Quantitative CT analysis using functional imaging is superior in describing disease progression in idiopathic pulmonary fibrosis compared to forced vital capacity.

BACKGROUND: Idiopathic pulmonary fibrosis (IPF) is chronic fibrosing pneumonia with an unpredictable natural disease history. Functional respiratory imaging (FRI) has potential to better characterize this disease. The aim of this study was to identify FRI parameters, which predict FVC decline in patients with IPF. METHODS: An IPF-cohort (treated with pamrevlumab for 48 weeks) was retrospectively studied using FRI. Serial CT's were compared from 66 subjects. Post-hoc analysis was performed using FRI, FVC and mixed effects models. RESULTS: Lung volumes, determined by FRI, correlated with FVC (lower lung volumes with lower FVC) (R2 = 0.61, p < 0.001). A negative correlation was observed between specific image based airway radius (siRADaw) at total lung capacity (TLC) and FVC (R2 = 0.18, p < 0.001). Changes in FVC correlated significantly with changes in lung volumes (R2 = 0.18, p < 0.001) and siRADaw (R2 = 0.15, p = 0.002) at week 24 and 48, with siRADaw being more sensitive to change than FVC. Loss in lobe volumes (R2 = 0.33, p < 0.001), increasing fibrotic tissue (R2 = 0.33, p < 0.001) and airway radius (R2 = 0.28, p < 0.001) at TLC correlated with changes in FVC but these changes already occur in the lower lobes when FVC is still considered normal. CONCLUSION: This study indicates that FRI is a superior tool than FVC in capturing of early and clinically relevant, disease progression in a regional manner.

Hepatic Changes in the Fontan Circulation: Identification of Liver Dysfunction and an Attempt to Streamline Follow-up Screening.

We tried to identify structural and functional liver aberrances in a palliated Fontan population and sought to determine useful screening modalities, in order to propose a screening protocol to detect patients at risk. Twenty nine patients, median age 23.7 years (interquartile range (IQR) 20.5-27.2) and median Fontan interval 19.7 years (IQR 4.5-21.4), were prospectively studied with echocardiography, blood analysis (including serum fibrosis scores Forns, APRI and FIB4), liver imaging (ultrasound (US), Doppler), and shear wave elastography to determine liver stiffness (LS). Laboratory tests predominantly showed abnormal values for gamma-glutamyltransferase. Forns index indicated moderate fibrosis in 29% of patients and correlated with Fontan interval (p = 0.034). US liver morphology was deviant in 46% of patients, with surface nodularity in 21% and nodular hyperplasia in 29%. Doppler assessment of flow velocities was within normal ranges for most patients. LS (mean 10.4 ± 3.7 kPa) was elevated in 96% of our population and higher LS values were significantly related to longer Fontan interval (p = 0.018). Adolescent and adult Fontan patients show moderate signs of liver dysfunction. Usefulness of serum parameters and fibrosis scores in post-Fontan screening remains ambiguous. The high percentage of morphologic liver changes in palliated patients supports the use of US in periodic follow-up. LS likely overestimates fibrosis due to liver congestion, arguing for the need of validation through sequential measurements. Screening should minimally encompass US assessment in combination with selective liver fibrosis scores. The role of LS measurement in Fontan follow-up and liver screening needs to be further elucidated.

[Music therapy and depression]. / Muziektherapie bij depressie.

BACKGROUND: Music therapy is a predominantly non-verbal psychotherapy based on music improvisation, embedded in a therapeutic relationship. This is the reason why music therapy is also used to treat depression. AIM: To examine the efficacy of music therapy and to report on the results of recent research into the value of music therapy as a treatment for depression. METHOD: We reviewed the literature on recent research into music therapy and depression, reporting on the methods used and the results achieved, and we assessed the current position of music therapy for depression in the context of evidence-based scientific research. RESULTS: A wide variety of research methods was used to investigate the effects of using music therapy as a psychotherapy. Most studies focused usually on the added value that music therapy brings to the standard form of psychiatric treatment, when administered with or without psychopharmacological support. Music therapy produced particularly significant and favourable results when used to treat patients with depression. CONCLUSION: Current research into music therapy and depression points to a significant and persistent reduction in patients' symptoms and to improvements in their quality of life. However, further research is needed with regard to the best methods of illustrating the effects of music therapy.

The new Ghent criteria for Marfan syndrome: what do they change?

The diagnosis of Marfan syndrome (MFS) is challenging and international criteria have been proposed. The 1996 Ghent criteria were adopted worldwide, but new diagnostic criteria for MFS were released in 2010, giving more weight to aortic root aneurysm and ectopia lentis. We aimed to compare the diagnosis reached by applying this new nosology vs the Ghent nosology in a well-known series of 1009 probands defined by the presence of an FBN1 mutation. A total of 842 patients could be classified as MFS according to the new nosology (83%) as compared to 894 (89%) according to the 1996 Ghent criteria. The remaining 17% would be classified as ectopia lentis syndrome (ELS), mitral valve prolapse syndrome or mitral valve, aorta, skeleton and skin (MASS) syndrome, or potential MFS in patients aged less than 20 years. Taking into account the median age at last follow-up (29 years), the possibility has to be considered that these patients would go on to develop classic MFS with time. Although the number of patients for a given diagnosis differed only slightly, the new nosology led to a different diagnosis in 15% of cases. Indeed, 10% of MFS patients were reclassified as ELS or MASS in the absence of aortic dilatation; conversely, 5% were reclassified as MFS in the presence of aortic dilatation. The nosology is easier to apply because the systemic score is helpful to reach the diagnosis of MFS only in a minority of patients. Diagnostic criteria should be a flexible and dynamic tool so that reclassification of patients with alternative diagnosis is possible, requiring regular clinical and aortic follow-up.

Pathogenic FBN1 mutations in 146 adults not meeting clinical diagnostic criteria for Marfan syndrome: further delineation of type 1 fibrillinopathies and focus on patients with an isolated major criterion.

Mutations in the FBN1 gene cause Marfan syndrome (MFS) and have been associated with a wide range of milder overlapping phenotypes. A proportion of patients carrying a FBN1 mutation does not meet diagnostic criteria for MFS, and are diagnosed with "other type I fibrillinopathy." In order to better describe this entity, we analyzed a subgroup of 146 out of 689 adult propositi with incomplete "clinical" international criteria (Ghent nosology) from a large collaborative international study including 1,009 propositi with a pathogenic FBN1 mutation. We focused on patients with only one major clinical criterion, [including isolated ectopia lentis (EL; 12 patients), isolated ascending aortic dilatation (17 patients), and isolated major skeletal manifestations (1 patient)] or with no major criterion but only minor criteria in 1 or more organ systems (16 patients). At least one component of the Ghent nosology, insufficient alone to make a minor criterion, was found in the majority of patients with isolated ascending aortic dilatation and isolated EL. In patients with isolated EL, missense mutations involving a cysteine were predominant, mutations in exons 24-32 were underrepresented, and no mutations leading to a premature truncation were found. Studies of recurrent mutations and affected family members of propositi with only one major clinical criterion argue for a clinical continuum between such phenotypes and classical MFS. Using strict definitions, we conclude that patients with FBN1 mutation and only one major clinical criterion or with only minor clinical criteria of one or more organ system do exist but represent only 5% of the adult cohort.

Contribution of molecular analyses in diagnosing Marfan syndrome and type I fibrillinopathies: an international study of 1009 probands.

BACKGROUND: The diagnosis of Marfan syndrome (MFS) is usually initially based on clinical criteria according to the number of major and minor systems affected following international nosology. The number of FBN1 mutation carriers, at risk of aortic complications who would not be properly diagnosed based only on clinical grounds, is of growing importance owing to the increased availability of molecular screening. The aim of the study was to identify patients who should be considered for FBN1 mutation screening. METHODS: Our international series included 1009 probands with a known FBN1 mutation. Patients were classified as either fulfilling or not fulfilling "clinical" criteria. In patients with unfulfilled "clinical" criteria, we evaluated the percentage of additional patients who became positive for international criteria when the FBN1 mutation was considered. The aortic risk was evaluated and compared in patients fulfilling or not fulfilling the "clinical" international criteria. RESULTS: Diagnosis of MFS was possible on clinical grounds in 79% of the adults, whereas 90% fulfilled the international criteria when including the FBN1 mutation. Corresponding figures for children were 56% and 85%, respectively. Aortic dilatation occurred later in adults with unfulfilled "clinical criteria" when compared to the Marfan syndrome group (44% vs 73% at 40 years, p<0.001), but the lifelong risk for ascending aortic dissection or surgery was not significantly different in both groups. CONCLUSIONS: Because of its implications for aortic follow-up, FBN1 molecular analysis is recommended in newly suspected MFS when two systems are involved with at least one major system affected. This is of utmost importance in patients without aortic dilatation and in children.

Cardiovascular characteristics in Marfan syndrome and their relation to the genotype.

Marfan syndrome (MFS) is a systemic disorder of connective tissue with autosomal dominant inheritance. The diagnosis of MFS is based on the identification of a combination of clinical manifestations in the ocular, musculoskeletal, and cardiovascular organ systems defined in the Ghent Nosology (De Paepe et al, 1996). Confirmation of the diagnosis in an individual requires the presence of major clinical manifestations in at least two organ systems associated with involvement of a third organ system. In relatives of an affected proband, major involvement of one organ system and involvement of a second organ system confirms the diagnosis. Major clinical criteria are very specific for MFS and include a combination of (4 out of 8) skeletal manifestations, ectopia lentis, dural ectasia and dilatation or dissection of the ascending aorta. The prevalence of- and the guidelines for the assessment of each of these major criteria are well established. Minor clinical criteria are less typical, but their importance in the diagnostic process should not be underestimated. Unfortunately, figures on the prevalence as well as practical guidelines for the assessment of most minor criteria are lacking, especially for those involving the cardiovascular system. The major cardiovascular manifestation in MFS is a progressive dilatation of the ascending aorta, leading to aortic aneurysm formation and eventually to fatal aortic rupture or dissection. Aortic dissection in early adult life is the leading cause of death in MFS. Early diagnosis of individuals at risk of the disease is extremely important as timely treatment of cardiovascular complications has greatly improved life expectancy in MFS. Despite progress in medical and surgical treatment of aortic aneurysms, MFS continues to be associated with significant morbidity and mortality. This may be related to inadequate diagnosis or treatment, but also to the occurrence of cardiovascular problems in ageing MFS patients that were unrecognised until now, such as left ventricular (LV) dysfunction.This thesis is focused on the study of cardiovascular manifestations of MFS which localize beyond the aortic root and on the presently unknown relationship between the severity of the cardiovascular phenotype and the genotype. In the first part, we have studied the prevalence and diagnostic value of the following cardiovascular manifestations of MFS: mitral valve prolapse (MVP) and calcification of the mitral valve annulus, dilatation of the main pulmonary artery (MPA) and dilatation or dissection of the descending aorta. We found a significantly higher prevalence of MVP in MFS patients compared to normal controls, indicating that this feature is useful in the diagnostic evaluation of the condition. In contrast, calcification of the mitral valve annulus appears to be very uncommon, difficult to quantify and therefore not useful in the diagnosis of MFS. We also studied the dimension of the MPA in a series of MFS patients and defined a cut-of value that can be used in the diagnostic evaluation of adult MFS patients. In addition, we showed that diameters of the aorta measured at different levels beyond the aortic root are increased in MFS patients compared to controls. Unfortunately, there was too much overlap with the values obtained in the normal control population to provide cut-off values for the descending aorta. Based on these findings, we developed practical guidelines for the cardiovascular evaluation of patients referred for MFS. In the second part, we studied LV function in MFS patients free of valvular heart disease using a combination of echocardiography (both conventional echocardiography and tissue Doppler imaging) and Magnetic Resonance Imaging. We could demonstrate that MFS patients present a combination of systolic and diastolic dysfunction that is not related to valvular heart disease. This may be attributed to a primary contractile dysfunction of the myocardium and is likely related to the underlying alterations in the elastic features of the myocardium, resulting from the microfibrillar defect. This observation is important in the development of new therapeutic strategies for MFS. Affected individuals may benefit from a treatment with agents that support myocardial function such as angiotensin converting enzyme--inhibitors or angiotensin II type-1 receptor blockers. Furthermore, since MFS patients survive longer thanks to improved medical and surgical treatments, LV dysfunction may become an important issue in the follow-up of these patients. In the third part, we have studied aspects of local and global wave reflection in the aorta of MFS patients. Early return of reflected waves boosts systolic pressure and presents an extra load for the heart and the central vessels. As such, these wave reflections are regarded as one of the important determinants of central blood pressure and can contribute to the development of aortic dilatation in MFS. However, we were unable to demonstrate clear differences in both local and global parameters of wave reflection between MFS patients and normal controls. This could be explained by the fact that increased length of the aorta on the one hand and increased aortic stiffness on the other hand counterbalance each other in MFS patients without yielding any net effect on wave reflection. In the last part of this thesis, we investigated the correlation between the severity of the cardiovascular phenotype in MFS and the type of FBN1 mutation. First, we investigated the correlation between parameters of aortic stiffness (distensibility and pulse wave velocity measured by Magnetic Resonance Imaging) and the type of FBN1 mutation (missense or in-frame deletions/insertions versus nonsense or out-of-frame deletions/insertions). We could not demonstrate any significant differences between these different mutation types, indicating that the FBN1 genotype is not the sole determinant of aortic stiffness. Second, we provided a detailed description of clinical findings in three unrelated MFS families in which an FBN1 mutation was identified and which demonstrate striking intrafamilial phenotypic variability as another illustration of the absence of genotype/phenotype correlations in MFS. This study also illustrated several important issues in MFS. First, repeated clinical examination of suspected patients can be necessary in order to establish a correct and final diagnosis. Second, extensive family history taking and clinical examination of first degree relatives can be highly contributory to the diagnosis. Third, patients with an 'atypical' MFS phenotype may show substantial clinical overlap with other connective tissue disorders such as Weill-Marchesani syndrome or Ehlers-Danlos syndrome and represent a diagnostic challenge. We demonstrated that additional mutational analysis of the FBN1 gene can be a valuable aid to the diagnosis and help to outline medical management options in these challenging cases. In conclusion, we have refined diagnostic guidelines for the assessment of minor cardiovascular manifestations in MFS, shown that LV dysfunction is part of the cardiovascular spectrum and should be followed in the management of MFS patients, and demonstrated that aortic wave reflection is not elevated in MFS. In this work, we also investigated genotype/phenotype correlations, illustrated the marked (intrafamilial) variability in phenotypic expression of the condition, and the value of molecular testing in the diagnosis of MFS. Overall, this thesis nicely illustrates that close interaction and collaboration between cardiology and genetics is an added value to the study of disease pathogenesis of MFS and aortic aneurysms in general.

Absence of arterial phenotype in mice with homozygous slc2A10 missense substitutions.

Arterial tortuosity syndrome (ATS, MIM# 208050) is a rare autosomal recessive connective tissue disease, mainly characterized by widespread arterial involvement with elongation, tortuosity, and aneurysms of the large and middle-sized arteries (Callewaert et al., 2008, Hum Mutat 29:150-158). Recently, mutations were identified in the SLC2A10 gene encoding the facilitative glucose transporter GLUT10 (Coucke et al., 2006, Nat Genet 38:452-457). It was hypothesized that loss-of-function of the transporter results in upregulation of the transforming growth factor beta (TGFbeta) signaling pathway (Coucke et al., 2006, Nat Genet 38:452-457). We anticipated that a mouse model would help to gain more insight in the complex pathophysiological mechanism of human ATS. Here, we report that two mouse models, homozygous respectively for G128E and S150F missense substitutions in glut10 do not present any of the vascular, anatomical, or immunohistological abnormalities as encountered in human ATS patients. We conclude that these mouse strains do not phenocopy human ATS and cannot help the further elucidation of pathogenetic mechanisms underlying this disease.

Arterial tortuosity syndrome: clinical and molecular findings in 12 newly identified families.

Arterial tortuosity syndrome (ATS) is a rare autosomal recessive connective tissue disease, characterized by widespread arterial involvement with elongation, tortuosity, and aneurysms of the large and middle-sized arteries. Recently, SLC2A10 mutations were identified in this condition. This gene encodes the glucose transporter GLUT10 and was previously suggested as a candidate gene for diabetes mellitus type 2. A total of 12 newly identified ATS families with 16 affected individuals were clinically and molecularly characterized. In addition, extensive cardiovascular imaging and glucose tolerance tests were performed in both patients and heterozygous carriers. All 16 patients harbor biallelic SLC2A10 mutations of which nine are novel (six missense, three truncating mutations, including a large deletion). Haplotype analysis suggests founder effects for all five recurrent mutations. Remarkably, patients were significantly older than those previously reported in the literature (P=0.04). Only one affected relative died, most likely of an unrelated cause. Although the natural history of ATS in this series was less severe than previously reported, it does indicate a risk for ischemic events. Two patients initially presented with stroke, respectively at age 8 months and 23 years. Tortuosity of the aorta or large arteries was invariably present. Two adult probands (aged 23 and 35 years) had aortic root dilation, seven patients had localized arterial stenoses, and five had long stenotic stretches of the aorta. Heterozygous carriers did not show any vascular anomalies. Glucose metabolism was normal in six patients and eight heterozygous individuals of five families. As such, overt diabetes is not related to SLC2A10 mutations associated with ATS.

Translocation of the insulin-regulated aminopeptidase to the cell surface: detection by radioligand binding.

BACKGROUND AND PURPOSE: Insulin-regulated aminopeptidase (IRAP) and the insulin-dependent glucose transporter GLUT4 colocalize in specific intracellular vesicles (that is, GLUT4 vesicles). These vesicles move slowly to the cell surface, but their translocation is markedly enhanced by insulin, resulting in higher glucose uptake. Previous studies of the insulin-mediated translocation of IRAP to the cell surface have been hampered by the laborious detection of IRAP at the cell surface. We aimed to develop a more direct and faster method to detect IRAP. To this end, we used model systems with well-characterized IRAP: CHO-K1 cells expressing endogenous IRAP and recombinant HEK293 cells expressing human IRAP. A more widespread application of the method was demonstrated by the use of 3T3-L1 adipocytes. EXPERIMENTAL APPROACH: After stimulation of the cells with insulin, internalization of IRAP was inhibited by the addition of phenyl arsine oxide (PAO). Then, cell-surface IRAP was detected by the high-affinity binding of radiolabelled angiotensin (Ang) IV (either 125I or 3H). KEY RESULTS: We monitored the time- and concentration dependence of insulin-mediated translocation of IRAP in both cell lines and 3T3-L1 adipocytes. A plateau was reached between 6 and 8 min, and 10(-7) M insulin led to the highest amount of IRAP at the cell surface. CONCLUSIONS AND IMPLICATIONS: Based on the capacity of the IRAP apoenzyme to display high affinity for radiolabelled Ang IV and on the ability of PAO to inhibit IRAP internalization, we developed a more direct and faster method to measure insulin-mediated translocation of IRAP to the cell surface.

Computational fluid dynamics can detect changes in airway resistance in asthmatics after acute bronchodilation.

The effect of a bronchodilator in asthmatics is only partially described by changes in spirometric values since no information on regional differences can be obtained. Imaging techniques like high-resolution computed tomography (HRCT) provide further information but lack detailed information on specific airway responses. The aim of the present study was to improve the actual imaging techniques by subsequent analysis of the imaging data using computational fluid dynamics (CFD). We studied 14 mild to moderately severe asthmatics. Ten patients underwent HRCT before and 4h after inhalation of a novel long acting beta(2) agonist (LABA) that acts shortly after inhalation. Four patients were studied for chronic effects and underwent CT scans twice after adequate wash-out of bronchodilators. In the active group, a significant bronchodilator response was seen with a forced expiratory volume in 1s (FEV1) increase of 8.78 +/- -6.27% pred vs -3.38 +/- 6.87% pred in the control group. The changes in FEV1 correlated significantly with the changes in distal airway volume (r = 0.69, p = 0.007), total airway resistance (r = -0.73, p = 0.003) and distal airway resistance (r = -0.76, p = 0.002) as calculated with the CFD method. The changes in distal R(aw) were not fully homogeneous. In some patients with normal FEV1 at baseline, CFD-based changes in R(aw) were still detectable. We conclude that CFD calculations, based on airway geometries of asthmatic patients, provide additional information about changes in regional R(aw). All changes in the CFD-based calculated R(aw) significantly correlate with the observed changes in spirometric values therefore validating the CFD method for the studied application.

Flow analyses in the lower airways: patient-specific model and boundary conditions.

Computational fluid dynamics (CFD) is increasingly applied in the respiratory domain. The ability to simulate the flow through a bifurcating tubular system has increased the insight into the internal flow dynamics and the particular characteristics of respiratory flows such as secondary motions and inertial effects. The next step in the evolution is to apply the technique to patient-specific cases, in order to provide more information about pathological airways. This study presents a patient-specific approach where both the geometry and the boundary conditions (BC) are based on individual imaging methods using computed tomography (CT). The internal flow distribution of a 73-year-old female suffering from chronic obstructive pulmonary disease (COPD) is assessed. The validation is performed through the comparison of lung ventilation with gamma scintigraphy. The results show that in order to obtain agreement within the accuracy limits of the gamma scintigraphy scan, both the patient-specific geometry and the BC (driving pressure) play a crucial role. A minimal invasive test (CT scan) supplied enough information to perform an accurate CFD analysis. In the end it was possible to capture the pathological features of the respiratory system using the imaging and computational fluid dynamics techniques. This brings the introduction of this new technique in the clinical practice one step closer.

Correlation between severity of sleep apnea and upper airway morphology based on advanced anatomical and functional imaging.

Determination of the apnea hypopnea index (AHI) as a measure of the severity of obstructive sleep apnea/hypopnea syndrome (OSAHS) is a widely accepted methodology. However, the outcome of such a determination depends on the method used, is time consuming and insufficient for prediction of the effect of all treatment modalities. For these reasons more methods for evaluating the severity of OSAHS, based on different imaging modalities, have been looked into and recent studies have shown that anatomical properties determined from three-dimensional (3D) computed tomography (CT) images are good markers for the severity of the OSAHS. Therefore, we correlated anatomical measurements of a 3D reconstruction of the upper airway together with flow simulation results with the severity of OSAHS in order to find a combination of variables to indicate the severity of OSAHS in patients. The AHI of 20 non-selected, consecutive patients has been determined during a polysomnography. All patients also underwent a CT scan from which a 3D model of the upper airway geometry was reconstructed. This 3D model was used to evaluate the anatomical properties of the upper airway in OSAHS patients as well as to perform computational fluid dynamics (CFD) computations to evaluate the airflow and resistance of this upper airway. It has been shown that a combination of the smallest cross-sectional area and the resistance together with the body mass index (BMI) form a set of markers that predict very well the severity of OSAHS in patients within this study. We believe that these markers can be used to evaluate the outcome of an OSAHS treatment.

Functional imaging using computational fluid dynamics to predict treatment success of mandibular advancement devices in sleep-disordered breathing.

Mandibular advancement devices (MADs) have emerged as a popular alternative for the treatment of sleep-disordered breathing. These devices bring the mandibula forward in order to increase upper airway (UA) volume and prevent total UA collapse during sleep. However, the precise mechanism of action appears to be quite complex and is not yet completely understood; this might explain interindividual variation in treatment success. We examined whether an UA model, that combines imaging techniques and computational fluid dynamics (CFD), allows for a prediction of the treatment outcome with MADs. Ten patients that were treated with a custom-made mandibular advancement device (MAD), underwent split-night polysomnography. The morning after the sleep study, a low radiation dose CT scan was scheduled with and without the MAD. The CT examinations allowed for a comparison between the change in UA volume and the anatomical characteristics through the conversion to three-dimensional computer models. Furthermore, the change in UA resistance could be calculated through flow simulations with CFD. Boundary conditions for the model such as mass flow rate and pressure distributions were obtained during the split-night polysomnography. Therefore, the flow modeling was based on a patient specific geometry and patient specific boundary conditions. The results indicated that a decrease in UA resistance and an increase in UA volume correlate with both a clinical and an objective improvement. The results of this pilot study suggest that the outcome of MAD treatment can be predicted using the described UA model.

Assessment of lung deposition and analysis of the effect of fluticasone/salmeterol hydrofluoroalkane (HFA) pressurized metered dose inhaler (pMDI) in stable persistent asthma patients using functional respiratory imaging.

BACKGROUND: Unambiguously for inhaled products, PK measures are best suited for ensuring that the total systemic exposure is equivalent for two products but cannot provide regional information about lung deposition and structural changes. Functional respiratory imaging (FRI) has been demonstrated to be sensitive for distinguishing small but imperative differences related to a single treatment. METHODS: In this study FRI is used in 16 asthmatic patients to assess equivalence in regional deposition for two products (fluticasone/salmeterol, test and reference) by directly measuring regional functional and structural changes within the lungs following its administration. RESULTS: No differences were observed between the lung deposition patterns and the effects on lung structure and function of two products, having the same formulation and manufactured by different organizations using FRI. CONCLUSIONS: Results using FRI complement PK assessments. The added value of this approach to the conventional clinical methods could be significant.

Comprehensive molecular screening of the FBN1 gene favors locus homogeneity of classical Marfan syndrome.

In order to estimate the contribution of mutations at the fibrillin-1 locus (FBN1) to classical Marfan syndrome (MFS) and to study possible phenotypic differences between patients with an FBN1 mutation vs. without, a comprehensive molecular study of the FBN1 gene in a cohort of 93 MFS patients fulfilling the clinical diagnosis of MFS according to the Ghent nosology was performed. The initial mutation screening by CSGE/SSCP allowed identification of an FBN1-mutation in 73 patients. Next, sequencing of all FBN1-exons was performed in 11 mutation-negative patients, while in nine others, DHPLC was used. This allowed identification of seven and five additional mutations, respectively. Southern blot analysis revealed an abnormal hybridization pattern in one more patient. A total of 23 out of the 85 mutations identified here are reported for the first time. Phenotypic comparison of MFS patients with cysteine-involving mutations vs. premature termination mutations revealed significant differences in ocular and skeletal involvement. The phenotype of the eight patients without proven FBN1 mutation did not differ from the others with respect to the presence of major cardiac, ocular, and skeletal manifestations or positive familial history. Most likely, a portion of FBN1-mutations remains undetected because of technical limitations. In conclusion, the involvement of the FBN1-gene could be demonstrated in at least 91% of all MFS patients (85/93), which strongly suggests that this gene is the predominant, if not the sole, locus for MFS.

Glycoprotein nature of alpha 2-adrenergic receptors labeled with p-azido[3H] clonidine in calf retina membranes.

alpha 2-Adrenergic receptors in calf retina membranes can be specifically labeled with the tritiated agonist p-azido[3H]clonidine. Saturation binding in the dark occurs with high affinity (1.3 +/- 0.3 nM) to a single class of sites (1122 +/- 67 fmol/mg protein). Irradiation of the membrane-bound radioligand results in the labeling of a peptide band with an apparent size of 65 kDa and a characteristic pharmacological profile for an alpha 2-adrenergic receptor. The carbohydrate moieties of the alpha 2-receptor are characterized by lectin affinity chromatography and glycosidase treatment. The Nonidet P-40-solubilized, p-azido[3H]clonidine-labeled receptors are completely retained by Con A- as well as WGA-Sepharose columns. Neuraminidase, alpha-mannosidase and TFMS do not affect the electrophoretic mobility of the receptor on SDS-PAGE whereas endoglycosidase F reduces the apparent size to 45 kDa.

Parameters of inflammation and infection in a community based case-control study of coronary heart disease.

BACKGROUND: increased levels of systemic inflammatory markers appear to be related to coronary heart disease (CHD) both in asymptomatic individuals and in subjects with established CHD. Whether these associations are related to confounding coronary risk factors or are explicable through chronic infectious conditions is not clear. OBJECTIVES: (1) to determine whether subjects with stable CHD differ from normal controls in inflammatory markers (CRP, SAA and fibrinogen) and/or in serostatus of four infectious agents (Helicobacter pylori, Chlamydia pneumoniae, CMV and EBV), independent of classical coronary risk factors. (2) To determine whether these inflammatory markers are related to the serostatus against these four infectious agents either in patients with CHD or in normal subjects. METHODS: in a large epidemiologic survey, 446 out of 16307 men at work, aged 35-59 years, had antecedents of myocardial infarction, CABG or PTCA or had prominent Q/QS waves on their resting ECG. They were compared with double the number (n=892) of men, matched for age, educational level and industry. Inflammatory biomarkers (CRP, fibrinogen and SAA) and antibodies against H. pylori, C. pneumoniae, CMV and EBV were measured, besides classical coronary risk factors. RESULTS: in univariate analyses, cases had higher CRP, fibrinogen and SAA levels than controls, but no differences were observed in serumantibody levels to any of the infectious agents. Markers of previous infections were not related to inflammatory biomarkers. In multivariate analyses CRP was significantly different between cases and controls independent of differences in other coronary risk factors and in the use of lipid lowering drugs and antiplatelet aggregants. CONCLUSIONS: in men at work with CHD, CRP levels are significantly different from controls, independent of known risk factors. No association was found between inflammatory biomarkers and positive serostatus against four infectious agents, neither in the patients nor in the healthy controls.

Imidazoline receptors, non-adrenergic idazoxan binding sites and alpha 2-adrenoceptors in the human central nervous system.

Both [3H]clonidine and [3H]idazoxan bind to alpha 2 adrenoceptors. The former also labels imidazoline receptors, and the latter non-adrenergic idazoxan binding sites. In order to investigate whether the imidazoline receptors and non-adrenergic idazoxan binding sites are identical, we compared the binding characteristics of [3H]clonidine and [3H]idazoxan to these sites by radioligand binding experiments on ultra-thin slices and homogenates of human striatum. A good correlation was found between the effect of different ions on the binding characteristics of [3H]clonidine and [3H]idazoxan, and the affinities of most competing drugs. However, clonidine and rilmenidine displayed a 100- and 10-fold lower affinity, respectively, for the idazoxan binding sites than for the imidazoline receptors. Autoradiography with [3H]clonidine showed that high densities of imidazoline receptors were present in the striatum, pallidum, gyrus dentatus of the hippocampus, amygdala, and substantia nigra. Moderate densities were found throughout the cerebral cortex, thalamus and several brainstem nuclei including the nucleus olivarius inferior. Low densities were seen in the cerebellum, spinal cord and pituitary gland. As for the non-adrenergic sites labelled by [3H]idazoxan, the imidazoline receptors can be found in all major brain areas examined. However, there are some striking differences between the concentrations of imidazoline receptors and non-adrenergic idazoxan binding sites in certain brain regions. To reconcile distribution and pharmacologic data, we propose that imidazoline receptors and non-adrenergic idazoxan binding sites represent different proteins or protein complexes and that at least in the nucleus reticularis lateralis and the striatum, imidazoline receptors and non-adrenergic idazoxan binding sites may be physically associated. The regional distribution of alpha 2 adrenoceptors within the human CNS was determined by quantitative autoradiography with [3H]RX821002. The highest densities of alpha 2 adrenoceptors were found in the cerebral and cerebellar cortex, and certain regions in the medulla oblongata (floor of the IV ventricle, reticular formation, hypoglossal nucleus and nucleus olivarius inferior). No alpha 2 adrenoceptors were detected in the pituitary gland. There exists no relationship between the distribution pattern of imidazoline receptors and alpha 2 adrenoceptors, indicating that these binding sites are independent from each other.

Distinction between surmountable and insurmountable selective AT1 receptor antagonists by use of CHO-K1 cells expressing human angiotensin II AT1 receptors.

1. CHO-K1 cells that were stably transfected with the gene for the human AT1 receptor (CHO-AT1 cells) were used for pharmacological studies of non-peptide AT1 receptor antagonists. 2. In the presence of 10 mM LiCl, angiotensin II caused a concentration-dependent and long-lasting increase of inositol phosphates accumulation with an EC50 of 3.4 nM. No angiotensin II responses are seen in wild-type CHO-K1 cells. 3. [3H]-Angiotensin II bound to cell surface AT1 receptors (dissociates under mild acidic conditions) and is subject to rapid internalization. 4. Non-peptide selective AT1 antagonists inhibited the angiotensin II (0.1 microM) induced IP accumulation and the binding of [3H]-angiotensin II (1 nM) with the potency order: candesartan > EXP3174 > irbesartan > losartan. Their potencies are lower in the presence of bovine serum albumin. 5. Preincubation with the insurmountable antagonist candesartan decreased the maximal angiotensin II induced inositol phosphate accumulation up to 94% and, concomitantly, decreased the maximal binding capacity of the cell surface receptors. These inhibitory effects were half-maximal for 0.6 nM candesartan and were attenuated by simultaneous preincubation with 1 microM losartan indicating a syntopic action of both antagonists. 6. Losartan caused a parallel rightward shift of the angiotensin II concentration-response curves and did not affect the maximal binding capacity. EXP3174 (the active metabolite of losartan) and irbesartan showed a mixed-type behavior in both functional and binding studies. 7. Reversal of the inhibitory effect was slower for candesartan as compared with EXP3174 and irbesartan and it was almost instantaneous for losartan, suggesting that the insurmountable nature of selective AT1 receptor antagonists in functional studies was related to their long-lasting inhibition.