Predominant 4-hydroxylation of estradiol by constitutive cytochrome P450s in the female ACI rat liver

The ACI rat is extremely sensitive to estrogens as mammary carcinogens, whereas the Sprague-Dawley strain is relatively resistant. Comparison of the disposition and effects of estrogens in these two strains should provide insights into the mechanisms of estrogen carcinogenicity. We have begun this investigation by comparing the metabolism of [(3)H]17beta-estradiol (E2) by liver microsomes prepared from female rats from each strain. Both strains produce estrone (E1) as the major product at E2 concentrations >1 microM, with smaller amounts of 2-hydroxy-E2 formed. As the E2 concentration is decreased, however, aromatic hydroxylation becomes a more dominant pathway for both strains. At starting E2 concentrations as low as 3 nM, Sprague-Dawley liver microsomes produced comparable yields of 2-hydroxy-E2 and E1. In contrast, ACI liver microsomes yielded a profound shift to aromatic hydroxylation as the dominant pathway as E2 concentrations dropped below 1 microM, and this shift reflected the production of 4-hydroxy-E2 as the predominant product. The apparent K(m) for 4-hydroxylation of E2 is <0.8 microM, as opposed to approximately 4 microM for 2-hydroxylation, suggesting that different cytochrome P450s (CYPs) are responsible. Western immunoblotting of the liver microsomal preparations from ACI and Sprague-Dawley rats for CYPs known to catalyze 2- and 4-hydroxylation of E2 revealed that both strains contained comparable amounts of CYP 2B1/2 and 3A1/2, but no detectable amounts of CYP 1B1, the proposed E2 4-hydroxylase. Although this enzyme is not a constitutive CYP in Sprague-Dawley rat liver, its presence in ACI liver could provide a ready explanation for the predominance of 4-hydroxy-E2 as a product. The identity of the estradiol 4-hydroxylase in ACI rat liver and the role of this unique reaction in the heightened sensitivity to E2 carcinogenicity remain to be elucidated.

Effects of monotherapy with intra-nasal corticosteroid or combined oral histamine and leukotriene receptor antagonists in seasonal allergic rhinitis

BACKGROUND

The combination of a leukotriene receptor antagonist with an antihistamine may have beneficial effects in seasonal allergic rhinitis (SAR).

OBJECTIVE

To determine how combined oral mediator blockade compares to monotherapy with intranasal corticosteroid in the treatment of SAR.

METHODS

Twenty-two patients with seasonal allergic rhinitis were enrolled in a placebo controlled crossover study comparing 2 weeks therapy of either (a) 200 microg intranasal mometasone furoate (MF) once daily or (b) 10 mg oral montelukast plus 10 mg oral cetirizine once daily (MON/CZ), with a 7-10 day placebo period prior to each treatment period. Domiciliary measures of symptoms and nasal flow were recorded daily. Measurements of posterior rhinomanometry, acoustic rhinometry and nasal nitric oxide were made after all treatment and placebo periods.

RESULTS

There were significant (P < 0.05) improvements in domiciliary peak nasal flow (l/min) with both MF (133 (3.8)) and MON/CZ (124 (3.8)) compared to pooled placebo (110 (4.0). Both treatments also showed significant improvement in terms of nasal blockage (units) (PL: 1.1(0.1), MF: 0.5 (0.1), MON/CZ 0.7 (0.1); and total nasal symptoms (units) (PL: 3.5 (0.3), MF 1.6 (0.3), MON/CZ 1.7 (0.3)), although there was no significant difference between the two active treatments. There were no significant differences between placebo and treatment for rhinomanometry, acoustic rhinometry or nitric oxide.

CONCLUSIONS

Both intranasal mometasone furoate as monotherapy and oral cetirizine plus montelukast as cotherapy were equally effective for objective and subjective measures of treatment response in SAR. Domiciliary measurements of symptoms and peak flow were more sensitive than laboratory measurements of rhinomanometry, acoustic rhinometry and nasal nitric oxide.

Mural endocarditis caused by Salmonella virchow: Survival with conservative treatment

We describe a case of endocarditis caused by Salmonella enterica serotype virchow, which was treated conservatively with antibiotics alone. It is the only reported case of survival from salmonella endocarditis with conservative treatment, and the first reported case of endocarditis caused by Salmonella virchow. The changing prevalence, virulence patterns and importance of salmonella species in endocarditis are discussed.

Widening of scars: foe coaxed into a friend? The Millard technique revisited

Widening of scars is a frustrating event that most if not all plastic surgeons have encountered. Several therapeutic modalities have been proposed, but frequently the result is disappointing. During revision surgery, it is advocated that the dermal scar be used in providing support to the tissues instead of being discarded. The author proposes a technique by which tension on the wound is carried by tough scar tissue instead of the suture line, thereby reducing the incidence of postoperative widening. This technique was used to treat 35 nonburn scars that had widened: 31 scars were facial (24 patients) and 4 were inframammary (2 male patients). All scars were at least 4 months old. The operations were performed between February of 1996 and December of 1998; follow-up was 9 to 14 months. Only one scar widened during the follow-up period. Overall, 71 percent of patients rated the improvement as marked. This is a revisiting of the original Millard's technique, which seems to have fallen into oblivion. The author recommends this technique in dealing with widened scars during revision surgery.

Dissociation of analgesic and rewarding effects of endomorphin-1 in rats

The mu-receptor is the primary mediator of the effects of morphine and the endogenous opiates, endomorphin-1 and endomorphin-2. Here we demonstrate a dissociation of the analgesic and rewarding effects of endomorphin-1 in rats. Tail-flick results revealed that endomorphin-1 produced significant analgesic effects within 10-min after injection. However, it failed to show reward properties in the standard 45- min conditioned place preference (CPP) paradigm or in an abbreviated 10-min pairing which paralleled the time frame of the tail-flick findings. Morphine induced both analgesia and reward. Endomorphin-1 therefore is the first mu opiate shown to produce potent analgesia in the absence of reward behavior, and thus may have significant clinical potential.

Effects of once-daily formoterol and budesonide given alone or in combination on surrogate inflammatory markers in asthmatic adults

OBJECTIVES

We wished to evaluate the effects of once-daily combination therapy on surrogate inflammatory markers.

METHODS

Fifteen patients with atopic persistent asthma were evaluated (mean age, 32.4 years; FEV(1), 75.2% predicted) in a randomized, double-blind, double-dummy, placebo-controlled crossover study with a 1-week placebo washout period, comparing the following once-daily nighttime treatments: (1) formoterol (FM), 12 microg, for 2 weeks and FM, 24 microg, for 2 weeks; or (2) budesonide (BUD), 400 microg, for 2 weeks and BUD, 800 microg, for 2 weeks; or (3) FM, 12 microg, plus BUD, 400 microg, for 2 weeks and FM, 24 microg, plus BUD, 800 microg, for 2 weeks. Adenosine monophosphate (AMP) bronchial challenge, exhaled nitric oxide (NO), and serum eosinophilic cationic protein (ECP) were evaluated at 12 h postdosing after administration of each placebo and after 2 and 4 weeks of each treatment.

RESULTS

The results of AMP challenge (provocative concentration causing a 20% fall in FEV(1)) at 4 weeks showed significant (p<0.05) improvements after patients had received all active treatments compared to placebo (20 mg/mL), with FM plus BUD, 261 mg/mL, being superior (p<0.05) to FM alone, 82 mg/mL, but not to BUD, 201 mg/mL. NO and ECP showed significant (p<0.05) reductions compared to placebo with FM plus BUD or BUD alone but not with FM alone. Combination therapy was associated with optimal patient preference (rank order, FM plus BUD > FM > BUD; p<0.0005), highest domiciliary peak expiratory flow, and lowest rescue inhaler usage. All three treatments produced equivalent improvements in spirometry.

CONCLUSIONS

Patients preferred once-daily combination therapy, but this had no greater effect on inflammatory markers than therapy with BUD alone. FM alone had no anti-inflammatory activity but exhibited bronchoprotection. This emphasizes the importance of first optimizing anti-inflammatory control with inhaled corticosteroids before considering adding a regular long-acting beta(2)-agonist.

Antiasthmatic effects of mediator blockade versus topical corticosteroids in allergic rhinitis and asthma

To compare the antiasthmatic efficacy of inflammatory mediator blockade versus topical corticosteroid therapy in patients with seasonal allergic rhinitis (SAR) and asthma, 14 patients were enrolled into a single-blind, double-dummy, placebo-controlled crossover study comparing 2 wk therapy of (1) 400 microgram orally inhaled budesonide plus 200 microgram intranasal budesonide (BUD) or (2) 10 mg oral montelukast plus 10 mg oral cetirizine (ML + CZ). Before each treatment period, patients received 7 to 10 d placebo washout. All treatments were given once daily in the morning. Throughout the study, patients recorded the following domiciliary measures: peak expiratory flow (PEF), rescue inhaler requirement, asthma symptoms, and daily activity score. Laboratory measurements were made at trough of adenosine monophosphate (AMP) bronchial challenge and exhaled nitric oxide (NO). Compared with pooled placebo (PL), there were significant (p < 0.05) improvements in all domiciliary measures with both treatments (mean PEF [L/min] PL: 463; BUD: 478; ML + CZ: 483). For geometric mean AMP PC(20) (mg/ml), there was an improvement (p < 0.05), compared with PL (47), for ML + CZ (133) but not for BUD (51); whereas for NO (ppb) there was significant suppression with BUD (7.6) but not ML + CZ (11.5) compared with PL (13.6). In conclusion, both combined mediator blockade and combined topical corticosteroids are equally effective antiasthma therapy in patients with asthma and SAR.

Effects of adding a leukotriene antagonist or a long-acting beta(2)-agonist in asthmatic patients with the glycine-16 beta(2)-adrenoceptor genotype

PURPOSE

In the United Kingdom, about 40% of patients with asthma are homozygous for the glycine-16 beta(2)-adrenoceptor polymorphism, which predisposes them to agonist-induced down-regulation and desensitization of the beta(2)-adrenoceptor. We assessed the effects of adding treatment with either a long-acting beta(2)-agonist (inhaled formoterol, 12 microg twice daily) or a leukotriene receptor antagonist (oral zafirlukast, 20 mg twice daily) to inhaled corticosteroid therapy in patients with this genotype.

SUBJECTS AND METHODS

We enrolled 24 patients with mild to moderate asthma who were being treated with inhaled corticosteroids. Patients were randomly assigned to receive one of three treatments (placebo, zafirlukast, or formoterol in addition to inhaled corticosteroids) for 1 week each in a crossover fashion, separated by a 1-week placebo run-in and washout period. Measurements of bronchoprotection (measured as the provocative dose of methacholine that produced a 20% decline in forced expiratory volume in 1 second [FEV(1)]), exhaled nitric oxide (a surrogate marker of airway inflammation), and symptoms were made before each treatment and 12 hours after the last dose of each treatment.

RESULTS

Both formoterol and zafirlukast were equally effective in maintaining asthma control compared with placebo: the geometric mean-fold difference in the methacholine provocative dose was 1.5-fold (95% confidence interval [CI]: 1.1- to 2.2-fold) for zafirlukast and 1.9-fold (95% CI: 1.2- to 2.9-fold) for formoterol. As compared with placebo, zafirlukast caused a significant suppression in exhaled nitric oxide (1.7-fold difference in geometric mean values, 95% CI: 1.1- to 2.6-fold) but formoterol did not (1.2-fold difference, 95% CI: 0.8- to 1.9-fold). Diary cards showed significant (P <0.05) improvements in the peak flow with formoterol (morning and evening) and zafirlukast (evening) as compared with placebo.

CONCLUSIONS

Formoterol and zafirlukast maintained asthma control in patients who might be genetically predisposed to fare worse with long-acting beta(2)-agonists. The reduction in exhaled nitric oxide with zafirlukast suggests that it may have anti-inflammatory effects in addition to those seen with inhaled corticosteroids.

Subjective and objective markers of treatment response in patients with seasonal allergic rhinitis

BACKGROUND

Although there is a recognized association between upper and lower allergic airways disease, it is unknown how seasonal allergic rhinitis (SAR) therapy will effect sensitive markers of airway function in patients with no history of asthma.

OBJECTIVE

To prospectively evaluate subjective and objective markers of treatment response in 26 patients with SAR who have been screened to exclude a diagnosis of asthma.

METHODS

The patients' usual treatment, with antihistamine alone (n = 13) or in combination with intranasal corticosteroid (n = 13), was withheld for 1 week to achieve a baseline and then resumed. Measurements were made after baseline and after 2 and 4 weeks of treatment for nasal peak inspiratory flow rate (nPIFR); airways resistance (Raw) and specific conductance (sGaw); and nasal nitric oxide (NO). Patients reported their symptom (nasal, throat and eye) scores, daily activity scores, and ocular sodium cromoglycate usage over the preceding 24 hours.

RESULTS

Compared with baseline, there were significant (P < .05) improvements with nPIFR, symptom scores and cromoglycate usage at 2 and 4 weeks of treatment. There was no significant suppression for NO at 2 or 4 weeks. There was a significant correlation between nPIFR and nasal symptoms (r = -0.52, P < .001). After 4 weeks of treatment there were significant (P < .05) improvements in sGaw (143.3% predicted) and Raw (91.6% predicted) compared with baseline (sGaw: 111.8%, Raw: 104.2% predicted).

CONCLUSION

Treatment of SAR improves upper and lower airway parameters but not NO. Nasal PIFR correlates significantly with nasal symptoms.

Low-dose continuous chemotherapy (LBCMVD-56) for refractory and relapsing lymphoma

BACKGROUND

Although lymphoid malignancies are generally chemosensitive, relapse is common. The use of high-dose therapy can make subsequent cytotoxic therapy intolerable. There is a need to develop regimens with low acute toxicity which are suitable for use in patients post-high dose therapy and following the failure of standard protocols.

PATIENTS AND METHODS

Twenty-six patients with lymphomas, fifteen of whom had received high-dose therapy, were treated with a novel regimen consisting of low-dose lomustine, chlorambucil, daily subcutaneous bleomycin, vincristine and methotrexate with dexamethasone on an eight-week cycle (LBCMVD-56). A median of three cycles was given.

RESULTS

The overall response rate at 12 weeks was 67% (21% complete remission (CR)) with a median overall survival of 13 months. A symptomatic response was seen in 72%. Previous high-dose therapy did not compromise the response rate. Toxicity was acceptable with grade 3-4 haematological toxicity seen in 27% of cycles, gastrointestinal toxicity seen in 11% and pulmonary toxicity seen in 8%. Thirty-one percent of patients required hospitalisation at some point during this treatment most commonly for neutropenic sepsis.

CONCLUSIONS

LBCMVD-56 is an inexpensive, outpatient-based regimen with low acute toxicity and a high response rate in this heavily pre-treated group of patients.

Enhanced metabolism of halogenated hydrocarbons in transgenic plants containing mammalian cytochrome P450 2E1

Chlorinated solvents, especially trichloroethylene (TCE), are the most widespread groundwater contaminants in the United States. Existing methods of pumping and treating are expensive and laborious. Phytoremediation, the use of plants for remediation of soil and groundwater pollution, is less expensive and has low maintenance; however, it requires large land areas and there are a limited number of suitable plants that are known to combine adaptation to a particular environment with efficient metabolism of the contaminant. In this work, we have engineered plants with a profound increase in metabolism of the most common contaminant, TCE, by introducing the mammalian cytochrome P450 2E1. This enzyme oxidizes a wide range of important pollutants, including TCE, ethylene dibromide, carbon tetrachloride, chloroform, and vinyl chloride. The transgenic plants had a dramatic enhancement in metabolism of TCE of up to 640-fold as compared with null vector control plants. The transgenic plants also showed an increased uptake and debromination of ethylene dibromide. Therefore, transgenic plants with this enzyme could be used for more efficient remediation of many sites contaminated with halogenated hydrocarbons.

Fitting second-order finite mixture models to data with many censored values using maximum likelihood estimation

Finite mixture models, that is, weighted averages of parametric distributions, provide a powerful way to extend parametric families of distributions to fit data sets not adequately fit by a single parametric distribution. First-order finite mixture models have been widely used in the physical, chemical, biological, and social sciences for over 100 years. Using maximum likelihood estimation, we demonstrate how a first-order finite mixture model can represent the large variability in data collected by the U.S. Environmental Protection Agency for the concentration of Radon 222 in drinking water supplied from ground water, even when 28% of the data fall at or below the minimum reporting level. Extending the use of maximum likelihood, we also illustrate how a second-order finite mixture model can separate and represent both the variability and the uncertainty in the data set.

Additive bronchoprotective and bronchodilator effects with single doses of salmeterol and montelukast in asthmatic patients receiving inhaled corticosteroids

OBJECTIVE

We wished to evaluate whether the combination of a leukotriene receptor antagonist and long-acting beta(2)-agonist might confer additive beneficial effects in terms of bronchoprotection and bronchodilatation, in mild to moderate asthmatic patients who were suboptimally controlled on inhaled corticosteroids alone.

METHODS

Twelve asthmatic patients were enrolled into a single-blind, placebo-controlled, crossover study, receiving additive therapy as either of the following: (1) montelukast alone, 10 mg (ML(10)); (2) inhaled salmeterol alone, 50 microg (SM(50)); (3) ML(10) and SM(50); (4) ML(10) and inhaled salmeterol, 100 microg (SM(100)); or (5) placebo inhaler and tablet. Trough measurements were made of adenosine monophosphate (AMP) bronchial challenge (the provocative concentration of a drug [AMP] causing a fall of >/= 20% in FEV(1) [PC(20)]) as the primary end point, and spirometry, following single doses of either placebo or active treatments (12 h after salmeterol, and 24 h after monteleukast, respectively).

RESULTS

Compared to placebo, all active treatments led to significant improvements (p < 0.05) in geometric mean AMP-PC(20): placebo, 42 mg/mL; ML(10), 106 mg/mL; SM(50), 115 mg/mL; ML(10) and SM(50), 183 mg/mL; and ML(10) and SM(100), 247 mg/mL. The effects of montelukast and salmeterol were numerically additive, with ML(10) and SM(100) being significantly different (p < 0.05) from ML(10) alone. For mean FEV(1) and forced expiratory flow rate between 25% and 75% of vital capacity, there were significant differences (p < 0.05) between both combination therapies vs ML(10) alone.

CONCLUSIONS

Our results suggest additive benefits of a single dose of a long-acting beta(2)-agonist and leukotriene antagonist, in terms of bronchoprotection and bronchodilation. Further studies in more severe asthmatics are required to evaluate long-term clinical effects.

Dose-response evaluation of the therapeutic index for inhaled budesonide in patients with mild-to-moderate asthma

PURPOSE

Inhaled corticosteroids have beneficial effects on pulmonary function and inflammation in patients with asthma, but they also cause systemic adverse effects, such as adrenal suppression. We evaluated the therapeutic index of inhaled corticosteroids in asthmatic patients by comparing their dose-response effects on lung function, surrogate markers of airway inflammation, and tests of adrenal function.

SUBJECTS AND METHODS

After a 10-day placebo run-in, we evaluated the effects of 200 microg, 400 microg, and 800 microg of inhaled budesonide, each dose given twice daily sequentially for 3 weeks in 26 patients, aged 35 +/- 12 years (mean +/- SD), with mild-to-moderate asthma. Measurements were made of bronchial reactivity, exhaled nitric oxide (a marker of airway inflammation), spirometry, serum eosinophilic cationic protein concentration, and 10-hour overnight urinary cortisol excretion. Plasma cortisol levels were measured at 8 AM and after stimulation with human corticotropin releasing factor.

RESULTS

For measurements of pulmonary function and exhaled nitric oxide, there was a plateau in the mean response to budesonide between 400 microg (low dose) and 800 microg (medium dose) per day, whereas for eosinophilic cationic protein and bronchial challenge, maximal benefits occurred between 800 and 1,600 microg (high dose) per day. Effects on plasma cortisol levels showed maximal suppression at 1,600 microg of budesonide per day. The proportion of patients with an optimal therapeutic index, in terms of a good airway response (fourfold decrease in bronchial hyperreactivity) and minimal systemic response (overnight urinary cortisol greater than 20 nmol), was similar at low-dose (46%) and at high-dose (52%) budesonide. The proportion of patients with a suboptimal therapeutic index, a good airway response with a marked systemic response (overnight urinary cortisol greater than 20 nmol), increased from 4% at low dose to 38% at high dose.

CONCLUSIONS

In patients with mild-to-moderate atopic asthma, there were dose-related effects of budesonide on surrogate markers of inflammation (bronchial hyperreactivity and serum eosinophilic cationic protein), although higher doses were associated with adrenal suppression and a decrease in the therapeutic index.

Asthma and Cushing's syndrome

A female patient was treated with high-dose inhaled fluticasone propionate for her asthma. Over 2 years, she developed features of Cushing's syndrome with proximal myopathy, osteopenia, hypertension, depressive psychosis, and cushingoid appearance. She had biochemical evidence of marked adrenal suppression with a 9:00 AM serum cortisol of 20 nmol/L that returned to normal (315 mol/L) after her therapy was changed to budenoside, 0.8 mg/d. Her appearance, mental state, and myopathy also improved with no loss of asthma control. This case illustrates the potential for developing clinically relevant adverse effects of inhaled corticosteroids when given at licensed doses.

In vitro evaluation of a novel prosthesis for laryngoplasty of horses with recurrent laryngeal neuropathy

A prosthesis, composed of a steel cable and stress-reducing washers, was developed to prevent failure of laryngoplasty, a common treatment for horses affected by recurrent laryngeal neuropathy. Laryngoplasties were performed on 15 cadaveric larynges using a polyester suture on one side and the cable prosthesis on the other. Each prosthesis was distracted at a displacement rate of 20 mm/s using a servohydraulic materials testing machine until laryngoplasty failed. Distraction force and actuator displacement were recorded and analysed. All 15 laryngoplasties performed with a suture failed at the muscular process at a mean +/- s.d. force of 55.8 +/- 13.1 N. Six laryngoplasties performed with the cable prosthesis failed at the muscular process at mean force 219.6 +/- 125.0 N. In the other 9, the arytenoid cartilage was avulsed from the larynx at mean force 206.4 +/- 75.3 N, and the cable then tore through the muscular process at mean force 357.0 +/- 32.0 N. The difference in force required to cause failure of laryngoplasty was significant (P<0.0001). Although the prosthesis resisted substantially higher forces than did the suture, the effects of the prosthesis in vivo must be evaluated.

Relationship between aesthetic motivation and preferences for aggressive and nonaggressive sports

Two studies were designed to replicate the finding that people scoring high on aesthetic motivation, as measured by Wann's Sport Fan Motivation Scale, tend to prefer nonaggressive sports. Study 1 correlated 75 college students' scores on aesthetic motivation with their enjoyment of watching aggressive sports. Study 2 correlated 44 college students' scores on aesthetic motivation with their enjoyment of watching a series of aggressive football plays. Neither study replicated the previous finding that people high on aesthetic motivation tend to prefer nonaggressive sports, suggesting that the earlier finding was an artifact of the method used.

Radiological study to evaluate suspected scapulohumeral joint dysplasia in Shetland ponies

A radiological study was performed to test the hypothesis that osteoarthritis of the scapulohumeral joint in Shetland ponies is secondary to shoulder dysplasia. Animals were selected into 3 groups: Group 1: Shetland ponies with a radiological and clinical diagnosis of scapulohumeral osteoarthritis (n = 8); Group 2: Shetland ponies without forelimb lameness (n = 12); Group 3: Horses/ponies without a history or clinical signs of forelimb lameness (n = 22). Anatomical indices were measured from mediolateral radiographs of a scapulohumeral joint from each animal. There was a significant difference in the mean radius of curvature of the glenoid cavity of the scapula (RCG) between the 3 groups (MANOVA test, P = 0.003). The mean RCG of both Group 1 (P = 0.001) and Group 2 (P = 0.022) was significantly greater than that of Group 3. There was no significant effect of group on the radius of curvature of the humeral head or on the Conformity Index. There was a significant effect of group on the Glenoid Ratio (MANOVA test, P = 3 x 10(-6)). The mean Glenoid Ratio was significantly lower in both Group 1 (P = 2 x 10(-6)) and in Group 2 (P = 0.006) than in Group 3. These results indicate that the glenoid cavity of the scapula is 'flatter' and 'shallower' in Shetland ponies which we postulate to be a primary dysplasia in this breed.

In vitro mechanical properties of different equine hoof wall crack fixation techniques

Hoof wall cracks need mechanical stabilisation to allow healing. Common techniques are fixation with screws, wires and plates or bonding of a patch across the crack. An in vitro system to determine the shear properties of equine hoof crack repairs is described. The force and displacement at yield, stiffness and ultimate force were determined for 4 repair techniques based on an acrylic material, polyurethane patch attached with cyanoacrylate adhesive, steel plate attached with screws and a transverse metal bar cut into the hoof wall. The cyanoacrylate bonded patch repair had lower values for all parameters measured (n = 8, P<0.05) and the other 3 repairs had similar mechanical properties. This study demonstrates that acrylic adhesive repairs can resist similar shear forces to traditional screw plate repairs without risk of penetrating into the sensitive structures of the foot. The transverse bar mounted across the crack had similar resistance to shear as the much larger screw plate and plain bonding repair techniques. This novel technique may be a useful adjunct to other repair methods.

Differences in lung bioavailability between different propellants for fluticasone propionate

The lung bioavailability (as adrenal suppression) of fluticasone propionate was about twofold greater with chlorofluorocarbons than hydrofluoroalkane as propellant. Direct switching between formulations on a microg equivalent may therefore be inadvisable.

Short-term dose-response relationships for the relative systemic effects of oral prednisolone and inhaled fluticasone in asthmatic adults

AIMS

To determine the systemic dose-response relationships with oral prednisolone and inhaled fluticasone propionate administered in a putative 11:1 mg equivalent basis, in terms of effects on adrenal, bone and haematological markers.

METHODS

Twelve asthmatic patients mean (s.e.) age, 28.8 [3.3] years, FEV1 94.7 [3.6]% predicted, FEF(25-75) 65.5 [6.1]% predicted were studied in a double-blind, double dummy randomised crossover design comparing placebo, inhaled fluticasone propionate via volumatic spacer given twice a day (ex actuator dose 0.44 mg day-1, 0.88 mg day-1, 1.76 mg day-1 ) and oral prednisolone given once daily (5 mg day-1, 10 mg day-1, 20 mg day-1 ). All treatments were for 4 days at each dose level with a 7-day washout at crossover. Measurements were made at 08.00 h after the last dose of each dose level for plasma cortisol, serum osteocalcin and blood eosinophil count.

RESULTS

There were significant dose-related effects for suppression of all three endpoints with both prednisolone and fluticasone propionate. Parallel slope analysis revealed a calculated dose ratio for relative potency of 8. 5:1 mg (95% CI 5.7-11.2) comparing Pred with FP for morning cortisol. The magnitude of suppression with FP was less for osteocalcin and eosinophils than for cortisol.

CONCLUSIONS

Systemic tissues exhibit different dose-response relationships for the effects of inhaled and oral corticosteroids with suppression of cortisol being greater than osteocalcin or eosinophils. For cortisol suppression we observed an 8.5:1 mg relative potency ratio comparing prednisolone with fluticasone propionate. Patients taking high dose inhaled fluticasone propionate should therefore be screened for evidence of impaired adrenal reserve.

Evaluation of the effect of a large volume spacer on the systemic bioactivity of fluticasone propionate metered-dose inhaler

BACKGROUND

Inhaled corticosteroids such as fluticasone propionate (FP) have dose-related systemic effects, including adrenal suppression. We have therefore investigated the effect of adding a large volume spacer on the systemic bioactivity of FP given via a pressurized metered-dose inhaler (pMDI).

METHODS

Fourteen healthy volunteers (mean age, 29.9 years old) were studied using an open, randomized, placebo-controlled, three-way crossover design. Single doses of the following were given at 5:00 PM in a randomized sequence: (1) eight puffs of FP by pMDI, 1.76 mg (250 microg ex-valve, 220 microg ex-actuator); (2) eight puffs of FP by pMDI, 250 microg, with 750-mL spacer (Volumatic; Allen & Hanburys; Uxbridge, UK); and (3) eight puffs of placebo by pMDI. Measurements were made after each dose, including overnight and early morning urinary cortisol/creatinine ratios and 8:00 AM serum cortisol.

RESULTS

Significant (p < 0.05) suppression of all three end points occurred with each active treatment compared to treatment with placebo. Furthermore, significant (p < 0.05) additional suppression occurred when comparing FP by pMDI alone to FP by pMDI with spacer. Geometric mean fold differences (95% confidence interval for fold difference) between FP by pMDI alone and FP by pMDI with spacer were 1.94-fold (1.00-3.78) for overnight urinary cortisol/creatinine ratio and 1.98-fold (1.26-3.10) for 8:00 AM serum cortisol. This was mirrored by a twofold rise in the number of values for uncorrected overnight urinary cortisol < 10 nmol/10 h: placebo treatment (none of 14 subjects); FP by pMDI (6 of 14 subjects; 43%); and FP by pMDI with spacer (12 of 14 subjects; 86%).

CONCLUSIONS

The use of a large volume spacer with FP by pMDI results in a twofold increase in the systemic bioavailability as assessed by sensitive measures of adrenal suppression. This, in turn, reflects a twofold improvement in respirable dose delivery with the spacer device.

Evaluation of the buccal component of systemic absorption with inhaled fluticasone propionate

BACKGROUND

Inhaled corticosteroids have dose related systemic effects determined by oral (swallowed or oropharyngeal absorption) and lung bioavailability. A study was undertaken to evaluate the significance of oropharyngeal absorption for fluticasone propionate.

METHODS

Sixteen healthy volunteers of mean age 29.3 years were studied using an open randomised, placebo controlled, four way crossover design. Treatments were: (a) fluticasone metered dose inhaler (pMDI) 250 microg, 8 puffs; (b) fluticasone pMDI 250 microg, 8 puffs + mouth rinsing/gargling (water); (c) fluticasone pMDI 250 microg, 8 puffs + mouth rinsing/gargling (charcoal); and (d) placebo pMDI, 8 puffs + mouth rinsing/gargling (water). Overnight (ONUC) and early morning (EMUC) urinary cortisol/creatinine ratios and 8 am serum cortisol (SC) levels were measured.

RESULTS

Significant (p<0. 05) suppression of ONUC, EMUC, and SC occurred with each active treatment compared with placebo. The mean values (95% CI for difference from placebo) were: (a) ONUC (nmol/mmol): fluticasone (2. 8, 95% CI 3.6 to 7.9), fluticasone + water (3.1, 95% CI 3.3 to 7.7), fluticasone + charcoal (2.3, 95% CI 4.1 to 8.5); placebo (8.6); (b) EMUC (nmol/mmol): fluticasone (5.6, 95% CI 8.4 to 24.5), fluticasone + water (7.6, 95% CI 6.6 to 22.4); fluticasone + charcoal (5.6, 95% CI 8.7 to 24.5); placebo (22.1). There were no significant differences between active treatments. The numbers of subjects with an overnight urinary cortisol of <20 nmol/10 hours were 0 (placebo), 11 (fluticasone), 12 (fluticasone + water), and 13 (fluticasone + charcoal).

CONCLUSIONS

Oropharyngeal absorption of fluticasone does not significantly contribute to its overall systemic bioactivity as assessed by sensitive measures of adrenal suppression. In view of almost complete hepatic first pass inactivation with fluticasone, there is no rationale to employ mouth rinsing to reduce its systemic effects although it may be of value for reducing oral candidiasis.

Comparison of antiplatelet activity of microencapsulated aspirin 162.5 Mg (Caspac XL), with enteric coated aspirin 75 mg and 150 mg in patients with atherosclerosis

AIMS

A new formulation, low dose microencapsulated aspirin, permits slow absorption of aspirin and presystemic acetylation of platelet cyclo-oxygenase within the portal circulation, potentially avoiding deleterious effects on gastric and systemic prostaglandin synthesis. The objective of this study was to determine whether the administration of microencapsulated aspirin was as effective as enteric coated (EC) aspirin as an inhibitor of platelet function in patients with atherosclerosis.

METHODS

One hundred and four patients were enrolled and randomised after a run in period of at least 14 days on aspirin EC 75 mg (day 0), to receive either microencapsulated aspirin 162.5 mg (n=34), aspirin EC 150 mg (n=36) or continue on aspirin EC 75 mg (n=34) for 28 days. Serum thromboxane B2 and collagen-induced platelet aggregation and release of 5-hydroxytryptamine (EC50 values) were measured on days 0 and 28. Aggregation/release EC50s were then repeated in the presence of a large dose of aspirin added in vitro to determine the EC50 at the maximum level of platelet inhibition.

RESULTS

Median thromboxane B2 levels were low after 14 days run-in therapy with aspirin EC 75 mg, but significant further reductions were seen on day 28 in patients randomised to microencapsulated aspirin 162.5 mg (P=0.0368) and aspirin EC 150 mg (P=0.0004) compared with those remaining on aspirin EC 75 mg. Median EC50 s on day 28 showed small but significant increases from baseline (day 0) in aggregation in patients randomised to microencapsulated aspirin 162.5 mg (0.62-0.85, P=0.0482) and in both aggregation and release in patients randomised to aspirin EC 150 mg (0.95-1.20, P=0.0002, 8.4-11.7, P<0. 0001, respectively) signifying enhanced antiplatelet activity. No changes were seen in patients continuing on aspirin EC 75 mg. Results following addition of high dose aspirin in vitro suggest that mechanisms other than thromboxane synthesis may be operative in the long term effects of microencapsulated aspirin 162.5 mg and aspirin EC 150 mg over aspirin EC 75 mg.

CONCLUSIONS

The results show good inhibition of thromboxane B2 synthesis and subsequent platelet activity by all preparations of aspirin, although both microencapsulated aspirin 162.5 mg and aspirin EC 150 mg are slightly more effective than aspirin EC 75 mg. A randomised trial is now required to determine whether microencapsulated aspirin is associated with fewer gastric side-effects.