Neutrophil maturation rate determines the effects of dipeptidyl peptidase 1 inhibition on neutrophil serine protease activity.

BACKGROUND AND PURPOSE: Neutrophil serine proteases (NSPs) are activated by dipeptidyl peptidase 1 (DPP1) during neutrophil maturation. The effects of neutrophil turnover rate on NSP activity following DPP1 inhibition was studied in a rat pharmacokinetic/pharmacodynamic model. EXPERIMENTAL APPROACH: Rats were treated with a DPP1 inhibitor twice daily for up to 14 days; NSP activity was measured in onset or recovery studies, and an indirect response model was fitted to the data to estimate the turnover rate of the response. KEY RESULTS: Maximum NSP inhibition was achieved after 8 days of treatment and a reduction of around 75% NSP activity was achieved at 75% in vitro DPP1 inhibition. Both the rate of inhibition and recovery of NSP activity were consistent with a neutrophil turnover rate of between 4-6 days. Using human neutrophil turnover rate, it is predicted that maximum NSP inhibition following DPP1 inhibition takes around 20 days in human. CONCLUSIONS AND IMPLICATIONS: Following inhibition of DPP1 in the rat, the NSP activity was determined by the amount of DPP1 inhibition and the turnover of neutrophils and is thus supportive of the role of neutrophil maturation in the activation of NSPs. Clinical trials to monitor the effect of a DPP1 inhibitor on NSPs should take into account the delay in maximal response on the one hand as well as the potential delay in a return to baseline NSP levels following cessation of treatment.

Women's reproductive health factors and body adiposity: findings from the UK Biobank.

OBJECTIVE: To conduct a comprehensive examination of the association between women's reproductive health factors and measures of body adiposity in a contemporary Western population. METHODS: A cross-sectional analysis of 502 664 individuals from the UK Biobank was conducted. Multivariable linear regression models were used to examine the association of age at menarche, age at first birth, parity and age at menopause with measures of general and central body adiposity, adjusted for age, smoking and socioeconomic status. The association between number of children and body adiposity in men was also assessed. RESULTS: Age at menarche was inversely associated with body mass index (BMI); adjusted mean BMI was 29.0 kg m(-2) in women with menarche before the age of 12 years, compared with 26.5 kg m(-2) in those who had menarche after 14 years of age. Age at first birth was linearly and inversely associated with BMI: 0.16 kg m(-2) lower BMI per year increase in age of first birth. Each additional live birth or child fathered was associated with a 0.22 kg m(-2) higher BMI in women and a 0.14 kg m(-2) higher BMI in men. There was no evidence for an association between age at menopause and BMI. Corresponding associations for other markers of general or abdominal adiposity were similar to those for BMI. Findings were broadly similar in analyses stratified by age, smoking status, socioeconomic status, ethnic background, and history of diabetes or cardiovascular disease. CONCLUSIONS: In women from a contemporary Western population, earlier age at menarche and age at first birth, and higher number of total live births were associated with higher levels of body adiposity. Prospective evaluations of the association between reproductive health factors, adiposity and the onset of cardiometabolic diseases are needed to assess causality, and to explore the mechanisms involved.

Physiologically based pharmacokinetic modeling in drug discovery and development: a pharmaceutical industry perspective.

The application of physiologically based pharmacokinetic (PBPK) modeling has developed rapidly within the pharmaceutical industry and is becoming an integral part of drug discovery and development. In this study, we provide a cross pharmaceutical industry position on "how PBPK modeling can be applied in industry" focusing on the strategies for application of PBPK at different stages, an associated perspective on the confidence and challenges, as well as guidance on interacting with regulatory agencies and internal best practices.

Contribution of cardiorespiratory fitness, relative to traditional cardiovascular disease risk factors, to common carotid intima-media thickness.

BACKGROUND: Studies have suggested that being slightly overweight but fit is better for cardiovascular health than being somewhat leaner but unfit. Here, we sought to determine the contribution of cardiorespiratory fitness (CRF), relative to the presence of risk factors, to common carotid intima-media thickness (CIMT), a measurement of atherosclerosis and cardiovascular disease risk. METHODS: Data were analysed from a cohort of 7300 German employed individuals aged 46 (±7) years who participated in a preventive health check-up at a specialized prevention centre. In addition to traditional cardiovascular disease risk factor assessment, participants performed an exercise test with spirometry to exhaustion, and common CIMT was measured. Individuals were defined as being fit or unfit based on the median age- and sex-specific relative maximum oxygen consumption. RESULTS: In a multivariable analysis, there was a strong inverse association between CRF and common CIMT. Individuals who were considered fit and did not have any cardiovascular disease risk factors had the lowest common CIMT values (reference group). Those who were unfit and had an increased risk factor level always had the highest common CIMT values. Good CRF partly compensated for the increased common CIMT due to a risk factor. However, unfit individuals without increased risk factor levels had a common CIMT that was not significantly different from that of the reference group, whereas fit individuals who smoked, had a high body mass index, a low HDL cholesterol concentration or a high systolic blood pressure had an increase in common CIMT. CONCLUSION: Cardiorespiratory fitness is a major determinant of common CIMT. Improved CRF does slightly, but not completely, abolish the adverse consequences of cardiovascular disease risk factors on common CIMT.

The future in clinical genetics: affective forecasting biases in patient and clinician decision making.

When clinicians facilitate and patients make decisions about predictive genetic testing, they often base their choices on the predicted emotional consequences of positive and negative test results. Research from psychology and decision making suggests that such predictions may often be biased. Work on affective forecasting-predicting one's future emotional states-shows that people tend to overestimate the impact of (especially negative) emotional events on their well-being; a phenomenon termed the impact bias. In this article, we review the causes and consequences of the impact bias in medical decision making, with a focus on applying such findings to predictive testing in clinical genetics. We also recommend strategies for reducing the impact bias and consider the ethical and practical implications of doing so.

Common carotid intima-media thickness does not add to Framingham risk score in individuals with diabetes mellitus: the USE-IMT initiative.

AIMS/HYPOTHESIS: The aim of this work was to investigate whether measurement of the mean common carotid intima-media thickness (CIMT) improves cardiovascular risk prediction in individuals with diabetes. METHODS: We performed a subanalysis among 4,220 individuals with diabetes in a large ongoing individual participant data meta-analysis involving 56,194 subjects from 17 population-based cohorts worldwide. We first refitted the risk factors of the Framingham heart risk score on the individuals without previous cardiovascular disease (baseline model) and then expanded this model with the mean common CIMT (CIMT model). The absolute 10 year risk for developing a myocardial infarction or stroke was estimated from both models. In individuals with diabetes we compared discrimination and calibration of the two models. Reclassification of individuals with diabetes was based on allocation to another cardiovascular risk category when mean common CIMT was added. RESULTS: During a median follow-up of 8.7 years, 684 first-time cardiovascular events occurred among the population with diabetes. The C statistic was 0.67 for the Framingham model and 0.68 for the CIMT model. The absolute 10 year risk for developing a myocardial infarction or stroke was 16% in both models. There was no net reclassification improvement with the addition of mean common CIMT (1.7%; 95% CI -1.8, 3.8). There were no differences in the results between men and women. CONCLUSIONS/INTERPRETATION: There is no improvement in risk prediction in individuals with diabetes when measurement of the mean common CIMT is added to the Framingham risk score. Therefore, this measurement is not recommended for improving individual cardiovascular risk stratification in individuals with diabetes.

Fetal growth profiles of macrosomic and non-macrosomic infants of women with pregestational or gestational diabetes.

OBJECTIVE: To assess fetal growth profiles in an unselected group of pregnant women with either type-1 diabetes (DM1), type-2 diabetes (DM2) or gestational diabetes (GDM), with emphasis on intergroup differences and development of disproportionate fetal growth and macrosomia. METHODS: Second- and third-trimester longitudinal ultrasound measurements of fetal growth were made in 77 women with DM1, 68 women with DM2 and in 99 women with GDM. Altogether 897 ultrasound examinations were performed and 145 uncomplicated pregnancies with 843 ultrasound examinations were included as controls. Ultrasound data included head circumference (HC), abdominal circumference (AC), femur length (FL) and HC/AC ratio. RESULTS: The AC, but not HC and FL, evolved differently in diabetic pregnancies, with a smaller AC in early pregnancy and larger AC at term (significant for DM1 and DM2). The most striking differences were found for the HC/AC ratio, especially in DM1 pregnancies. HC/AC growth trajectories of both macrosomic and non-macrosomic fetuses differed from that of the controls, and the HC/AC ratio at term was lower in all diabetic subgroups except in non-macrosomic DM2 cases. CONCLUSION: We found altered (disproportionate) fetal growth in macrosomic and non-macrosomic fetuses of women with DM1, DM2 and GDM. This indicates that the abnormal intrauterine environment affects the majority of these infants. Growth profiles differed among these groups, the most prominent growth deviations being found in the fetuses of women with DM1. The latter was most probably caused by poor glucose control. In monitoring fetal growth in diabetic pregnancies the HC/AC ratio should be used to assess altered fetal growth.

Manual or semi-automated edge detection of the maximal far wall common carotid intima-media thickness: a direct comparison.

BACKGROUND: Automated edge detection is thought to be superior to manual edge detection in quantification of the far wall common carotid intima-media thickness (CIMT), yet published evidence making a direct comparison is not available. METHODS: Data were used from the METEOR study, a randomized placebo-controlled trial among 984 individuals showing that rosuvastatin attenuated the rate of change of 2 year change in CIMT among low-risk individuals with subclinical atherosclerosis. For this post hoc analysis, CIMT images of the far wall of the common carotid artery were evaluated using manual and semi-automated edge detection and reproducibility, relation to cardiovascular risk factors, rates of change over time and effects of lipid-lowering therapy were assessed. RESULTS: Reproducibility was high for both reading methods. Direction, magnitude and statistical significance of risk factor relations were similar across methods. Rate of change in CIMT in participants assigned to placebo was 0.0066 mm per year (SE: 0.0027) for manually and 0.0072 mm per year (SE: 0.0029) for semi-automatically read images. The effect of lipid-lowering therapy on CIMT changes was -0.0103 mm per year (SE: 0.0032) for manual reading and -0.0111 mm per year (SE: 0.0034) for semi-automated reading. CONCLUSION: Manual and semi-automated readings of the maximal far wall of the common CIMT images both result in high reproducibility, show similar risk factor relations, rates of change and treatment effects. Hence, choices between semi-automated and manual reading software for CIMT studies likely should be based on logistical and cost considerations rather than differences in expected data quality when the choice is made to use far wall common CIMT measurements.

Increased age, high body mass index and low HDL-C levels are related to an echolucent carotid intima-media: the METEOR study.

INTRODUCTION: Echolucent plaques are related to a higher cardiovascular risk. Studies to investigate the relationship between echolucency and cardiovascular risk in the early stages of atherosclerosis are limited. We studied the relationship between cardiovascular risk factors and echolucency of the carotid intima-media in low-risk individuals. METHODS: Data were analysed from the Measuring Effects on Intima-Media Thickness: an Evaluation of Rosuvastatin (METEOR) study, a randomized placebo-controlled trial including 984 individuals which showed that rosuvastatin attenuated the rate of change of carotid intima-media thickness (CIMT). In this post hoc analysis, duplicate baseline ultrasound images from the far wall of the left and right common carotid arteries were used for the evaluation of the echolucency of the carotid intima-media, measured by grey-scale median (GSM) on a scale of 0-256. Low GSM values reflect echolucent, whereas high values reflect echogenic structures. The relationship between baseline GSM and cardiovascular risk factors was evaluated using linear regression models. RESULTS: Mean baseline GSM (± SD) was 84 ± 29. Lower GSM of the carotid intima-media was associated with older age, high body mass index (BMI) and low levels of high-density lipoprotein cholesterol (HDL-C) [beta -4.49, 95% confidence interval (CI) -6.50 to -2.49; beta -4.51, 95% CI -6.43 to -2.60; beta 2.45, 95% CI 0.47 to 4.42, respectively]. Common CIMT was inversely related to GSM of the carotid intima-media (beta -3.94, 95% CI -1.98 to -5.89). CONCLUSION: Older age, high BMI and low levels of HDL-C are related to echolucency of the carotid intima-media. Hence, echolucency of the carotid intima-media may be used as a marker of cardiovascular risk profile to provide more information than thickness alone.

C-reactive protein lowering with rosuvastatin in the METEOR study.

OBJECTIVES: In addition to its LDL-C-lowering effects, statin treatment reduces the level of C-reactive protein (CRP). Long-term data on this effect in low-risk populations are limited. Furthermore, whether the CRP reduction is a consequence of LDL-C lowering or occurs independently remains unclear. We studied these aspects in the Measuring Effects on intima media Thickness: an Evaluation Of Rosuvastatin (METEOR) study, a randomized placebo-controlled trial amongst 984 low-risk subjects. METHODS: METEOR is a randomized placebo-controlled trial that evaluated the effect of 40 mg of rosuvastatin on 2-year change in carotid intima media thickness (CIMT) amongst 984 low-risk patients (10-year Framingham risk < 10%) with modest CIMT (CIMT > or = 1.2 and < 3.5 mm) and elevated LDL-C. CRP levels were measured at baseline and after 2 years of treatment. RESULTS: Median baseline CRP was 1.4 mg L(-1). Rosuvastatin lowered CRP significantly compared with placebo: -36% in the rosuvastatin group versus no change in the placebo group. There was no relation between change in CRP and change in LDL-C (Spearman correlation: 0.08; SE: 0.04). Stratified analyses showed that the CRP-lowering effect was present amongst all strata of baseline characteristics, including baseline lipids and CRP levels. However, the magnitude of CRP reduction was larger amongst women and participants older than 60 years. CONCLUSIONS: Rosuvastatin (40 mg) lowers CRP independently from its effects on LDL-C in low-risk subjects with normal baseline CRP levels and modest CIMT.

[Muscular magnetic resonance imaging for evaluation of myopathies in children]. / Myopathien im Kindesalter - Evaluation mittels Kernspintomografie der Muskulatur.

BACKGROUND: Myopathies present with a broad diagnostic spectrum which may ultimately require muscle biopsy. MRI has been established as a non-invasive method in diagnosing adult myopathies; not only does MRI reveal characteristic findings which point in a diagnostic direction, but also aids in determining optimal biopsy sites and controlling therapeutic interventions. Muscle MRI is increasingly finding application to pediatric myopathies, especially dystrophies and myositides. The following paper serves to illustrate the use of MRI using exemplary clinical vignettes. PATIENTS/METHODS: From 1999 until 2006, 180 children with myopathies of unknown aetiology, ages 10 months to 18 years, were examined with a standardised MRI protocol (axial T1-SE and T2-weighted TIRM sequences). The protocol included imaging of the lower extremities whereas sequences displaying the upper extremities were only acquired in selected patients. Furthermore, intravenous contrast agent was only administered in selected children. RESULTS: All investigations could be performed without sedation due to an examination time of 12 to 15 minutes. The illustrated cases of limb-girdle muscular dystrophy, Duchenne's muscular dystrophy, dermatomyositis, pyomyositis, and chronic neurogenic disease with secondary myopathy all showed disease-characteristic MRI patterns which substantially helped to reach the ultimate diagnosis. CONCLUSIONS: Muscle MRI is a non-invasive and effective instrument in helping to diagnose pediatric myopathies of unknown aetiology. It may facilitate muscle biopsy and serves to control therapeutical effects and disease course. Furthermore, muscle MRI may be applicated even to children of less than 4 years of age without sedation.

Giant arachnoid granulation: differential diagnosis of acute headache.

We present a case of intense, rapidly evolving headache clinically mimicking meningitis, subarachnoid haemorrhage or venous sinus thrombosis. Clinical examination, standard blood work and central nervous system studies were non-contributory and effectively ruled out these diagnoses. Cranial multidetector CT studies before and after application of intravenous contrast medium performed prior to lumbar tap disclosed a non-enhancing ovoid mass filling the superior sagittal sinus. This lesion posed a differential to venous sinus thrombosis, but ultimately fulfilled the criteria of a giant arachnoid granulation. The imaging characteristics and differential diagnosis of giant arachnoid granulations are discussed.

The predictive value of total serum IgE for a positive allergen specific IgE result.

BACKGROUND: Measurement of total serum IgE and allergen specific IgE is often requested to assess possible allergy. As public awareness increases, so do requests for allergy assessment; unless there is a clear "allergen suspect" in the history, several allergen specific IgE requests may be made. This increases the likelihood of detecting borderline increases in allergen specific IgE of uncertain relevance, and has important cost implications for the service. AIMS: To provide an evidence base for this observation. METHODS: In this retrospective observational study, results from 301 patients under 16 years of age from whom blood was taken for "allergy testing" from March 2001 to February 2003 were studied. RESULTS: Allergen specific IgE testing in children with low total serum IgE concentrations (<10 IU/litre) yielded very few positive results (three of 73 children), except in those being investigated for an acute reaction to a single food; when IgE was 11-20 kU/litre, 13 of 73 children had positive allergen specific IgE; in the 21-40 kU/litre IgE group, 16 of 74 children had positive allergen specific IgE and in the 41-80 kU/litre group, 22 of 81 had positive allergen specific IgE. CONCLUSIONS: Allergen specific IgE testing in children with low IgE concentrations (<10 kU/litre) produces few positive results in patients with non-specific symptoms. Laboratories should perform allergy testing for specific allergens regardless of total IgE concentration only when there are convincing clinical reasons to do so, and should not proceed with this if the total IgE is <10 kU/litre and the presenting symptoms are non-specific.

Fits, pyridoxine, and hyperprolinaemia type II.

The rare inherited disorder hyperprolinaemia type II presents with fits in childhood, usually precipitated by infection. A diagnosis of hyperprolinaemia type II and vitamin B(6) deficiency was made in a well nourished child with fits. It is thought that pyridoxine deficiency was implicated in her fits and was the result of inactivation of the vitamin by the proline metabolite, pyrroline-5-carboxylate.

The contribution of risk factors to the effect of early otitis media with effusion on later language, reading, and spelling.

A cohort of 946 children who were screened for otitis media with effusion (OME) from the ages of 2 to 4 were studied for language, reading, and spelling at 7 years of age. The effects of OME in combination with single risk factors and with increasing numbers of risk factors were investigated. An interaction with an additional risk factor was found only for gender and OME, with boys' spelling influenced negatively by a history of OME. OME in combination with preterm birth and low birthweight also appears to put children at risk for later language and educational problems. Although a negative linear relation between the number of risk factors and later functioning was found, it is suggested that OME, even when combined with a number of other risk factors, produces only minor effects on later language, reading, and spelling.

Vitamin E supplementation in cystic fibrosis.

Vitamin E is an antioxidant and may have a role in the protection of lung tissue against oxidative damage in cystic fibrosis. Previous studies of vitamin E status in cystic fibrosis have used plasma or serum concentrations, which vary with levels of carrier lipoproteins and hence may not reflect the concentration of vitamin E in tissues, where it is found in highest concentration in membranes. Erythrocyte vitamin E concentration has been shown to correlate well with tissue concentrations of the vitamin in animals, but it has not previously been studied in patients with cystic fibrosis. Current guidelines on vitamin supplementation in cystic fibrosis include vitamin E. It is not presently clear which level of supplementation is most appropriate. To address this question, we examined the effect on erythrocyte vitamin E levels of supplementation with either 15 mg or 100 mg per day of vitamin E. Analysis was performed by high performance liquid chromatography before and 1 year after initiation of supplementation in children with cystic fibrosis. Erythrocyte vitamin E concentrations were below the normal range in almost all unsupplemented patients and rose into the normal range with a supplement of 100 mg per day, but not 15 mg per day. This rise was not accounted for by changes in general dietary treatment. We conclude that tissue vitamin E levels are low in patients with cystic fibrosis who do not receive supplements but can be normalized in most children with 100 mg of vitamin E. per day.

The cowpea mosaic virus RNA 1-encoded 112 kDa protein may function as a VPg precursor in vivo.

Processing of the 112 kDa ('112K') protein encoded by cowpea mosaic virus RNA 1 was examined in cowpea mesophyll protoplasts using a transient expression system. Cleavage of the 112K protein occurred via two alternative pathways either into VPg and 110K (24K + 87K) or into 26K (VPg + 24K) and 87K proteins. The 26K protein can be further cleaved into VPg and 24K proteins. The results support a model in which the 112K protein functions as the precursor of VPg during initiation of replication.

The NTP-binding motif in cowpea mosaic virus B polyprotein is essential for viral replication.

We have assessed the functional importance of the NTP-binding motif (NTBM) in the cowpea mosaic virus (CPMV) B-RNA-encoded 58K domain by changing two conserved amino acids within the consensus A and B sites (GKSRTGK500S and MDD545, respectively). Both Lys-500 to Thr and Asp-545 to Pro substitutions are lethal as mutant B-RNAs were no longer replicated in cowpea protoplasts. Transiently produced mutant proteins were not able to support trans-replication of CPMV M-RNA in cowpea protoplasts in contrast to transiently produced wild-type B proteins. Therefore loss of viral RNA synthesis was a result of a protein defect rather than an RNA template defect. Mutant B polyproteins were correctly processed in vitro and in vivo and the regulatory function of the 32K protein on processing of B proteins was not affected by these mutations. Since regulation of processing by the 32K protein depends on interaction with the 58K domain, the mutations in the NTBM apparently do not interfere with this interaction. The Asp-545 to Pro substitution left intact the binding properties of the 84K precursor of the 58K protein, with respect to ATP-agarose, whereas the Lys-500 to Thr substitution decreased the binding capacity of the 84K protein, suggesting that the Lys-500 residue is directly involved in ATP binding. The Lys-500 to Thr substitution in the 58K domain resulted in an altered distribution of viral proteins, which failed to aggregate into large cytopathic structures as observed in protoplasts infected with wild-type B-RNA. However viral proteins containing the Asp-545 to Pro substitution showed a normal distribution in protoplasts.