Basophils are recruited to inflamed lungs and exacerbate memory Th2 responses in mice and humans

BACKGROUND

Although the contribution of basophils as inducers or amplifiers of Th2 responses is still debated, prolonged basophil/CD4 T cell interactions were observed in lungs but not lymph nodes (LNs) of parasite-infected mice. However, the impact of basophils on the function of tissue CD4 effector T cells remains unknown.

METHODS

Basophils were purified from the lungs of ovalbumin (OVA)-sensitized and OVA-challenged (OVA-immunized) mice or human peripheral blood for in vivo and in vitro functional studies. Pulmonary basophils were adoptively transferred to OVA-sensitized hosts to assess airway inflammation in bronchoalveolar lavage fluid (BALF) and Th2 responses in lung explants and draining LNs. Basophils were co-cultured with effector T cells or Ag-specific naïve T cells alone or in combination with dendritic cells (DCs); IL-4 production was determined by flow cytometry and ELISA.

RESULTS

Basophils accumulated in lungs of OVA-immunized mice. Adoptive transfer of basophils to OVA-sensitized hosts enhanced lung IL-4 and IL-13 release while co-administration of OVA further aggravated airway inflammation and Th2 responses in LNs. Mechanistic in vitro studies revealed that pulmonary basophils interacted with lung CD4 effectors, in the absence of DCs, to increase T cell survival and Th2 cytokine expression at the single cell level but amplified OVA-loaded DC-driven Th2 differentiation. Finally, human basophils augmented in vitro IL-4 expression in effector memory CD4 T cells that include CRTH2(+) cells through IL-4 and TCR-independent pathways.

CONCLUSIONS

Basophils may worsen Th2 inflammatory disorders through direct interactions with pathogenic CD4 T cells as well as by enhancing DC-induced Th2 cell development.

MicroRNAs in metamorphic and non-metamorphic transitions in hemimetabolan insect metamorphosis

Background

Previous work showed that miRNAs play key roles in the regulation of metamorphosis in the hemimetabolan species Blattella germanica. To gain insight about which miRNAs might be important, we have constructed two miRNA libraries, one of the penultimate, pre-metamorphic nymphal instar (N5) and the other of the last, metamorphic nymphal instar (N6).

Results

High throughput sequencing gave 61 canonical miRNAs present in the N5 and N6 libraries, although at different proportions in each. Comparison of both libraries led to the identification of three and 37 miRNAs significantly more expressed in N5 and N6 respectively. Twelve of these 40 miRNAs were then investigated further by qRT-PCR and results indicated that miR-252-3p was well expressed in N5 but not in N6, whereas let-7-5p, miR-100-5p and miR-125-5p showed the reverse pattern. 20-Hydroxyecdysone (20E) tended to stimulate miRNA expression, whereas juvenile hormone (JH) inhibited the 20E stimulatory effect. Expression of let-7, miR-100 and miR-125 was increased by 20E, which has also been observed in D. melanogaster. The only miRNA that was inhibited by 20E was miR-252-3p. The involvement of let-7, miR-100 and miR-125 in metamorphosis has been demonstrated in other insects. Depletion of miR-252-3p caused growth and developmental delays, which suggests that this miRNA is involved in regulating these processes prior to metamorphosis.

Conclusions

The comparative analysis of miRNA libraries from pre-metamorphic (N5) and metamorphic stages (N6) of B. germanica proved to be a useful tool to identify miRNAs with roles in hemimetabolan metamorphosis. Three miRNAs emerged as important factors in the metamorphic stage (N6): let-7-5p, miR-100-5p and miR-125-5p, whereas miR-252-3p appears to be important in the pre-metamorphic stage (N5).

On the N1-H and N3-H Bond Dissociation in Uracil by Low Energy Electrons: A CASSCF/CASPT2 Study

The dissociative electron-attachment (DEA) phenomena at the N1-H and N3-H bonds observed experimentally at low energies (<3 eV) in uracil are studied with the CASSCF/CASPT2 methodology. Two valence-bound π(-) and two dissociative σ(-) states of the uracil anionic species, together with the ground state of the neutral molecule, are proven to contribute to the shapes appearing in the experimental DEA cross sections. Conical intersections (CI) between the π(-) and σ(-) are established as the structures which activate the DEA processes. The N1-H and N3-H DEA mechanisms in uracil are described, and experimental observations are interpreted on the basis of two factors: (1) the relative energy of the (U-H)(-) + H fragments obtained after DEA with respect to the ground-state equilibrium structure (S0) of the neutral molecule (threshold for DEA) and (2) the relative energy of the CIs also with respect to S0 (band maxima). The π1(-) state is found to be mainly responsible for the N1-H bond breaking, whereas the π2(-) state is proved to be involved in the cleavage of the N3-H bond.

Anaesthetic and cardiorespiratory effects of a constant-rate infusion of alfaxalone in desflurane-anaesthetised sheep

A prospective, randomised, blinded controlled study was performed to determine the anaesthetic and cardiorespiratory effects of a constant-rate infusion (CRI) of alfaxalone in 12 sheep anaesthetised with desflurane, and undergoing experimental orthopaedic surgery. Sheep were sedated with dexmedetomidine (4 μg/kg, intravenously) and butorphanol (0.3 mg/kg, intravenously). Anaesthesia was induced with alfaxalone (1 mg/kg/minute to effect, intravenously) and maintained with desflurane in oxygen and alfaxalone 0.07 mg/kg/minute or saline for 150 minutes (range 150-166 minutes). The anaesthetic induction dose of alfaxalone, the desflurane expiratory fraction required for anaesthetic maintenance, cardiorespiratory measurements and blood-gases were recorded at predetermined intervals. Quality of sedation, anaesthetic induction and recovery were assessed. The alfaxalone induction dose was 1.7 mg/kg (1.2 to 2.6 mg/kg). The desflurane expiratory fraction was lower (22 per cent) in sheep receiving alfaxalone CRI (P=0). Also, heart rate (P=0), cardiac index (P=0.002), stroke index (P=0) and contractility (P=0) were higher, and systemic vascular resistance (P=0.002) was lower. Although respiratory rate tended to be higher with alfaxalone, there was no difference in PCO2 between the groups. Recovery times were significantly longer in sheep given alfaxalone (25.4 v 9.5 minutes) but recovery quality was similar. Alfaxalone reduced requirements of desflurane and maintained similar cardiorespiratory function, but recovery time was more prolonged.

[Complete regression of melanocytic nevi: correlation between clinical, dermoscopic, and histopathologic findings in 13 patients]

BACKGROUND

The complete regression of melanocytic tumors, confirmed by histology, has rarely been reported in the literature. It is very difficult to determine the malignant or benign nature of a regressed tumor, and on occasions, the only indication of malignancy is the subsequent development of metastasis.

MATERIAL AND METHODS

We performed a descriptive study of melanocytic nevi that had undergone complete, histologically confirmed regression prior to excision in the dermatology department of our hospital over a period of 3 years. We included only lesions in which dermoscopy performed prior to regression showed features that suggested benignity. We assessed various clinical, dermoscopic, histologic, and immunohistochemical features.

RESULTS

The mean time to complete regression was 6.4 months. The main dermoscopic patterns observed were reticular and mixed reticular/globular. Unlike what is generally seen in melanomas, the main histologic finding was the presence of fine or lamellar fibrosis. In all cases, there was a predominance of CD8+ T cells.

CONCLUSIONS

The clinical, dermoscopic, and histologic features of the melanocytic nevi studied suggest the existence of a highly characteristic form of tumor regression characterized by very rapid regression and the involvement of a cytotoxic mechanism.

[Low-fluence photodynamic therapy in chronic central serous chorioretinopathy]

OBJECTIVE

To evaluate safety and efficacy of low-fluence photodynamic therapy (LFPDT) with verteporfin in patients affected with chronic central serous chorioretinopathy (CCSC), in terms of visual acuity (VA) and macular morphology measured with optical coherence tomography (OCT).

METHODS

A retrospective, non-randomized and interventionist analysis was performed on 16 eyes in 15 patients with CCSC treated with LFPDT. Best corrected visual acuity (BCVA) with ETDRS optotypes and central foveal thickness (CFT) in OCT were evaluated as outcome measures.

RESULTS

The mean follow-up was 10.8 months. The mean BCVA improved from 58.12 to 68.68 ETDRS letters, and CFT decreased from 280.5 to 172.18 microns, with subretinal fluid resolution in 14 eyes (87.5%), two of them after a second LFTPD. No complications related to treatment were recorded.

CONCLUSIONS

LFPDT with verteporfin can be useful in CCSC to stabilise or improve BCVA, reabsorb subretinal fluid and reduce CFT. Randomised studies with a longer follow-up are required to assure the role of this treatment and to optimise parameters for higher efficacy and safety in CCSC patients.

Results of drug hypersensitivity evaluations in a large group of children and adults

BACKGROUND

Proven IgE or T-cell mediated drug hypersensitivity reactions (DHRs) seem less common in children compared with adults. However, this has never been proved by data.

OBJECTIVE

To determine and compare proven DHR prevalence in children and adults.

METHODS

Using the DAHD (Drug Allergy and Hypersensitivity Database) cohort, children with proven DHRs were compared with adults. The international EAACI-ENDA recommendations were followed. Patients were divided into four groups: index reaction and test during childhood (C/C), index reaction at childhood and test at adulthood (C/A), index reactions at childhood and adulthood and test at adulthood (CA/A), index reaction and test at adulthood (A/A).

RESULTS

A total of 3275 patients (67.9% female), comprising a total of 4370 patient-episodes, were evaluated (74.5% belonged to the A/A group). Prevalence of positive tests was 15.2% (95%CI, 14.1-16.2) for all tested classes, 10.6% (8.3-13.0) for C/C, 10.6% (7.5-13.6) for C/A, 22.1% (12.8-31.3) for CA/A and 16.5% (15.2-17.8) for A/A. The prevalence was lower in group C/C compared with groups A/A (P < 0.0001) and CA/A (P = 0.003). It was also lower in group C/A compared with the two latter groups (respectively P = 0.003 and P = 0.005). Significant differences were found for maculopapular exanthemas only, and not for urticaria/angiœdema and anaphylaxis. The difference was mainly observed with β-lactams and not for NSAIDs.

CONCLUSION AND CLINICAL RELEVANCE

Suspicions of DHRs are less likely to be confirmed in children.

Specific cutaneous lesions in patients with systemic sarcoidosis: relationship to severity and chronicity of disease

BACKGROUND

Specific (granulomatous) cutaneous lesions are seen in 9-37% of cases of systemic sarcoidosis, and are usually classified into maculopapules, plaques, lupus pernio (LP), scar sarcoidosis, and subcutaneous sarcoidosis. Their prognostic significance has not been fully established.

AIM

To analyse the relationship between the clinical type of granulomatous cutaneous lesions and the systemic features and prognosis of systemic sarcoidosis.

METHODS

The clinical charts of 86 patients (19 men, 67 women, mean age 46.82 years) with systemic sarcoidosis and granulomatous cutaneous involvement followed up for > 2 years at Bellvitge University Hospital were reviewed.

RESULTS

Cutaneous lesions developed before or at the time of diagnosis of systemic sarcoidosis in 80.23% of patients. The main cutaneous lesions were classified as maculopapules (28 patients), plaques (31), LP (6), scar sarcoidosis (7) and subcutaneous sarcoidosis (14). Erythema nodosum (EN) was seen in 30 patients. Radiological stage was 0 for 8 patients, I for 48, II for 24, III for 5 and IV for 1. Systemic sarcoidosis activity persisted for > 2 years in 47 patients, and 42 received systemic corticosteroid treatment for their disease. Maculopapular and subcutaneous sarcoidosis were mainly seen in patients with EN and radiological stage I. Plaques and LP were associated with chronic disease and requirement for systemic corticosteroids.

CONCLUSIONS

Cutaneous granulomatous lesions are usually present at the diagnosis of systemic sarcoidosis, and the type of cutaneous involvement may have prognostic significance.

The retinoid, 6-[3-adamantyl-4-hydroxyphenyl]-2-napthalene carboxylic acid, controls proliferative, morphological, and inflammatory responses involved in microglial activation without cytotoxic effects

Activation of microglia is regulated by controlling both its population size (through modulation of proliferation/death) and the production of inflammatory mediators. Retinoids control cellular proliferation, differentiation, and death. Natural retinoids have been shown to exhibit anti-inflammatory actions against activated microglia. However, the synthetic forms, which are regarded to be more stable in their actions, have not been explored for their capacity to modulate microglial activation, proliferation, and/or trigger cell death. The aim of the current study was to address these issues by using a model, lipopolysaccharide (LPS)-activated primary cultures of rat microglia, and the stable synthetic retinoid, 6-[3-adamantyl-4-hydroxyphenyl]-2-napthalene carboxylic acid (AHPN). Morphological observations of cluster of differentiation (CD) 11b (CD11b)-positive cells suggested that low concentration of AHPN (i.e. 5 μM) reduced LPS (1 μg/ml, 24 h)-activated morphology of microglia possibly toward a lower activated state, while attenuating nitrite production and the level of its synthesizing enzyme, inducible nitric oxide synthase (iNOS), as well as the chemokine, monocyte chemotactic protein-1 (MCP-1). The mechanisms behind these anti-inflammatory actions likely involved decreased activation of nuclear factor kappa B (NF-κB) as shown by the attenuated phosphorylation of its p65 subunit. In addition, fluorescence-activated cell sorting revealed that AHPN reduced the immunophenotypic marker of activation, CD68. LPS-mediated increase in cell number was reduced by low concentration AHPN, which resulted from inhibition of proliferation, based on decreased labeling for Ki-67 and reduced protein expression of cyclin D1, and not cell death. Higher concentrations of AHPN (50-100 μM) attenuated activation and cell number; however, the release of lactate dehydrogenase and appearance of annexin V and propidium iodide-positive cells suggested that cell death was its primary cause for reduced microglial activity. Overall, the current study shows that synthetic retinoids, such as AHPN, at low concentration attenuate microglial activation-associated responses, possibly via the inhibition of their cell proliferation without triggering cell death.

Deep sequencing of organ- and stage-specific microRNAs in the evolutionarily basal insect Blattella germanica (L.) (Dictyoptera, Blattellidae)

Background

microRNAs (miRNAs) have been reported as key regulators at post-transcriptional level in eukaryotic cells. In insects, most of the studies have focused in holometabolans while only recently two hemimetabolans (Locusta migratoria and Acyrthosiphon pisum) have had their miRNAs identified. Therefore, the study of the miRNAs of the evolutionarily basal hemimetabolan Blattella germanica may provide valuable insights on the structural and functional evolution of miRNAs.

Methodology/Principal Findings

Small RNA libraries of the cockroach B. germanica were built from the whole body of the last instar nymph, and the adult ovaries. The high throughput Solexa sequencing resulted in approximately 11 and 8 million reads for the whole-body and ovaries, respectively. Bioinformatic analyses identified 38 known miRNAs as well as 11 known miRNA*s. We also found 70 miRNA candidates conserved in other insects and 170 candidates specific to B. germanica. The positive correlation between Solexa data and real-time quantitative PCR showed that number of reads can be used as a quantitative approach. Five novel miRNA precursors were identified and validated by PCR and sequencing. Known miRNAs and novel candidates were also validated by decreasing levels of their expression in dicer-1 RNAi knockdown individuals. The comparison of the two libraries indicates that whole-body nymph contain more known miRNAs than ovaries, whereas the adult ovaries are enriched with novel miRNA candidates.

Conclusions/Significance

Our study has identified many known miRNAs and novel miRNA candidates in the basal hemimetabolan insect B. germanica, and most of the specific sequences were found in ovaries. Deep sequencing data reflect miRNA abundance and dicer-1 RNAi assay is shown to be a reliable method for validation of novel miRNAs.

Consensus statement on the diagnosis, management, and treatment of angioedema mediated by bradykinin. Part I. Classification, epidemiology, pathophysiology, genetics, clinical symptoms, and diagnosis

BACKGROUND

There are no Spanish guidelines or consensus statement on bradykinin-induced angioedema.

AIM

To review the pathophysiology, genetics, and clinical symptoms of the different types of bradykinin-induced angioedema and to draft a consensus statement in light of currently available scientific evidence and the experience of experts. This statement will serve as a guideline to health professionals.

METHODS

The consensus was led by the Spanish Study Group on Bradykinin-Induced Angioedema (SGBA), a working group of the Spanish Society of Allergology and Clinical Immunology. A review was conducted of scientific papers on different types of bradykinin-induced angioedema (hereditary and acquired angioedema due to C1 inhibitor deficiency, hereditary angioedema related to estrogens, angioedema induced by angiotensin-converting enzyme inhibitors). Several discussion meetings of the SGBA were held in Madrid to reach the consensus.

RESULTS

The pathophysiology, genetics, and clinical symptoms of the different types of angioedema are reviewed. Diagnostic approaches are discussed and the consensus reached is described.

CONCLUSIONS

A review of bradykinin-induced angioedema and a consensus on diagnosis are presented.