Bullous pemphigoid induced by m-TOR inhibitors in renal transplant recipients.

BACKGROUND: Bullous pemphigoid (BP) is an acquired autoimmune disease, with typical histology and immune pathological findings, which might be associated with drug therapy. The list of responsible drugs increases every year, but a current literature revision do not include the mammalian target of rapamycin (mTOR) inhibitors. By converse, bullous pemghigoid cases have been described in renal transplant recipients and associated with the allogenic graft itself, causing a cross reaction against the skin, or unbalancing the immune response, through a chronic cell-mediated suppression, non-specifically favouring the autoantibody production. OBJECT AND RESULTS: Two cases of BP occurred, respectively, 10 days to 2 months after the addition to their current regimen of everolimus in a 35-year-old woman and sirolimus in a 65-year-old man. The graft functionality was within normal range. General corticosteroids therapy resistance, immediate improvement after drug discontinuation (dechallenge) and relapse after re-exposure (rechallenge) were striking criteria supporting a causative role of the drugs, grouped in the mTOR inhibitors class. CONCLUSIONS: The diagnosis of drug-induced events is crucial for early management, and particularly bullous eruptions affect patients' health and quality of life. Additional research is necessary to confirm the m-TOR inhibitors association, which exploit the possible mechanisms and eventually point out preventive measures.

Effect of different diet composition on the fat profile of two different black soldier fly larvae populations.

Black soldier fly larvae (Hermetia illucens; BSFL) can transform organic wastes into nutritional biomass useful in animal feeding. The aim of this work was to study the effect of five diets (meat, fruit, vegetable substrates, a mix of them and control) on the profile of fatty acids (FAs) and sterols of BSFL. For a more exhaustive characterization of the nutritional properties, the profile of esterified FAs in the sn-2 position of the triglycerides, the most absorbed lipid component during animal digestion was evaluated. The dietary effect was estimated on two different Hermetia illucens populations (Greek - UTH and Italian - UNIPI). The diet affected all the lipid fractions examined. Regardless of diet, the fat was characterized mainly of lauric acid and other saturated FAs, which were found to be synthesized by the larvae, as it was not present in any of the five substrates. In general, UTH larvae contained a higher level of lipids (7.38 vs 2.48 g/100 g of larvae; P < 0.001) and saturated FAs (49.71 vs 36.10 g/100 g of Total Lipids; P < 0.001) and a lower percentage of monounsaturated FAs (14.74 vs 26.70 g/100 g of Total Lipids), C18:3n-3 (0.67 vs 1.13 g/100 g of Total Lipids; P < 0.001), and C18:2c9t11 (2.02 vs 2.80 g/100 g of Total Lipids; P < 0.001). Irrespective of the populations, BSFL reared on control and fruit substrates showed higher level of lipids (8.06 and 5.61 g/100 g of larvae, respectively), and saturated FA (38.99 and 71.19 g/100 g of Total Lipids, respectively), while the presence of meat increased the level of C20:4n-6, C20:5n-3 and C22:5n-3 (0.70, 0.13 and 0.45 g/100 g of Total Lipids, respectively). The results confirmed that BSFL accumulate phytosterols in their lipid fraction. The sterol profile was strongly influenced by the substrate on which the larvae were reared, with higher levels of cholesterol in the larvae of the meat group (38.55 mg/100 g of Total Lipids) and of stigmasterol and campesterol (9.04 and 15.23 mg/100 g of Total Lipids, respectively) in those of the vegetable group. The sterol content between the two populations was significantly different, with a higher percentage in UTH larvae (113.28 vs 34.03 mg/100 g of Total Lipids; P < 0.001). Finally, BSFLs showed a high plasticity of the lipid profile depending on both the substrate and the metabolism linked to the different populations. This variability allows the nutritional characteristics of the BSFL to be shaped by modifying the substrate, to adapt it to the technological and feeding needs to which the larvae are destined.

Effect of propolis on Th2 and Th17 cells: interplay with EtxB- and LPS-treated dendritic cells.

Dendritic cells (DCs) are antigen-presenting cells that drive the differentiation of T CD4+ cells into different profiles according to the nature of the antigen or immunomodulator. Propolis is a resinous product made by bees that has numerous pharmacological properties, including an immunomodulatory action. To assess whether propolis can modulate the activation of CD4+ T cells by stimulating DCs with heat-labile enterotoxin B subunit (EtxB) or lipopolysaccharide (LPS), we aimed to elucidate the mechanisms affected by propolis in the differential activation of T lymphocytes. Cell viability, lymphocyte proliferation, gene expression (GATA-3 and RORc), and cytokine production (interleukin (IL)-4 and IL-17A) were analyzed. Propolis, EtxB, and LPS induced a higher lymphoproliferation compared with the control. Propolis induced GATA-3 expression and, in combination with EtxB, maintained the baseline levels. Propolis alone or in combination with LPS inhibited RORc expression. EtxB alone and in combination with propolis increased IL-4 production. Propolis in combination with LPS prevented LPS-induced IL-17A production. These results opened perspectives for the study of biological events that may be favored by propolis by promoting Th2 activation or helping in the treatment of inflammatory conditions mediated by Th17 cells.

Induction of an in vitro reversible hypometabolism through chitosan-based nanoparticles.

OBJECTIVE: Chitosan-based nanoparticles (NPs) were prepared to promote intracellular sustained delivery of the synthetic delta opioid D-Ala(2)-D-Leu(5)-enkephalin (DADLE), prolonging peptide activity and inducing a safe and reversible hypometabolic state. MATERIALS AND METHODS: NPs were prepared by combining ionotropic gelation and ultrasonication treatment. NP uptake studies and the effects of encapsulated DADLE on HeLa cells proliferation were tested by transmission electron microscopy (TEM) analysis, by immuno-fluorescence and immuno-cytochemistry. RESULTS: DADLE-loaded NPs are produced with suitable characteristics, a satisfactory process yield (55.4% ± 2.4%) and encapsulation efficiency (64.6% ± 2.1%). NPs are effective in inducing a hypometabolic stasis at a 10(-4) M DADLE concentration. Moreover, as seen from the immunofluorescence study, the effect persists through the recovery period (72 h). Indeed, NPs labelled by anti-enkephalin antibody inside cell nucleus reassert that the in vivo release of the peptide can be prolonged with respect to the case of free peptide supply. CONCLUSION: The nanoparticulate drug delivery system described seems to be effective in inducing and prolonging a sort of hibernation-like state in the cells.

Thoracic paravertebral anaesthesia for awake video-assisted thoracoscopic surgery daily.

Thoracic paravertebral blockade has been described as an effective alternative to epidural blockade for the management of postoperative pain after thoracic surgery. Here we present what we believe is the first description of the use of thoracic paravertebral block as the sole anaesthetic for video-assisted thoracoscopy. Two oncology patients with severe respiratory disease presented for video-assisted thoracoscopic surgery. Thoracic paravertebral block provided excellent surgical conditions and postoperative pain relief for these patients and allowed an optimal assessment of the anaesthetic impact on respiratory function.

Author Correction: Essential oils sensory quality and their bioactivity against the mosquito Aedes albopictus.

A correction to this article has been published and is linked from the HTML and PDF versions of this paper. The error has not been fixed in the paper.

Non-viral dried powders for respiratory gene delivery prepared by cationic and chitosan loaded liposomes.

The aim of this work was to investigate lipid-based dried powders as transfection competent carriers capable of promoting the expression of therapeutic genes. The lipid-based vectors were prepared by combining different cationic lipids 1,2-dioleoyl-3-trimethylammoniumpropane chloride (DOTAP), 1,2-dioleoyl-sn-glycero-3-phosphoethanolamine (DOPE), 1,2-dioleoyl-sn-glycero-3-phosphocholine (DOPC) and 3beta(N(N',N-dimethylaminoethane) carbamoyl) cholesterol hydrochloride (DC-Chol) or by mixing of anionic lipids (1,2-dimyristoyl-sn-glycero-3-phospocholine (DMPC), 1,2-dimyristoyl-sn-glycero-3-phospho-rac-glycerol sodium salt (DMPG) and chitosan salts. Spray drying of the formulations was performed using carbohydrates as thermoprotectant excipients and some amino acids as aerosolisation enhancers. Both the lipidic vectors and the dried powders were characterized for morphology, size, zeta potential (Z-potential) and a yield of the process. Agarose gel electrophoresis was used to examine the structural integrity of dehydrated plasmid DNA (pDNA). The biological functionality of the powders was quantified using the in vitro cell transfection. Among the several lipids and lipid-polymer mixtures tested, the best-selected formulations had spherical shape, narrow size distribution (mean diameter<220 nm, P.I.<0.250), a positive zeta-potential (>25 mV) with a good yield of the process (>65%). The set-up spray drying parameters allowed to obtain good yield of the process (>50%) and spherically shaped particles with the volume-weighted mean diameter (d[4,3])<6 microm in the respirable range. The set-up conditions for the preparation of the lipid dried powders did not adversely affect the structural integrity of the encapsulated pDNA. The powders kept a good transfection efficiency as compared to the fresh colloidal formulations. Lipid-based spray dried powders allowed the development of stable and viable formulations for respiratory gene delivery. In vitro dispersibility and deposition studies are in progress to determine the aerosolisation properties of the powders.

Site-directed PEGylation as successful approach to improve the enzyme replacement in the case of prolidase.

The first aim of this work was to perform site-directed PEGylation of the enzyme prolidase at sulphydril groups by methoxy-polyethylene glycol-maleimide (Mal-PEG, Mw 5000 Da) in order to obtain a safe conjugation product more stable than the native enzyme. Prolidase is a cytosolic aminoacyl-l-proline hydrolase whose deficiency causes the onset of rare autosomal recessive disorder called prolidase deficiency (PD). The second purpose of this work was to investigate whether biodegradable chitosan nanoparticles loaded with PEGylated prolidase could be effective in releasing active enzyme inside fibroblasts as a possible therapeutic approach for PD. The SDS-PAGE analysis and the ESI-MS spectra confirmed the presence of the PEGylated prolidase: in particular the main conjugation product (m/z=about 65,000 Da) corresponded to the enzyme with two residues of Mal-PEG. In this study it was demonstrated the lack of toxicity (MTT assay) and the prolonged activity (40.6+/-2.6% after 48h of incubation at 37 degrees C) of the PEGylated enzyme. The PEGylated prolidase loaded chitosan nanoparticles had spherical shape, narrow size distribution (271.6+/-45.5 nm), a positive zeta-potential (15.93+/-0.26 mV) with a good preparation yield (54.6+/-3.6%) and protein encapsulation efficiency (44.8+/-4.6%). The ex vivo evaluation of prolidase activity on PD fibroblasts individuated a good level of prolidase activity replaced (about 72% after only 2 days of incubation) up to 10 days with improved morphological cell features.

Efficacy of oleuropein against UVB irradiation: preliminary evaluation.

Oleuropein, a phenolic compound derived from olive leaves and oil, is known to possess several biological properties, many of which may be attributed to its antioxidant and free radical-scavenging activities. Nevertheless, up to now, the cosmetic activity of this molecule has not been extensively investigated. The aim of this work was to evaluate the cosmetic properties of oleuropein against UVB-induced erythema. To this end, an emulsion and an emulgel containing oleuropein were prepared, applied and evaluated on healthy volunteers who had undergone UVB irradiation to investigate its protective and/or lenitive activity. Protective effect was assayed by application of topical preparations before irradiation and lenitive effect was evaluated after erythema induction. Vitamin E was used as the reference compound. Our study was carried out by using noninvasive techniques to assess specific skin parameters: barrier function, skin colour and microcirculation. Results clearly showed that oleuropein formulations highlighted lenitive efficacy by reducing erythema, transepidermal water loss and blood flow of about 22%, 35% and 30% respectively. The study allowed us to point out the lenitive property of oleuropein, opening the way to further trials to deepen our specific knowledge about this natural molecule, which could be used in association with other active ingredients in cosmetics to repair UV damages.

Poly(D,L-lactide) nanoencapsulation to reduce photoinactivation of a sunscreen agent.

The use of sunscreens is the 'gold standard' for protecting the skin from ultraviolet light. Octyl methoxycinnamate (OMC) is one of the most widely used UVB filter but it can act as a sensitizer or photoallergen. When exposed to sunlight, OMC can change from the primary trans-form to cis-form and the isomerization, not reversible, conducts to a reduction of the UVB filtering efficiency because the trans-form has a higher extinction coefficient. Photostability is the most important characteristic of effective sunscreens and it can be influenced by formulation ingredients and by applying technological strategies. In this work, photostability experiments, performed on emulsion-gels containing different percentages of OMC free or loaded in poly(D,L-lactide) nanoparticles, were carried out. The presence of a polymeric envelop may act to protect the active ingredient. In this study, the influence of poly(D,L-lactide) matrices on the photochemical stability of the sunscreen agent was investigated. As highlighted in this study, free OMC in different formulations has different photoisomerization degree. Moreover, a dissimilar behaviour was observed by studying different sunscreen concentrations in the same cosmetic formulation. Photostability results show a significant reduction in photoisomerization degree for formulations containing sunscreen loaded in nanoparticles, highlighting that the encapsulation is a suitable strategy to improve OMC photostability. Moreover, sun protection factor (SPF) results show that the UVB filter protective power is also maintained after encapsulation.

gamma-irradiation of PEGd,lPLA and PEG-PLGA multiblock copolymers: II. effect of oxygen and EPR investigation.

The purpose of this research was to evaluate how the presence of oxygen can affect irradiation-induced degradation reactions of PEGd,lPLA and PEG-PLGA multiblock copolymers submitted to gamma irradiation and to investigate the radiolytic behavior of the polymers. PEGd,lPLA, PEG-PLGA, PLA, and PLGA were irradiated by using a (60)Co irradiation source in air and under vacuum at 25 kGy total dose. Mw and Mn were evaluated by gel permeation chromatography. The stability study was carried out on three samples sets: (a) polymer samples irradiated and stored in air, (b) polymer samples irradiated and stored under vacuum, and (c) polymer samples irradiated under vacuum and stored in air. The thermal and radiolytic behavior was investigated by differential scanning calorimetry and electron paramagnetic resonance (EPR), respectively. Samples irradiated in air showed remarkable Mw and Mn reduction and Tg value reduction due to radiation-induced chain scission reactions. Higher stability was observed for samples irradiated and stored under vacuum. EPR spectra showed that the presence of PEG units in multiblock copolymer chains leads to: (a) decrease of the radiolytic yield of radicals and (b) decrease of the radical trapping efficiency and faster radical decay rates. It can be concluded that the presence of oxygen during the irradiation process and the storage phase significantly increases the entity of irradiation-induced damage.

gamma-Irradiation of PEGd,lPLA and PEG-PLGA multiblock copolymers. I. Effect of irradiation doses.

To evaluate the effects of different gamma irradiation doses on PEGd,lPLA and PEG-PLGA multiblock copolymers. The behaviour of the multiblock copolymers to irradiation was compared to that of PLA, PLGA polymers. PEGd,lPLA, PEG-PLGA, PLA and PLGA polymers were irradiated by using a (60)Co irradiation source at 5, 15, 25 and 50 kGy total dose. Characterization was performed on all samples before and after irradiation, by nuclear magnetic resonance (NMR), infrared absorption spectrophotometry (FTIR) and gel permeation chromatography (GPC). The effect of gamma irradiation on polymer stability was also evaluated. Results of NMR and FTIR suggest an increase in -OH and -COOH groups, attributed to scission reactions induced by irradiation treatment. Data of GPC analysis showed that the weight average molecular weight (Mw) of polymer samples decreased with increasing irradiation dose. The extent of Mw degradation expressed as percentage of Mw reduction was more prominent for polymers with high molecular weight as PEGd,lPLA and PLA. The dominant effect of gamma-irradiation on both polymer samples was chain scission. The multiblock copolymer PEGd,lPLA presented higher sensitivity to irradiation treatment with respect to PLA, likely due to the presence of PEG in the matrix. The effect of gamma irradiation continues over a much longer period of time after gamma irradiation has been performed. It is suggested that the material reacts with oxygen to form peroxyl free radicals, which may further undergo degradation reactions during storage after irradiation.

Multivariate analysis for the optimization of microfluidics-assisted nanoprecipitation method intended for the loading of small hydrophilic drugs into PLGA nanoparticles.

Design of Experiment-assisted evaluation of critical process (total flow rate, TFR, flow rate ratio, FRR) and formulation (polymer concentration and structure, drug:polymer ratio) variables in a novel microfluidics-based device, a staggered herringbone micromixer (SHM), for poly(lactic-co-glycolic acid) copolymer (PLGA) nanoparticles (NPs) manufacturing was performed in order to systematically evaluate and mathematically describe their effects on NPs sizes and drug encapsulation; a small hydrophilic moiety, N-acetylcysteine, was chosen as challenging model drug. SHM-assisted nanoprecipitation method consistently yielded NPs with tailor made sizes (in the range of 100-900 nm) and polydispersity index range from 0.061 to 0.286. Significant effects on NPs sizes were highlighted for TFR and FRR: increasing TFR (from 5 to 15 mL/min) and decreasing FRR (from 1:1 to 1:5 v/v, acetonitrile: buffer) NPs with mean diameter <200 nm were obtained. SHM technique allowed for flexible, application-specific tuning of PLGA NPs size using organic solvents with relatively low toxicity (acetone, acetonitrile), varying aqueous phase composition (Tris buffer vs PVA aqueous solution) and PLGA characteristics (Mw ranging from 25-90 kDa, capped or un-capped PLGA, different lactide:glycolide molar ratio). A very satisfactory N-Ac encapsulation efficiency (more than 67%) and a prolonged release (by 168 h) were achieved.

Essential oils sensory quality and their bioactivity against the mosquito Aedes albopictus.

Repellents are a main tool to prevent the outbreak of mosquito-borne diseases that represents a threat for millions of people worldwide. Plant-based products are very promising, low-toxic and eco-friendly alternative to synthetic repellents. Here, we performed an olfactory screening of the essential oils (EOs) of Artemisia verlotiorum Lamotte (Asteraceae), Lavandula dentata L. (Lamiaceae), and Ruta chalepensis L. (Rutaceae) for their possible use as ingredients in topical repellents. The EOs smell profiles were then matched with their repellence against the mosquito Aedes albopictus (Skuse) (Diptera Culicidae). To obtain a more complete bioactivity description, we also tested the EOs oviposition deterrence and the larvicidal activity. The best smell profile was associated with A. verlotiorum EO, while R. chalepensis EO showed the lowest overall pleasantness. All the EOs had a significant activity as skin repellent against Ae. albopictus, deterred the oviposition in the field, and exerted a clear larvicidal activity. Beside the best smell profile, A. verlotiorum EO showed also the longest lasting repellent effect, assuring the complete protection of the treated skin against Ae. albopictus for a time 60% longer than the synthetic repellent DEET.

Study on hydrophilicity and degradability of chitosan/polylactide-co-polycaprolactone nanofibre blend electrospun membrane.

Electrospinning is an interesting technique to produce polymer membranes made of entangled nanofibres. The technique is raising interest in pharmaceutical and biomedical areas. Either electrospun membranes are studied for tissue regeneration purposes, or incorporation of nanoparticles in electrospun membranes can be an opportunity to control the delivery of drug or to obtain dual drug delivery system. In this work suspensions of hydrochloride chitosan salt in copolymer polylactide-co-polycaprolactone (PLA-PCL) solution were electrospun in order to assess an advanced study for developing polymer nanofibre blend membrane loaded with chitosan polymer. The aim of the work was to investigate the properties and stability of chitosan/PLA-PCL electrospun membranes considering their application for tissue regeneration and drug delivery. The electrospun membranes were characterized for their physico-chemical (FT-IR) morphology (SEM) and in vitro biological properties (cytocompatibility and cells engraftment). Results show that homogeneous electrospun PLA-PCL/chitosan blend nanofibres in the range size 800 nm were obtained. Chitosan was loaded inside the nanofibres up to 27.2% (w/w) without modifying nanofibre shape, and only 6% of the loaded chitosan resulted to be on the nanofibre surface. The presence of chitosan in the nanofibres has shown to accelerate the electrospun membranes degradation in vitro.

Effect of propolis on Th2 and Th17 cells: interplay with EtxB- and LPS-treated dendritic cells

Dendritic cells (DCs) are antigen-presenting cells that drive the differentiation of T CD4+ cells into different profiles according to the nature of the antigen or immunomodulator. Propolis is a resinous product made by bees that has numerous pharmacological properties, including an immunomodulatory action. To assess whether propolis can modulate the activation of CD4+ T cells by stimulating DCs with heat-labile enterotoxin B subunit (EtxB) or lipopolysaccharide (LPS), we aimed to elucidate the mechanisms affected by propolis in the differential activation of T lymphocytes. Cell viability, lymphocyte proliferation, gene expression (GATA-3 and RORc), and cytokine production (interleukin (IL)-4 and IL-17A) were analyzed. Propolis, EtxB, and LPS induced a higher lymphoproliferation compared with the control. Propolis induced GATA-3 expression and, in combination with EtxB, maintained the baseline levels. Propolis alone or in combination with LPS inhibited RORc expression. EtxB alone and in combination with propolis increased IL-4 production. Propolis in combination with LPS prevented LPS-induced IL-17A production. These results opened perspectives for the study of biological events that may be favored by propolis by promoting Th2 activation or helping in the treatment of inflammatory conditions mediated by Th17 cells.

Emerging and re-emerging infectious disease in otorhinolaryngology.

SUMMARY: Emerging and re-emerging infectious disease in otorhinolaryngology (ENT) are an area of growing epidemiological and clinical interest. The aim of this section is to comprehensively report on the epidemiology of key infectious disease in otorhinolaryngology, reporting on their burden at the national and international level, expanding of the need of promoting and implementing preventive interventions, and the rationale of applying evidence-based, effective and cost- effective diagnostic, curative and preventive approaches. In particular, we focus on i) ENT viral infections (HIV, Epstein-Barr virus, Human Papilloma virus), retrieving the available evidence on their oncogenic potential; ii) typical and atypical mycobacteria infections; iii) non-specific granulomatous lymphadenopathy; iv) emerging paediatric ENT infectious diseases and the prevention of their complications; v) the growing burden of antimicrobial resistance in ENT and the strategies for its control in different clinical settings. We conclude by outlining knowledge gaps and action needed in ENT infectious diseases research and clinical practice and we make references to economic analysis in the field of ENT infectious diseases prevention and care.

Identification of RASSF8 as a candidate lung tumor suppressor gene.

The RASSF8 gene, which maps close to the KRAS2 gene, contains a RAS-associated domain and encodes a protein that is evolutionarily conserved from fish to humans. Analysis of the RASSF8 transcript revealed a complex expression pattern of 5'-UTR mRNA isoforms in normal lung and in lung adenocarcinomas (ADCAs), with no apparent differences. However, RASSF8 gene transcript levels were approximately seven-fold-lower in lung ADCAs as compared to normal lung tissue. Expression of RASSF8 protein by transfected lung cancer cells led to inhibition of anchorage-independent growth in soft agar in A549 cells and reduction of clonogenic activity in NCI-H520 cells. These results raise the possibility protein encoded by RASSF8 is a novel tumor suppressor for lung cancer.

Stress induced morphological microglial activation in the rodent brain: involvement of interleukin-18.

The present study investigated the possibility that acute stress might activate microglial cells. Wistar rats were exposed to 2 h period of restraint combined with water immersion stress prior to brain analysis by immunohistochemistry with OX-42, a marker of complement receptor CR3. A single session of stress provoked robust morphological microglial activation in the thalamus, hypothalamus, hippocampus, substantia nigra and central gray. These effects appeared as early as at 1 h of exposure and were further intensified at 2 h. Morphological activation was not accompanied with changes in markers of functional activation or of inflammation including interleukin-1beta (IL-1beta), interleukin-6 (IL-6) and inducible nitric oxide synthase (iNOS). Similar results were obtained with mice where the effects of stress were compared in animals null for interleukin-18 (IL-18 KO), a cytokine previously demonstrated to be modulated by stress and to contribute to microglia activation. The results demonstrated significant reduction of stress-induced microglial activation in IL-18 KO mice. The present study reports evidence that physical/emotional stress may induce morphological microglial activation in the brain and this activation is in part mediated by interleukin-18.

Interleukin-18 mRNA expression in the rat pituitary gland.

The present study investigated the expression of IL-18 mRNA under several stimuli, and molecular structures of IL-18 mRNA of the rat pituitary. Real-time PCR demonstrated that IL-18 mRNA, highly expressed in anterior pituitary, significantly increased following stress and adrenalectomy. In situ hybridization combined with immunohistochemistry demonstrated that corticotrope cells expressed IL-18 mRNA. RACE and sequence analysis demonstrated that pituitary IL-18 mRNA possesses five new exons at the upstream of exon 1 and between exon 1 and exon 2, indicating the preferential usage of promoter 1. The present study suggests that IL-18 in the corticotrope cells may play some roles in stress responses.