Status and perspectives of biomarker validation for diagnosis, stratification, and treatment.

OBJECTIVES: The aim of this study was to discuss the status of and perspective for biomarker validation in view of the challenges imposed on national healthcare systems due to an increasing number of citizens with chronic diseases and new expensive drugs with effects that are sometimes poorly documented. The demand for a paradigm shift toward stratification of patients or even 'personalized medicine' (PM) is rising, and the implementation of such novel strategies has the potential to increase patient outcomes and cost efficiency of treatments. The implementation of PM depends on relevant and reliable biomarkers correlated to disease states, prognosis, or effect of treatment. Beyond biomarkers of disease, personalized prevention strategies (such as individualized nutrition guidance) are likely to depend on novel biomarkers. STUDY DESIGN: We discuss the current status of the use of biomarkers and the need for standardization and integration of biomarkers based on multi-omics approaches. METHODS: We present representative cases from laboratory medicine, oncology, and nutrition, where present and emerging biomarkers have or may present opportunities for PM or prevention. RESULTS: Biomarkers vary greatly in complexity, from single genomic mutations to metagenomic analyses of the composition of the gut microbiota and comprehensive analyses of metabolites, metabolomics. Using biomarkers for decision-making has previously often relied on measurements of single biomolecules. The current development now moves toward the use of multiple biomarkers requiring the use of machine learning or artificial intelligence. Still, the usefulness of biomarkers is often challenged by suboptimal validation, and the discovery of new biomarkers moves much faster than standardization efforts. To reap the potential benefits of personalization of treatment and prevention, healthcare systems and regulatory authorities need to focus on validation and standardization of biomarkers. CONCLUSION: There is a great public health need for better understanding of the usefulness, but also limitations, of biomarkers among policy makers, clinicians, and scientists, and efforts securing effective validation are key to the future use of novel sets of complex biomarkers.

Alterations in molecular muscle mass regulators after 8 days immobilizing Special Forces mission.

In military operations, declined physical capacity can endanger the life of soldiers. During special support and reconnaissance (SSR) missions, Special Forces soldiers sustain 1-2 weeks full-body horizontal immobilization, which impairs muscle strength and performance. Adequate muscle mass and strength are necessary in combat or evacuation situations, which prompt for improved understanding of muscle mass modulation during SSR missions. To explore the molecular regulation of myofiber size during a simulated SSR operation, nine male Special Forces soldiers were biopsied in m. vastus lateralis pre and post 8 days immobilizing restricted prone position. After immobilization, total mammalian target of rapamycin protein was reduced by 42% (P < 0.05), whereas total and phosphorylated protein levels of Akt, ribosomal protein S6k, 4E-BP1, and glycogen synthase kinase3ß were unchanged. Messenger RNA (mRNA) levels of the atrogenes forkhead box O3 (FoxO3), atrogin1, and muscle ring finger protein1 (MuRF1) increased by 36%, 53%, and 71% (P < 0.01), MuRF1 protein by 51% (P = 0.05), whereas FoxO1 and peroxisome proliferator-activated receptor γ coactivator-1 ß mRNAs decreased by 29% and 40% (P < 0.01). In conclusion, occupational immobilization in Special Forces soldiers led to modulations in molecular muscle mass regulators during 8 days prone SSR mission, which likely contribute to muscle loss observed in such operations. The present data expand our knowledge of human muscle mass regulation during short-term immobilization.

Effects of a coccidiosis challenge on dietary methionine recommendations in broilers.

Broilers are commonly exposed to coccidiosis infections, and the use of dietary strategies to reduce losses in growth performance has practical implications for the poultry industry. Methionine (Met) is typically the first limiting amino acid for broilers and is involved in metabolic and immunological pathways; however, literature is conflicting on how dietary Met requirements are affected by environmental stressors. Our objective was to assess how the Met requirement changes during coccidiosis based on results of growth performance, carcass traits, and health outcomes. Two trials were conducted using 780 male Ross 308 broiler chicks in floor pens randomly assigned to 1 of 12 experimental treatments. All birds received common starter (d 0-10) and finisher (d 24-35, Trial 2 only) diets, and only differed based on their assigned experimental grower diet (d 10-24). Trial 1 experimental grower diets ranged from 2.61 to 6.21 g/kg digestible Met. Trial 2 experimental grower diets were formulated to contain 15% below, at, or 15% above the Met requirement determined in Trial 1. Birds were exposed to a coccidiosis challenge on d 11, with blood and tissue collection (1 bird/pen) on d 18 and carcass processing on d 35 (2 birds/pen) in Trial 2. Data were analyzed using a 1- or 2-way ANOVA. A non-linear regression analysis was conducted in Trial 1 to determine the Met requirement of 4.32 g of digestible Met/kg of diet using BW gain. Coccidiosis infection reduced (P < 0.05) growth performance during the experimental grower and overall study periods in Trial 2. Increasing dietary Met from below requirement to meeting requirement during the grower period improved (P < 0.001) BW gain and feed conversion ratio (FCR), but this effect was only significant between treatments below and above the requirement for the overall study period. There was an interactive effect (P = 0.038) on FCR for the overall study period. These findings provide evidence that the Met requirement is likely increased during coccidiosis based on growth performance outcomes.

Defining optimal dietary starch, oil, and amino acid inclusion levels for broilers experiencing a coccidiosis challenge.

Alternative methods to alleviate coccidiosis in broilers are of interest to producers, including dietary strategies to minimize disruptions in growth rate and efficiency when faced with health challenges. Our objective was to determine optimal combinations of dietary starch, amino acids (AA), and oil to benefit productivity of broilers experiencing Eimeria-induced immune activation. Two trials were conducted using 1,536 male Ross 308 broiler chicks in floor pens randomly assigned to 1 of 17 experimental treatments. All birds received common starter (d 0-10) and finisher (d 24-35) diets, and only differed based on their assigned experimental grower diet (d 10-24). Trial 1 experimental grower diets ranged from 2,700 to 3,300 kcal/kg AME. Trial 2 included 10 experimental grower diets following a simplex lattice design consisting of 3 basal lots formulated to have the highest starch (45.4%), oil (10.2%), or AA density (120, 1.33% digestible Lys) and mixed in 4 equally spaced levels for each component (0, 0.33, 0.67, 1). These mixtures enabled varying densities of AA (80-120% of recommendation), starch:oil (4:1-20:1), and AME (2,940-3,450 kcal/kg). Bird and feeder weights were collected on d 0, 10, 24, and 35, and birds were exposed to an Eimeria challenge on d 11 or 12. In trial 2, excreta samples were collected for AME determination and carcasses were processed on d 36. Data were analyzed using ANOVA, t test, or regression. In Trial 1, BW gain and feed conversion were improved (P < 0.05) by increasing dietary AME. In Trial 2, birds receiving diets containing AA at 93 to 107% of recommendations and higher oil exhibited improved (P < 0.05) performance, but increased starch at the expense of oil reduced performance (P < 0.05). Relative breast and fat pad weights were not influenced by diet in Trial 2. We determined that broilers mildly challenged with Eimeria would exhibit highest BW gain when receiving diets containing 35.8% starch, 8.9% oil, and 101.3% of AA recommendations, which can be utilized by producers to maintain productivity under health-challenged conditions.

Myostatin expression during human muscle hypertrophy and subsequent atrophy: increased myostatin with detraining.

Myostatin is a potent negative regulator of skeletal muscle mass, but its role in human skeletal muscle hypertrophy and atrophy is sparsely described. Muscle biopsies were obtained from young male subjects before and after 30 and 90 days of resistance training as well as after 3, 10, 30, 60 and 90 days of subsequent detraining. Myostatin mRNA increased significantly with detraining. We observed a 28 kDa myostatin immunoreactive protein, which, however, was also present in myostatin knock out mice skeletal muscle. As a novel finding we consistently detected a 10 kDa band, which may represent a mature myostatin monomer under reducing conditions or a novel, unknown myostatin form. Further, we observed a significant increase in this 10 kDa band after 3 days of detraining preceding the rapid type II fiber atrophy, in which almost half of the acquired fiber area was lost after only 10 days of detraining. Accordingly, an increase in the level of the 10 kDa protein is associated with rapid type II fiber atrophy, suggesting myostatin-mediated specific type II fiber atrophy, which in combination with our mRNA data support a role for myostatin in the negative regulation of adult human skeletal muscle mass.

Hormone therapy affects plasma measures of factor VII-activating protease in younger postmenopausal women.

OBJECTIVES: Current reviews indicate that hormone therapy (HT) has a protective role in coronary heart disease (CHD) in younger postmenopausal women, whereas HT contributes to CHD in older women. Factor VII-activating protease (FSAP) is a serine protease that accumulates in unstable atherosclerotic plaques. FSAP is presumably involved in plaque stability and rupture. Reduced plasma concentration of FSAP may be associated with the development and expression of atherosclerosis and may thus contribute to precipitation of CHD. Here we address the potential influence of various HT regimens on plasma measures of FSAP in postmenopausal women treated for 1 year with different HT formulations or no HT. METHODS: Six groups of postmenopausal women (n = 139) were allocated to five different HT modalities or no HT. Samples were collected at baseline and after 12 months of treatment. Prototype assays were used for the determination of FSAP antigen and FSAP activity. RESULTS: The FSAP measures were comparable at baseline. No significant changes were observed in the control group after 12 months. HT in general induced a significant increase in FSAP antigen (7.7 microg/ml at baseline and 8.0 microg/ml after 12 months, p = 0.05), FSAP activity (1.54 PEU/ml at baseline and 1.68 PEU/ml after 12 months, p < 0.001) and FSAP ratio (202 mPEU/microg at baseline and 210 mPEU/microg after 12 months, p = 0.01). CONCLUSIONS: HT increases the plasma measures of FSAP. This increase may contribute to the protective effect on CHD induced by HT in younger postmenopausal women.

Effects of methylsulfonylmethane and neutralizing anti-IL-10 antibody supplementation during a mild Eimeria challenge infection in broiler chickens.

A 28-day experiment was conducted in broilers to study the effects of feeding methylsulfonylmethane (MSM) and IL-10-neutralizing antibody from dried egg product (DEP) on the growth performance, immune responsivity, oxidative stress parameters, and gut health outcomes during a mild infection with mixed species of Eimeria. A total of 500 male Ross 308 chicks were allocated to five treatments: sham-inoculated (uninfected) chickens fed control diet (UCON), Eimeria-infected chickens fed control diet (ICON), and Eimeria-infected chickens fed control diet supplemented with 287 U/tonne of DEP (I-DEP), 0.4% MSM, or their combination (I-DEP-MSM), with 10 replicate cages of 10 birds per treatment. All infected groups received 1 mL of an oral inoculum containing Eimeria acervulina (10,000 oocysts), Eimeria maxima (5,000 oocysts), and Eimeria tenella (5,000 oocysts) on study days 7 and 14. Data were analyzed as a two-way ANOVA for all treatments including Eimeria-infected groups, in addition to a single degree of freedom contrast to compare uninfected and infected groups receiving the control diet. Mild Eimeria infection did not influence the growth performance in ICON compared with UCON at any time points. Overall (day 0-28) growth performance parameters were not influenced by either infection or dietary supplementation of MSM or DEP. However, birds in I-DEP-MSM showed improved ADG during study day 7 to 14 (i.e., 7 d after primary inoculation) indicating a beneficial effect immediately after Eimeria infection. Although MSM supplementation reduced thiobarbituric acid reactive substances (day 21 and 28), both MSM and DEP improved the total antioxidant capacity (day 21) in the plasma of infected birds. Histopathological outcomes were not influenced by treatments, and fecal oocyst output was higher in MSM- and DEP-supplemented groups than with ICON, indicating no beneficial effects. Similarly, expression of cecal inflammatory cytokines (IL-10, IL-1ß, and interferon-γ) was not affected by MSM, DEP, or their combination. Overall, the current results suggest that both MSM and DEP supplementation may benefit birds during a mild Eimeria infection as indicated by improvements in ADG and oxidative stress outcomes.

Dietary supplementation with anti-IL-10 antibody during a severe Eimeria challenge in broiler chickens.

Attenuation of host IL-10 activity during Eimeria infection may elicit a robust Th1 response to eliminate the parasite from the gut epithelium. An experiment was conducted to study the effects of feeding IL-10 neutralizing antibody delivered via a dried egg product (DEP) on growth performance, immune responsivity, and gut health outcomes during a severe challenge with either Eimeria acervulina (study 1) or Eimeria tenella (study 2) following FDA CVM #217 protocol to test anticoccidial products. A total of 720 male Ross 308 chicks were used in each study, with 15 replicate cages of 12 birds and the following 4 treatments: sham-inoculated (uninfected) control diet (UCON), Eimeria-infected control diet (ICON), and Eimeria-infected control diet supplemented with DEP at 2 levels (165 [I-165] or 287 [I-287] U/tonne in study 1 and 143 [I-143] or 287 [I-287] U/tonne in study 2). Individual birds assigned to infected treatment groups received a single oral dose of either 200,000 E. acervulina (study 1) or 80,000 E. tenella (study 2) oocysts at 12 d of age (i.e., d post inoculation [DPI] 0), whereas uninfected birds were sham-inoculated with tap water. A one-way ANOVA was performed on outcomes including growth performance, hematology, serum chemistry profiles, immunophenotyping profiles, and intestinal lesion scores. In both studies, DPI 0 to 7 weight gain, feed intake, and feed conversion ratio were worse (P < 0.05) in all infected groups compared with the UCON group. Compared with ICON, DEP supplementation elicited no differences on overall growth performance. Histopathology and lesion scores revealed severe damage to the gut epithelium owing to the Eimeria challenge, yet DEP supplementation did not improve these outcomes or oocyst shedding, hematological measurements, or serum chemistry. However, DEP supplementation improved (P < 0.05) the percentage of circulating CD3+ cells at 6 DPI in study 2. These results indicate that DEP does not appear to elicit a coccidiostatic effect during a severe infection with E. acervulina or E. tenella.

Transmission of Salmonella between wildlife and meat-production animals in Denmark.

AIMS: To investigate the transmission of Salmonella spp. between production animals (pigs and cattle) and wildlife on production animal farms in Denmark. METHODS AND RESULTS: In the winter and summer of 2001 and 2002, 3622 samples were collected from Salmonella-infected and noninfected herds of pigs and cattle and surrounding wildlife. Salmonella was detected in wildlife on farms carrying Salmonella-positive production animals and only during the periods when Salmonella was detected in the production animals. The presence of Salmonella Typhimurium in wild birds significantly correlated to their migration pattern and food preference. CONCLUSIONS: Salmonella was transmitted from infected herds of production animals (cattle and pigs) to wildlife that lived amongst or in close proximity to them. SIGNIFICANCE AND IMPACT OF THE STUDY: Salmonella in animal food products is associated with the occurrence of Salmonella in primary animal production. Strategies to control the introduction and spread of infection should include wildlife management, as the nearby wildlife may act as reservoirs for Salmonella spp. and/or may be passive carriers of the bacteria.

The effect of continuous combined conjugated equine estrogen plus medroxyprogesterone acetate and tibolone on cardiovascular metabolic risk factors.

OBJECTIVES: Hormone treatment (HT) after the menopause affects lipid and carbohydrate metabolism and inflammation and may modify risk factors relevant for the clinical expression of the metabolic syndrome and cardiovascular disease. Tibolone has pharmacodynamic properties different from other hormone preparations. Here, we compare the effect of combined HT and tibolone on metabolic risk markers for the development of cardiovascular disease. METHODS: Postmenopausal women were randomly assigned to 1.25 or 2.5 mg/day of tibolone or oral continuous combined conjugated equine estrogen plus medroxyprogesterone acetate (CEE/MPA). Cardiovascular risk factors were determined at baseline and after 12 months of treatment. RESULTS: Body mass index and blood pressure were unaffected by the HT. HOMA-IR decreased in the CEE/MPA group (3.69 vs. 3.38; p = 0.02). Treatment with tibolone increased tissue-type plasminogen activator activity (0.87 IU/ml vs. 1.21 IU/ml; p = 0.005) and C-reactive protein (0.83 mg/l vs. 1.88 mg/l; p < 0.001), and decreased plasminogen activator inhibitor activity (6.9 IU/ml vs. 2.0 IU/ml; p < 0.001) and triglycerides (0.99 vs. 0.87 mmol/l; p = 0.004). Both treatments decreased total cholesterol significantly. CONCLUSIONS: CEE/MPA and tibolone have comparable effects on most metabolic risk factors investigated. The effect of tibolone on fibrinolysis and triglycerides suggests that tibolone has a favorable pharmacological profile on these risk factors when compared to CEE/MPA.

International collaborative study for the calibration of proposed International Standards for thromboplastin, rabbit, plain, and for thromboplastin, recombinant, human, plain.

Essentials Two candidate International Standards for thromboplastin (coded RBT/16 and rTF/16) are proposed. International Sensitivity Index (ISI) of proposed standards was assessed in a 20-centre study. The mean ISI for RBT/16 was 1.21 with a between-centre coefficient of variation of 4.6%. The mean ISI for rTF/16 was 1.11 with a between-centre coefficient of variation of 5.7%. SUMMARY: Background The availability of International Standards for thromboplastin is essential for the calibration of routine reagents and hence the calculation of the International Normalized Ratio (INR). Stocks of the current Fourth International Standards are running low. Candidate replacement materials have been prepared. This article describes the calibration of the proposed Fifth International Standards for thromboplastin, rabbit, plain (coded RBT/16) and for thromboplastin, recombinant, human, plain (coded rTF/16). Methods An international collaborative study was carried out for the assignment of International Sensitivity Indexes (ISIs) to the candidate materials, according to the World Health Organization (WHO) guidelines for thromboplastins and plasma used to control oral anticoagulant therapy with vitamin K antagonists. Results Results were obtained from 20 laboratories. In several cases, deviations from the ISI calibration model were observed, but the average INR deviation attributabled to the model was not greater than 10%. Only valid ISI assessments were used to calculate the mean ISI for each candidate. The mean ISI for RBT/16 was 1.21 (between-laboratory coefficient of variation [CV]: 4.6%), and the mean ISI for rTF/16 was 1.11 (between-laboratory CV: 5.7%). Conclusions The between-laboratory variation of the ISI for candidate material RBT/16 was similar to that of the Fourth International Standard (RBT/05), and the between-laboratory variation of the ISI for candidate material rTF/16 was slightly higher than that of the Fourth International Standard (rTF/09). The candidate materials have been accepted by WHO as the Fifth International Standards for thromboplastin, rabbit plain, and thromboplastin, recombinant, human, plain.

Comparison of local International Sensitivity Index calibration and 'Direct INR' methods in correction of locally reported International Normalized Ratios: an international study.

BACKGROUND: It is no longer feasible to check local International Normalized Ratios (INR) by the World Health Organization International Sensitivity Index (ISI) calibrations because the necessary manual prothrombin time technique required has generally been discarded. OBJECTIVES: An international collaborative study at 77 centers has compared local INR correction using the two alternative methods recommended in the Scientific and Standardization Committee of the International Society on Thrombosis and Haemostasis guidelines: local ISI calibration and 'Direct INR'. METHODS: Success of INR correction by local ISI calibration and with Direct INR was assessed with a set of 27 certified lyophilized plasmas (20 from patients on warfarin and seven from normals). RESULTS: At 49 centers using human thromboplastins, 3.0% initial average local INR deviation from certified INR was reduced by local ISI calibration to 0.7%, and at 25 centers using rabbit reagents, from 15.9% to 7.5%. With a minority of commercial thromboplastins, mainly 'combined' rabbit reagents, INR correction was not achieved by local ISI calibration. However, when rabbit combined reagents were excluded the overall mean INR deviation after correction was reduced further to 3.9%. In contrast, with Direct INR, mean deviation using human thromboplastins increased from 3.0% to 6.6%, but there was some reduction with rabbit reagents from 15.9% to 10% (12.3% with combined reagents excluded). CONCLUSIONS: Local ISI calibration gave INR correction for the majority of PT systems but failed at the small number using combined rabbit reagents suggesting a need for a combined reference thromboplastin. Direct INR correction was disappointing but better than local ISI calibration with combined rabbit reagents. Interlaboratory variability was improved by both procedures with human reagents only.

Genetic influence on thrombotic risk markers in the elderly--a Danish twin study.

OBJECTIVE: Several hemostatic variables are identified as cardiovascular risk markers. In young and middle-aged individuals, plasma concentrations of these variables are partly determined by genetic factors. The genetic contribution to cardiovascular disease (CVD) decreases with increasing age, and it is therefore important to determine the heritability of hemostasis also in the elderly. METHODS: The heritability of plasma levels of factor VII, fibrinogen, tissue factor, tissue factor pathway inhibitor, von Willebrand factor, thrombin activatable fibrinolysis inhibitor (TAFI), and D-dimer was determined in 130 monozygotic and 155 dizygotic same-sex twin pairs, aged 73-94 years, who participated in the Longitudinal Study of Aging of Danish Twins. Furthermore, we determined the influence of promoter polymorphisms in corresponding genes on the plasma level variation. RESULTS: Genetic factors accounted for 33% (D-dimer) to 71% (TAFI) of the variation in plasma levels. Polymorphisms were associated with concentrations of FVII and TAFI in sib-pair based analyses, but in linkage analyses the polymorphisms did not explain a significant part of the genetic variation for any of the variables. CONCLUSIONS: Concentrations of hemostatic variables have a substantial genetic variation in the elderly, but in this study the promoter polymorphisms only explained a minimal part of this variation.

Lack of hepatic metabolism of C-telopeptides of type I collagen.

BACKGROUND: Bone biochemical markers have been used in dynamic studies of bone metabolism, and, for accurate interpretation of measured marker levels, it is essential to have information of extra-skeletal metabolism. Therefore, the objective of the present study was to investigate if the circulating C-telopeptides of type I collagen (CTX) was subject to hepatic extraction. METHODS: Splanchnic plasma flow, total plasma volume and the plasma concentration of CTX was determined in an artery and the liver vein of eight healthy female volunteers. For comparison, the concentration of N-terminal propeptide of type I collagen, PINP, was measured. RESULTS: No change in plasma level of CTX could be detected over the liver. In contrast, PINP decreased from an average of 52.9 ng/ml in the artery to 42.4 ng/ml in the vein, corresponding to a 19.8% reduction. CONCLUSIONS: The C-telopeptides of type I collagen (CTX) are not subject to hepatic metabolism.

Depression of factor XII-dependent fibrinolytic activity characterizes patients with early myocardial reinfarction after recombinant tissue-type plasminogen activator therapy.

Twenty patients with acute myocardial infarction treated with recombinant tissue-type plasminogen activator (rt-PA) had endogenous factor XII-dependent fibrinolytic activity levels measured throughout the hospital period and those levels were prospectively correlated with the incidence of recurrent myocardial infarction until 8 weeks after hospital discharge. Within the follow-up period, recurrent myocardial infarction was observed in 8 patients, whereas the remaining 12 patients showed no clinical evidence of recurrence. The patients in the reinfarction group were characterized by a more pronounced depletion of and sustained lower levels of factor XII-dependent fibrinolytic activity than were the patients with no reinfarction (p less than 0.05). The decrease in fibrinolytic activity during rt-PA therapy was significantly associated with a depletion of functional alpha 2-antiplasmin, the primary plasmin inhibitor. These results indicate that, paradoxically, coronary thrombolysis with rt-PA involves depletion of endogenous factor XII-dependent fibrinolytic activity levels, which constitutes a risk for early myocardial reinfarction.

Long-lasting depression of the factor XII-dependent fibrinolytic system in patients with myocardial infarction undergoing thrombolytic therapy with recombinant tissue-type plasminogen activator: a randomized placebo-controlled study.

In a randomized placebo-controlled study, seven patients with acute myocardial infarction allocated to intravenous treatment with 100 mg of recombinant tissue-type plasminogen activator (rt-PA) and seven patients allocated to placebo were studied during eight sampling periods before and after treatment. Seven patients with acute myocardial infarction treated intravenously with 1.5 million U of streptokinase were later studied during two sampling periods before and after treatment. The placebo group showed no significant deviations of endogenous factor XII-dependent fibrinolytic activity (p greater than 0.05). In the rt-PA group, this activity decreased significantly (p less than 0.001) after the infusion and remained depressed throughout the 1st 4 days. A significant decrease in activity (p less than 0.05) was also found in the streptokinase-treated patients. The depletion of factor XII-dependent fibrinolytic activity was not due to generation of inhibition or a depletion of factor XII, prekallikrein and plasminogen, but could be related to the proactivator of this system. It is concluded that rt-PA (and streptokinase) treatment in patients with acute myocardial infarction causes a prolonged depletion of factor XII-dependent fibrinolytic activity. This depression of endogenous fibrinolytic activity needs to be evaluated in relation to the enhanced risk of coronary reocclusion after thrombolytic therapy.

European Concerted Action on Anticoagulation. A multicentre calibration study of WHO international reference preparations for thromboplastin, rabbit (RBT/90) and human (rTF/95).

A 10 centre calibration was performed after six years to determine the international sensitivity index (ISI) of rTF/95 relative to RBT/90, and to assess any international normalised ratio (INR) bias compared with the original multicentre calibration. After exclusion of one outlying centre, the follow up calibration gave a mean ISI for rTF/95 of 0.99, which although a small difference, is significantly greater than the mean ISI of 0.94 obtained previously. The change in ISI for international reference preparation (IRP) rTF/95 relative to RBT/90 would lead to a slight bias in INR for human compared with rabbit thromboplastins. At a theoretical INR of 3.0, the INR bias is 6.0%, and this is below the accepted 10% level of clinical relevance. Ongoing stability monitoring of World Health Organisation thromboplastin IRP is advised.

Report on the Dutch consensus development meeting for implementation and further development of population screening for colorectal cancer based on FOBT.

A consensus development meeting was held to evaluate whether or not in the Netherlands all requirements were fulfilled for implementation of population screening with FOBT for colorectal cancer, or whether consensus was present that fulfilment by additional research or organisational actions could be obtained within 2-3 years. There was consensus that all classical Wilson and Jungner (1968) criteria, and six additional ones added more recently, had already been fulfilled or could be fulfilled within 2-3 years. Consequently, it was concluded that a national population screening for colorectal cancer should be implemented and carried out in the Netherlands in line with current national and European cancer screening programmes. A list of organisational actions to be taken was established. Research that is needed before the actual national launch of the screening within 2-3 years has been defined. Priorities have to be set for research and organisational actions for the coming 2-3 years for the implementation of population screening. In addition, research suggestions have been defined for the next 10-15 years for evaluation and/or improvement of implemented FOBT screening, and for future screening methodology. It was considered essential that infrastructure for future research would be embedded in the screening programme. A project group to arrange this should be formed.

Dietary factor VII activation does not increase plasma concentrations of prothrombin fragment 1+2 in patients with stable angina pectoris and coronary atherosclerosis.

Studies in healthy subjects showed that blood coagulation factor VII (FVII) is activated postprandially after consumption of high-fat meals, but accompanying thrombin formation has not been demonstrated. In patients with coronary atherosclerosis, the arterial intima is supposed to present more tissue factor, the cofactor of FVII, to circulating blood; therefore, thrombin formation in response to FVII activation is more likely to occur in such patients. This hypothesis was tested in a randomized crossover study of 30 patients (aged 43 to 70 years) with stable angina pectoris and angiographically verified coronary atherosclerosis. They were served a low-fat (5% of energy from fat) breakfast and lunch and a high-fat (40% of energy from fat) breakfast and lunch on 2 different days. Venous blood samples were collected at 8:15 AM (fasting), 12:30 PM, 2:00 PM, 3:30 PM, and 4:45 PM and analyzed for triglycerides, activated FVII (FVIIa), FVII protein concentration (FVII:Ag), prothrombin fragment 1+2 (F1+2), and soluble fibrin. Triglyceride levels increased from fasting levels on both diets, but they increased most markedly on the high-fat diet. FVIIa and FVIIa/FVII:Ag increased with the high-fat diet and decreased with the low-fat diet. For both diets, FVII:Ag and F1+2 decreased slightly. No postprandial changes were observed for soluble fibrin. Postprandial mean values of triglycerides, FVIIa, FVII:Ag, and FVIIa/FVII:Ag were significantly higher for the high-fat diet than for the low-fat diet. Our findings confirm that high-fat meals cause immediate activation of FVII. The clinical implication is debatable because FVII activation was not accompanied by an increase in plasma F1+2 concentrations in patients with severe atherosclerosis. However, a local thrombin generation on the plaque surface cannot be excluded.

Scanning electron microscopy of foreleg tarsal sense organs of the poultry red mite, Dermanyssus gallinae (DeGeer) (Acari:Dermanyssidae).

Scanning electron microscopy (SEM) studies on the poultry red mite, Dermanyssus gallinae (DeGeer), showed that the tip of the foreleg tarsus of both sexes and early instar stages (larvae, protonymph and deutonymph) bears a cluster of 10 blunt peg-type sensillae. Diversity in size, shape and surface features of the wall of these sensillae characterize the sensilla complex (sensory field). Two short setae (1 and 2) with smooth walls lack detectable pores, whereas three medium-sized setae (4, 5 and 8) bear pores in the wall. Four medium or long setae (3, 6, 7 and 9) have longitudinal grooves or ribs in the wall, whilst one seta (10) possesses both pores and grooves in the wall. Based on the morphology, it is suggested that the porous setae could be olfactory receptors, and the grooved setae could be mechanoreceptors.