Novel PCR assay for determining the genetic sex of mice.

A number of studies require the determination of the genetic sex of mouse embryos before sexual differentiation and/or of mutant mice that display partial or complete sex reversal. The majority of current methods for sexing by PCR involve multiplexing of 2 primer pairs. We have developed a novel sexing PCR using a single primer pair that amplifies fragments from the X and the Y chromosome with a clear size difference between the respective amplicons. This assay provides a rapid and reliable method to identify the genetic sex of mice across different mouse strains.

Prospective follow-up of novel markers of bone turnover in persistent asthmatics exposed to low and high doses of inhaled ciclesonide over 12 months.

CONTEXT: In asthmatic patients receiving long-term inhaled corticosteroid therapy, there are concerns regarding the potential for developing systemic adverse effects on bone metabolism, possibly even in the absence of adrenal suppression. OBJECTIVE: The aim of this study was to investigate whether exposure to inhaled ciclesonide at high vs. low doses over 1 yr causes any significant systemic adverse effect on sensitive biomarkers of bone turnover in asthmatic patients. DESIGN: Post hoc analysis of stored samples was performed in a subgroup of patients from a prospective, randomized parallel group trial with 1 yr follow-up. SETTING: We conducted a primary care study in Tayside, Scotland. PARTICIPANTS: A total of 164 mild-moderate persistent asthmatics aged 18-65 yr with evidence of airway hyperresponsiveness using mannitol bronchial challenge were enrolled into the original study. Of the 119 completed patients per protocol, 100 participants had bone marker samples available for analysis. INTERVENTIONS: Ciclesonide was titrated to control persistent asthma against either mannitol bronchial challenge [airway hyperresponsiveness (AHR) strategy] or a control group (based on symptoms, reliever use, and pulmonary function) over 1 yr. OUTCOME MEASURES: We measured markers of bone formation [amino-terminal propeptide of type I collagen (PINP), amino-terminal propeptide of type III collagen (PIIINP)], resorption [carboxy-terminal telopeptide of type I collagen (ICTP), type I collagen cross-linked C-telopeptide (CTx)], and adrenal suppression (overnight urinary cortisol/creatinine ratio) at 0 and 12 months. RESULTS: Mean ciclesonide doses after 12 months were: AHR, 507 µg/d (n = 50); and controls, 202 µg/d (n = 50) (P < 0.00001). There were no significant differences between AHR and control groups either at baseline or after 12 months in PINP, PIIINP, ICTP, or CTx; or in ratios of bone turnover as PINP/ICTP, PIIINP/CTx, or overnight urinary cortisol/creatinine ratio. CONCLUSION: Higher doses of inhaled ciclesonide do not adversely affect sensitive markers of bone turnover in persistent asthmatics over 12 months.

Non-coding RNAs in mammalian sexual development.

The present decade is witnessing a paradigm shift in our understanding of gene regulation. RNA, once relegated to an intermediary between DNA and protein, has emerged as a key contributor in the coordination of complex developmental pathways. For sexually reproducing organisms, propagation of the species is accomplished via an elaborate sexual phenotype. In mammals this consists of a highly complex cell lineage that has the capacity for intricate self-differentiation whilst maintaining the potential to generate all cell types upon fertilization. In addition, mammals possess a diverse range of somatic reproductive tissues and organs that often undergo dynamic morphological changes in response to a variety of external and internal cues. Although the protein component required to mediate these processes continues to be vigorously investigated, it is becoming increasingly apparent that an understanding of the non-coding RNA (ncRNA) component is required to develop a comprehensive picture of mammalian sexual development.

Differential anti-inflammatory effects of large and small particle size inhaled corticosteroids in asthma.

BACKGROUND: Extra-fine particle formulations of hydrofluoroalkane-134a beclometasone dipropionate (HFA-BDP) exhibit clinical effects comparable with conventional particle formulations of chlorofluorocarbon beclometasone dipropionate (CFC-BDP) at half the dose. There is little data comparing their effects on inflammation. We have evaluated the effects of HFA-BDP and CFC-BDP on pulmonary and systemic markers of asthmatic inflammation. METHODS: A double-blind randomized crossover trial was undertaken comparing the anti-inflammatory effects of HFA-BDP (100 and 400 microg/day) and CFC-BDP (200 and 800 microg/day). Treatment with montelukast was evaluated as add-on to the higher dose of BDP. RESULTS: Compared with baseline after withdrawal of usual asthma therapy, 100 microg of HFA-BDP significantly attenuated serum eosinophilic cationic protein levels (0.61-fold change, 95% CI 0.49-0.77; a 39% reduction, P < 0.001), but 200 microg of CFC-BDP did not (0.87-fold change, 95% CI 0.63-1.23; P = 1). A dose of 800 microg of CFC-BDP and 400 microg of HFA-BDP led to reductions in exhaled nitric oxide (0.57-fold change, 95% CI 0.44-0.73; a 43% reduction, P < 0.001 and 0.65-fold change, 95% CI 0.47-0.91; a 35% reduction, P = 0.008, respectively); and peripheral eosinophils (-74 cells/microl, 95% CI -146 to -2; P = 0.020 and -77 cells/microl, 95% CI -140 to -14; P = 0.012, respectively). Montelukast further reduced exhaled nitric oxide (0.81-fold change, 95% CI 0.66-0.98; P = 0.028) with 400 microg HFA-BDP and eosinophils (-44 cells/microl, 95% CI -80 to -8; P = 0.012) with 800 microg CFC-BDP, but not vice versa. CONCLUSION: Chlorofluorocarbon beclometasone dipropionate and HFA-BDP have differential effects on pulmonary and systemic inflammation, which dictate the additive effects of montelukast.

Effects of low dose fluticasone/salmeterol combination on surrogate inflammatory markers in moderate persistent asthma.

BACKGROUND: Noninvasive surrogate markers provide valuable information on the asthmatic inflammatory process. We wished to examine the effects of low dose fluticasone/salmeterol combination on different commonly used inflammatory markers in moderate persistent asthma. METHODS: Twenty-five moderate persistent atopic asthmatics were enrolled of whom 20 completed an open label study. Following an initial 4 week steroid washout period in which patients took salmeterol 50 microg dry powder inhaler 1 puff BD, they received the addition of fluticasone as fluticasone 100 microg/salmeterol 50 microg combination dry powder inhaler 1 puff BD for the next 2 weeks. Exhaled nitric oxide, spirometry, methacholine PD20, sputum/blood eosinophils and sputum/serum eosinophil cationic protein (ECP) were measured following the salmeterol only and fluticasone/salmeterol combination treatment periods. RESULTS: Compared to salmeterol alone (i.e. after the steroid washout), the use of fluticasone/salmeterol combination conferred significant improvements (P < 0.05) in all surrogate markers of inflammation apart from serum ECP. Geometric mean fold changes were 4.3-fold/1.3-fold for sputum/blood eosinophils, 2.2-fold/1.2-fold for sputum/serum ECP, 2.3-fold for methacholine PD20 and 1.8-fold for exhaled nitric oxide. CONCLUSIONS: Surrogate markers apart from serum ECP may be used as a guide to evaluate the anti-inflammatory effects of low dose inhaled corticosteroids. Sputum markers tend to be more sensitive than blood when assessing the anti-inflammatory response.

Determinants of absconding by patients on acute psychiatric wards.

Determinants of absconding by patients on acute psychiatric wards Absconding by patients from acute psychiatric wards is a high risk behaviour and has been linked to harm to self and others. Previous research on the characteristics of absconders has been overly reliant on officially generated statistics and small numbers of variables, limiting the conclusions that may be drawn. This paper reports on a prospective study of absconders from 12 acute admission wards in three English National Health Service Trusts over 5 months, compared to a control group matched for ward. Extensive data on absconder and control characteristics were collected from case records and from nursing staff. Absconders were significantly different from controls in many respects. Absconding is linked to other forms of non-compliant patient behaviour, e.g. medication refusal and involvement in violent incidents. Significant variations in the rates of absconding were found between different wards, and between different consultant psychiatrists. Predictive factors were identified by logistic regression. Study in the diverse fields of non-compliance should be brought together as these phenomena are likely to be interrelated. Further investigation is required to determine exactly what it is that consultant psychiatrists and ward nurses do that affects absconding rates.

Ovarian hormones in man: their effects on resting vascular tone, angiotensin converting enzyme activity and angiotensin II-induced vasoconstriction.

AIMS: Oestrogens in women have been shown to cause vasodilation which may reflect alterations in the activity of vascular angiotensin converting enzyme (ACE) and/or sensitivity to angiotensin II. The aim of this study was to assess the effect of ovarian hormones on vascular tone, vascular ACE activity and vasoconstriction to angiotensin II in males. METHODS: Eight volunteers were randomised in a crossover design to oestradiol, medroxy-progesterone, and placebo. Vasoconstriction to angiotensin I and angiotensin II was assessed by forearm plethysmography. RESULTS: Although baseline forearm flow was increased with oestradiol, suggesting generalized vasodilation, there were no changes in the vasoconstrictor responses to angiotensin I or angiotensin II. Medroxy-progesterone affected neither baseline flow nor vasoconstrictor responses. The results expressed as percentage reduction in flow (mean +/- s.d.) were: angiotensin I 48 pmol ml-1: placebo -48 +/- 14%; oestradiol -42 +/- 16%; medroxyprogesterone -43 +/- 8% and for angiotensin II 16 pmol ml-1: placebo -42 +/- 10%; oestradiol -39 +/- 11%; medroxyprogesterone -46 +/- 13%. CONCLUSIONS: Acute administration of oestradiol caused vasodilation in males, the effect was not due to alterations in vascular ACE activity or to altered sensitivity to angiotensin II.

Comparative trough effects of formoterol and salmeterol on lymphocyte beta2-adrenoceptor--regulation and bronchodilatation.

OBJECTIVES: The primary aim of the present study was to evaluate comparative trough effects of formoterol and salmeterol on beta2-adrenoceptor regulation and bronchodilator response after regular twice-daily treatment, with a secondary aim to evaluate any possible association with beta2-adrenoceptor polymorphism. METHODS: Sixteen asthmatic subjects, with mean (SD) age 33(9) years, all taking inhaled corticosteroids and with a forced expiratory volume in 1 s (FEV1) of 81(12)% predicted were recruited to take part in a randomised single-blind, three-way cross-over study. The subjects received three treatments each for 1 week, with 1-week washout periods in between: (1) formoterol dry powder, 12 microg twice daily, (2) salmeterol dry powder, 50 microg twice daily, or (3) placebo, twice daily. Spirometry and lymphocyte beta2-adrenoceptor parameters were measured before the first dose and 12 h after the last dose of each treatment, as well as domiciliary peak flow during each treatment. RESULTS: There were no differences in beta2-adrenoceptor density (Bmax) between the three treatments prior to the first dose; whereas, after the last dose, Bmax was lower with both active treatments than with placebo, but was significant for salmeterol only--a 1.2-fold geometric mean fold difference (95% CI 1- to 1.4-fold), P = 0.04. Compared with placebo, there were n = 9 of 16 subjects with salmeterol and n = 6 of 16 with formoterol who had a greater than 15% fall in Bmax. Post-hoc trend analysis of polymorphism showed that the propensity for downregulation appeared to be related to the occurrence of an allelic substitution of glycine at codon 16-8 of 13 for salmeterol versus 5 of 13 for formoterol with a greater than 15% fall compared with placebo. There were no significant differences between salmeterol and formoterol in terms of mean or individual values for downregulation. There was evidence of persistent bronchodilator activity with both active treatments compared with placebo; this was significant for forced expiratory flow rate between 25% and 75% of vital capacity (FEF25-75)--the mean difference versus salmeterol was 0.39 1/s (95% CI 0.06-0.70), P = 0.02, and versus formoterol was 0.35 1/s (95% CI 0.16-0.53), P = 0.001. These effects were mirrored by significant improvements in morning peak flow rate compared with placebo--mean difference versus salmeterol was 24 1/min (95% CI 7-42), P = 0.01, and versus formoterol was 36 1/min (95% CI 25-48), P < 0.0001. CONCLUSION: There were no differences between regular treatment with formoterol and salmeterol in their effects on lymphocyte beta2-adrenoceptor regulation at the end of a 12-h dosing interval, with both drugs exhibiting a residual degree of bronchodilator activity at the same time point. Further studies to evaluate receptor regulation and bronchodilator response are required in susceptible patients who have the homozygous glycine-16 polymorphism.

Is routine synovial fluid analysis necessary? Lessons and recommendations from an audit.

This audit of 408 synovial fluid samples, analysed for cell counts and crystals, revealed that crystals were present in only 25 samples (6.1%). Of these, in only three patients was the diagnosis uncertain and therefore the analysis helpful. Cell counts and types generally reflected known underlying diagnoses of inflammatory arthritis or osteoarthritis. Routine synovial fluid analysis does not contribute to diagnosis or management in established rheumatic disorders and should be performed only when the underlying cause is uncertain or in newly presenting patients. Major savings can be made by abandoning routine synovial fluid analysis.

Absconding: why patients leave.

Absconding by patients from acute psychiatric care poses a significant problem to professional staff, and can involve significant risks for patients and others. This paper describes the methodology of a major prospective study of absconding recently completed in the East End of London, and reports the findings on why patients abscond from hospital. Interviews with 52 patients who returned to their wards showed that they abscond because they are bored, frightened of other patients, feel trapped and confined, have household responsibilities they feel they must fulfil, feel cut off from relatives and friends, or are worried about the security of their home and property. Psychiatric symptoms also contribute to the decision to leave, but in nearly every case patients can give additional and rational reasons for their abscond. Some patients leave impulsively and in anger following unwelcome news about delayed permission for leave or discharge. Others leave specifically in order to carry out some activity outside the hospital. In order to reduce absconding and rejection of care, nurses may need to carefully consider the meaning admission has for patients, and the impact it can have upon their everyday lives.

Absconding: how and when patients leave the ward.

Information about how and when patients abscond from acute psychiatric wards may provide important clues to effective prevention strategies. This paper reports relevant findings from a large scale study of absconding conducted in the East End of London. In contrast to the findings in previous studies, the vast majority of absconders left from the ward directly, mostly via the front door. Some were known to be at risk of absconding, and although more than half had declared their intention to leave, they still succeeded in getting away. On some occasions they circumvented locked or guarded doors, or special nursing observation. Shift handovers were a peak time for absconds, possibly due to decreased nursing surveillance of the ward. Most absconds occur during the first few weeks of admission, and most absconders simply went home and engaged in normal, everyday activities. The findings indicate that physical security measures alone are not a sufficient answer to the problem of absconding, and nurses need to work harder to develop supportive alliances with patients.

Absconding: outcome and risk.

Absconding by patients from acute psychiatric wards is known to be linked to self harm and harm to others. Previous research has focused only on officially reported absconds, thus missing out many patients who although they abscond and pose a risk, are never officially processed. This paper reports the findings of a large prospective study of absconding in the East End of London using an objective definition of absconding not linked to official bureaucratic processes. Absconders are considered by staff to be high risk patients, and many have histories of violence and/or suicide attempts. Nevertheless nurses only request the aid of the police in returning patients on 47% of occasions. The actions of the police are very variable, and range from two policemen calling at the patient's house, to an entire team in riot gear appearing at the patient's door in the early hours of the morning. Most absconds result in no harm to anyone, and most absconders return by themselves. Relatives and carers also play a significant role in persuading the patient to return or bringing them back. Nurses should develop more sophisticated ways of working with the police and with relatives to maintain absconding patients' safety.

Absconding: nurses views and reactions.

Absconding from acute psychiatric wards is common. This paper reports the views of 25 staff nurses working on acute mental health wards in East London about absconding. Interviews explored how staff feel when a patient absconds, the complexities of risk assessment and observation policies, who is blamed when patients abscond and what might reduce absconding. The assessment of the level of risk which a patient posed varied considerably, with some wards using standard risk assessment tools and others talking about their own methods. There was some evidence of conflict with medical staff about what measures should be put in place to manage the risk (observation level, leave). The interviewees were aware of serious consequences of absconding, and this made them worry when patients absconded. Following an abscond most nurses look for an explanation, and this can lead to blame of other members of the team. A sizeable minority spoke of feeling unsupported by their managers, and that their jobs could be at risk following an abscond. The nurses felt that absconding could be reduced through a number of measures, principally raising staffing levels and reducing the reliance on agency nurses.

Effects of intranasal corticosteroids on adrenal, bone, and blood markers of systemic activity in allergic rhinitis.

BACKGROUND: Intranasal corticosteroids are regarded as the first-line treatment for allergic rhinitis, but few studies have directly compared their systemic effects. OBJECTIVE: The purpose of this study was to compare the systemic bioactivity of aqueous formulations of intranasal budesonide, mometasone furoate (MF), and triamcinolone acetonide (TAA) in terms of adrenal, bone, and white blood cell markers. METHODS: Twenty patients with allergic rhinitis, mean age (SE) 35.7 (3.5) years were studied in a single-blind, randomized, 4-way crossover design, with treatments separated by 7-day washout periods, comparing placebo with budesonide 200 micro(g) once daily, MF 200 micro(g) once daily, and TAA 220 micro(g) once daily. After 5 days of treatment at steady-state, serial blood and urine samples were taken for 24 hours. Collective and fractionated measurements (daytime, overnight, and 8 AM) were done on plasma cortisol and urine cortisol/creatinine excretion. Plasma osteocalcin and blood eosinophil counts were measured at 8 AM. RESULTS: There was no significant difference between placebo and the active treatments with any of the markers of adrenal suppression. Mean values (SE) for 24-hour area under the curve plasma cortisol (nmol/L.hr) were placebo, 6312.9 (564.4); budesonide, 5908.8 (496.8); MF, 6374.1 (509.9); and TAA, 6239.2 (552.0). Twenty-four hour urinary cortisol/creatinine ratio (nanomoles per millimoles) showed placebo, 9.2 (0.5); budesonide, 8.5 (0.5); MF, 8.6 (0.4); and TAA, 8.6 (0.4). The diurnal circadian rhythm was unaffected, and there were only occasional patients with abnormally low cortisol values. There was also no suppression in terms of osteocalcin (placebo, 1.27 nmolL; budesonide, 1.22 nmol/L; MF, 1.33 nmol/L; and TAA, 1.24 nmol/L) and blood eosinophil count (placebo, 0.29 x 10(9)/L; budesonide, 0.27 x 10(9)/L; MF, 0.25 x 10(9)/L; and TAA, 0.24 x 10(9)/L). CONCLUSION: Neither budesonide, MF, nor TAA produced significant systemic suppression of adrenal, bone, or white blood cell markers at the doses studied. This reflects the good safety profile of these aqueous intranasal formulations when taken at clinically recommended doses.

Systemic bioactivity profiles of oral prednisolone and nebulized budesonide in adult asthmatics.

STUDY OBJECTIVE: Because nebulized budesonide may be used as an alternative to maintenance oral prednisolone in the treatment of severe chronic asthma, it is important to compare these two drugs to determine their relative systemic bioactivity profiles in terms of effects on adrenal, bone, and hematologic markers. DESIGN: Twelve asthmatic patients (mean age; 34.7 years; mean FEV1; 88.3% predicted; mean forced expiratory flow between 25% and 75% of FVC, 54.8% predicted) were studied in a double-blind, double-dummy, randomized crossover design to compare placebo, low, medium, and high doses of nebulized budesonide given bid (1, 2, and 4 mg/d, respectively), and oral prednisolone given qd (5, 10, and 20 mg/d). All treatments and both placebos were given for 4 days at each dose level with a 7-day washout period between each treatment block with budesonide or prednisolone. All measurements were made at 8 AM after the last dose of each dose increment for plasma cortisol, serum osteocalcin, and blood eosinophil count. RESULTS: Regression analysis showed significant dose-related suppression with prednisolone for 8 AM plasma cortisol (p<0.0001), osteocalcin (p<0.05), and blood eosinophil count (p<0.0005), but not with budesonide. Compared with placebo, there were significant differences only with prednisolone, at the medium- and high-dose levels for all three markers. CONCLUSIONS: For all three systemic bioactivity markers (8 AM plasma cortisol, serum osteocalcin, and blood eosinophils), there was significant dose-related suppression with prednisolone but not with budesonide. Further long-term studies are required in more severe asthmatics in order to evaluate the therapeutic index.

Concomitant inhaled corticosteroid resensitises cardiac beta2-adrenoceptors in the presence of long-acting beta2-agonist therapy.

OBJECTIVE: The aim of the present study was to evaluate the effects of concomitant inhaled corticosteroid therapy on the sensitivity of cardiac beta2-adrenoceptors in patients receiving regular long-acting beta2-agonists. METHODS: Twelve healthy subjects (6 female), mean age 29 years, were randomised in a double-blind cross-over study to receive either inhaled placebo or inhaled budesonide 1.2 mg twice daily, each for 7 days, with a minimum of 7 days washout period between the two treatments. Patients also received concomitant treatment with inhaled eformoterol 24 microg twice daily during each of the 2 treatment periods. The patients attended the laboratory during both treatment periods at 0730 hours, when a dose-response curve for systemic beta2-adrenoceptor responses to inhaled salbutamol (0.8-3.2 mg) was constructed before and after completing 7 days of each treatment. Early morning (0800 hours) plasma cortisol was also evaluated as a marker of systemic glucocorticoid activity. RESULTS: There was a significant fall in 0800 hours plasma cortisol induced by budesonide comparing pre- and post-values (407 vs 322 nmol.1(-1), but not with placebo. There were no differences in the response to salbutamol prior to treatment when comparing eformoterol with placebo versus eformoterol with budesonide. Comparing before and after within-treatment heart rate response, there was a significant reduction in peak salbutamol response with eformoterol and placebo, which was partially reversed by eformoterol and budesonide. For between-treatment comparisons after eformoterol treatment, the heart rate was significantly higher in the presence of budesonide in comparison with placebo for peak salbutamol response (change from baseline), i.e. 24.2 vs 34.7 beats min(-l). There was, however, no significant difference in the peak delta potassium response to salbutamol after eformoterol treatment when comparing budesonide with placebo (-0.39 vs -0.48 mmol.1(-1)). CONCLUSION: Concomitant therapy with inhaled budesonide resensitised the cardiac beta2-adrenoceptor response to salbutamol in subjects who were receiving regular twice-daily eformoterol. This may be of clinical relevance in terms of the propensity for systemic beta2-mediated adverse effects with repeated puffs of salbutamol, which might conceivably occur in the setting of acute asthma.

Effects of repeated once daily dosing of three intranasal corticosteroids on basal and dynamic measures of hypothalamic-pituitary-adrenal-axis activity.

BACKGROUND: Intranasal corticosteroids are regarded as the first-line treatment for allergic rhinitis, but few studies have directly compared their systemic effects. OBJECTIVE: We sought to compare the hypothalamic-pituitary-adrenal (HPA)-axis suppression with three intranasal corticosteroids in terms of basal and dynamic adrenocortical activity. METHODS: Sixteen healthy volunteers (mean age, 30.7 years) were studied in a single-blind, randomized, four-way crossover study comparing placebo with 200 microg/day fluticasone propionate (FP), 220 microg/day triamcinolone acetonide (TAA), and 336 microg/day beclomethasone dipropionate (BDP). After 4 days of treatment, an overnight urine collection was taken for cortisol and creatinine excretion starting at 10 PM (14 hours after the fourth dose), and blood was taken for serum cortisol at 8 AM (24 hours after the fourth dose) and after stimulation with adrenocorticotrophic hormone (ACTH) (0.5 microg). RESULTS: For overnight urinary cortisol excretion compared with placebo (20.8 nmol), there was a significant (p < 0.05) degree of suppression with FP (11.8 nmol) but not with TAA (16.0 nmol) or BDP (16.5 nmol). In terms of fold difference (95% CI for difference) from placebo, this amounted to 1.75-fold (1.01 to 3.03) for FP (43% suppression), 1.30-fold (0.75 to 2.25) for TAA (23% suppression), and 1.26-fold (0.73 to 2.18) for BDP (21% suppression). There was also a trend towards suppression of overnight urinary cortisol/creatinine excretion, but this was not statistically significant (placebo, 5.2 nmol/mmol; TAA, 5.0 nmol/mmol; BDP, 4.3 nmol/mmol; and FP, 4.3 nmol/mmol). Values for serum cortisol before and after ACTH stimulation showed no significant suppression. CONCLUSION: Suppression of overnight urinary cortisol occurred with intranasal FP (43%), TAA (23%), and BDP (21%), although this was only statistically significant with FP. None of the drugs were associated with blunting of the response to ACTH stimulation. Further studies are indicated to establish whether the systemic effects of inhaled and intranasal corticosteroids are additive.

Beta2-adrenoceptor regulation and bronchodilator sensitivity after regular treatment with formoterol in subjects with stable asthma.

OBJECTIVE: We have previously found that beta2-adrenoceptor downregulation and bronchodilator desensitization to albuterol occurred at 36 hours after stopping regular treatment with twice daily salmeterol. In this study we have evaluated these same effects with formoterol given once or twice daily on a regular basis. METHODS: In a randomized, placebo-controlled, double-blind, double-dummy crossover study, 16 subjects with mild-to-moderate stable asthma (mean [SD] age, 32.5 [15.3] years; mean [SD] FEV1, 73.2 [12.1] percent predicted) receiving regular inhaled corticosteroid therapy received 1 week of treatment with formoterol dry powder (24 microg twice daily [8 AM/8 PM]), formoterol (24 microg once daily [8 PM]), or identical placebo. Lymphocyte beta2-adrenoceptor parameters and a dose-response curve to inhaled albuterol (200 to 1600 microg) were evaluated at 36 hours after the last dose of each treatment period. RESULTS: There were no significant differences in the mean values for albuterol dose-response effects among the three treatment regimens. Comparison of maximal bronchodilator responses between treatments (mean and SEM as change from baseline) revealed no significant differences between treatments for FEV1 (0.47 L [0.06 L] for placebo vs 0.48 L [0.07 L] for 24 microg once daily formoterol vs 0.51 L [0.08 L] for 24 microg twice daily formoterol) or for forced expiratory flow, mid-expiratory phase (FEF25-75) (0.80 L/sec [0.12 L/sec] for placebo vs 0.80 L/sec [0.16 L/sec] for 24 microg once daily formoterol vs 0.89 L/sec [0.14 L/sec] for 24 microg twice daily formoterol). Formoterol also had no significant effect on mean lymphocyte beta2-adrenoceptor density. However, in five of seven patients with the homozygous Gly-16 polymorphism, beta2-adrenoceptor density was downregulated by twice daily formoterol, whereas only two such cases exhibited a reduction in maximal FEV1 response to albuterol. CONCLUSIONS: The results of this study showed that for patients taking inhaled corticosteroids, overall beta2-adrenoceptor regulation and associated bronchodilator sensitivity to inhaled albuterol were unaltered at 36 hours after stopping regular treatment with formoterol. However, in a subset of patients who were Gly-16 homozygous, there was a tendency towards downregulation but not desensitization. Further studies in subjects with more severe asthma are required to assess the clinical relevance of these findings.

Beta2-adrenoceptor regulation and function in female asthmatic patients receiving the oral combined contraceptive pill.

STUDY OBJECTIVES: Previously it has been shown that there is abnormal hormonal control of beta2-adrenoceptors in asthmatic women. Exogenous progesterone but not estradiol produces paradoxic downregulation and desensitization of beta2-adrenoceptors in asthmatic women when compared with nonasthmatic subjects. This study investigates the effect of the oral combined contraceptive pill (OCP) on beta2-adrenoceptor regulation and function in female asthmatic patients. PATIENTS: The study population was comprised of 11 women with stable mild to moderate asthma. The mean age was 25 years; the FEV1 was 89% of predicted, and the forced expiratory flow, mid-expiratory phase (FEF25-75%) was 69% of predicted. DESIGN: Patients were evaluated while on (day 20 to 21) and off (day 5 to 7) the OCP during a 28-day calendar period. MEASUREMENTS: Serum sex hormones, lymphocyte beta2-adrenoceptor parameters, and bronchodilator and systemic dose-response curves (DRCs) to albuterol (Salbutamol) (100 to 1,600 microg) were measured at both on and off periods. RESULTS: Serum levels of endogenous estradiol and progesterone were both suppressed by the OCP. Baseline FEV1 were not different while patients were on (2.70 L) and off (2.72 L) the OCP. There were no significant differences in lymphocyte beta2-adrenoceptor parameters between the two phases of the cycle. Receptor density (geometric mean Bmax) was 1.78 (on OCP) vs 1.86 (off OCP) fentomole/10(6) cells, maximal cyclic adenosine monophosphate response to isoprenaline was 6.60 (on OCP) vs 7.58 (off OCP) pmol/10(6) cells, and binding affinity was 14.0 (on OCP) and 13.6 (off OCP) pmol/L. Likewise, there were no significant differences in the bronchodilator and systemic DRCs constructed at both phases of the cycle as evaluated: area-under-curve (AUC) FEV1 was 0.53 (on OCP) vs 0.56 (off OCP) L.h; and AUC FEF25-75% was 3,130 (on OCP) vs 3,640 (off OCP) L. Potassium (K) and finger tremor responses were unaltered between the two periods: AUC K was 0.50 (on OCP) vs 0.44 (off OCP) mmol . h/L and AUC tremor was 0.72 (on OCP) vs 0.89 (off OCP) log units.h. CONCLUSION: The OCP did not alter beta2-adrenoceptor regulation and function in stable female asthmatic patients. Further studies are required in patients who have premenstrual asthma.