Protocol for photo-controlling the assembly of cyclic peptide nanotubes in solution and inside microfluidic droplets

In this protocol, we describe how to perform the photo-isomerization of cyclic peptides containing an unsaturated β-amino acid. This process triggers the formation or disassembly of cyclic peptide nanotubes under appropriate light irradiation. Specifically, we start by describing the solid-phase synthesis of the cyclic peptide component. We also present a technique for performing isomerization studies in solution and how to extend it to microfluidic aqueous droplets. For complete details on the use and execution of this protocol, please refer to Vilela-Picos et al.1.

Prevalence of Long COVID Symptoms Related to SARS-CoV-2 Strains

BACKGROUND

Few studies have assessed the differences of patterns of Long COVID (L-COVID) with regards to the pathogenetic SARS-CoV-2 strains.

OBJECTIVES

To investigate the relationship between demographic and clinical characteristics of acute phase of infection and the persistence of L-COVID symptoms and clinical presentation across different SARS-CoV-2 strains.

METHODS

In this observational-multicenter study we recorded all demographic and clinical characteristics, severity of infection, presence/persistence of symptoms of fatigue, dyspnoea and altered quality of life (QoL) at baseline and after 6 months, in a sample of Italian patients from Liguria between March 2020 and March 2022.

RESULTS

308 patients (mean age 63.2 years; 55.5% men) with previous COVID were enrolled. Obese patients were 21.2% with a significant difference in obesity prevalence across the second and third wave (p = 0.012). Treatment strategies differed between waves (p < 0.001): more patients required invasive mechanical ventilation in the first wave, more patients were treated with high-flow nasal cannula/non-invasive ventilation in the in the second and more patients were treated with oxygen-therapy in the fourth wave. At baseline, a high proportion of patients were symptomatic (dyspnoea and fatigue), with impairment in some QoL indicators. A higher prevalence of patients with pain, were seen in the first wave compared to later infections (p = 0.01). At follow-up, we observed improvement of dyspnoea, fatigue and some dimensions of QoL scale evaluation such as mobility, usual activities, pain evaluations; instead there was no improvement in remaining QoL scale indicators (usual care and anxiety-depression).

CONCLUSIONS

There were no significant differences in the prevalence of the most frequent L-COVID symptoms, except for QoL pain domain that was especially associated with classical variant. Our results show substantial impact on social and professional life and usual care activities. These findings highlight the importance of multidisciplinary post COVID follow-up care including mental health support and rehabilitation program.

Contribution of Genetic Background to the Radiation Risk for Cancer and Non-Cancer Diseases in Ptch1+/- Mice

Experimental mouse studies are important to gain a comprehensive, quantitative and mechanistic understanding of the biological factors that modify individual risk of radiation-induced health effects, including age at exposure, dose, dose rate, organ/tissue specificity and genetic factors. In this study, neonatal Ptch1+/- mice bred on CD1 and C57Bl/6 background received whole-body irradiation at postnatal day 2. This time point represents a critical phase in the development of the eye lens, cerebellum and dentate gyrus (DG), when they are also particularly susceptible to radiation effects. Irradiation was performed with γ rays (60Co) at doses of 0.5, 1 and 2 Gy, delivered at 0.3 Gy/min or 0.063 Gy/min. Wild-type and mutant mice were monitored for survival, lens opacity, medulloblastoma (MB) and neurogenesis defects. We identified an inverse genetic background-driven relationship between the radiosensitivity to induction of lens opacity and MB and that to neurogenesis deficit in Ptch1+/- mutants. In fact, high incidence of radiation-induced cataract and MB were observed in Ptch1+/-/CD1 mutants that instead showed no consequence of radiation exposure on neurogenesis. On the contrary, no induction of radiogenic cataract and MB was reported in Ptch1+/-/C57Bl/6 mice that were instead susceptible to induction of neurogenesis defects. Compared to Ptch1+/-/CD1, the cerebellum of Ptch1+/-/C57Bl/6 mice showed increased radiosensitivity to apoptosis, suggesting that differences in processing radiation-induced DNA damage may underlie the opposite strain-related radiosensitivity to cancer and non-cancer pathologies. Altogether, our results showed lack of dose-rate-related effects and marked influence of genetic background on the radiosensitivity of Ptch1+/-mice, supporting a major contribution of individual sensitivity to radiation risk in the population.

miRNA-Signature of Irradiated Ptch1+/- Mouse Lens is Dependent on Genetic Background

One harmful long-term effect of ionizing radiation is cataract development. Recent studies have been focused on elucidating the mechanistic pathways involved in this pathogenesis. Since accumulating evidence has established a role of microRNAs in ocular diseases, including cataract, the goal of this work was to determine the microRNA signature of the mouse lens, at short time periods postirradiation, to understand the mechanisms related to radio-induced cataractogenesis. To evaluate the differences in the microRNA profiles, 10-week-old Patched1 heterozygous (Ptch1+/-) mice, bred onto two different genetic backgrounds (CD1 and C57Bl/6J), received whole-body 2 Gy γ-ray irradiation, and 24 h later lenses were collected. Next-generation sequencing and bioinformatics analysis revealed that genetic background markedly influenced the list of the deregulated microRNAs and the mainly predicted perturbed biological functions of 2 Gy irradiated Ptch1+/- mouse lenses. We identified a subset of microRNAs with a contra-regulated expression between strains, with a key role in regulating Toll-like receptor (TLR)-signaling pathways. Furthermore, a detailed analysis of miRNome data showed a completely different DNA damage response in mouse lenses 24 h postirradiation, mainly mediated by a marked upregulation of p53 signaling in Ptch1+/-/C57Bl/6J lenses that was not detected on a CD1 background. We propose a strict interplay between p53 and TLR signaling in Ptch1+/-/C57Bl/6J lenses shortly after irradiation that could explain both the resistance of this strain to developing lens opacities and the susceptibility of CD1 background to radiation-induced cataractogenesis through activation of epithelial-mesenchymal transition.

Molecular Plumbing to Bend Self-Assembling Peptide Nanotubes

Light-induced molecular piping of cyclic peptide nanotubes to form bent tubular structures is described. The process is based on the [4+4] photocycloaddition of anthracene moieties, whose structural changes derived from the interdigitated flat disposition of precursors to the corresponding cycloadduct moieties, induced the geometrical modifications in nanotubes packing that provokes their curvature. For this purpose, we designed a new class of cyclic peptide nanotubes formed by β- and α-amino acids. The presence of the former predisposes the peptide to stack in a parallel fashion with the β-residues aligned along the nanotube and the homogeneous distribution of anthracene pendants.

Double Orthogonal Click Reactions for the Development of Antimicrobial Peptide Nanotubes

A new class of amphipathic cyclic peptides, which assemble in bacteria membranes to form polymeric supramolecular nanotubes giving them antimicrobial properties, is described. The method is based on the use of two orthogonal clickable transformations to incorporate different hydrophobic or hydrophilic moieties in a simple, regioselective, and divergent manner. The resulting cationic amphipathic cyclic peptides described in this article exhibit strong antimicrobial properties with a broad therapeutic window. Our studies suggest that the active form is the nanotube resulted from the parallel stacking of the cyclic peptide precursors. Several techniques, CD, FTIR, fluorescence, and STEM, among others, confirm the nanotube formation.

Polymorphic Self-Organization of Lauroyl Peptide in Response to pH and Concentration

Amphipathic peptides are attractive building blocks for the preparation of self-assembling, bio-inspired, and stimuli responsive nanomaterials with pharmaceutical interest. The bioavailability of these materials can be improved with the insertion of d amino acid residues to avoid fast proteolysis in vivo. With this knowledge, a new lauroyl peptide consisting of a sequence of glycine, glycine, d-serine, and d-lysine was designed. In spite of its simple sequence, this lipopeptide self-assembles into spherical micelles at acid pH, when the peptide moiety adopts disordered conformations. Self-aggregates reshape toward fibers at basic pH, following the conformational transition of the peptide region from random coil to β-sheet. Finally, hydrogels are achieved at basic pH and higher concentrations. The transition from random coil to β-sheet conformation of the peptide headgroup obtained by increasing pH was monitored by circular dichroism and vibrational spectroscopy. A structural analysis, performed by combining dynamic light scattering, small-angle X-ray scattering, transmission electron microscopy, and molecular dynamic simulations, demonstrated that the transition allows the self-assemblies to remodel from spherical micelles to rodlike shapes, to long fibers with rectangular cross-section and a head-tail-tail-head structure. The viscoelastic behavior of the hydrogels formed at the highest pH was investigated by rheology measurements.

Switchable length nanotubes from a self-assembling pH and thermosensitive linear l,d-peptide-polymer conjugate

Preparation and characterization of a pH and thermosensitive linear l,d-octapeptide-poly(dimethylamino ethyl methacrylate) ((l-Val-d-Val)₄-PDMAEMA) conjugate is reported. The hydrophobic uncharged linear (l-Val-d-Val)₄ octapeptide was designed to self-assemble in nanotubes by exploiting the tubular self-assembling properties of linear peptides with regularly alternating enantiomeric sequences. pH and thermosensitive PDMAEMA was obtained by atom transfer radical polymerization (ATRP). The conjugate was prepared by click-chemistry on the solid phase synthetized peptide. Because of the strong interactions between the peptide moieties, long single channel nanotubes (0.2-1.5 μm) are formed also at acidic pH with the fully charged polymer. At 25 °C and basic pH the size of the nanotubes did not change significantly. In basic conditions and temperature above the PDMAEMA lower critical solution temperature (LCST) a significant increase of the length of the nanotubes up to several micrometers is observed. The size is retained for several days after cooling back to room temperature. Sonication significantly reduces the nanotube length (0.2-0.5 μm) forming low polydisperse nanotubes. The elongation of the nanotubes is fully reversible by restoring acidic pH. This is the first example, to our knowledge, of thermosensitive peptide-polymer single channel nanotubes with length that can be varied from hundreds of nanometers to several micrometers.

Comorbidities are associated with different features of severe asthma

Background

According to ATS/ERS document on severe asthma (SA), the management of these patients requires the identification and proper treatment of comorbidities, which can influence the control of asthma.

Methods

The aim of this study was to assess the independent effect of different comorbidities on clinical, functional and biologic features of SA. Seventy-two patients with SA according to GINA guidelines were examined. We collected demographic data, smoking habit, asthma history, and assessment of comorbidities. Pulmonary function, inflammatory biomarkers, upper airway disease evaluation, asthma control and quality of life were carefully assessed.

Results

The mean age of patients was 59.1 years (65.3% female, 5.6% current smokers). Comorbidities with higher prevalence were: chronic rhinosinusitis with or without nasal polyps (CRSwNP or CRSsNP), obesity and gastro-esophageal reflux (GERD), with some overlapping among them. In an univariate analysis comparing patients with single comorbidities with the other ones, asthmatics with CRSwNP had lower lung function and higher sputum eosinophilia; obese asthmatics had worse asthma control and quality of life, and tended to have lower sputum eosinophils; asthmatics with GERD showed worse quality of life. In multivariate analysis, obesity was the only independent factor associated with poor asthma control (OR 4.9), while CRSwNP was the only independent factor associated with airway eosinophilia (OR 16.2). Lower lung function was associated with the male gender and longer duration of asthma (OR 3.9 and 5.1, respectively) and showed a trend for the association with nasal polyps (OR 2.9, p = 0.06).

Conclusion

Our study suggests that coexisting comorbidities are associated with different features of SA.

Electronic supplementary material

The online version of this article (10.1186/s12948-018-0103-x) contains supplementary material, which is available to authorized users.

FAM49B, a novel regulator of mitochondrial function and integrity that suppresses tumor metastasis

Mitochondrial dysregulation plays a central role in cancers and drives reactive oxygen species (ROS)-dependent tumor progression. We investigated the pro-tumoral roles of mitochondrial dynamics and altered intracellular ROS levels in pancreatic ductal adenocarcinoma (PDAC). We identified 'family with sequence similarity 49 member B' (FAM49B) as a mitochondria-localized protein that regulates mitochondrial fission and cancer progression. Silencing FAM49B in PDAC cells resulted in increased fission and mitochondrial ROS generation, which enhanced PDAC cell proliferation and invasion. Notably, FAM49B expression levels in PDAC cells were downregulated by the tumor microenvironment. Overall, the results of this study show that FAM49B acts as a suppressor of cancer cell proliferation and invasion in PDAC by regulating tumor mitochondrial redox reactions and metabolism.

Benzimidazole-based derivatives as privileged scaffold developed for the treatment of the RSV infection: a computational study exploring the potency and cytotoxicity profiles

Respiratory syncytial virus (RSV) has been identified as a main cause of hospitalisation in infants and children. To date, the current therapeutic arsenal is limited to ribavirin and palivizumab with variable efficacy. In this work, starting from a number of in-house series of previously described anti-RSV agents based on the benzimidazole scaffold, with the aim at gaining a better understanding of the related chemical features involved in potency and safety profiles, we applied a computational study including two focussed comparative molecular fields analysis (CoMFA) and comparative molecular similarity indices analysis (CoMSIA). The results allowed us to derive useful suggestions for the design of derivatives and also to set up statistical models predicting the potency and selectivity index (SI = CC₅₀/EC₅₀) of any new analogue prior to synthesis. Accordingly, here, we discuss preliminary results obtained through the applied exhaustive QSAR analyses, leading to design and synthesise more effective anti-RSV agents.

PEGylated β-Sheet Breaker Peptides as Inhibitors of β-Amyloid Fibrillization

Three PEGylated β-sheet breaker peptides are designed as new inhibitors of β-amyloid fibrillization. The peptide Ac-Leu-Pro-Phe-Phe-Asp-NH₂ , considered the lead compound, and hexamers in which taurine and β-alanine substitute the acetyl group, are conjugated to poly(ethylene glycol); this conjugates self-assemble into nanoparticles. The activity of the PEGylated peptides as inhibitors of amyloid fibrillization are tested in vitro using circular dichroism spectroscopy and scanning electron microscopy. The experimental results indicate that PEGylation does not impair the ability of the β-sheet breaker peptides to inhibit fibrillogenesis in vitro. Moreover, microscopy images of β-amyloid incubated for 6 days with the taurine-containing peptide, suggest that this conjugate has major anti-fibrillogenesis activity and demonstrate the important role of the sulfonamide function against the amyloid aggregation.

New arylsparteine derivatives as positive inotropic drugs

Positive inotropic agents are fundamental in the treatment of heart failure; however, their arrhythmogenic liability and the increased myocardial oxygen demand strongly limit their therapeutic utility. Pursuing our study on cardiovascular activities of lupin alkaloid derivatives, several 2-(4-substituted-phenyl)-2-dehydrosparteines and 2-(4-substituted-phenyl)sparteines were prepared and tested for inotropic and chronotropic activities on isolated guinea pig atria. Four compounds (6b, 6e, 7b, and 7f) exhibited significant inotropism that, at the higher concentrations, was followed by negative inotropism or toxicity. Compound 7e (2-(4-tolyl)sparteine) exhibited a steep dose-depending inotropic activity up to the highest concentration tested (300 µM) with an E_max of 116.5 ± 3.4% of basal force, proving less potent but much more active in comparison to the highest concentrations tested of digoxin and milrinone having E_max of 87.5 ± 3.1% and 52.2 ± 1.1%, respectively. Finally, docking studies suggested that the relevant sparteine derivatives could target the sigma-1 receptor, whose involvement in cardiac activity is well documented.

Novel celecoxib analogues inhibit glial production of prostaglandin E2, nitric oxide, and oxygen radicals reverting the neuroinflammatory responses induced by misfolded prion protein fragment 90-231 or lipopolysaccharide

We tested the efficacy of novel cyclooxygenase 2 (COX-2) inhibitors in counteracting glia-driven neuroinflammation induced by the amyloidogenic prion protein fragment PrP90-231 or lipopolysaccharide (LPS). In search for molecules with higher efficacy than celecoxib, we focused our study on its 2,3-diaryl-1,3-thiazolidin-4-one analogues. As experimental models, we used the immortalized microglial cell line N9, rat purified microglial primary cultures, and mixed cultures of astrocytes and microglia. Microglia activation in response to PrP90-231 or LPS was characterized by growth arrest, morphology changes and the production of reactive oxygen species (ROS). Moreover, PrP90-231 treatment caused the overexpression of the inducible nitric oxide synthase (iNOS) and COX-2, with the consequent nitric oxide (NO), and prostaglandin E₂ (PGE₂) accumulation. These effects were challenged by different celecoxib analogues, among which Q22 (3-[4-(sulfamoyl)phenyl]-2-(4-tolyl)thiazolidin-4-one) inhibited microglia activation more efficiently than celecoxib, lowering both iNOS and COX-2 activity and reducing ROS release. During neurodegenerative diseases, neuroinflammation induced by amyloidogenic peptides causes the activation of both astrocytes and microglia with these cell populations mutually regulating each other. Thus the effects of PrP90-231 and LPS were also studied on mixed glial cultures containing astrocytes and microglia. PrP90-231 treatment elicited different responses in the co-cultures induced astrocyte proliferation and microglia growth arrest, resulting in a differential ability to release proinflammatory molecules with the production of NO and ROS mainly attributable on microglia, while COX-2 expression was induced also in astrocytes. Q22 effects on both NO and PGE₂ secretion were more significant in the mixed glial cultures than in purified microglia, demonstrating Q22 ability to revert the functional interaction between astrocytes and microglia. These results demonstrate that Q22 is a powerful drug able to revert glial neuroinflammatory responses and might represent a lead to explore the chemical space around celecoxib frameworks to design even more effective agents, paving the way to novel approaches to contrast the neuroinflammation-dependent toxicity.

Allele-specific silencing of EEC p63 mutant R304W restores p63 transcriptional activity

EEC (ectrodactily-ectodermal dysplasia and cleft lip/palate) syndrome is a rare genetic disease, autosomal dominant inherited. It is part of the ectodermal dysplasia disorders caused by heterozygous mutations in TP63 gene. EEC patients present limb malformations, orofacial clefting, skin and skin's appendages defects, ocular abnormalities. The transcription factor p63, encoded by TP63, is a master gene for the commitment of ectodermal-derived tissues, being expressed in the apical ectodermal ridge is critical for vertebrate limb formation and, at a later stage, for skin and skin's appendages development. The ΔNp63α isoform is predominantly expressed in epithelial cells and it is indispensable for preserving the self-renewal capacity of adult stem cells and to engage specific epithelial differentiation programs. Small interfering RNA (siRNA) offers a potential therapy approach for EEC patients by selectively silencing the mutant allele. Here, using a systemic screening based on a dual-luciferase reported gene assay, we have successfully identified specific siRNAs for repressing the EEC-causing p63 mutant, R304W. Upon siRNA treatment, we were able to restore ΔNp63-WT allele transcriptional function in induced pluripotent stem cells that were derived from EEC patient biopsy. This study demonstrates that siRNAs approach is promising and, may pave the way for curing/delaying major symptoms, such as cornea degeneration and skin erosions in young EEC patients.

Asthma Control and Airway Inflammation in Patients with Eosinophilic Granulomatosis with Polyangiitis

BACKGROUND

Eosinophilic granulomatosis with polyangiitis (EGPA) is a systemic necrotizing vasculitis that occurs in patients with asthma, nasal disease, blood and tissue eosinophilia, and extrapulmonary manifestations.

OBJECTIVE

The aim of our study was to assess the clinical, functional, and inflammatory status of upper and lower airways in 37 patients with EGPA, examined 6.4 ± 4.7 years after diagnosis, when they were in partial or complete remission from systemic involvement while on treatment with low-dose oral corticosteroids as maintenance therapy.

METHODS

All patients performed spirometry and were assessed for bronchial hyperreactivity, sputum eosinophilia, and fractional exhaled nitric oxide; asthma control was evaluated according to the Global Initiative for Asthma (GINA) guidelines and the Asthma Control Test. Markers of systemic disease were compared with the data available at diagnosis. Nasal involvement was evaluated by using the Sino-Nasal Outcome Test, nasal endoscopy, and nasal cytology. The impact on the quality of life was evaluated by using generic (36-item short form health survey) and organ-specific questionnaires.

RESULTS

At the time of the study visit, almost all patients were receiving low-dose oral corticosteroids and immunomodulating drugs, but only 50% were being treated with inhaled corticosteroids. Although low systemic disease activity was documented in the large majority of patients, poorly controlled asthma and rhinosinusitis with eosinophilic airway inflammation were demonstrated in almost all patients. A significant correlation was found between sputum and blood eosinophilia and between fractional exhaled nitric oxide and asthma control. The 36-item short form health survey questionnaire results significantly correlated with the Sino-Nasal Outcome Test but not with the Asthma Control Test.

CONCLUSIONS

Systemic treatment controls systemic involvement in EGPA, but not asthma and nasal diseases, which negatively affects patients' quality of life.

Antiviral activity of benzotriazole derivatives. 5-[4-(Benzotriazol-2-yl)phenoxy]-2,2-dimethylpentanoic acids potently and selectively inhibit Coxsackie Virus B5

A library of 64 benzotriazole derivatives (17 of which were [4-(benzotriazol-2-yl)phenoxy]alkanoic acids) were screened for antiviral activity against a panel of twelve DNA and RNA viruses. Twenty-six compounds (12 of which were [4-(benzotriazol-2-yl)phenoxy]alkanoic acids) displayed activity against one or more viruses. CVB-5, RSV, BVDV, Sb-1 and YFV were, in decreasing order, the more frequently and effectively affected viruses; DENV-2, WNV, HIV-1 and Reo-1 were only occasionally and modestly affected, while the remaining viruses were not affected by any of the tested compounds. Worth of note were compounds 33 and 35; the former for the activity against Sb-1 (EC50=7 μM) and the latter for the large spectrum of activity including six viruses with a mean EC50=12 μM. Even more interesting were the alkanoic acids 45-48 and 50-57 for their activity against RSV and/or CVB-5. In particular, compound 56 displayed a potent and selective activity against CVB-5 with EC50=0.15 μM and SI=100, thus representing a valuable hit compound for the development of antiviral agents for the treatment of human pathologies related to this virus.

Synthesis and Antiplasmodial Activity of Novel Chloroquine Analogues with Bulky Basic Side Chains

Chloroquine is commonly used in the treatment and prevention of malaria, but Plasmodium falciparum, the main species responsible for malaria-related deaths, has developed resistance against this drug. Twenty-seven novel chloroquine (CQ) analogues characterized by a side chain terminated with a bulky basic head group, i.e., octahydro-2H-quinolizine and 1,2,3,4,5,6-hexahydro-1,5-methano-8H-pyrido[1,2-a][1,5]diazocin-8-one, were synthesized and tested for activity against D-10 (CQ-susceptible) and W-2 (CQ-resistant) strains of P. falciparum. Most compounds were found to be active against both strains with nanomolar or sub-micromolar IC50 values. Eleven compounds were found to be 2.7- to 13.4-fold more potent than CQ against the W-2 strain; among them, four cytisine derivatives appear to be of particular interest, as they combine high potency with low cytotoxicity against two human cell lines (HMEC-1 and HepG2) along with easier synthetic accessibility. Replacement of the 4-NH group with a sulfur bridge maintained antiplasmodial activity at a lower level, but produced an improvement in the resistance factor. These compounds warrant further investigation as potential drugs for use in the fight against malaria.

Can Sputum Eosinophilia Be a Constant Feature in Severe Refractory Asthmatics? A 3-Year Longitudinal Study

In difficult-to-treat asthmatics, uncontrolled despite a high level of therapy and followed for 3 years with a mean number of sputum samples/patient = 10, sputum eosinophilia (≥3%) was observed in 87% of all sputum samples. Persistent sputum eosinophilia is a characteristic of severe uncontrolled asthma.

Multitarget Therapeutic Leads for Alzheimer's Disease: Quinolizidinyl Derivatives of Bi- and Tricyclic Systems as Dual Inhibitors of Cholinesterases and β-Amyloid (Aβ) Aggregation

Multitarget therapeutic leads for Alzheimer's disease were designed on the models of compounds capable of maintaining or restoring cell protein homeostasis and of inhibiting β-amyloid (Aβ) oligomerization. Thirty-seven thioxanthen-9-one, xanthen-9-one, naphto- and anthraquinone derivatives were tested for the direct inhibition of Aβ(1-40) aggregation and for the inhibition of electric eel acetylcholinesterase (eeAChE) and horse serum butyrylcholinesterase (hsBChE). These compounds are characterized by basic side chains, mainly quinolizidinylalkyl moieties, linked to various bi- and tri-cyclic (hetero)aromatic systems. With very few exceptions, these compounds displayed inhibitory activity on both AChE and BChE and on the spontaneous aggregation of β-amyloid. In most cases, IC50 values were in the low micromolar and sub-micromolar range, but some compounds even reached nanomolar potency. The time course of amyloid aggregation in the presence of the most active derivative (IC50 =0.84 μM) revealed that these compounds might act as destabilizers of mature fibrils rather than mere inhibitors of fibrillization. Many compounds inhibited one or both cholinesterases and Aβ aggregation with similar potency, a fundamental requisite for the possible development of therapeutics exhibiting a multitarget mechanism of action. The described compounds thus represent interesting leads for the development of multitarget AD therapeutics.

Sputum eosinophilia is a determinant of FEV1 decline in occupational asthma: results of an observational study

OBJECTIVE

To evaluate the potential determinants of forced expiratory volume in 1 s (FEV1) decline in workers with occupational asthma (OA) still exposed to the causative agent. We hypothesised that sputum eosinophilia might be a predictor of poor asthma outcome after diagnosis.

SETTING, DESIGN AND PARTICIPANTS

In a specialistic clinical centre of the University Hospital of Pisa, we studied 39 participants (28 M, 11 F) diagnosed as having OA, routinely followed up between 1990 and 2009. They were a subgroup of 94 participants diagnosed as affected by OA in that period: 9 had been removed from work at the diagnosis, 21 were excluded for having ceased occupational exposure after few months from diagnosis, and 25 were lost at the follow-up or had no acceptable sputum measurements at the diagnosis. Estimates of the decline in FEV1 were obtained by means of simple regression analysis during the period of occupational exposure after diagnosis. Logistic regression was used to analyse the effects of factors (baseline FEV1 and sputum inflammatory cells, duration and type of exposure) that may potentially influence FEV1 decline.

RESULTS

At follow-up (5.7+3.7 years), most participants were still symptomatic despite inhaled corticosteroids (ICS) treatment and had their occupational exposure reduced. Participants with higher sputum eosinophils (>3%) at baseline had a significantly greater decline of FEV1 (-52.5 vs -18.6 mL/year, p=0.012). Logistic regression showed that persistent exposure and sputum eosinophilia were significantly associated with a greater decline in FEV1 (OR 11.5, 95% CI 1.8 to 71.4, p=0.009 and OR 6.7, 95% CI 1.1 to 41.7, p= 0.042, respectively).

CONCLUSIONS

Sputum eosinophilia at diagnosis, together with the persistence of occupational exposure during follow-up, may contribute to a greater decline in FEV1 in patients with OA still at work. Further long-term studies are required as to whether intensive ICS treatment may be beneficial for patients with OA and increase ad eosinophilic inflammation.

Are sputum eosinophil cationic protein and eosinophils differently associated with clinical and functional findings of asthma?

BACKGROUND

Sputum eosinophil counts and eosinophil cationic protein (ECP) levels are usually increased in asthmatic patients. The correlation between sputum eosinophils or ECP and clinical findings of asthma has been previously investigated but many of these studies have been performed on small samples of asthmatic patients, considering only few clinical indices and often including patients on oral or inhaled corticosteroids, which might be confounding when interpreting the relationship between disease activity and airway inflammation.

OBJECTIVE

To assess whether sputum eosinophils and ECP were differently related to functional and clinical parameters of asthma in a large number of steroid-naïve asthmatic patients, taking into account several potential determinants of activity and chronicity of asthma.

METHODS

One hundred and twenty-nine patients with mild-moderate asthma were studied. Sputum was induced by hypertonic saline inhalation and processed using the whole sample method.

RESULTS

Sputum eosinophils and ECP significantly correlated with each other (r = 0.41, P < 0.001). When patients were grouped on the basis of high/low sputum eosinophils and high/low sputum ECP levels, significant differences were observed among groups, with patients with high sputum eosinophils and ECP showing the greatest asthma severity. In the overall sample, disease duration inversely correlated with sputum eosinophils, whereas FEV1 and peak expiratory flow (PEF) inversely correlated with sputum ECP. Rescue β2 -agonist use and total symptom score positively correlated with both eosinophil counts and sputum ECP. Stepwise regression analysis showed that symptom score and disease duration accounted for 17.6% of sputum eosinophil variance, whereas symptom score and FEV1 accounted for 14.7% of sputum ECP variance.

CONCLUSIONS AND CLINICAL RELEVANCE

Both sputum eosinophils and ECP are weakly related to clinical markers of asthma severity. However, ECP was more closely related to lung function parameters than eosinophil counts.

Asthma control in severe asthmatics under treatment with omalizumab: a cross-sectional observational study in Italy

Few data are available on the proportion of asthmatics achieving a good asthma control (according GINA guidelines) and on the level of airway inflammation during omalizumab treatment. The aim of this cross-sectional national observational study was to assess the level of control (according to GINA guidelines) achieved in a group of asthmatics on omalizumab treatment, and to characterize the factors that influence the lack of control. We studied 306 asthmatics under omalizumab treatment for a median of 32 months (range 4-120). The level of control according to GINA was good in 25.2%, partial in 47.1% and poor in 24.5% of patients (data were missing for the remaining 3.2%). Comparison between poorly controlled and partially or well controlled asthmatics showed a statistically significant higher prevalence of some comorbidities in the first group, namely obesity, gastro-oesophageal reflux disease (GORD), aspirin intolerance and mental disorders (all p < 0.001). Similarly, asthmatics with at least one exacerbation in the last year showed a significantly higher prevalence of obesity, chronic rhinosinusitis, nasal polyps, GORD, and aspirin intolerance (all p < 0.05) than patients without exacerbations. When we selected patients without relevant comorbidities (upper airways disease, GORD, obesity, aspirin intolerance) and not currently smoking (N = 73), the percentage of well or partially controlled asthmatics was significantly higher than in patients with comorbidities (84.9% vs 71.1%, p = 0.02); the rate of asthmatics without exacerbations in the last year was also higher (73.6% vs 51.1%, p = 0.001). During omalizumab treatment, a high percentage of asthmatics obtain a good or partial control of asthma. Comorbidities are associated with the lack of asthma control and persistence of exacerbations.

Tiotropium: a new therapeutic option in asthma

Although bronchial hyperresponsiveness to cholinergic agents is a main feature of asthma, the role of anticholinergic drugs in chronic asthma management has been largely underestimated. Several single-dose studies comparing acute bronchodilation induced by ipratropium bromide with salbutamol have shown that salbutamol is more effective than ipratropium in treating asthma. Recently, tiotropium has been studied in asthma, when added to low-medium dose inhaled corticosteroids (ICS) in unselected moderate asthmatics or in patients with uncontrolled asthma, or with COPD and history of asthma. Later, studies on patients with Arg/Arg beta2-receptor polymorphism demonstrated a similar efficacy of tiotropium in comparison with salmeterol, when both were added to ICS. More recently, pivotal long-term studies have been performed on severe asthmatics uncontrolled under ICS/LABA combination, showing the efficacy of tiotropium in improving lung function and in increasing the time until the first severe asthma exacerbation. These data support the use of tiotropium on top of ICS/LABA combination in moderate-severe asthmatic patients. New studies are going to be published on the use of tiotropium in mild and moderate asthmatics, when added to low or medium dose ICS, in comparison with ICS alone or with ICS/LABA combination. These data might extend the indication for using tiotropium in asthma. Therefore, tiotropium represents now a valid therapeutic option, in addition to the current therapy available for severe asthmatics, and in alternative to LABA in selected asthma populations. The specific asthma phenotype which may be appropriate for tiotropium treatment should still be defined.

Determinants of the prognosis of idiopathic pulmonary fibrosis

OBJECTIVE

Fibrotic idiopathic interstitial pneumonias are chronic and progressive lung diseases with different prognosis, with idiopathic pulmonary fibrosis (IPF) having the worst prognosis. Many patients need a surgical lung biopsy for the definite diagnosis of IPF but age and the clinical context often contraindicate this procedure. The aim of this study is to identify predictors of survival, apart from lung biopsy, in patients with definite and possible IPF.

PATIENTS AND METHODS

We studied 42 patients with HRCT pattern of definite or possible IPF, by assessing the mortality in relationship with baseline HRCT and functional findings. HRCT was assessed both as prevalent pattern (definite vs possible UIP) and as score of the different abnormalities (in particular, honeycombing (HC) and total fibrotic score). Pulmonary function was assessed as baseline FVC, TLC and DLCO values, as well as change over 6 months of follow-up. Both univariate and multivariate analyses were performed in order to detect predictors of mortality.

RESULTS

During follow-up, 10 out of 42 patients died. Mortality rate was not different according to the qualitative pattern of fibrosis at HRCT. Among the different HRCT scores, a cut-off of 15% in the HC score differentiated patients with higher mortality rate. A lower baseline FVC, and a greater decrease in pulmonary function after 6 months, were both associated with higher mortality. In a logistic analysis taking in consideration clinical, radiological and functional findings, only baseline FVC and FVC change after 6 months resulted significant predictors of mortality.

CONCLUSIONS

Functional evaluation at the baseline and during follow-up is more relevant than HC score for the prognosis of patients with definite and possible IPF.

Early expression of the fractalkine receptor CX3CR1 in pancreatic carcinogenesis

BACKGROUND

In pancreatic ductal adenocarcinoma (PDAC), fractalkine receptor CX3CR1 contributes to perineural invasion (PNI). We investigated whether CX3CR1 expression occurs early in PDAC and correlates with tumour features other than PNI.

METHODS

We studied CX3CR1 and CX3CL1 expression by immunohistochemistry in 104 human PDAC and coexisting Pancreatic Intraepithelial Neoplasia (PanIN), and in PdxCre/LSL-Kras(G12D) mouse model of PDAC. CX3CR1 expression in vitro was studied by a spheroid model, and in vivo by syngenic mouse graft of tumour cells.

RESULTS

In total, 56 (53.9%) PDAC expressed CX3CR1, 70 (67.3%) CX3CL1, and 45 (43.3%) both. CX3CR1 expression was independently associated with tumour glandular differentiation (P=0.005) and PNI (P=0.01). Pancreatic Intraepithelial Neoplasias were more frequently CX3CR1+ (80.3%, P<0.001) and CX3CL1+ (86.8%, P=0.002) than matched cancers. The survival of PDAC patients was better in those with CX3CR1+ tumour (P=0.05). Mouse PanINs were also CX3CR1(+) and -CL1(+). In vitro, cytokines significantly increased CX3CL1 but not CX3CR1 expression. Differently, CX3CR1 was upregulated in tumour spheroids, and in vivo only in well-differentiated tumours.

CONCLUSION

Tumour differentiation, rather than inflammatory signalling, modulates CX3CR1 expression in PanINs and PDAC. CX3CR1 expression pattern suggests its early involvement in PDAC progression, outlining a potential target for interfering with the PanIN transition to invasive cancer.

Speed limit of the insulator-metal transition in magnetite

As the oldest known magnetic material, magnetite (Fe3O4) has fascinated mankind for millennia. As the first oxide in which a relationship between electrical conductivity and fluctuating/localized electronic order was shown, magnetite represents a model system for understanding correlated oxides in general. Nevertheless, the exact mechanism of the insulator-metal, or Verwey, transition has long remained inaccessible. Recently, three-Fe-site lattice distortions called trimerons were identified as the characteristic building blocks of the low-temperature insulating electronically ordered phase. Here we investigate the Verwey transition with pump-probe X-ray diffraction and optical reflectivity techniques, and show how trimerons become mobile across the insulator-metal transition. We find this to be a two-step process. After an initial 300 fs destruction of individual trimerons, phase separation occurs on a 1.5±0.2 ps timescale to yield residual insulating and metallic regions. This work establishes the speed limit for switching in future oxide electronics.

Baseline airway inflammation may be a determinant of the response to ozone exposure in asthmatic patients

CONTEXT

It is well known that ozone exposure decreases lung function and increases airway neutrophilia, but large variability has been observed among asthmatic patients.

OBJECTIVE

To find possible predictors of functional and inflammatory airway response to ozone in asthmatic patients.

MATERIALS AND METHODS

We studied 120 patients with mild-to-moderate asthma, randomly exposed to either air or ozone (0.3 ppm for 2 h) in a challenge chamber. Symptoms and pulmonary function test (PFT) were measured before and immediately after exposure. Six hours after exposure, induced sputum was collected. Patients were evaluated according to their functional (FEV₁ responders) or neutrophilic (neutrophil responders) response to ozone. We considered, as possible predictors of response: age, baseline FEV₁, previous treatment with inhaled corticosteroids (ICS), baseline sputum neutrophils, baseline sputum eosinophils, methacholine responsiveness, atopy and smoking habit.

RESULTS

FEV₁ responders had lower baseline FEV₁, and a lower percentage of these had received ICS treatment. Neutrophil responders were younger, with lower baseline sputum inflammation and greater methacholine responsiveness. These results were confirmed by multivariate logistic analysis.

DISCUSSION AND CONCLUSION

Patients not previously treated with ICS and patients with lower FEV₁ are more prone to functional response to ozone. Lower baseline airway inflammation and greater bronchial hyperresponsiveness may predict neutrophilic airway response to ozone in asthmatic patients. Thus, determinants of functional and inflammatory responses to ozone are different.

(+)-Laburnamine, a natural selective ligand and partial agonist for the α4β2 nicotinic receptor subtype

(+)-Laburnamine (1), a rare alkaloid extracted from Laburnum anagyroides seeds (∼4 mg from 1 kg), was shown to bind with high affinity (Ki, 293 nM) to the α4β2 nicotinic receptor subtype, which is, respectively, 126 and 136 times higher than to the α3β4 (Ki 37 μM) and α7 subtypes (Ki 40 μM). When its ability to release [(3)H]-dopamine from striatal slices was tested in a functional assay, compound 1 behaved as a partial agonist with an EC50 of 5.8 μM and an Emax that was 43% that of nicotine. When incubated with nicotine in the same assay, 1 prevented a maximal effect from being reached.

Mild improvement in symptoms and pulmonary function in a long-term follow-up of patients with toluene diisocyanate-induced asthma

BACKGROUND

Long-term follow-up of diisocyanate-induced occupational asthma has been occasionally reported.

METHODS

We studied the outcome of toluene diisocyanate (TDI)-induced asthma in 46 patients at diagnosis and after a follow-up of 11 ± 3.6 years. Symptoms, anti-asthma therapy, forced expiratory volume in 1 s (FEV1) and bronchial hyperresponsiveness to methacholine were assessed.

RESULTS

A significant improvement in FEV1 (% predicted) and PD20FEV1 methacholine was observed at follow-up in comparison with diagnosis. Anti-asthma treatment was performed by 42% of patients at diagnosis and by 70% at follow-up. At the time of follow-up, 32 subjects had been removed from exposure for 6.0 ± 6.9 years, whereas 14 subjects continued to work with reduced exposure to TDI. There was a significant reduction in the prevalence of attacks of shortness of breath and dyspnoea at follow-up, but only in unexposed patients. PD20FEV1 was significantly improved only in patients with a lower FEV1 at diagnosis and in those who have ceased work. Logistic regression analysis, using different models with some independent variables, showed that there were no significant determinants of improvement in FEV1 at follow-up, while a shorter duration of symptoms before diagnosis was a significant predictor of improvement in PD20FEV1 at follow-up.

CONCLUSIONS

Asthma-like symptoms, bronchial hyperresponsiveness and airway obstruction improved, but did not normalize, after a long-term follow-up with cessation or reduction in TDI exposure, mainly in subjects with an early diagnosis of occupational asthma and in patients with a lower baseline FEV1 no longer exposed to TDI.

Efficacy of anticholinergic drugs in asthma

Although bronchial hyperresponsiveness to cholinergic agents is a main feature of asthma, the role of anticholinergic drugs in chronic asthma management has been largely underestimated. Several single-dose studies comparing acute bronchodilation induced by ipratropium bromide with salbutamol have shown that salbutamol was more effective than ipratropium in asthma treatment. Recently, tiotropium has been studied in asthma, when added to low-dose inhaled corticosteroids in unselected moderate asthmatics or in patients with uncontrolled asthma, or patients with chronic obstructive pulmonary disease and history of asthma. Later, studies on patients with Arg/Arg β(2)-receptor polymorphism demonstrated a similar efficacy of tiotropium in comparison with salmeterol when both were added to low-dose inhaled corticosteroids. Further long-term studies are currently in progress, for the evaluation of the efficacy of tiotropium on clinical asthma control, and on the rate and severity of asthma exacerbations, as well as the potential modification of inflammatory mechanisms and varying efficacy in specific asthma phenotypes (such as smoking asthmatics).

Evaluation of underreporting tuberculosis in Central Italy by means of record linkage

Background

Tuberculosis (TB) surveillance systems have some pitfalls outside of a National Tuberculosis Program and lack of efficient surveillance hampers accurate epidemiological quantification of TB burden.

In the present study we assessed the quality of surveillance at the University Hospital in Pisa (UHP), Italy, and TB incidence rates over a ten year period (1999–2008).

Methods

Assessment of underreporting was done by record-linkage from two sources: databases of TB diagnoses performed in the UHP and the Italian Infectious Disease Surveillance (IIDS) system. Two different databases were examined: a) TB diagnoses reported in the Hospital Discharge Records (HDR) from three Units of UHP (Respiratory Pathophysiology, Pulmonology and Infectious Diseases Units) (TB database A); b) TB diagnoses reported in HDR of all Units of UHP plus TB positive cases obtained by the Laboratory Register (LR) of UHP (TB database B). For the TB database A, the accuracy of TB diagnosis in HDR was assessed by direct examination of the Clinical Record Forms of the cases. For the TB database B, clinical and population data were described, as well as the trend of incidence and underreporting over 10 yrs.

Results

In the first study 293 patients were found: 80 patients (27%) with a confirmed TB diagnosis were underreported, 39 of them were microbiologically confirmed. Underreporting was related to age (Reported vs Non Reported, mean age: 49.27 ± 20 vs 55 ± 19, p < 0.005 ), diagnosis (smear positive vs negative cases 18.7 vs 81.2%, p = 0.001), microbiological confirmation (49% vs 51%, p < 0.05), X-ray findings (cavitary vs non-cavitary cases: 12.5 vs 87.5%, p = 0.001) but not to nationality.

In the second study, 666 patients were found. Mean underreporting rate was 69.4% and decreased over time (68% in 1999, 48% in 2008). Newly diagnosed TB cases were also found to decrease in number whereas immigration rate increased. Underreporting was related to nationality (Immigrants vs Italians: 18% vs 68%, p < 0.001), diagnosis (microbiological confirmation: 25% vs 75%, p < 0.01), kind of hospital regimen (hospitalized patients vs Day Hospital: 70% vs 16%, p < 0.001), and position of TB code in the HDR (TB code in first position vs in the following position: 39,5% vs 45% p < 0.001).

Conclusions

TB is underreported in Pisa, particularly in older patients and those without microbiological confirmation. The TB code in first position of HDR seems fairly accurate in confirming TB diagnosis.

Asthma control test (ACT): comparison with clinical, functional, and biological markers of asthma control

BACKGROUND

Asthma Control Test (ACT) is a simple tool for assessing the level of asthma control in clinical practice, and it has been validated in comparison with a general clinical assessment of asthma control, including forced expiratory volume in the first second (FEV(1)).

OBJECTIVE

To evaluate the relationship between ACT score and clinical and functional findings of asthma control and biomarkers of airway inflammation.

METHODS

A total of 68 asthmatic patients observed in our asthma clinic (33 regularly treated with inhaled corticosteroids (ICS) and 35 ICS-naïve) filled ACT questionnaire and underwent the following measurements: (a) FEV(1) before and after salbutamol; (b) exhaled nitric oxide; (c) bronchial hyperresponsiveness to methacholine; (d) sputum eosinophil count; and (e) daytime and nighttime symptoms, rescue salbutamol, and twice-daily peak expiratory flow (PEF) recording on a 4-week diary card.

RESULTS

ACT score significantly correlated with symptom score, rescue medication use, and PEF variability, but not with FEV(1), FEV(1) reversibility, and markers of airway inflammation, which could not distinguish controlled from uncontrolled patients according to ACT, regardless of ICS treatment.

CONCLUSION

ACT score is a valid tool to simply assess the current level of asthma control in terms of symptoms, rescue medication use, and PEF variability. Pulmonary function and biomarkers of airway inflammation are not related to the clinical asthma control as assessed by ACT and may represent additional measurements potentially useful in asthma management.

May the reduction of exposure to specific sensitizers be an alternative to work cessation in occupational asthma? Results from a follow-up study

BACKGROUND

Few data are reported on the effects of a reduction of exposure to specific sensitizers in occupational asthma (OA). The objective of this study was to evaluate the clinical outcome of subjects with OA, comparing the effect of a reduction with that of the persistence or cessation of occupational exposure to the specific sensitizer.

SUBJECTS AND METHODS

Forty-one subjects with OA due to different sensitizers were diagnosed via a specific inhalation challenge. After a follow-up interval of 3.5 years, subjects were reexamined by clinical assessment, bronchial hyperresponsiveness (BH) and induced sputum.

RESULTS

At follow-up, subjects who had reduced occupational exposure (n = 22) showed a significant improvement in BH and a nonsignificant improvement in sputum eosinophilia (from 5.3 to 1.1%, n.s.), while subjects still exposed (n = 10) showed a significant decrease in FEV(1). Subjects who ceased work (n = 9) showed a trend of improvement in BH and sputum eosinophilia. Logistic analysis showed that the major determinant of improvement in BH at follow-up was the severity of BH at diagnosis, with a minimal contribution from the duration of exposure and treatment with inhaled corticosteroids during follow-up; reduction of work exposure did not enter into any model.

CONCLUSION

The reduction of occupational exposure could not be considered to be as effective as work cessation, which remained the best treatment for OA. However, it was not associated with a deterioration of FEV(1) as observed in subjects with persistent exposure.

Are Italian pulmonologists aware of the guidelines for asthma management and do they know how to apply them?

BACKGROUND

Since 1995 GINA (Global Initiative on Asthma) guidelines for asthma management have been updated annually and published in order to promote better management of asthma in real life situations. The aim of our study was to assess the level of implementation of GINA Guidelines among Italian Pulmonary Specialists (PSs).

METHODS

A detailed questionnaire was sent to 296 Respiratory Units (RUs) in Italy in order to collect information about personnel involved in the management of asthma patients, availability and use of diagnostic tools, recommended treatment according to the degree of asthma severity, educational activity. Data were analysed by using the SPSS programme.

RESULTS

74 (25%) questionnaires were returned and analysed. Most RUs (70%) do not have a dedicated asthma clinic; however, spirometry is available in more than 90% of RUs, although it is performed in no more than 50% of patients in most RUs. Asthma treatment concurs with GINA recommendations in most RUs. Educational activity is performed by almost all RUs, usually in informal manner, during clinical visits, whereas only few RUs arrange individual educational sessions or "asthma school".

CONCLUSIONS

GINA guidelines for asthma management are applied by most Italian RUs included in this study in regard to educational activity and, to a lesser extent, to treatment. Surprisingly, many RUs perform spirometry in a relatively small number of patients despite its availability.

Malondialdehyde in exhaled breath condensate as a marker of oxidative stress in different pulmonary diseases

BACKGROUND

Oxidative stress plays a role in the pathogenesis of many chronic inflammatory lung diseases. Exhaled breath condensate (EBC) collection is a noninvasive method to investigate pulmonary oxidative stress biomarkers such as malondialdehyde (MDA).

SUBJECTS AND METHODS

We measured MDA levels in EBC in a large number of patients (N = 194) with respiratory diseases: asthma (N = 64), bronchiectasis (BE, N = 19), chronic obstructive pulmonary disease (COPD, N = 73), idiopathic pulmonary fibrosis (IPF, N = 38). Fourteen healthy nonsmoking subjects were included as controls.

RESULTS

Excluding IPF subjects, MDA levels were significantly higher in all disease groups than in control group. MDA was significantly higher in COPD than asthmatic and BE subjects. Among asthmatics, corticosteroids-treated subjects had lower MDA levels than untreated subjects. COPD subjects showed an inverse correlation between MDA concentrations and FEV(1)% (rho:  -0.24, P < .05).

CONCLUSIONS

EBC-MDA is increased in subjects with chronic airway disorders, particularly in COPD, and it is related to FEV(1) reduction.

Comparison between Airway Responses to High versus Low Molecular Weight Compounds in Occupational Asthma

Occupational asthma (OA) is a heterogeneous disease, and the characteristics of the sensitizer responsible for OA may induce different clinical, functional, and biological manifestations. We examined the characteristics of 74 patients with OA induced by low molecular weight compounds (LMWC) or by high molecular weight compounds (HMWC) and diagnosed by specific inhalation challenge (SIC). Patients with OA induced by LMWC had a longer occupational exposure before the beginning of symptoms, a lower sputum eosinophilia, and a higher prevalence of late airway response (LAR), in comparison with patients with OA induced by HMWC. Pulmonary function tended to be poorer and atopy tended to be less frequent in LMWC-induced OA than in HMWC-induced OA. These data confirm and extend previous observations showing that the characteristics of the specific sensitizer inducing OA may determine different clinical, functional, and biological features, probably related to the difference pathogenetic mechanisms underlying these different types of OA.