The Effects of Lumbricus rubellus Extract on Staphylococcus aureus Colonization and IL-31 Levels in Children with Atopic Dermatitis

Background and Objectives: The ineffective combination of corticosteroids and antibiotics in treating some atopic dermatitis (AD) cases has been concerning. The skin barrier defects in AD ease the colonization of Staphylococcus aureus (S. aureus), which results in a rise in interleukin-31 (IL-31). Lumbricus rubellus (L. rubellus) has shown antimicrobial and antiallergic effects but has not been studied yet to decrease the growth of S. aureus and IL-31 levels in AD patients. This study aimed to analyze the effect of L. rubellus extract in reducing S. aureus colonization, the IL-31 level, and the severity of AD. Materials and Methods: A randomized controlled trial (RCT) (international registration number TCTR20231025004) was conducted on 40 AD patients attending Dermatology and Venereology Polyclinic, Mother and Child Hospital (RSIA), Aceh, Indonesia, from October 2021 to March 2022. AD patients aged 8-16 who had a Scoring Atopic Dermatitis (SCORAD) index > 25, with total IgE serum level > 100 IU/mL, and had healthy weight were randomly assigned into two groups: one received fluocinolone acetonide 0.025% and placebo (control group) and one received fluocinolone acetonide 0.025% combined with L. rubellus extract (Vermint®) (intervention group). The S. aureus colony was identified using a catalase test, coagulase test, and MSA media. The serum IL-31 levels were measured using ELISA assay, while the SCORAD index was used to assess the severity of and improvement in AD. Mean scores for measured variables were compared between the two groups using an unpaired t-test and Mann-Whitney U test. Results: A significant decline in S. aureus colonization (p = 0.001) and IL-31 (p = 0.013) in patients receiving L. rubellus extract was found in this study. Moreover, fourteen AD patients in the intervention group showed an improvement in the SCORAD index of more than 35% (p = 0.057). Conclusions: L. rubellus extract significantly decreases S. aureus colonization and the IL-31 level in AD patients, suggesting its potential as an adjuvant therapy for children with AD.

Intravitreal Fluocinolone Acetonide Implant (ILUVIEN®) for the Treatment of Retinal Conditions. A Review of Clinical Studies

Fluocinolone acetonide (FAc) intravitreal implant (Iluvien®) is a corticosteroid implant indicated for the treatment of diabetic macular oedema (DMO) in patients who have previously received conventional treatment without good response, non-infectious posterior uveitis, and as an off-label treatment of the macular oedema secondary to retinal vein occlusion. FAc is a non-biodegradable 0.19 mg intravitreal implant which is designed to release FAc over 3 years at a rate of approximately 0.2 mcg per day. The aim of this review is to describe the special pharmacological properties of Iluvien and display the outcomes of the most important clinical trials and real-world studies regarding its efficacy and safety for the management of the above retinal disorders.

Characterization of Transcriptomic and Proteomic Changes in the Skin after Chronic Fluocinolone Acetonide Treatment

While topical corticosteroid (TCS) treatment is widely used for many skin diseases, it can trigger adverse side effects, and some of such effects can last for a long time after stopping the treatment. However, molecular changes induced by TCS treatment remain largely unexplored, although transient changes in histology and some major ECM components have been documented. Here, we investigated transcriptomic and proteomic changes induced by fluocinolone acetonide (FA) treatment in the mouse skin by conducting RNA-Seq and quantitative proteomics. Chronic FA treatment affected the expression of 4229 genes, where downregulated genes were involved in cell-cycle progression and ECM organization, and upregulated genes were involved in lipid metabolism. The effects of FA on transcriptome and histology of the skin largely returned to normal by two weeks after the treatment. Only a fraction of transcriptomic changes were reflected by proteomic changes, and the expression of 46 proteins was affected one day after chronic FA treatment. A comparable number of proteins were differentially expressed between control and FA-treated skin samples even at 15 and 30 days after stopping chronic FA treatment. Interestingly, proteins affected during and after chronic FA treatment were largely different. Our results provide fundamental information of molecular changes induced by FA treatment in the skin.

Design, characterization and skin permeating potential of Fluocinolone acetonide loaded nanostructured lipid carriers for topical treatment of psoriasis

The aim of the current study was to develop and optimize Fluocinolone acetonide (FA) loaded nanostructured lipid carriers (NLC) and to evaluate its potential as topical delivery system for management of psoriasis. FA loaded NLCs were successfully developed by modified microemulsion method and optimized using 3-level Box-Behnken design. NLCs were evaluated for particle size, polydispersity index, zeta potential, drug entrapment efficiency and drug loading. Further X-ray diffraction (XRD) and Differential scanning calorimetry (DSC), in vitro release, in vitro skin distribution and stability study were also performed. Transmission electron microscopy confirmed spherical shape of prepared NLCs. Complete encapsulation of drug in the nanoparticles was confirmed by XRD and DSC. Release study showed prolonged drug release from the NLCs following Higuchi release kinetics and Zero order release kinetics, whereas pure FA suspension exhibited faster drug release following Zero order release kinetics with R(2) value of 0.995. Stability study confirmed that NLCs were stable for 3months at 4°C. Furthermore, in vitro skin distribution studies showed presence of significant amount of FA in the epidermal and dermal layer of skin when treated with FA loaded NLCs suspension while plain FA suspension showed significantly lesser amount of FA in the epidermis and dermis. Moreover, selective retention of FA in the epidermis might eliminate adverse side effects associated with systemic exposure. Thus FA loaded NLCs could be a potential system for psoriasis treatment but to create clinical value of the present system further studies are needed in clinically relevant models.

Fitness and competitive ability of Botrytis cinerea field isolates with dual resistance to SDHI and QoI fungicides, associated with several sdhB and the cytb G143A mutations

Respiration inhibitors such as the succinate dehydrogenase inhibitors (SDHIs) and the quinone outside inhibitors (QoIs) are fungicide classes with increasing relevance in gray mold control. However, recent studies have shown that dual resistance to both fungicide classes is a common trait in Botrytis cinerea populations from several hosts throughout the world. Resistance of B. cinerea to SDHIs is associated with several mutations in the sdhB, sdhC, and sdhD genes, while resistance to QoIs, in most cases, is associated with the G143A mutation in the cytb gene. The objective of the current study was to investigate the fitness and the competitive ability of B. cinerea field strains possessing one of the H272Y/R/L, N230I, or P225F sdhB substitutions and the G143A mutation of cytb. Fitness parameters measured were (i) mycelial growth and conidia germination in vitro, (ii) aggressiveness and sporulation capacity in vivo, (iii) sclerotia production in vitro and sclerotia viability under different storage conditions, and (iv) sensitivity to oxidative stress imposed by diquat treatments. The competitive ability of the resistant isolates was measured in the absence and presence of the SDHI fungicides boscalid and fluopyram selection pressure. The measurements of individual fitness components showed that the H272R/G143A isolates had the lower differences compared with the sensitive isolates. In contrast, the groups of H272Y/L/G143A, N230I/G143A, and P225F/G143A isolates showed reduced fitness values compared with the sensitive isolates. Isolates possessing only the cytb G143A substitution did not show any fitness cost. The competition experiments showed that, in the absence of fungicide selection pressure, after four disease cycles on apple fruit, the sensitive isolates dominated in the population in all the mixtures tested. In contrast, when the competition experiment was conducted under the selection pressure of boscalid, a gradual decrease in the frequency of sensitive isolates was observed, whereas the frequency of H272L and P225F isolates was increased. When the competition experiment was conducted in the presence of fluopyram, the sensitive isolates were eliminated even after the first disease cycle and the P225F mutants dominated in the population. Such results suggest that the sdhB mutations may have adverse effects on the mutants. The observed dominance of sensitive isolates in the competition experiments conducted in the absence of fungicides suggest that the application of SDHIs in alternation schemes may delay the selection or reduce the frequency of SDHI-resistant mutants.

Glucocorticoid compounds modify smoothened localization and hedgehog pathway activity

The Hedgehog signaling pathway is linked to a variety of diseases, notably a range of cancers. The first generation of drug screens identified Smoothened (Smo), a membrane protein essential for signaling, as an attractive drug target. Smo localizes to the primary cilium upon pathway activation, and this transition is critical for the response to Hedgehog ligands. In a high content screen directly monitoring Smo distribution in Hedgehog-responsive cells, we identified different glucocorticoids as specific modulators of Smo ciliary accumulation. One class promoted Smo accumulation, conferring cellular hypersensitivity to Hedgehog stimulation. In contrast, a second class inhibited Smo ciliary localization and signaling activity by both wild-type Smo, and mutant forms of Smo, SmoM2, and SmoD473H, that are refractory to previously identified Smo antagonists. These findings point to the potential for developing glucocorticoid-based pharmacological modulation of Smo signaling to treat mutated drug-resistant forms of Smo, an emerging problem in long-term cancer therapy. They also raise a concern about potential crosstalk of glucocorticoid drugs in the Hedgehog pathway, if therapeutic administration exceeds levels associated with on-target transcriptional mechanisms of glucocorticoid action.

Effects of the tropical ginger compound,1'-acetoxychavicol acetate, against tumor promotion in K5.Stat3C transgenic mice

The purpose of the current study was to determine whether a tropical ginger derived compound 1'-acetoxychavicol acetate (ACA), suppresses skin tumor promotion in K5.Stat3C mice. In a two-week study in which wild-type (WT) and K5.Stat3C mice were co-treated with either vehicle, ACA, galanga extract, or fluocinolone acetonide (FA) and tetradecanoyl phorbol acetate (TPA), only the galanga extract and FA suppressed TPA-induced skin hyperproliferation and wet weight. None of these agents were effective at suppressing p-Tyr705Stat3 expression. However, ACA and FA showed promising inhibitory effects against skin tumorigenesis in K5.Stat3C mice. ACA also suppressed phospho-p65 NF-κB activation, suggesting a potential mechanism for its action.

Strength and endurance of the respiratory and handgrip muscles after the use of flunisolide in normal subjects

OBJECTIVE

To evaluate the effects of the inhaled flunisolide upon the strength and endurance of the respiratory and peripheral muscles of normal subjects.

DESIGN

A randomized, double blind and placebo-controlled study.

SETTING

A university-affiliated teaching hospital.

PARTICIPANTS

Thirteen normal volunteers selected from a graduation course.

INTERVENTION

Subjects were randomly allocated to receive a placebo or corticosteroid (flunisolide) to be inhaled twice a day for 4 weeks. After 2 weeks of a washout period, subjects who were receiving the placebo, received flunisolide and vise versa for another 4-week period.

MEASUREMENTS AND RESULTS

Spirometry was used to define the volunteers as being normal in terms of pulmonary function. During the study, subjects performed tests of respiratory muscle function (strength and endurance), measurements of handgrip strength and endurance and anthropometric measurements. Muscle strength was measured each week while muscle endurance was measured every 2 weeks. There was no significant difference in the maximal inspiratory and expiratory pressure and handgrip strength during weeks 1-4 when the subjects used either flunisolide or placebo. However, we observed an increase in the endurance time of the respiratory and handgrip muscles in the 4th week of both flunisolide and placebo use, what may be considered due to a learning effect.

CONCLUSION

Inhalation of flunisolide by normal subjects for 1 month does not cause any acute or clinically perceived effect in the peripheral or respiratory muscles.

Topical glucocorticosteroids in rhinitis: clinical aspects

The introduction of nasal glucocorticosteroids, 30 years ago, has been the most important therapeutic progress in rhinitis management since the introduction of the first generation of antihistamines. Our knowledge of the mode of action of glucocorticosteroids in the nose has improved as the airway mucous membrane of the nose is easily accessible for investigation. However, the exact mechanism behind the marked clinical effect remains unclear. Topical glucocorticosteroids are highly effective in diseases characterized by eosinophil-dominated inflammation (allergic rhinitis, nasal polyposis), but not in diseases characterized by neutrophil-dominated inflammation (common cold, infectious rhinosinusitis). Experience for 30 years and a long series of controlled studies have shown that the treatment is highly effective and that the side effects are few and benign. Intranasal glucocorticosteroids can therefore be considered as first-line treatment for allergic and non-allergic, non-infectious rhinitis and nasal polyps.

Inhaled flunisolide suppresses the hypothalamic-pituitary-adrenocortical axis, but has minimal systemic immune effects in healthy cats

Feline bronchial disease is commonly treated with oral glucocorticoids (OGC), which might be contraindicated in cats with certain infectious, endocrine, renal, or cardiac diseases. Inhalant GC (IGC) maximize local efficacy and minimize systemic bioavailability. We evaluated systemic endocrine and immune effects of IGC (flunisolide, 250 microg/puff q12h) versus OGC (prednisone, 10 mg/d PO) and placebo. Six healthy cats received each drug for 2 weeks followed by a 1-month washout. Testing included determination of single early morning cortisol concentration, results of ACTH stimulation, the urine cortisol-to-creatinine ratio (UC: Cr), lymphocyte phenotype, lymphocyte blastogenesis, serum total IgA and IgM concentrations, and cytokine profiles. Significant differences between treatments were not apparent for serum immunoglobulin concentrations, or expression (mRNA) for the cytokines, interleukin (IL-) 2, IL-4, and IL-10, or gamma interferon. Single early morning cortisol concentration was lower for IGC (0.68 - 0.74 microg/dL), compared with that associated with placebo (2.82 +/- 1.94 microg/dL; P = .033). The ACTH-stimulated peak cortisol concentrations were lower after treatment in cats receiving IGC (before, 8.5 +/- 50.2 microg/dL; after, 2.9 +/- 3.3 microg/dL, P = .0004), but not OGC (before, 8.0 +/- 6.1 microg/dL; after, 6.0 +/- 4.5 microg/dL, P = .07). Similarly, UC: Cr (0.8 +/- 0.8) before IGC was lower than the value (5.02 +/- 3.62; P = .019) after IGC. Compared with placebo, cats given OGC, but not IGC, had significantly lower total percentages of T and B cells. Lymphocyte proliferation was decreased in cats receiving OGC, but not IGC, in comparison with placebo (6.9 +/- 3.3; 24.0 +/- 6.5; 18.8 +/- 14.0, respectively). Significantly more IL-10 mRNA transcription was detected in cats administered OGC or IGC, compared with placebo. Although IGC suppress the hypothalamic-pituitary-adrenocortical axis, IGC had minimal effects on the systemic adaptive immune system.

A comprehensive review of the long-term and short-term treatment of melasma with a triple combination cream

Melasma is a common disorder of hyperpigmentation and generally involves areas of the face and neck. Hyperpigmentation is especially prevalent in darker complected patients and is often difficult to treat. Hydroquinone, tretinoin, and topical corticosteroids are well established monotherapeutic agents for treating melasma and hyperpigmentation; however, a stable, once-daily formulation triple combination cream containing 0.05% tretinoin, 4.0% hydroquinone, and 0.01% fluocinolone acetonide (Tri-Luma) represents the only commercially available combination of all three agents. This product is approved by the US FDA for the treatment of facial melasma. A number of publications have described the safety and efficacy of triple combination cream in over 2000 patients with melasma, some of whom were treated for >12 months. In the initial 8-week study, 29% of patients experienced complete clearing of melasma by week 8, and 77% were clear or almost clear by week 8. Similarly, good results were seen in the two long-term studies, with the clear/mild rate ranging from 78% to 84% of patients at month 6 and from 81% to 94% of patients at month 12. Adverse events were almost always mild in severity and typically occurred only at the application site. The primary concern for most physicians using corticosteroid-containing products on the face is skin atrophy. However, only two cases of skin atrophy were reported across the three published studies. Overall, the results of these extensive studies indicate that triple combination cream is efficacious in treating melasma and exhibits a safe profile with low potential for adverse events.

Retisert (Bausch & Lomb/Control Delivery Systems)

Retisert (Envision TD), a sustained release intraocular implant containing fluocinolone acetonide, has been developed and launched in the US by Bausch & Lomb and Control Delivery Systems for the treatment of chronic non-infectious uveitis affecting the posterior segment of the eye.

Photochemistry and phototoxicity of fluocinolone 16,17-acetonide

Fluocinolone 16,17-acetonide is a corticosteroid used topically to treat various inflammatory skin diseases. Its photoreactivity was studied under UV-A and UV-B light in aqueous buffer in the presence of oxygen. This drug is photolabile under UV-B light and, to a lesser extent, under UV-A light, which is absorbed far less. In phosphate buffer, approximately 80% of fluocinolone acetonide decomposes after 5 J/cm2 of UV-B irradiation, whereas under 30 J/cm2 of UV-A light approximately only 20% decomposes. Both the drug and its photoproducts have been evaluated through a battery of in vitro studies and found to cause photohemolysis and induce photodamage to proteins (erythrocyte ghosts, bovine serum albumin) and linoleic acid. In addition, one of the photoproducts (the 17-hydroperoxy derivative) is highly toxic in the dark. Therefore, both loss of therapeutic activity and light-induced adverse effects may be expected when patients expose themselves to sunlight after drug administration. A major mechanism for phototoxicity involves radicals forming from drug breakdown, at least under UV-B, although reactive oxygen species may play a role, particularly under UV-A.

In vitro effects of flunisolide on MMP-9, TIMP-1, fibronectin, TGF-beta1 release and apoptosis in sputum cells freshly isolated from mild to moderate asthmatics

BACKGROUND

Corticosteroids play an important role in inflammation and remodelling of airways and are considered an important therapeutic target in asthma. Inflammation in asthma is characterized by a dysregulation of eosinophil apoptosis and of markers of airways remodelling. We evaluated the ability of flunisolide to inhibit in vitro the release of metalloproteinases-9 (MMP-9), tissue inhibitor metalloproteinases-1 (TIMP-1), transforming growth factor (TGF-beta) and fibronectin by sputum cells (SC) as well as to induce sputum eosinophil apoptosis.

METHODS

The SC, isolated from induced sputum samples of 12 mild-to-moderate asthmatics, were cultured for 24 h in the presence or absence of flunisolide (1, 10 and 100 microM). The release of mediators was assessed by enzyme-linked immunosorbent assay (ELISA) whereas apoptosis was studied by TUNEL technique.

RESULTS

Flunisolide (10 microM) significantly reduced MMP-9 and TIMP-1 (P = 0.0011 and P < 0.0001 respectively) and increased MMP-9/TIMP-1 molar ratio (P = 0.004). In addition, flunisolide decreased TGF-beta and fibronectin release by SC (P = 0.006; and P < 0.0001 respectively) and increased eosinophil apoptosis (P < 0.001).

CONCLUSIONS

These results demonstrate that flunisolide may play an important role in the inhibition of airway inflammation and remodelling, by promoting the resolution of eosinophilic inflammation and by inhibiting the release of MMP-9, TIMP-1, TGF-beta and fibronectin.

Enhanced Anti-Inflammatory Potency of a Nitric Oxide-Releasing Derivative of Flunisolide: Role of Nuclear Factor-κB

Glucocorticoids remain among the most commonly used anti-inflammatory drugs, despite significant adverse effects. Other anti-inflammatory drugs, including aspirin, have been coupled through an ester linkage to a nitric oxide-releasing moiety, resulting in an increase in potency and a decrease in adverse effects. Prednisolone has similarly been modified, with marked improvement of its therapeutic index. In the present study, we have evaluated whether a nitric oxide-releasing derivative of another glucocorticoid, flunisolide, would increase its potency as an anti-inflammatory agent and would decrease its systemic toxicity. To evaluate anti-inflammatory potency and efficacy, the carrageenan-airpouch model in the rat was used. Flunisolide and NCX-1024 (flunisolide-21-[4'-(nitrooxymethyl) benzoate]) were compared across a range of doses, with both direct injection into the airpouch and oral administration. The ability of these agents to protect the stomach against indomethacin-induced damage also was assessed. Effects of oral administration of the two drugs on body weight gain and adrenal suppression were also evaluated. With direct application into the airpouch, NCX-1024 was found to be 41 times more potent than flunisolide in reducing leukocyte accumulation and prostaglandin E2 generation. The increased potency may be related to an enhanced ability of NCX-1024 to prevent nuclear factor-kappaB activation. When given orally, the two compounds exhibited similar potency. However, orally administered NCX-1024 was more potent at protecting against indomethacin-induced gastric damage, caused less reduction of body weight, and, unlike flunisolide, did not cause adrenal atrophy. These studies suggest that NCX-1024 may be an attractive alternative to conventional glucocorticoids, particularly for applications involving topical administration.

Poor sleep and daytime somnolence in allergic rhinitis: significance of nasal congestion

Patients with allergic rhinitis frequently present with symptoms of nasal congestion, runny nose, sneezing, daytime somnolence and fatigue associated with decreased cognitive performance and impaired quality of life. Recent research has suggested that daytime somnolence in allergic rhinitis can be attributed to chronic inflammation of the nasal mucosa leading to nasal congestion and obstructed nasal passageways resulting in disturbed sleep. Treating daytime somnolence due to allergic rhinitis requires a reduction in obstruction caused by nasal congestion. Currently available therapy for allergic rhinitis includes topical corticosteroids, sedating and nonsedating antihistamines, topical cromolyn sodium (sodium cromoglycate), decongestants, immunotherapy and topical ipratropium bromide. The effectiveness of antihistamines in patients with allergic rhinitis has long been established. However, results of placebo-controlled trials investigating the effects of azelastine on sleep and daytime somnolence have produced conflicting results. Sleep improved with azelastine therapy, but there was a lack of evidence that azelastine significantly affected daytime sleepiness, sleep severity and nasal congestion. Sedating antihistamines exacerbate daytime somnolence and should be avoided in patients with allergic rhinitis. In a separate study, desloratadine failed to benefit sleep, but did not worsen daytime somnolence. Topical nasal cromolyn sodium is inconvenient to use and is unlikely to have a major effect on nasal congestion. Decongestants do decrease nasal congestion but the effect this has on sleep has not been adequately studied. Recent research has shown that topical corticosteroids are an effective treatment for alleviating nasal congestion secondary to allergic rhinitis. However, few studies have assessed the effect of topical corticosteroids on daytime fatigue and sleep. In 20 patients with allergic rhinitis and symptoms of daytime sleepiness, flunisolide significantly improved sleep quality and congestion but daytime sleepiness was not significantly improved. A similar study with fluticasone propionate showed improvement in nasal congestion and sleep but there was no significant change in objective sleep measurements recorded on polysomnography. Further research involving objective measures of sleep quality is necessary to determine the efficacy of medications in the treatment of allergic rhinitis associated with fatigue and daytime somnolence.

Multiple-dose proportionality study of flunisolide hydrofluoroalkane

The hydrofluoroalkane (HFA) formulation of the inhaled corticosteroid flunisolide is a modification of the original chlorofluorocarbon formulation. HFA flunisolide substitutes an HFA for a chlorofluorocarbon propellant and uses a built-in spacer in its pressurized metered-dose inhaler. An open-label, randomized, three-way crossover, multiple-dose study evaluated the dose proportionality of three doses of flunisolide HFA. Twenty-one healthy volunteers received the following doses twice daily for 4.5 days: 85, 170, and 340 micrograms. Plasma levels of flunisolide and of the flunisolide metabolite 6 beta-OH flunisolide were measured after single- and multiple-dose administration. After a single dose, dose proportionality was observed across the three dose levels for peak plasma concentration (Cmax) and the area under the plasma concentration-time curve (AUC) up to both the time corresponding to the last measurable concentration (AUC0-tau) and the time to infinity (AUC0-infinity). After multiple doses, dose proportionality was observed for both Cmax and AUC at the medium and high doses. Predose plasma levels of flunisolide measured on day 4 were below the limit of detection. The elimination half-life of flunisolide ranged from 0.95 to 1.34 hours. After both single and multiple doses, dose proportionality was observed in dose-adjusted Cmax and AUC0-infinity for the inactive 6 beta-OH metabolite. HFA flunisolide was well tolerated. The lack of accumulation after repeated administration of HFA flunisolide suggests that the systemic exposure of flunisolide is low, which is a safety goal for inhaled corticosteroids.

Deciphering the phosphorylation "code" of the glucocorticoid receptor in vivo

The glucocorticoid receptor (GR) is phosphorylated at multiple serine residues in a hormone-dependent manner, yet progress on elucidating the function of GR phosphorylation has been hindered by the lack of a simple assay to detect receptor phosphorylation in vivo. We have produced antibodies that specifically recognize phosphorylation sites within human GR at Ser(203) and Ser(211). In the absence of hormone, the level of GR phosphorylation at Ser(211) was low compared with phosphorylation at Ser(203). Phosphorylation of both residues increased upon treatment with the GR agonist dexamethasone. Using a battery of agonists and antagonists, we found that the transcriptional activity of GR correlated with the amount of phosphorylation at Ser(211), suggesting that Ser(211) phosphorylation is a biomarker for activated GR in vivo. Mechanistically, the kinetics of Ser(203) and Ser(211) phosphorylation in response to hormone differed, with Ser(211) displaying a more robust and sustained phosphorylation relative to Ser(203). Analysis of GR immunoprecipitates with phospho-GR-specific antibodies indicated that the receptor was phosphorylated heterogeneously at Ser(203) in the absence of hormone, whereas in the presence of hormone, a subpopulation of receptors was phosphorylated at both Ser(203) and Ser(211). Interestingly, biochemical fractionation studies following hormone treatment indicated that the Ser(203)-phosphorylated form of the receptor was predominantly cytoplasmic, whereas Ser(211)-phosphorylated GR was found in the nucleus. Likewise, by immunofluorescence, Ser(203)-phosphorylated GR was located in the cytoplasm and perinuclear regions of the cell, but not in the nucleoplasm, whereas strong phospho-Ser(211) staining was evident in the nucleoplasm of hormone-treated cells. Our results suggest that differentially phosphorylated receptor species are located in unique subcellular compartments, likely modulating distinct aspects of receptor function.

A comparison of methods for assessing hypothalamic-pituitary-adrenal (HPA) axis activity in asthma patients treated with inhaled corticosteroids

Suppression of the hypothalamic-pituitary-adrenal (HPA) axis is an accepted indicator of potential side effects from inhaled corticosteroids. Although cortisol monitoring is frequently used to detect changes in HPA axis activity, the optimal method for identifying the subset of asthma patients on inhaled steroids who experience severe cortisol suppression of potential clinical significance has not been established. The objective of this study was to compare several methods for assessing HPA axis activity in asthma patients taking inhaled corticosteroids. After screening, 153 patients with mild to moderate asthma were randomly assigned to receive inhaled fluticasone propionate (110, 220, 330, or 440 microg bid), flunisolide (500 microg or 1000 microg bid), or one of two control regimens (prednisone or placebo) for 21 days. Salivary (8 a.m.) and urinary (24-h) cortisol determinations were compared against 22-hour area under the serum cortisol concentration-time curve (AUC0-22 h) measured at baseline and on day 21. Comparisons were also made against 8 a.m. serum cortisol. A significant positive correlation was found between AUC0-22 h of serum cortisol and 8 a.m. serum cortisol level (r = 0.5140; p = 0.0001). The AUC0-22 h of serum cortisol was weakly correlated with 24-hour urinary cortisol levels, both corrected (r = 0.4388; p = 0.0001) and uncorrected (r = 0.3511; p = 0.0001) for creatinine excretion. The 8 a.m. salivary cortisol level correlated positively with the 8 a.m. serum cortisol level (r = 0.5460; p = 0.0001). Salivary cortisol was both sensitive and specific for the detection of a 50% decline in AUC0-22 h of serum cortisol. Cortisol reductions of this magnitude have been observed following repeated use of inhaled steroids. Because it is noninvasive, salivary cortisol measurement offers distinct advantages as a screening method for detecting pronounced HPA axis suppression in asthma patients receiving corticosteroid therapy.

Transactivation of RARE and GRE in the cellular response to arsenic

Arsenic compounds are a somewhat unique class of metals, which have been considered as both carcinogens and chemotherapeutic agents for cancers. Tumor promotion effects of arsenic are believed to be associated with its transactivational activities on transcription factors, such as AP-1 and NFkappaB, while the induction of cell apoptosis and differentiation by arsenic is considered to be a mechanism for the chemotherapeutic effects of arsenic. Here, we found that exposure of cells to arsenite and arsenate leads to transactivation of retinoic acid response elements (RARE) and glucocorticoid response elements (GRE) in mouse epidermal JB6 cells. These inductions occur in a time-dependent manner. Furthermore, induction of RARE activity by arsenic was synergistically enhanced by co-treatment of cells with retinoic acid, while GRE activation by arsenic was not affected by combined treatment of cells with fluocinolone acetonide (FA). In consideration of the important role of RARE and GRE in induction of cell differentiation, we speculate that transactivation of RARE and GRE by arsenic may be involved in its induction of cell differentiation and anti-cancer activities in addition to its induction of apoptosis.

Efficacy of voriconazole in a guinea pig model of disseminated invasive aspergillosis

Voriconazole (VRC) was evaluated in an immunosuppressed-guinea pig model of invasive aspergillosis. VRC was more effective than amphotericin B or similar doses of itraconazole in the clearance of Aspergillus from tissues. VRC treatment regimens improved survival and significantly reduced tissue colony counts compared with those of controls.

Biphasic effect of protein kinase C activators on spontaneous and glucocorticoid-induced apoptosis in primary mouse thymocytes

Spontaneous and glucocorticoid (fluocinolone acetonide, FA)-induced apoptosis of primary mouse thymocytes was inhibited by protein kinase C (PKC) activators such as bryostatin-1 and phorbol ester 12-O-tetradecanoyl-phorbol-13 acetate (TPA) within the first 2-4 h of incubation but was enhanced upon prolonged treatment. Only the anti-apoptotic but not the pro-apoptotic effect of TPA was completely suppressed by the PKC inhibitor Goe 6983 and moderately inhibited by Goe 6976. Immunoblot analysis revealed distinct PKC alpha, beta, delta, eta, theta, mu and zeta signals, a very faint PKCepsilon and no PKCgamma signal. Upon prolonged TPA treatment all PKC isoenzymes became downregulated, albeit at different rates (PKCdelta>alpha>mu>beta,theta>>eta,zeta). No significant generation of caspase-derived catalytic PKC fragments, as found to be produced upon induction of apoptosis and to be pro-apoptotic in other systems, was observed in FA- or TPA-treated thymocytes. It is concluded that the early anti-apoptotic effect of TPA depends on the activation of n-type PKC isoenzymes, whereas stimulation of spontaneous and FA-induced apoptosis by TPA ensues, at least partially, from a downregulation (or inactivation) of anti-apoptotic PKC species, i.e. in primary thymocytes PKC activation is primarily involved in a negative regulation of apoptosis.

An interactive algorithm for the assessment of cumulative cortisol suppression during inhaled corticosteroid therapy

The objective of the study was to develop an algorithm based on a pharmacokinetic-pharmacodynamic (PK/PD) modeling approach to quantify and predict cumulative cortisol suppression (CCS) as a surrogate marker for the systemic activity of inhaled corticosteroid therapy. Two Excel spreadsheets, one for single dose and another for steady-state multiple doses of inhaled steroids, were developed for predicting CCS. Four of the commonly used inhaled steroids were chosen for the purposes of simulation: fluticasone propionate (FP), budesonide (BUD), flunisolide (FLU), and triamcinolone acetonide (TAA). Drug-specific PK and PD parameters were obtained from previous single- and multiple-dose studies. In cases in which multiple-dose data were not available, the single-dose data were extrapolated. The algorithm was designed to calculate CCS based on 5 input parameters: name of drug, dose, dosing interval, time(s) of dosing, and type of inhaler device. In addition, a generalized algorithm was set up to calculate CCS based on clearance, volume of distribution, absorption rate, protein binding, pulmonary deposition, oral bioavailability, and unbound EC50 of the corticosteroid of interest. The spreadsheet allowed predictions of CCS for single doses as well as steady-state conditions. A simple method has been developed that facilitates comparisons between various drugs and dosing regimens and has the potential to significantly reduce the number of comparative clinical trials to be performed for evaluating the short-term systemic activity of inhaled corticosteroids.

Molecular mechanisms of increased nitric oxide (NO) in asthma: evidence for transcriptional and post-translational regulation of NO synthesis

Evidence supporting increased nitric oxide (NO) in asthma is substantial, although the cellular and molecular mechanisms leading to increased NO are not known. Here, we provide a clear picture of the events regulating NO synthesis in the human asthmatic airway in vivo. We show that human airway epithelium has abundant expression of NO synthase II (NOSII) due to continuous transcriptional activation of the gene in vivo. Individuals with asthma have higher than normal NO concentrations and increased NOSII mRNA and protein due to transcriptional regulation through activation of Stat1. NOSII mRNA expression decreases in asthmatics receiving inhaled corticosteroid, treatment effective in reducing inflammation in asthmatic airways. In addition to transcriptional mechanisms, post-translational events contribute to increased NO synthesis. Specifically, high output production of NO is fueled by a previously unsuspected increase in the NOS substrate, l -arginine, in airway epithelial cells of asthmatic individuals. Finally, nitration of proteins in airway epithelium provide evidence of functional consequences of increased NO. In conclusion, these studies define multiple mechanisms that function coordinately to support high level NO synthesis in the asthmatic airway. These findings represent a crucial cornerstone for future therapeutic strategies aimed at regulating NO synthesis in asthma.

Time dependent effects of glucocorticoids on adrenocorticotropin secretion of rat pituitaries ex-vivo

Different glucocorticoids have been compared with respect to the inhibition of corticotropin-releasing factor (CRF)-mediated adrenocorticotropin (ACTH) secretion from pituitary fragments of the rat. The influence of time of exposure to glucocorticoids and glucocorticoid concentration has been investigated. CRF-stimulated ACTH secretion of perifused rat pituitary fragments was measured by a chemiluminescence immunoassay. ACTH secretion was monitored over three days. Inhibition of CRF-stimulated ACTH secretion by glucocorticoids was quantified by the area under the curve of CRF-stimulated ACTH secretion over baseline. Concentrations needed to inhibit ACTH secretion decreased with the receptor affinities of the glucocorticoids as follows: fluticasone propionate; receptor affinity 1800, concentration 10(-8) M; budesonide, 935 and 3-2.5 x 10(-8) M; flunisolide, 478 and 5 x 10(-7) M; prednisolone, 10 and 10(-6) M. CRF-stimulated secretion was inhibited by glucocorticoids after incubation for 1 min at concentrations between 10(-8) and 10(-6) M. The same absolute quantity of the glucocorticoids produced no inhibition when incubation was prolonged to 50 min or when a lower concentration was used. Immediately after the perifusion stimulation of ACTH secretion was observed. The results suggest the possibility of minimizing the side effects of glucocorticoids by prolonging drug release.

Effects of high-dose inhaled corticosteroids on plasma cortisol concentrations in healthy adults

BACKGROUND

Recent studies suggest that inhaled corticosteroids may differ significantly in their systemic effects.

OBJECTIVE

To compare the systemic effects, as measured by plasma cortisol suppression, of inhaled beclomethasone dipropionate, budesonide, flunisolide, fluticasone propionate, and triamcinolone acetonide at doses of approximately 1000 microg twice daily.

METHODS

Sixty healthy adult male volunteers participated in this randomized, open-label, parallel-design study. Twenty-four-hour plasma cortisol determinations (cortisol-AUC24) were measured after a single dose of placebo medication and after a single dose and 7 consecutive doses of active medication.

RESULTS

After a single dose, all inhaled corticosteroid preparations caused statistically significant mean reductions in cortisol-AUC24 compared with placebo as follows: flunisolide, 7% (P= .02); budesonide, 16% (P= .001); beclomethasone, 18% (P= .003); triamcinolone, 19% (P=.001); and fluticasone, 35% (P<.001). After multiple doses, flunisolide was not significantly different from placebo (5%; P = .24), while budesonide (18%; P = .002), triamcinolone (25%; P<.001), beclomethasone (28%; P<.001), and fluticasone (79%; P<.001) all resulted in statistically significant suppression of cortisol-AUC24. After both single and multiple doses, beclomethasone, budesonide, flunisolide, and triamcinolone were not statistically different from each other, while fluticasone was significantly (P<.001) more suppressive than the other 4 medications.

CONCLUSIONS

These results indicate that there are differences in the systemic effects of inhaled corticosteroids when used in high doses and emphasize the importance of using the minimum dose of inhaled corticosteroids required to maintain control of asthma symptoms.

Dorsal skin reactions of hairless dogs to topical treatment with corticosteroids

Dorsal skin reactions to continuous topical treatment with different types of corticosteroids were histologically investigated in hairless descendants of Mexican hairless dogs. The preparations tested were prednisolone (ST-1; weak), fluocinolone acetonide (ST-2; moderate), diflucortolone valrerate (ST-3; strong), and mometasone furoate (ST-4; very strong). Grossly, the sites treated with ST-3 and ST-4 showed moderate inflammatory reactions. After completion of the corticosteroid treatment, both sites were less pigmented and had a thin texture. The severity of histologic changes in the skin was dependent on the efficacy of the corticosteroids. The epidermis was prominently thinned from 1 wk after treatment with the corticosteroids, resulting in a flat dermis-epidermis junction. By the end of the corticosteroid treatment, these lesions became progressively more severe. At 2 wk after completion of topical treatment, the epidermal thickness in the sites treated with ST-1 and ST-2 began to return to normal values, whereas the epidermis of the skin treated with ST-3 and ST-4 became thinner. At 3-4 wk after topical treatment with ST-3 and ST-4, the dermis showed hyalinization of collagen bundles. These dermatologic findings in hairless dogs are in accordance with steroid-induced skin atrophy of human beings. These results suggest that the skin of hairless dogs responds sensitively to topical corticosteroids and that these animals are a useful model for investigating the efficacy and adverse effects of cutaneous topical corticosteroids.

Induction of thioredoxin, thioredoxin reductase and glutaredoxin activity in mouse skin by TPA, a calcium ionophore and other tumor promoters

We have measured the levels of thioredoxin, thioredoxin reductase and glutaredoxin enzyme activity in mouse skin following topical application of the phorbol ester 12-O-tetradecanoylphorbol-13-acetate (TPA), a protein kinase C (PKC) activator and tumor promoter. The specific activity of thioredoxin and thioredoxin reductase in extracts from normal epidermis increased by 40 and 50%, respectively, after single or multiple application of TPA. Multiple applications (twice per week for 2 weeks) of TPA increased glutaredoxin activity by >300%. Induction of the proteins lasted several days. Other PKC activators, like 12-O-retinoylphorbol 13-acetate, mezerein, 1-oleoyl-2-acetylglycerol and the calcium ionophore A23187, also induced all the enzyme activities. Phorbol and 4-O-methyl-12-O-tetradecanoylphorbol-13-acetate, weak activators of PKC, selectively induced the thioredoxin system only and did not influence glutaredoxin activity. Multiple applications of TPA to tumor initiated (7,12-dimethyl[a]benzanthracene-treated) skin resulted in elevated levels of both the thioredoxin and glutaredoxin systems when examined 6 days after the last phorbol ester treatment. Induction of thioredoxin, thioredoxin reductase and glutaredoxin activities by TPA and calcium ionophores may play a general role in the epigenetic mechanism of tumor promotion via thiol redox control mechanisms.

Hyperbaric oxygen increases plasma exudation in rat trachea: involvement of nitric oxide

This study investigates the microvascular permeability changes in tracheal tissue of rats exposed to hyperbaric oxygen (HBO). Rats, following exposure to HBO or ambient air (control animals) for 1.5, 3 and 6 h, were prepared for recording of nitric oxide exhaled (FENO) in air using a chemiluminescence analyser. The level of FENO was not statistically different in the two groups. Plasma exudation, evaluated by measuring the leakage of Evans blue (EB) dye into the tracheal tissue, was significantly elevated (48, 86 and 105% at 1.5, 3 and 6 h, respectively) in HBO-treated rats. Plasma exudation in the trachea of control rats was significantly increased (42%, P<0.05) by NG-nitro-L-arginine methyl ester (L-NAME), whereas it was significantly reduced (31%, P<0.05) in rats exposed to HBO for 3 h. N-acetylcysteine (NAC) and flunisolide significantly prevented the increase in plasma leakage in HBO-treated rats. In contrast, indomethacin was devoid of anti-exudative activity in these experiments. Western immunoblot showed a significant increase in the level of inducible nitric oxide synthase (iNOS) protein in the tracheal homogenates of HBO-treated rats, as compared to basal levels. These results indicate that nitric oxide (NO) is involved in the maintenance of microvascular permeability in tracheal tissue of rats. The protective effect observed with the steroid seems to support this hypothesis. Furthermore, the beneficial action of NAC underlines that reactive oxygen species participate in the microvascular permeability changes observed in tracheal tissue of rats exposed to HBO.

Effects of low and high doses of inhaled flunisolide and triamcinolone acetonide on basal and dynamic measures of adrenocortical activity in healthy volunteers

The objective of this study was to evaluate the effects of inhaled flunisolide (FN) and triamcinolone acetonide (TAA) on basal and dynamic adrenocortical activity. A randomized cross-over design was used, comparing placebo (PL), low (L) and high (H) doses of FN (Aerobid; 250 microg/actuation; without spacer; L, 1000 microg; H, 2000 microg/day), and TAA (Azmacort; 100 microg/actuation; with integrated actuator/spacer; L, 800 microg; H, 1600 microg/day). Each dose was given at 0800 and 2200 h for 3 days, and treatments were separated by a 10-day washout. Twelve normal volunteers (mean +/- SE age, 24.2 +/- 2.4 yr) were studied. After 3 days of treatment, blood samples were taken before ACTH stimulation at 0800 h (10 h after the sixth dose) and after ACTH (0.5 microg) stimulation for determination of serum cortisol. Overnight (starting at 2200 h on the third day of treatment) and early morning urine collections were taken for measurements of urinary cortisol corrected for creatinine excretion. For serum cortisol (pre- and post-ACTH stimulation), there was no significant difference compared with placebo for either drug. Post-ACTH cortisol (nanomoles per L) values were: PL, 666.3; H FN, 617.0; H TAA, 591.4; L FN, 699.2; and L TAA, 686.0. For overnight corrected urinary cortisol/creatinine excretion (nanomoles per mmol) compared with PL (6.4), there was a significant suppression (P < 0.05) at the high dose of both drugs (H FN, 2.6; H TAA, 2.3) but not at the low dose (L FN, 4.2; L TAA, 4.5). Likewise, values for early morning corrected urinary cortisol/creatinine (nanomoles per mmol) showed significant suppression (P < 0.05) only with high doses of both drugs (PL, 39.0; H FN, 26.5; H TAA, 26.6; L FN, 37.2; L TAA, 36.5). The following conclusions were reached. 1) Overnight and early morning corrected urinary cortisol/creatinine excretion was more sensitive at detecting adrenocortical suppression than basal 0800 h serum cortisol or response to 0.5 microg ACTH stimulation. 2) There were no significant differences between inhaled FN (without spacer) and TAA (with integrated actuator/spacer), which only produced detectable adrenocortical suppression at the highest recommended doses and was not associated with impaired adrenal reserve. 3) Even at the high dose, the suppression observed with both drugs is unlikely to be of clinical relevance.

Inhaled corticosteroids and beta-agonists inhibit oxidant production by bronchoalveolar lavage cells from normal volunteers in vivo

To study the anti-inflammatory mechanisms of inhaled corticosteroids and beta-agonist therapies, we evaluated basal and stimulus-induced superoxide production by human airway inflammatory cells obtained by bronchoalveolar lavage from normal volunteers before and after 3 weeks of an inhaled corticosteroid (flunisolide) and beta-agonist (metaproterenol). Assay of superoxide production by the bronchoalveolar lavage cells was performed in the presence of media alone or media containing phorbol ester by optical density determination of reduced ferricytochrome c at 550 nm. Interleukin-1 beta released from unstimulated cells and cells stimulated with lipopolysaccharide was quantitated by enzyme immunoassay. Interestingly, phorbol ester-stimulated superoxide production was strikingly inhibited (P < 0.05) by inhaled therapies, while stimulus induced Interleukin-1 beta production was not significantly affected (P = 0.12). Suppression of oxidant production by airway inflammatory cells may be a major mechanism for the beneficial anti-inflammatory effects of inhaled corticosteroids and beta-agonists.

Resistance of transformed mouse keratinocytes to growth inhibition by glucocorticoids

Glucocorticoid hormones are strong inhibitors of normal keratinocyte proliferation, but established mouse skin papillomas and carcinomas become resistant to these hormones. The biological effect of glucocorticoids is mediated through a highly specific glucocorticoid receptor (GR). To study the possible mechanisms of glucocorticoid resistance of transformed mouse keratinocytes, we evaluated GR expression and function in non-tumorigenic (3PC), papilloma-producing (MT1/2 and P1/17), and squamous cell carcinoma-producing (Ca3/7 and Ca8/29) keratinocyte cell lines and analyzed the DNA sequence of GR in glucocorticoid-sensitive and glucocorticoid-resistant keratinocytes. All transformed keratinocyte cell lines studied appeared to be completely resistant to the growth inhibition by the glucocorticoid fluocinolone acetonide (FA), whereas the untransformed cell line 3PC was very sensitive to FA. Despite the glucocorticoid resistance, all the tumorigenic keratinocyte cell lines expressed high levels of GR mRNA and protein. Southern blot analysis and direct sequencing of the DNA-binding domain of the GR gene revealed no significant changes in GR gene structure in transformed keratinocytes. To test the functional capability of GR, we compared the effect of FA on the expression of glucocorticoid-responsive genes. FA strongly induced metallothionein 1 expression in 3PC cells, slightly induced metallothionein 1 expression in P1/17 and Ca3/7 cells, and did not affect its expression in MT1/2 and Ca8/29 cells. These data suggest that resistance to the growth inhibition of glucocorticoids is an important feature of tumorigenic keratinocyte cell lines. It is likely that this hormone-resistant phenotype is a result of alteration of GR function but not of GR expression or gene structure.

Dependency of cortisol suppression on the administration time of inhaled corticosteroids

Endogenous cortisol suppression is one of the major systemic side effects of inhaled corticosteroids in the treatment of asthma. A previously developed pharmacokinetic/ pharmacodynamic approach was used to evaluate the influence of administration time on the cumulative cortisol suppression (CCS) after single doses of the inhaled corticosteroids flunisolide and fluticasone propionate. Administration time-dependent simulations of CCS were performed with drug-specific pharmacokinetic and pharmacodynamic parameters obtained from previous clinical trials. Both drugs showed similar diurnal variation in CCS, dependent on the administration time, with maximum suppression when administered in the early morning at approximately 3 AM. The optimum administration time for minimized CCS was in the afternoon but was shifted from 3 PM for fluticasone propionate to later time points around 7 PM for flunisolide, probably because of the shorter terminal elimination half-life of flunisolide. Regarding peak to trough fluctuation, however, CCS after fluticasone propionate showed only half the administration time dependency as after flunisolide. Therefore, the ratio between CCS after flunisolide and after fluticasone propionate also followed administration time-dependent variations. This led to the conclusion that administration time has to be considered as a pivotal influential factor in clinical studies comparing CCS among different inhaled corticosteroids.

Blocking activator protein-1 activity, but not activating retinoic acid response element, is required for the antitumor promotion effect of retinoic acid

Retinoic acid is one of the most promising drugs for chemotherapy and chemoprevention of cancer. Either blocking activator protein-1 (AP-1) activity or activating retinoic acid response element (RARE) have been proposed to be responsible for its antitumor activity. However, evidence for this hypothesis is lacking in vivo studies. To address this issue, we used an AP-1-luciferase transgenic mouse as a carcinogenesis model and new synthetic retinoids that are either selective inhibitors of AP-1 activation or selective activators of the RARE. The results showed that the SR11302, an AP-1 inhibition-specific retinoid, and other AP-1 inhibitors such as trans-retinoic acid and fluocinolone acetonide, markedly inhibit both 12-O-tetradecanoylphorbol-13-acetate-induced papilloma formation and AP-1 activation in 7,12-dimethyl benz(a)anthracene-initiated mouse skin (P < 0.05). In contrast, repeated applications of SR11235, a retinoid with RARE transactivating activity, but devoid of AP-1 inhibiting effect, did not cause significant inhibition of papilloma formation and AP-1 activation (P > 0.05). These results provide the first in vivo evidence that the antitumor effect of retinoids is mediated by blocking AP-1 activity, but not by activation of RARE.

Altered glucocorticoid receptor expression and function during mouse skin carcinogenesis

Glucocorticoids are the most potent inhibitors of tumor promotion in mouse skin, when applied with a promoting agent at the early stages of promotion. However, established skin papillomas become resistant to growth inhibition by glucocorticoids. Glucocorticoid control of cellular functions is mediated by the glucocorticoid receptor (GR), a well-known transcription factor. Here we present data on GR expression and function in mouse papillomas and squamous cell carcinomas. Tumors were produced in SENCAR mice by a 7,12-dimethylbenz[a]anthracene and 12-O-tetradecanoylphorbol-13-acetate two-stage protocol. In early papillomas (after 15-20 wk of promotion), northern blotting revealed a decrease in the GR mRNA level that was confirmed by a binding assay. However, in late papillomas (after 30-40 wk of promotion), and especially in squamous cell carcinomas, the level of GR in both assays was similar to or higher than the GR level in normal epidermis. To test the functional capability of GR in tumors, we compared the effect of the synthetic glucocorticoid fluocinolone acetonide (FA) on keratinocyte proliferation and on expression of glucocorticoid-responsive genes in normal epidermis, hyperplastic skin surrounding tumors, and mouse skin papillomas. FA strongly inhibited DNA synthesis in keratinocytes in normal skin and tumor-surrounding skin but had no effect on DNA synthesis in papillomas. In addition, FA strongly induced metallothionein 1 expression and inhibited connexin 26 expression in skin but did not affect expression of these genes in tumors. These data suggest that alteration of both the expression and function of GR may be an important mechanism of tumor promotion in skin.

Glucocorticosteroids inhibit degradation in bovine cartilage explants stimulated with concomitant plasminogen and interleukin-1 alpha

OBJECTIVE

Glucocorticosteroids are beneficial in the treatment of osteoarthritis (OA) in humans, and have been shown to protect cartilage in animal models of OA. Therefore, we undertook the present study to investigate the in vitro effect of several glucocorticosteroids on cartilage degradation.

METHODS

Bovine articular cartilage explants labeled with [35S] Sulfate and stimulated either with IL-1 alpha alone or with concomitant plasminogen plus IL-1 alpha were used in this study as an in vitro model of cartilage degradation. Clobetasol propionate, fluocinolone-acetonide-21-acetate, prednisolone, triamcinolone and triamcinolone hexacetonide were the glucocorticosteroids investigated in a series of experiments, at concentrations ranging from 10 picomolar to 10 micromolar. Degradation in [35S] Sulfate-labeled bovine articular cartilage explants was induced with IL-1 alpha or with concomitant IL-1 alpha plus human plasminogen. The effects of several glucocorticosteroids were studied, and a comparison between efficacy in explants stimulated with IL-1 alpha alone or IL-1 alpha plus concomitant plasminogen was made. Glucocorticosteroid efficacy was expressed as percent inhibition of degradation, and their IC50S were also calculated.

RESULTS

Glucocorticosteroids showed no protective effects on cartilage degradation in the presence of IL-1 alpha alone. When degradation was induced by IL-1 alpha in the presence of concomitant human plasminogen, all the glucocorticosteroids showed statistically significant.inhibition (p < 0.05) with calculated IC50S of 450-2500 picomolar.

CONCLUSION

The inhibition of cartilage degradation by glucocorticosteroids may be due to down-regulation of urokinase plasminogen activator (u-PA) activity. It has been shown that u-PA may be the first enzyme in the cascade of activation of pro-matrix metalloproteinases by the fibrinolytic system. Inhibition of u-PA activity may be one explanation for the efficacy of glucocorticosteroids observed in animal models of OA and with intraarticular injection in patients with OA.

Mechanism of skin tumorigenesis by contact sensitizers: the effect of the corticosteroid fluocinolone acetonide on inflammation and tumor induction by 2,4 dinitro-1-fluorobenzene in the skin of the TG.AC (v-Ha-ras) mouse

The effect of the corticosteroid fluocinolone acetonide (FA) on skin tumor induction and inflammation by the contact sensitizer dinitrofluorobenzene (DNFB) was examined. This study broadly relates to the question of whether contact sensitizers, as electrophilic chemicals that produce protein adduction, may constitute an environmental cancer hazard. The specific aim of this study was to evaluate the extent to which the immunogenic inflammatory response to DNFB, in contrast to DNFB cytotoxicity, might be responsible for tumor induction. Experiments were conducted on a transgenic (TG.AC) mouse, incorporating a mutated ras oncogene (v-Ha-ras) that responds rapidly and profusely with skin papillomas to tumor promoters as if it were genetically initiated. Various doses and patterns of DNFB and FA were applied to the skin in a 2-week period; DNFB was given four times and FA was given either with the DNFB or daily. The tumor response to DNFB was completed by 8 weeks from the first dose and was consistent with a dose-squared relationship. FA was not tumorigenic alone; when given with DNFB, it caused only a small reduction in inflammation and tumor yield. When given daily, FA increased ulcerative skin damage, inflammation, and the yield tumors. The results suggest that tumorigenesis by DNFB, in the high-dose short-term regimen used here, is mainly due to its cytotoxicity and not contact sensitization.

Drug-induced reversion of progression phenotype is accompanied by reversion of AP-1 phenotype in JB6 cells

Transformed JB6 cells can be stably reverted to nontransformed phenotype by AP-1 inhibiting gluccorticoid fluocinolone (FA) and cAMP elevator forskolin (FN), yielding stable revertants of promotion resistant (P-) and promotion sensitive (P+) phenotypes. AP-1 activity of nontransformed P- and P+ revertant clones was decreased under a variety of experimental conditions compared with their transformed counterparts. Moreover, AP-1 activity in P+ cells under anchorage-independent conditions was induced by 12-0-tetradecanoyl-phorbol-13-acetate (TPA) while AP-1 activity in the reverted P- cells was not induced, just as observed for the original P+ and P- variants. Taken together these data suggest that changes in AP-1 activity may be one key mediator not only of forward progression but also of reversion of tumor cells to nontransformed phenotype. In addition, the higher transfection efficiency of the new reverted P- and P+ cells renders them useful for studying the role of transcription factors in tumor promotion.

Changes in adrenal carbonyl reductase activity in pregnant rats

Changes in adrenal carbonyl reductase (CR) activity during pregnancy and postparturition in rats were investigated using two substrates, 13,14-dihydro-15-keto-prostaglandin F2 alpha (15KD-PGF2 alpha) and p-nitroacetophenone (PNAP). 15KD-PGF2 alpha reductase activity showed the lowest level on day 16 of pregnancy and steeply increased on the morning of postpartum day 1. PNAP reductase activity did not change up to day 18 of pregnancy, then was gradually increased and maintained the highest levels between day 19 and the morning of day 21 of pregnancy. Thereafter, the enzyme activity was rapidly decreased after parturition, on the contrary of changes in the 15KD-PGF2 alpha reductase activity. On the other hand, exogenous glucocorticoid treatment increased the 15KD-PGF2 alpha activity and decreased the PNAP reductase activity in adrenal glands of nonpregnant animals. Thus, it is found that the adrenal CRs in the above two classes are regulated by different mechanisms. As maternal corticosterone level is increased rapidly during late pregnancy by maternal transfer of fetal corticosterone, the present results suggest that adrenal CR activity during pregnancy, in particular at periparturition, may be influenced by fetal corticosteroids.

A bioassay for topical and systemic effect of three inhaled corticosteroids

BACKGROUND

Comparisons of relative potency for the three inhaled corticosteroids in the United States are limited to assessment of skin blanching.

OBJECTIVE

Development of a method for comparing relative potencies of inhaled corticosteroids for topical effect on human airway and systemic effect.

METHODS

With use of partial suppression of immediate response to inhaled allergen and 24-hour urinary free cortisol output, three-point dose-response curves were constructed for beclomethasone dipropionate (50 micrograms/puff), triamcinolone acetonide (100 micrograms/puff), and flunisolide (250 micrograms/puff). A randomized, parallel, single-blind study design was used. Dosing began with one puff four times a day for flunisolide and two puffs four times a day for the others. Doses were doubled after 1 week and again after a second week.

RESULTS

Twenty-five patients completed the study. Dose-response relationships were shown for each inhaled corticosteroid for both topical and systemic effect. Dose-response curves for the three preparations were similar when response was plotted against delivered dose in micrograms.

CONCLUSION

Within the limits of the assays, relative potencies of the three preparations appeared to be approximately equivalent for both topical and systemic effect when dose was expressed in micrograms. Relative potency per puff is therefore approximately proportional to the dose delivered. This method has potential for evaluation of relative potency of newer inhaled corticosteroids and the relative advantage of alternative delivery systems.

Phospholipid peroxidation in tumor promoter-exposed mouse skin

We have investigated lipid peroxidation in the skin of CD1 mice following single or repeated topical applications of the tumor promoter, 12-O-tetradecanoylphorbol-13-acetate (TPA). A substantial accumulation of hydroxyphospholipids, to levels 3-5 times control values, followed exposure to two or more TPA treatments (24-72 h intervals), whereas single applications were ineffective. Sodium borohydride reduction increased the yield of product by approximately 50%, suggesting the additional presence of phospholipid hydroperoxides in the oxidized lipids. Straight phase HPLC analysis of the constituent hydroxy fatty acids, followed by gas chromatography/mass spectrometry, revealed that oxidized derivatives of linoleic acid, including 9- and 13-hydroxyoctadecadienoic acids (9- and 13-HODE), were the primary products. Stereochemical analysis showed ratios of S to R stereoisomers of 1.3 for 13-HODE and 1.27 for 9-HODE, which implied that TPA-induced peroxidation was primarily due to free radical oxidation, although a partial contribution of enzyme (lipoxygenase) activity is possible. The TPA-induced peroxidation was greater in the epidermis than in the dermis. Pre-exposure of mouse skin to the anti-inflammatory agent fluocinolone acetonide, antioxidants and enzyme (phospholipase A2 and lipoxygenase) inhibitors lowered the peroxidation response to subsequent exposure to TPA. Phospholipid peroxidation products may be useful markers of oxygen radical production in TPA-exposed mouse skin with possible relevance to tumor promotion.

Blocking of tumor promoter-induced AP-1 activity inhibits induced transformation in JB6 mouse epidermal cells

AP-1 transcriptional activity is stimulated by the transformation promoters phorbol 12-myristate 13-acetate ("12-O-tetradecanoylphorbol 13-acetate," TPA) and epidermal growth factor (EGF) in promotion-sensitive (P+) but not in promotion-resistant (P-) JB6 mouse epidermal cell lines. Although TPA stimulates expression of the jun and fos family genes, only c-jun expression shows higher elevation in P+ cells than in P- cells. The present study tests the hypothesis that induced AP-1 activity is required for tumor promoter-induced transformation in JB6 P+ cells. Both retinoic acid and the glucocorticoid fluocinolone acetonide inhibited basal and TPA-induced AP-1 activities that were tested with a stromelysin promoter-chloramphenicol acetyltransferase reporter gene in P+ cells. Since both retinoic acid and fluocinolone acetonide are active in inhibiting TPA-induced anchorage-independent transformation of P+ cells in the dose range that blocks TPA-induced AP-1 activity, their antipromoting effects may occur through inhibition of AP-1 activity. To test the hypothesis with a more specific inhibitor, stable clonal transfectants of P+ cells expressing dominant negative c-jun mutant encoding a transcriptionally inactive product were analyzed. All transfectants showed a block in TPA and EGF induction of AP-1 activity. All transfectants also showed inhibition of TPA-induced transformation, and most transfectants showed a block in EGF-induced transformation. These results indicate that AP-1 activity is required for TPA- or EGF-induced transformation. This work demonstrates that a specific block in induced AP-1 activity inhibits tumor promoter-induced transformation.

Effect of anti-inflammatory agents on ricin-induced macrophage toxicity

The toxicity of ricin in susceptible cells is well characterized biochemically, but the pathophysiological implications of its toxicity and the immune response to ricin challenge in the lung are unknown. Incubating macrophage cell line with ricin (1 pM-10 nM) for 4 hours markedly inhibited 3H-leucine incorporation (acid insoluble) into protein (> 95%, at 1 nM) without affecting the acid-soluble radioactivity. In spite of increased uptake of total thymidine (141 +/- 13.5%) and total uridine (135 +/- 17.2%), DNA synthesis in ricin-treated cells was progressively inhibited although RNA synthesis was not affected. Fluocinolone (an anti-inflammatory glucocorticoid) pretreatment increased the ricin-induced inhibition of protein synthesis. The synergistic effect of fluocinolone on ricin-induced protein synthesis inhibition was due to an increased binding (167%, p < 0.01) and internalization (134 +/- 12%, p < 0.025) of ricin. Partial protection from ricin-induced inhibition of protein synthesis by indomethacin (nonsteroidal, anti-inflammatory agent) was due to decreased binding and internalization of ricin. These results show that macrophages are sensitive to ricin and that pharmacologically active drugs may regulate ricin's toxicity, perhaps by controlling synthesis and release of certain mediators of fast death.

Quantitative vasoconstrictor assay for topical corticosteroids: the puzzling case of fluocinolone acetonide

BACKGROUND

The validity of the vasoconstrictor test has been questioned because of the apparent nonequivalence of some generic corticosteroid products.

OBJECTIVE

Our purpose was to determine the vasoconstrictor activity of a generic 0.025% fluocinolone acetonide ointment by two different methods, dilution by volume and dilution by area of application.

METHODS

Vasoconstrictor activity on a visual 4-point scale was measured in 20 volunteers. Topical fluocinolone acetonide ointment (0.025%) was tested by comparing dilution by volume (1:1, 1:3, and 1:7) in petrolatum and dilution by area of application. Fluocinolone release from the diluted ointments was also measured with an in vitro method.

RESULTS

Dilution by area gave the expected results, a decreasing average vasoconstrictor score; but dilution by volume did not. Both the 1:1 and 1:3 dilutions inexplicably showed greater activity than the full-strength product; this finding was similarly reflected in the in vitro studies that showed a greater rate of drug release from the 1:1 and 1:3 dilutions.

CONCLUSION

Dilution by area provides a useful quantitative assay for comparative vasoconstrictor activity.

Inhibitory effects of inhaled flunisolide on inflammatory functions of alveolar macrophages

We have studied 15 patients with slight or moderate bronchial obstruction, all of whom were being treated by inhalation of the beta-mimetic fenoterol 4 x 400 micrograms/day, and 7 of whom were also receiving inhaled flunisolide 2 x 500 micrograms/day. The therapy had been given for longer than 1 month in each case. Bronchoscopy and bronchoalveolar lavage (BAL) was done for diagnosis or follow up of bronchial diseases. None of the patients showed signs of any interstitial lung disease. Conditioned culture supernatants were produced by cultivating alveolar macrophages (AM) for 24 h using standard conditions. To detect all the biological effects both of IL-1 alpha and IL-1 beta in the culture supernatants a modification of the standard mouse IL-1 thymocyte bioassay was used. The TNF concentration in culture supernatants was measured by ELISA. Free oxygen radical release by alveolar macrophages was determined by the detection of chemiluminescence. Both IL-1 and TNF production were significantly lower in patients receiving fenoterol plus flunisolide than in patients on fenoterol alone. In contrast, no difference could be observed in the release of free oxygen radicals from alveolar macrophages. Thus, for the first time an ex vivo study has revealed an interrelation between inhaled glucocorticoid therapy and inhibition of important mediators of inflammatory processes in the lower respiratory tract.

The cutaneous corticosteroid vasoconstriction assay: a reflectance spectroscopic and laser-Doppler flowmetric study

Cutaneous vasoconstriction induced by topical corticosteroids was investigated using non-invasive bioengineering techniques. Corticosteroids of different potency in alcoholic solution were applied topically, under occlusion, and cutaneous blanching was investigated using visual scoring, reflectance spectroscopy (RS) and laser-Doppler flowmetry (LDF). The RS technique allowed separation of cutaneous haemoglobin content into arterial oxygenated (OH) and venous deoxygenated haemoglobin (DOH) components. Application of alcohol decreased total haemoglobin by 10%, with a corresponding 8% increase in blood flow (BF). Clobetasol propionate was the most potent vasoconstrictor, inducing significant visible blanching and decreasing DOH (30%), OH (33%) and BF (18%) (P < 0.01). Fluocinolone acetonide, betamethasone-17-valerate and dexamethasone also caused visible blanching (P < 0.01). There was no significant decrease in BF, but reflectance spectroscopy showed a decrease in DOH (P < 0.01). Tixocortol, CMJ and hydrocortisone acetate did not produce significant blanching, although DOH was decreased compared with the alcohol control. Measured by reflectance spectroscopy, corticosteroid-induced blanching was predominantly venoconstriction and only the most potent corticosteroid caused a significant decrease in OH and blood flow. This may explain why previous attempts to improve cutaneous vasoconstriction assays using laser-Doppler flowmetry have been unsuccessful.

[Pharmacologic study of the glucocorticoid activity of flunisolide compared with other steroids in the rat]

Flunisolide (FLU), beclomethasone dipropionate (BDP) and its pulmonary metabolites beclomethasone monopropionate (BMP) and beclomethasone (B) were studied in rat for: their relative binding affinity (RBA) for the 5 classes of steroid receptors, their in vitro glucocorticoid activity on rat thymocytes, their in vivo glucocorticoid activity by oral route. These compounds displayed a strong RBA for rat lung, thymus and liver glucocorticoid receptors (FLU > or = BMP > BDP > or = B). They were also shown to have a moderate RBA for both mineralocorticoid and progestin receptors, while being devoid of any binding to androgen and oestrogen receptors. On rat thymocytes FLU exhibited the highest glucocorticoid activity (FLU > B > or = BMP > BDP). In rat oral FLU displayed a strong glucocorticoid activity with a slight first-pass metabolism as opposed to what has been reported in human.