data for diabetes related analytes.

BACKGROUND: Objective interpretation of laboratory test results used to diagnose and monitor diabetes mellitus in part requires the application of biological variation data (BVD). The quality of published BVD has been questioned. The aim of this study was to quality assess publications reporting BVD for diabetes-related analytes using the Biological Variation Data Critical Appraisal Checklist (BIVAC); to assess whether published BVD are fit for purpose and whether the study design and population attributes influence BVD estimates and to undertake a meta-analysis of the BVD from BIVAC-assessed publications. METHODS: Publications reporting data for glucose, HbA1c, adiponectin, C-peptide, fructosamine, insulin like growth factor 1 (IGF-1), insulin like growth factor binding protein 3 (IGFBP-3), insulin, lactate and pyruvate were identified using a systematic literature search. These publications were assessed using the BIVAC, receiving grades A, B, C or D, where A is of highest quality. A meta-analysis of the BVD from the assessed studies utilised weightings based upon BIVAC grades and the width of the data confidence intervals to generate global BVD estimates. RESULTS: BIVAC assessment of 47 publications delivered 1 A, 3 B, 39C and 4 D gradings. Publications relating to adiponectin, C-peptide, IGF-1, IGFBP-3, lactate and pyruvate were all assessed as grade C. Meta-analysis enabled global BV estimates for all analytes except pyruvate, lactate and fructosamine. CONCLUSIONS: This study delivers updated and evidence-based BV estimates for diabetes-related analytes. There remains a need for delivery of new high-quality BV studies for several clinically important analytes.

A Paleolithic-type diet results in iodine deficiency: a 2-year randomized trial in postmenopausal obese women.

BACKGROUND/OBJECTIVES: Different diets are used for weight loss. A Paleolithic-type diet (PD) has beneficial metabolic effects, but two of the largest iodine sources, table salt and dairy products, are excluded. The objectives of this study were to compare 24-h urinary iodine concentration (24-UIC) in subjects on PD with 24-UIC in subjects on a diet according to the Nordic Nutrition Recommendations (NNR) and to study if PD results in a higher risk of developing iodine deficiency (ID), than NNR diet. SUBJECTS/METHODS: A 2-year prospective randomized trial in a tertiary referral center where healthy postmenopausal overweight or obese women were randomized to either PD (n=35) or NNR diet (n=35). Dietary iodine intake, 24-UIC, 24-h urinary iodine excretion (24-UIE), free thyroxin (FT4), free triiodothyronine (FT3) and thyrotropin (TSH) were measured at baseline, 6 and 24 months. Completeness of urine sampling was monitored by para-aminobenzoic acid and salt intake by urinary sodium. RESULTS: At baseline, median 24-UIC (71.0 µg/l) and 24-UIE (134.0 µg/d) were similar in the PD and NNR groups. After 6 months, 24-UIC had decreased to 36.0 µg/l (P=0.001) and 24-UIE to 77.0 µg/d (P=0.001) in the PD group; in the NNR group, levels were unaltered. FT4, TSH and FT3 were similar in both groups, except for FT3 at 6 months being lower in PD than in NNR group. CONCLUSIONS: A PD results in a higher risk of developing ID, than a diet according to the NNR. Therefore, we suggest iodine supplementation should be considered when on a PD.

Light-induced protoporphyrin release from erythrocytes in erythropoietic protoporphyria.

The photohemolysis of normal erythrocytes incubated with protoporphyrin is reduced in the presence of albumin. When globin is added to normal erythrocytes loaded with protoporphyrin, protoporphyrin is bound to globin. During irradiation protoporphyrin moves from globin to the erythrocyte membrane and photohemolysis is initiated. Erythrocytes in patients with erythropoietic protoporphyria contain large amounts of protoporphyrin bound to hemoglobin. Upon irradiation of these cells in the absence of albumin, 40% of protoporphyrin and 80% of hemoglobin is released after 240 kJ/m2. The released protoporphyrin is hemoglobin bound. In contrast, when albumin is present only 8% of hemoglobin is released whereas protoporphyrin is released to 76%. The released protoporphyrin is albumin bound. A hypothesis for the release of erythrocyte protoporphyrin in erythropoietic protoporphyria without simultaneous hemolysis is proposed. Upon irradiation protoporphyrin photodamages its binding sites on hemoglobin, moves through the plasma membrane, and is bound to albumin in plasma.

Measurement of the tensile strength of the ventral abdominal wall in comparison with scar tissue.

BACKGROUND: Paramedian laparotomies lead to incisional hernias in approximately 30% of cases. In contrast, incisional hernias occur very rarely in the linea alba or the ventral abdominal wall. In this setting we investigated the difference between scar tissue and the non-incised abdominal wall tissue. METHODS: At the post mortem examination of 66 recently deceased individuals, accurately measured pieces of resected tissue from the linea alba, the anterior and the posterior rectus sheath, and scar tissue following median laparotomy, were exposed to tensile loads. FINDINGS: In the epigastric region the tissue ruptured at a mean horizontal load of 10.0 (SD 3.4) N/mm(2) in the linea alba and 6.9 (SD 2.5) N/mm(2) in scar tissue (P<0.001), and at a mean vertical load of 4.5 (SD 2.0) N/mm(2) in the linea alba and 3.3 (SD 1.6) N/mm(2) in scar tissue (P<0.05). In the hypogastric region as well, scar tissue was significantly less resistant in the main direction of load. INTERPRETATION: Scar tissue has a significantly lesser loading capacity than the intact ventral abdominal wall and therefore poses a permanent risk for herniation. For this reason, closure of the abdominal wall should be given due consideration and subjected to further investigation. Specifically, sustained reinforcement of scar tissue by means of suture techniques or non-absorbable sutures warrants further study. When constructing meshes for reinforcement of incisional hernias, the two-fold tensile load on the midline in horizontal direction as opposed to the craniocaudal direction must be taken into account.

European porphyria initiative (EPI): a platform to develop a common approach to the management of porphyrias and to promote research in the field.

Porphyrias are uncommon inherited diseases of haem biosynthesis for which the diagnosis and treatment varies in individual countries. Despite the existence of guidelines recommended by porphyria experts concerning the diagnosis and management of the acute porphyrias, and of specialist centres in most European countries, many clinicians still do not apply these guidelines. The European Porphyia Initiative (EPI) network was formed in 2001 in order to compare experience among countries to attempt to develop a common approach to the management of the porphyrias, particularly concerning recommendation of safe and unsafe drugs, and to facilitate international collaborative clinical and biological research. The main achievements of EPI during this period have been: * Drafting and agreeing to consensus protocols for the diagnosis and management of acute hepatic porphyrias. * Creation of a multilingual website, particularly focusing on guidelines for common prescribing problems in acute porphyria and on providing information for patients that is now available in 10 languages: (www.porphyria-europe.org). EPI's current objectives are to develop the EPI platform, expand to new countries, extend to non-acute porphyrias and design European research and clinical trials in porphyria. The project will focus on: 1. Setting up a European laboratory external quality assurance scheme (EQAS) for biochemical and molecular investigations and their interpretation 2. Establishing a consensus drug list in collaboration with the Nordic porphyria network 3. Improving patient counseling 4. Developing large multi-centre, multi-national research projects. Due to the rarity of the porphyrias, it would be very difficult for any one country to provide this data with a sufficient number of patients and within a reasonable timescale. The progress achieved will facilitate improvements in the treatment and development of new therapeutic strategies. It will set a pattern for establishing, and subsequently harmonising, between countries best clinical practice for a rare but important group of diseases, and will help to develop the optimal therapy and ensure its cost effectiveness.

Porphyrin-sensitized photodynamic damage of isolated rat liver mitochondria.

The respiration rates and the respiratory control ratios of isolated rat liver mitochondria have been measured following exposure to 0--160 kJ/m2 of near-ultraviolet radiation (blacklight) in the presence of low concentrations of porphyrins (0.1--0.2 mumol/l). Depending on the light dose, the concentration and the type of porphyrin, the following sequence of reactions occurred: uncoupling and inhibition of oxidative phosphorylation, energy dissipation, inhibition of respiration and swelling and disruption of the mitochondria. The detrimental effects could not be elicited in the absence of oxygen, neither could they be elicited by porphyrins or light alone. At equimolar concentrations, the effectiveness of the porphyrins as photosensitizers were: deuteroporphyrin greater than protoporphyrin much greater than coproporphyrin greater than uroporphyrin. The results may be of importance to explain the skin lesions seen when porphyrins of different hydrophobicity accumulate in the skin.