Endoplasmic reticulum-associated degradation of the mouse PC1/3-N222D hypomorph and human PCSK1 mutations contributes to obesity.

BACKGROUND: The proprotein convertase 1/3 (PC1/3), encoded by proprotein convertase subtilisin/kexin type 1 (PCSK1), cleaves and hence activates several orexigenic and anorexigenic proproteins. Congenital inactivation of PCSK1 leads to obesity in human but not in mice. However, a mouse model harboring the hypomorphic mutation N222D is obese. It is not clear why the mouse models differ in phenotype. METHODS: Gene expression analysis was performed with pancreatic islets from Pcsk1(N222D/N222D) mice. Subsequently, biosynthesis, maturation, degradation and activity were studied in islets, pituitary, hypothalamus and cell lines. Coimmunoprecipitation of PC1/3-N222D and human PC1/3 variants associated with obesity with the endoplasmic reticulum (ER) chaperone BiP was studied in cell lines. RESULTS: Gene expression analysis of islets of Pcsk1(N222D/N222D) mice showed enrichment of gene sets related to the proteasome and the unfolded protein response. Steady-state levels of PC1/3-N222D and in particular the carboxy-terminally processed form were strongly reduced in islets, pituitary and hypothalamus. However, impairment of substrate cleavage was tissue dependent. Proinsulin processing was drastically reduced, while processing of proopiomelanocortin (POMC) to adrenocorticotropic hormone (ACTH) in pituitary was only mildly impaired. Growth hormone expression and IGF-1 levels were normal, indicating near-normal processing of hypothalamic proGHRH. PC1/3-N222D binds to BiP and is rapidly degraded by the proteasome. Analysis of human PC1/3 obesity-associated mutations showed increased binding to BiP and prolonged intracellular retention for all investigated mutations, in particular for PC1/3-T175M, PC1/3-G226R and PC1/3-G593R. CONCLUSIONS: This study demonstrates that the hypomorphic mutation in Pcsk1(N222D) mice has an effect on catalytic activity in pancreatic islets, pituitary and hypothalamus. Reduced substrate processing activity in Pcsk1(N222D/N222D) mice is due to enhanced degradation in addition to reduced catalytic activity of the mutant. PC1/3-N222D binds to BiP, suggesting impaired folding and reduced stability. Enhanced BiP binding is also observed in several human obesity-associated PC1/3 variants, suggesting a common mechanism.

A nonsense loss-of-function mutation in PCSK1 contributes to dominantly inherited human obesity.

BACKGROUND: A significant proportion of severe familial forms of obesity remain genetically elusive. Taking advantage of our unique cohort of multigenerational obese families, we aimed to assess the contribution of rare mutations in 29 common obesity-associated genes to familial obesity, and to evaluate in these families the putative presence of nine known monogenic forms of obesity. METHODS: Through next-generation sequencing, we sequenced the coding regions of 34 genes involved in polygenic and/or monogenic forms of obesity in 201 participants (75 normal weight individuals, 54 overweight individuals and 72 individuals with obesity class I, II or III) from 13 French families. In vitro functional analyses were performed to investigate the mutation PCSK1-p.Arg80* which was identified in a family. RESULTS: A novel heterozygous nonsense variant in PCSK1 (p.Arg80*), encoding a propeptide truncated to less than two exons (out of 14), was found to co-segregate with obesity in a three-generation family. We demonstrated that this mutation inhibits PCSK1 enzyme activity and that this inhibition most likely does not involve a strong physical interaction. Furthermore, both mutations PCSK1-p.Asn180Ser and POMC-p.Phe144Leu, which had previously been reported to be associated with severe obesity, were also identified in this study, but did not co-segregate with obesity. Finally, we did not identify any rare mutations co-segregating with obesity in common obesity susceptibility genes, except for CADM2 and QPCTL, where we found two novel variants (p.Arg81His and p.Leu98Pro, respectively) in three obese individuals. CONCLUSIONS: We showed for the first time that a nonsense mutation in PCSK1 was likely to cause dominantly inherited human obesity, due to the inhibiting properties of the propeptide fragment encoded by the null allele. Furthermore, the present family sequencing design challenged the contribution of previously reported mutations to monogenic or at least severe obesity.

Cellular and ultra structural evidence for cytoskeletal localization of prolyl endopeptidase-like protein in neurons.

The biochemical properties and subcellular localization of prolyl endopeptidase (PREP) in brain are well characterized and its implications in the realization of cognitive processes and in the pathogenesis of neurodegenerative disorders are a matter of intensive investigation. In contrast, very little is known about its homolog, the PREP-like protein (PREPL). In order to obtain initial hints about the involvement of PREPL in physiological processes, a differential proteomic screen was performed with human skin fibroblasts from controls and patients with PREPL deficiency (hypotonia-cystinuria syndrome). The majority of affected proteins represented cytoskeletal proteins, including caldesmon, tropomyosin α3 chain, lamin A, ß-actin, γ-actin, vimentin and zyxin. Therefore, the analysis of PREPL subcellular localization by confocal laser scanning and electron microscopy in mouse neurons was focused on the cytoskeleton. The co-localization of PREPL with cytoskeletal marker proteins such as ß-actin and microtubulin-associated protein-2 was observed, in addition to the presence of PREPL within Golgi apparatus and growth cones. In the mouse brain, PREPL is neuronally expressed and highly abundant in neocortex, substantia nigra and locus coeruleus. This mirrors to some extent the distribution pattern of PREP and points toward redundant functions of both proteins. In the human neocortex, PREPL immunostaining was found in the cytoplasm and in neuropil, in particular of layer V pyramidal neurons. This staining was reduced in the neocortex of Alzheimer's disease (AD) patients. Moreover, in AD brains, PREPL immunoreactivity was observed in the nucleus and in varicose neuritic processes. Our data indicate physiological functions of PREPL associated with the cytoskeleton, which may be affected under conditions of cytoskeletal degeneration.

Limitations of inhibitory activities of polyphenols on furin-mediated substrate processing.

Recently, selected polyphenols were reported to exert proprotein convertase (PC) inhibitory activities on in vitro cleavage of a fluorogenic peptide substrate and it was concluded that this anti-protease activity might be responsible for the reported anti-cancer properties of these polyphenols. This prompted investigations to identify PC inhibiting polyphenols that could affect IGF-1R-mediated tumorigenesis since pro-IGF-1R is bioactivated by PCs like furin. Initial screening of polyphenols for their impact on in vitro cleavage of fluorogenic peptide substrate Pyr-RTKR-AMC by human furin (hfurin(573)) indeed revealed varying inhibitory effects. (-)EGCG, chrysin, and quercetin, were subsequently evaluated using uncleaved diphtheria toxin as substrate in vitro. However, none displayed any inhibitory impact on processing. Binding of (-)EGCG to both furin and the diphtheria toxin protein was demonstrated. Subsequently, it was found that for seven polyphenols tested, addition of casein or gamma globulin led to reduction or even annihilation of in vitro Pyr- RTKR-AMC cleavage inhibition. No such effect was seen with the furin inhibitor nona-D-arginine. Western blot studies to investigate possible effects of selected polyphenols on processing in cells of the tumorigenesis-linked proproteins pro-IGF-1R and pro-GPC3 also revealed no inhibitory effects. In conclusion, our results confirm the reported PC inhibitory effects of polyphenols on fluorogenic peptide substrate cleavage in vitro. However, the data show that polyphenolic inhibitory effects on hfurin(573)-mediated in vitro fluorogenic peptide substrate cleavage cannot be extrapolated to similar effects on processing of genuine proproteins, whether in vitro or in cells. This undermines the anti-protease rationale for the reported polyphenolic anti-cancer properties.

The autism candidate gene Neurobeachin encodes a scaffolding protein implicated in membrane trafficking and signaling.

Autism is a developmental disorder of the central nervous system characterized by impairments in social interaction, communication and restricted repetitive and stereotyped behavior. It is generally assumed that in most cases autism has a polygenic cause, but the pathogenesis is still unknown. Neurobeachin (NBEA) has recently been identified as a candidate gene for autism in a patient with a de novo chromosomal translocation and three patients with a monoallelic deletion. This multidomain scaffolding protein has been suggested to be involved in neuronal post-Golgi membrane traffic. Knockout of Nbea in two independent mouse models has demonstrated a role in neurotransmitter release and synaptic functioning. Knockdown in a cell line has shown a role as negative regulator of secretion of large dense-core vesicles (LDCVs) and haploinsufficiency in blood platelets results in dense granules with an aberrant morphology. A potential role in vesicle transport is further supported by a study of SEL-2, the C.elegans homologue of NBEA. This protein was identified as a negative regulator of LIN-12/Notch activity, probably due to defects in endosomal trafficking. Members of the Notch pathway have also been shown to be modifiers of the NBEA homologue in Drosophila, rugose. These new insights in the function of NBEA may help identifying novel pathways affected in autistic patients. In particular, it suggests that impaired functionality of LDCVs, which contain neurotrophins, neuropeptides and monoamines, might contribute to the pathogenesis of autism in at least a subgroup of patients.

The impact of rapid aneuploidy detection (RAD) in addition to karyotyping versus karyotyping on maternal quality of life.

OBJECTIVE: To assess the impact of rapid aneuploidy detection (RAD) combined with fetal karyotyping versus karyotyping only on maternal anxiety and health-related quality of life. METHODS: Women choosing to undergo amniocentesis were selected into group 1, i.e. receiving a karyotype result only (n = 132) or to group 2, i.e. receiving both the result of RAD and karyotyping (n = 181). RESULTS: There were no systematic differences in time of RAD combined with karyotyping versus karyotyping only in terms of anxiety (P = 0.91), generic physical health (P = 0.76, P = 0.46), generic mental health (P = 0.52, P = 0.72), personal perceived control (P = 0.91) and stress (P = 0.13). RAD combined with karyotyping reduced anxiety and stress two weeks earlier compared to karyotyping only. CONCLUSION: RAD as add-on to karyotyping reduces anxiety and stress in the short term but it does not influence overall anxiety, stress, personal perceived control, and generic mental and physical health when compared to a karyotype-only strategy.

Aclidinium bromide provides long-acting bronchodilation in patients with COPD.

Aclidinium bromide is a novel, long-acting, muscarinic antagonist in phase III development for the maintenance treatment of COPD. This phase IIb study investigated the efficacy and safety of aclidinium for the treatment of moderate to severe COPD to establish the optimal dose for phase III studies. A total of 464 patients with moderate to severe stable COPD were randomised to double-blind, once-daily treatment with aclidinium (25, 50, 100, 200, or 400microg), placebo, or open-label tiotropium (18microg) for 4 weeks. Spirometric measurements were performed at 22-24h after the first dose and then at weekly intervals, and from 0.5 to 6h post-dose on day 1 and day 29. Compared with placebo, aclidinium 200microg and 400microg significantly increased trough FEV(1) on day 29 versus baseline. During the first 6h post-dose, the bronchodilatory effect of aclidinium (all doses) on day 1 was comparable to that on day 29. Time to peak FEV(1) was 3h for aclidinium 100-400microg. Aclidinium was well tolerated, with no dose-dependent effect on ECG, laboratory parameters, or adverse events. The incidence of AEs was generally comparable to placebo. Aclidinium produced sustained bronchodilation over 24h and was well tolerated during this short-term study. Based on these data, aclidinium 200microg was selected as the investigational dose for future clinical trials in COPD.

Insulin crystallization depends on zinc transporter ZnT8 expression, but is not required for normal glucose homeostasis in mice.

Zinc co-crystallizes with insulin in dense core secretory granules, but its role in insulin biosynthesis, storage and secretion is unknown. In this study we assessed the role of the zinc transporter ZnT8 using ZnT8-knockout (ZnT8(-/-)) mice. Absence of ZnT8 expression caused loss of zinc release upon stimulation of exocytosis, but normal rates of insulin biosynthesis, normal insulin content and preserved glucose-induced insulin release. Ultrastructurally, mature dense core insulin granules were rare in ZnT8(-/-) beta cells and were replaced by immature, pale insulin "progranules," which were larger than in ZnT8(+/+) islets. When mice were fed a control diet, glucose tolerance and insulin sensitivity were normal. However, after high-fat diet feeding, the ZnT8(-/-) mice became glucose intolerant or diabetic, and islets became less responsive to glucose. Our data show that the ZnT8 transporter is essential for the formation of insulin crystals in beta cells, contributing to the packaging efficiency of stored insulin. Interaction between the ZnT8(-/-) genotype and diet to induce diabetes is a model for further studies of the mechanism of disease of human ZNT8 gene mutations.

Deletion of C2orf34, PREPL and SLC3A1 causes atypical hypotonia-cystinuria syndrome.

Hypotonia-cystinuria syndrome (HCS) and 2p21 deletion syndrome are two recessive contiguous gene deletion syndromes associated with cystinuria type I. In HCS patients, only SLC3A1 and PREPL are disrupted. In the 2p21 deletion syndrome, two additional genes (C2orf34 and PPM1B) are lost. Molecular analysis of the SLC3A1/PREPL locus was performed in the patients using quantitative polymerase chain reaction (PCR) methods. HCS in both siblings was confirmed with the deletion screen of the SLC3A1/PREPL locus. Fine mapping of the breakpoint revealed a deletion of 77.4 kb, including three genes: SLC3A1, PREPL and C2orf34. Features not present in classical HCS were a mild/moderate mental retardation and a respiratory chain complex IV deficiency. We report the first patients with a deletion of SLC3A1, PREPL and C2orf34. They present with a phenotype intermediate between HCS and 2p21 deletion syndrome.

[Alpha-foetoprotein assessment in amniotic fluid for the detection of neural tube defects: limited added value beyond week 20 ultrasound; retrospective study]. / Alfafoetoproteïnebepaling in vruchtwater voor de detectie van neuralebuisdefecten: beperkte meerwaarde boven de 20-wekenecho; retrospectiefonderzoek.

OBJECTIVE: To evaluate the diagnostic additional value of routine alpha-foetoprotein (AFP) assessment in amniotic fluid for the detection of neural tube defects (NTDs), compared with week 20 ultrasonographic examination. DESIGN: Retrospective. METHOD: We retrospectively determined AFP concentrations in amniotic fluid obtained from 7981 women who had undergone amniocentesis for karyotyping and AFP assessment. An AFP concentration greater than 2.5 times the median was considered abnormal. Women were categorised into 4 groups based on the indication for invasive prenatal diagnostic assessment: advanced maternal age (group I; n = 6179), increased risk of foetal NTDs (group II; n = 258), ultrasonographically confirmed foetal NTDs (group III; n = 55) or other indications (group IV; n = 1489). RESULTS: In group I, 18 of 6179 samples had increased AFP levels (0.3%), 2 of which were associated with NTDs. In group II, 2 of 258 samples had increased AFP levels (0.8%); both were associated with NTDs. Increased AFP levels were found in 44 of 55 samples from group III (80%), and 223 of 1489 samples from group IV (15.0%). CONCLUSION: Routine assessment of AFP in amniotic fluid based on advanced maternal age provides little additional value in the detection of NTDs beyond that of week 20 ultrasound.

Deletion of C2orf34, PREPL and SLC3A1 causes atypical hypotonia-cystinuria syndrome.

BACKGROUND: Hypotonia-cystinuria syndrome (HCS) and 2p21 deletion syndrome are two recessive contiguous gene deletion syndromes associated with cystinuria type I. The deletions differ in size and the number of genes involved. In HCS patients, only SLC3A1 and PREPL are disrupted. In the 2p21 deletion syndrome, two additional genes (C2orf34 and PPM1B) are lost. OBJECTIVE: Clinical and molecular analysis of two siblings who presented with an atypical HCS phenotype. METHODS: Molecular analysis of the SLC3A1/PREPL locus was performed in the patients using quantitative polymerase chain reaction (PCR) methods. RESULTS: HCS in both siblings was confirmed with the deletion screen of the SLC3A1/PREPL locus. Fine mapping of the breakpoint revealed a deletion of 77.4 kb, including three genes: SLC3A1, PREPL and C2orf34. Features not present in classical HCS were a mild/moderate mental retardation and a respiratory chain complex IV deficiency documented in patient 2. CONCLUSIONS: We report the first patients with a deletion of SLC3A1, PREPL and C2orf34. They present with a phenotype intermediate between HCS and 2p21 deletion syndrome. These patients facilitate the elucidation of the contribution of each gene to the phenotype in the different 2p21 deletion syndromes.

Prenatal diagnosis of cerebral lesions in Tuberous sclerosis complex (TSC). Case report and review of the literature.

Tuberous sclerosis complex (TSC) is an autosomal-dominant neurocutaneous disorder with multi-organ involvement. The diagnosis is suspected at fetal ultrasound on the discovery of multiple cardiac rhabdomyomas (CRs). They typically develop in utero and undergo spontaneous regression during the first years of live. With developing neuroradiological methods more light is shed on antenatal cerebral lesions like cortical tubers or giant cell astrocytomas. Unfortunately these do not regress, but instead are in principle progressive in size and number, correlated with epilepsy, mental retardation and behavioral problems. It is unknown whether fetal cerebral lesions, are always correlated with a poor neurological outcome or a progressive course of disease. This makes prenatal counseling extremely difficult. We report one case of de novo TSC with first detection of cortical tubers on fetal ultrasound, later developing multiple CRs. The pregnancy was continued and the child is developing well during 16 months of follow-up. Minor motor seizures from the 10th month onwards are successfully treated with Valproate. The published cases with antenatal diagnosis of TSC are revised, trying to get more insight into the postnatal course of prenatally diagnosed TSC. This is crucial, either when termination of pregnancy (TOP) is considered, but even more for proper postnatal care and follow-up.

Once-daily dosing with budesonide/formoterol compared with twice-daily budesonide/formoterol and once-daily budesonide in adults with mild to moderate asthma.

Adherence to maintenance therapy is often poor in patients with asthma. Simplifying dosing regimens has the potential to improve both adherence and asthma-related morbidity. In this 12-week, randomized, double-blind, double-dummy, parallel-group study, 617 patients with mild to moderate persistent asthma (mean forced expiratory volume in 1s [FEV1] 78.5% predicted) who were not optimally controlled on inhaled corticosteroids (200-500 microg/day) were randomized to once-daily budesonide/formoterol (80/4.5 microg, 2 inhalations in the evening), twice-daily budesonide/formoterol (80/4.5 microg, 1 inhalation), or a corresponding dose of budesonide once-daily (200 microg, 1 inhalation in the evening). All patients received budesonide (100 microg twice daily) during a 2-week run-in. Changes in mean morning peak expiratory flow (PEF) were similar for od budesonide/formoterol (23.4 l/min) and twice-daily budesonide/formoterol (24.1 l/min), and both were greater than with budesonide (5.5 l/min; both P<0.001). Evening PEF, symptom-free days, reliever-free days, and asthma control days were improved with budesonide/formoterol therapy vs. budesonide (P<0.05 vs. budesonide for all variables). All treatments were well tolerated. Budesonide/formoterol administered once daily in the evening is a convenient treatment regimen that is as effective in improving asthma control as twice-daily dosing in patients with mild to moderate persistent asthma.

Profiles of measured and perceived bronchodilation. A placebo-controlled cross-over trial comparing formoterol and salmeterol in moderate persistent asthma.

BACKGROUND AND OBJECTIVE: Long-acting beta(2)-agonists have acquired an indispensable position in the management of bronchial symptoms in patients with asthma. The objective of this study was to compare onset-of-action and clinical effectiveness of formoterol and salmeterol during 2 weeks of treatment. We also investigated the association between bronchodilator effects and perceived relieve of dyspnoea. METHODS: A multi-centre randomized double-blind placebo-controlled cross-over trial was performed in 35 subjects with moderate persistent asthma. Treatment periods existed of 2 weeks formoterol (12 microg bid), salmeterol (50 microg bid) and placebo, all administered by pressurized metered dose inhaler. FEV(1) and Visual Analogue Scale (VAS) scores were repeatedly measured until 180 min post-bronchodilation (post-BD), before as well as after each treatment period. Onset-of-action was defined as a >/=15% increase in FEV(1). Subjects kept diaries of morning and evening PEFR values and use of rescue bronchodilator. RESULTS: Formoterol and salmeterol both caused a significant increase in FEV(1) (0.45L [95% CI 0.01, 0.80] and 0.27L [95% CI 0.08, 0.62] respectively). At 3' post-BD, three times as many subjects demonstrated onset-of-action on formoterol compared to salmeterol (36% versus 13%, P = 0.063), at 6' post-BD 42% versus 27% (P = 0.063). VAS scores were similar for formoterol and salmeterol at pre-treatment assessment, but tended to be higher for formoterol after 2weeks treatment. No differences between formoterol and salmeterol were observed for PEFR values or use of rescue medication. 50% of the subjects preferred formoterol, 29% salmeterol (P < 0.001). Significant associations between FEV(1) and VAS ratings existed only at 10', 15' and 30' post-BD, not before or after these time points. CONCLUSION: The earlier described faster onset-of-action of formoterol as compared to a equipotent dosage of salmeterol was confirmed in this study. Perception of decreasing airflow obstruction may be delayed after acute bronchodilation.

Comparable efficacy and tolerability of formoterol (Foradil) administered via a novel multi-dose dry powder inhaler (Certihaler) or the Aerolizer dry powder inhaler in patients with persistent asthma.

BACKGROUND: For maximum treatment compliance there is a need to provide asthma patients with devices that suit their particular preferences. The Foradil Certihaler is a novel multi-dose dry powder inhaler developed to increase the choice of devices available. OBJECTIVES: To evaluate the safety and efficacy of formoterol administered via the Foradil Certihaler, or via the single-dose inhaler Foradil Aerolizer. METHODS: This was a randomized, placebo-controlled, double-dummy, incomplete block crossover, dose-ranging and pharmacokinetic study in patients with persistent asthma. Sixty-seven patients (mean 48.0 years) were randomized to formoterol 5, 10, 15 and 30 microg twice daily via the Certihaler, 12 microg formoterol b.i.d. via the Aerolizer, or placebo in four 1-week double-blind treatment periods separated by 1-week single-blind washouts. RESULTS All formoterol doses delivered via the Certihaler or the Aerolizer significantly increased FEV(1) compared with placebo (p < 0.0001). Formoterol demonstrated an onset of action of <3 min. All active treatments were well tolerated. Tremor was the most common adverse event and was more pronounced at high doses. At lower doses the incidence of tremor with the Certihaler was similar to that observed with placebo or the Aerolizer. The pharmacokinetic evaluation comprised 41 patients (mean 45.9 years). Urinary excretion of unchanged formoterol and total formoterol increased with dose delivered via the Certihaler. The optimum dose of formoterol via the Certihaler was 10 microg. CONCLUSION: Delivery of formoterol via the Certihaler or Aerolizer combines rapid relief with enduring control and provides convenient bronchodilation in patients with persistent asthma.

Once-daily budesonide/formoterol in a single inhaler in adults with moderate persistent asthma.

Patients with moderate persistent asthma (n = 523; mean FEV1 77.4%) not fully controlled with inhaled corticosteroids (ICS; 400-1000 microg/day) were randomized to receive either once-daily budesonide/formoterol (160/4.5 microg, two inhalations); or twice-daily budesonide/formoterol (160/4.5 microg, one inhalation); or budesonide (400 microg) once-daily for 12 weeks. Once-daily dosing was administered in the evening and twice-daily dosing was administered in the morning and evening. All patients received twice-daily budesonide (200 microg) during a 2-week run-in. Compared with budesonide alone, change in mean morning and evening peak expiratory flow was greater in the once-daily budesonide/formoterol group (27 and 171 min(-1), respectively; P < 0.001) and twice-daily budesonide/formoterol group (23 and 24 l min(-1), respectively; P < 0.001). Night awakenings, symptom-free days, reliever-use-free days and asthma-control days were all improved during once-daily budesonide/formoterol therapy vs. budesonide (P < or = 0.05). Similar improvements were also seen with twice-daily budesonide/formoterol (P < or = 0.05). The risk of a mild exacerbation was reduced after once- and twice-daily budesonide/formoterol vs. budesonide (38% and 35%, respectively; P < 0.002). All treatments were well tolerated. Budesonide/formoterol, once- or twice-daily, in a single inhaler improved asthma symptoms and exacerbations compared with budesonide. In the majority of patients with moderate persistent asthma requiring ICS and long-acting beta-agonists, once-daily formoterol/budesonide provided sustained efficacy over 24 h, similar to twice-daily dosing.

An efficient and reproducible method for measuring hydrogen peroxide in exhaled breath condensate.

We investigated the sensitivity and reproducibility of a test procedure for measuring hydrogen peroxide (H202) in exhaled breath condensate and the effect of storage of the condensate on the H2O2 concentration, and compared the results to previous studies. Twenty stable COPD patients breathed into our collecting device twice for a period of 10 min. The total exhaled air volume (EAV) and condensate volume were measured both times and the H2O2 concentration of the condensate was determined fluorimetrically. The concentration was measured again after freezing the reaction product at -70 degrees C for a period of 10, 20 and 40 days. We collected 2-5 ml condensate in 10 min. The EAV and condensate volumes were strongly correlated. There was no significant difference between the mean H2O2 concentration of the first and second test. We obtained a detect on limit for the H2O2 concentration of 0.02 micromoll(-1). The H2O2 concentration appeared to remain stable for a period up to 40 days of freezing. Compared to previous studies we developed a more efficient breath condensate collecting device and obtained a lower H2O2 detection limit. The measurement of exhaled H2O2 was reproducible. In addition, storage of the samples up to 40 days showed no changes in H2O2 concentration.

Cilomilast, a selective phosphodiesterase-4 inhibitor for treatment of patients with chronic obstructive pulmonary disease: a randomised, dose-ranging study.

BACKGROUND: Chronic obstructive pulmonary disease (COPD) is a common, progressive respiratory disease that causes great morbidity and mortality despite treatment. There is evidence for airway inflammation in COPD. Cilomilast is an orally active, potent, selective phosphodiesterase type 4 inhibitor, which in vitro can affect cells thought to be of clinical importance in COPD. Our aim was to assess the safety, efficacy, and dose response of cilomilast in the treatment of patients with this disease. METHODS: We did a 6-week, randomised, dose-ranging study in 424 patients with COPD (forced expiratory volume in 1 s [FEV(1)] 46.8% of predicted, FEV(1)/forced vital capacity [FVC] 54.6%, and postsalbutamol reversibility 5.4%). We randomly assigned individuals at 60 European centres to receive cilomilast 5 (n=109), 10 (n=102), or 15 (n=107) mg twice daily, or placebo (n=106). The main outcome measure was trough FEV(1) before and after use of a bronchodilator. Analyses were by intention to treat. FINDINGS: Cilomilast 15 mg twice daily significantly improved FEV(1) compared with placebo (mean 130 mL vs -30 mL [95% CI 90-240] at week 6, p<0.0001). FVC and peak expiratory flow were also improved (p=0.001 and p<0.0001, respectively). Quality of life measures did not differ significantly between the groups. There were no significant differences in serious adverse events between the groups. INTERPRETATION: Cilomilast 15 mg twice daily might be an effective maintenance treatment for COPD. Further clinical studies are underway.

In vitro loading of human synovial membrane with 5-hydroxydopamine: evidence for dense core secretory granules in type B cells.

Ultrastructural studies of the synovial membrane were performed on tissue samples obtained from the human lumbar facet joint. Ultrastructural changes in synoviocytes were studied after loading synovial samples with 5-hydroxydopamine (5-OHDA) in an oxygenated Krebs' solution, prior to fixation. Synoviocytes were set loosely in the intimal matrix and classified into type A (phagocytic) and type B (secretory) cells. In general, type A cells populated the surface of the synovial lining, whereas type B cells were located deeper in the tissue, extending a process into the synovial fluid. Type B cells in control samples contained sparse secretory granules. Free nerve endings were not found in the synovial intima. In response to incubation in 5-OHDA, a precursor of biogenic monoamines, synoviocytes clustered and established contact. The ultrastructure of type B cells in the loaded group clearly differed from controls. They possessed typical membrane-bound vesicles, containing an electron dense interior surrounded by a lucent space. The size of these dense core vesicles ranged from 100 to 260 nm (on average 180 nm). They were in relation to microtubules and located preferentially in the marginal area of the cytoplasm, close to the Golgi complex. The ultrastructure of type A cells was not significantly altered. The present observations provide morphological evidence for the amine-handling properties of type B cells, indicating that they might be added to the list of 'APUD' cells of the diffuse neuroendocrine system. A recepto-secretory function for type B cells is discussed.