Frovatriptan: a review of drug-drug interactions

OBJECTIVE

To investigate the potential for interactions involving drugs likely to be coadministered with frovatriptan.

BACKGROUND

Frovatriptan is a new 5-hydroxytryptamine (5-HT)(1B/1D) agonist. Preclinical data suggest that the pharmacokinetic and pharmacological profile of frovatriptan may differ from that of the currently available triptans.

METHODS

The potential for interactions between frovatriptan and other drugs was investigated using in vitro methods, studies in healthy volunteers, and retrospective analysis of data from phase I trials.

RESULTS

In vitro, frovatriptan was principally metabolized by cytochrome P-450 (CYP) 1A2 but was found not to be an inhibitor or inducer of this or other CYP isoenzymes. Frovatriptan was only a weak inhibitor of monoamine oxidase at very high concentrations in vitro and was not a substrate for this enzyme (unlike some other triptans). Coadministration with moclobemide, at doses known to inhibit monoamine oxidase-A, did not affect the pharmacokinetics of frovatriptan. Binding to plasma proteins was low (15%), and binding to erythrocytes was moderate (60%) and unlikely to be a source of interaction with other drugs. The pharmacokinetics of frovatriptan were not affected by moderate alcohol intake. There were slight increases in area under the curve and maximum concentration on concomitant administration with the combined oral contraceptives, propranolol, and fluvoxamine; and slight decreases in these parameters on concomitant administration with ergotamine and in tobacco smokers; these findings were considered to have no clinical significance in view of frovatriptan's large therapeutic index (well tolerated at doses ranging from 2.5 to 40 mg). These effects can be attributed primarily to modification of CYP1A2 activity but their impact is limited, probably due to frovatriptan also undergoing renal clearance and the likely role of blood cell binding in controlling the amount of unbound drug available for elimination.

CONCLUSIONS

Because it has no inhibitory or inducing effect on CYP isoenzymes and is only slightly bound to plasma proteins, it is unlikely that frovatriptan will alter the pharmacokinetics of concomitantly administered drugs. Frovatriptan, therefore, appears to have a low risk of interaction with other drugs, and adjustments of dose are unlikely to be required when it is coadministered with other agents.

Clinical pharmacokinetics of frovatriptan

OBJECTIVE

To review available data on the clinical pharmacokinetics of frovatriptan.

BACKGROUND

Preclinical data suggest that the pharmacokinetic profile of frovatriptan may differ from that of the currently available triptans.

METHODS

Studies of healthy volunteers, subjects with renal or hepatic impairment, elderly subjects, and patients with migraine during and between attacks were reviewed.

RESULTS

Oral bioavailability of frovatriptan is 22% to 30%, and although the time to maximum concentration is typically 2 to 3 hours, approximately 60% to 70% of plasma maximum concentration is achieved within 1 hour of dosing. Frovatriptan distributes into erythrocytes, with binding reversible and time dependent. The relatively long terminal elimination half-life (about 26 hours) confers good systemic exposure and may produce a long duration of therapeutic action, thus reducing migraine recurrence and the need for redosing. Systemic exposure to frovatriptan generally correlates with dose between 1 and 100 mg. Blood and plasma frovatriptan concentrations are consistently higher in females, but there is no need to adjust dose according to gender. Pharmacokinetics are essentially unaffected by food and were predictable after repeat dosing; steady state is approached in about 4 to 5 days. Pharmacokinetics were changed only slightly in subjects with renal impairment or mild-to-moderate hepatic impairment, elderly individuals, and during migraine attacks. Frovatriptan is principally metabolized by the CYP1A2 isoenzyme of cytochrome P-450 and is cleared by the kidney and liver, each having sufficient capacity to compensate for impairment of the other.

CONCLUSIONS

Frovatriptan can be taken without regard for food intake, and because of the large therapeutic margin and shallow dose-response curve, there is no need for dosage adjustment in the elderly, in women taking a combined oral contraceptive, in patients with mild-to-severe renal impairment, mild-to-moderate hepatic impairment, or according to gender. The long duration of exposure may reduce the likelihood of early migraine recurrence.

Airway inflammation, basement membrane thickening and bronchial hyperresponsiveness in asthma

BACKGROUND

There are few data in asthma relating airway physiology, inflammation and remodelling and the relative effects of inhaled corticosteroid (ICS) treatment on these parameters. A study of the relationships between spirometric indices, airway inflammation, airway remodelling, and bronchial hyperreactivity (BHR) before and after treatment with high dose inhaled fluticasone propionate (FP 750 microg bd) was performed in a group of patients with relatively mild but symptomatic asthma.

METHODS

A double blind, randomised, placebo controlled, parallel group study of inhaled FP was performed in 35 asthmatic patients. Bronchoalveolar lavage (BAL) and airway biopsy studies were carried out at baseline and after 3 and 12 months of treatment. Twenty two normal healthy non-asthmatic subjects acted as controls.

RESULTS

BAL fluid eosinophils, mast cells, and epithelial cells were significantly higher in asthmatic patients than in controls at baseline (p<0.01). Subepithelial reticular basement membrane (rbm) thickness was variable, but overall was increased in asthmatic patients compared with controls (p<0.01). Multiple regression analysis explained 40% of the variability in BHR, 21% related to rbm thickness, 11% to BAL epithelial cells, and 8% to BAL eosinophils. The longitudinal data corroborated the cross sectional model. Forced expiratory volume in 1 second improved after 3 months of treatment with FP with no further improvement at 12 months. PD(20) improved throughout the study. BAL inflammatory cells decreased following 3 months of treatment with no further improvement at 12 months (p<0.05 v placebo). Rbm thickness decreased in the FP group, but only after 12 months of treatment (mean change -1.9, 95% CI -3 to -0.7 microm; p<0.01 v. baseline, p<0.05 v. placebo). A third of the improvement in BHR with FP was associated with early changes in inflammation, but the more progressive and larger improvement was associated with the later improvement in airway remodelling.

CONCLUSION

Physiology, airway inflammation and remodelling in asthma are interrelated and improve with ICS. Changes are not temporally concordant, with prolonged treatment necessary for maximal benefit in remodelling and PD(20). Determining the appropriate dose of inhaled steroids only by reference to symptoms and lung function, as specified in current international guidelines, and even against indices of inflammation may be over simplistic. The results of this study support the need for early and long term intervention with ICS, even in patients with relatively mild asthma.

Increased soluble CD14 in bronchoalveolar lavage fluid of stable lung transplant recipients

Macrophages, neutrophils and infection have been implicated in the genesis of the bronchiolitis obliterans syndrome (BOS) post lung transplantation. sCD14 is a soluble form of a shed-cell surface protein. It is capable of promoting cytokine-induced inflammation and it's presence in clinically stable lung transplant recipients (LTR) might be important as an early marker of BOS. Bronchalveolar lavage (BAL) and blood samples were taken from 26 stable LTR, at or near their best forced expiratory volume in one second who were free from infection. sCD14 levels were measured via enzyme-linked immunosorbent assay. Cell counts were performed on unfiltered BAL. LTR neutrophil count, BAL sCD14 and serum sCD14 levels were higher than controls (median 3.8% versus 1.3%, p<0.05; 11.5 ng x mL(-1) versus 6 ng x mL(-1), p<0.001; 6.2 microg x mL(-1) versus 2.4 microg x mL(-1), p<0.05, respectively). BAL albumin and sCD14 correlated (regression coefficient: 0.77, p<0.001). In this hypothesis-generating, cross-sectional study, the authors have described for the first time soluble CD14 levels in the bronchoalveolar lavage and serum of stable lung transplant recipients, and show that these are elevated compared to controls. This is a practicable candidate marker system, which can be tested for a predictive role in bronchiolitis obliterans syndrome following lung transplantation. The origin of this cellular protein and its temporal relationship to the development of the bronchiolitis obliterans syndrome remains to be elucidated in more definitive longitudinal studies, which should include other measurements potentially relevant to the innate immune system, such as bronchoalveolar lavage endotoxin levels.

HIV/AIDS and legal issues in Australia

In Australia, a "blueprint" for HIV and AIDS-related law reform was produced in the early 1990s, but progress in achieving reform has been uneven. In 2000, discrimination against people with HIV/AIDS continues, and there are new threats to some of the very measures that are responsible for Australia's remarkable success in fighting the HIV/AIDS epidemic among injection drug users. This article, by Chris Ward, a member of the Legal Working Group of the Australian National Council on AIDS, Hepatitis C and Related Diseases, provides an overview of the law reforms achieved in Australia, and of current and future challenges. It concludes that the overarching challenge Australia faces in promoting an enabling legal environment is the waning impetus for reform, at a time when substantial areas of legislation and practice still warrant attention.

European Community Respiratory Health Survey calibration project of dosimeter driving pressures

Two potential sources of systematic variation in output from Mefar dosimeters, the system used in the European Community Respiratory Health Survey (ECRHS) study have been evaluated: individual nebulizer characteristics and dosimeter driving pressure. Output variation from 366 new nebulizers produced in two batches for the second ECRHS were evaluated, using a solute tracer method, at a fixed driving pressure. The relationship between dosimeter driving pressure was then characterized and between-centre variation in dosimeter driving pressure was evaluated in an Internet-based survey. A systematic difference between nebulizers manufactured in the two batches was identified. Batch one had a mean+/-SD output of 7.0+/-0.8 mg x s(-1) and batch two, 6.3+/-0.7 mg x s(-1) (p<0.005). There was a wide range of driving pressures generated by Mefar dosimeters as set, ranging between 70-245 kPa, with most outside the quoted manufacturer's specification of 180+/-5%. Nebulizer output was confirmed as linearly related to dosimeter driving pressure (coefficient of determination (R2)=0.99, output=0.0377 x driving pressure-0.4151). The range in driving pressures observed was estimated as consistent with a variation of about one doubling in the provocative dose causing a 20% fall in forced expiratory volume in one second. Systematic variation has been identified that constitutes potentially significant confounders for between-centre comparisons of airway responsiveness in the European Community Respiratory Health Survey, with the dosimeter driving pressure representing the most serious issue. This work confirms the need for appropriate quality control of both nebulizer output and dosimeter driving pressure, in laboratories undertaking field measurements of airway responsiveness. In particular, appropriate data on driving pressures need to be collected and factored into between-centre comparisons. Comprehensive collection of such data to optimize quality control is practicable and has been instigated by the organizing committee for the European Community Respiratory Health Survey II.

Control of hepatitis A through routine vaccination of children

CONTEXT

The impact of routine hepatitis A vaccination of children living in large communities with elevated disease rates has not been evaluated.

OBJECTIVE

To determine the effect of routine vaccination of children on disease incidence in a community with recurrent hepatitis A epidemics.

DESIGN, SETTING, AND PARTICIPANTS

Community-based demonstration project conducted from January 12, 1995, through December 31, 2000, in Butte County, California, among children aged 2 to 17 years.

INTERVENTION

In 1995, vaccination was offered to children aged 2 to 12 years during vaccination clinics conducted on 2 occasions 6 to 12 months apart at most schools in the county. In 1996-2000, vaccine was distributed to community health care clinicians, who vaccinated eligible children without charge. Vaccine was also available at health department clinics, selected child care centers, and other sites.

MAIN OUTCOME MEASURES

Hepatitis A vaccination coverage, hepatitis A incidence, and vaccine effectiveness.

RESULTS

During the study period, 29 789 (66.2%) of an estimated 44 982 eligible children received at least 1 vaccine dose; 17 681 (39.3%) received a second dose. The number of hepatitis A cases among the entire county population declined 93.5% during the study period, from 57 cases in 1995 to 4 in 2000, the lowest number of cases reported in the county since hepatitis A surveillance began in 1966. The 2000 incidence rate of 1.9 per 100 000 population was the lowest of any county in the state. Of the 245 cases reported during the 6-year period, 40 (16.3%) occurred among children 17 years of age or younger, of which 16 (40%) occurred in 1995 and only 1 in 2000. One of the 27 case patients eligible for vaccination had been vaccinated, having received the first dose 3 days before symptom onset. The estimated protective vaccine efficacy was 98% (95% confidence interval, 86%-100%).

CONCLUSIONS

In this population, hepatitis A vaccine was highly effective in preventing disease among recipients. Childhood vaccination appears to have decreased hepatitis A incidence among children and adults and controlled the disease in a community with recurrent epidemics.

Reduced airway distensibility, fixed airflow limitation, and airway wall remodeling in asthma

The airways of individuals with asthma are less distensible than normal and it has been assumed that this may be due to airway remodeling associated with chronic inflammation, although there are currently no available data directly relating these two aspects of asthma. We have therefore carried out a study of the relationship between airway distensibility (DeltaVD) and subepithelial reticular basement membrane (RBM) thickening as an index of airway remodeling, in a group of patients with relatively mild but symptomatic asthma. Our methods included a cross-sectional study of DeltaVD in patients with mild to moderate atopic asthma, with matched airway biopsy for structural components. We confirmed that DeltaVD was lower in patients with asthma than in normal individuals (19.8 +/- 1.1 versus 24.1 +/- 1.5; p < 0.05) and that RBM thickness was increased in patients with asthma (9.1 +/- 2.2 versus 7.7 +/- 1.2 microm; p < 0.01). There was a negative correlation between DeltaVD and RBM thickness in asthma (r = -0.37, p = 0.03) and positive correlations between percent predicted postbronchodilator large and small airway function (for percent predicted FEV(1 )versus DeltaVD, r = 0.59, p < 0.001). We conclude that, cross-sectionally, DeltaVD was related to airway remodeling (RBM thickening) and airflow limitation (percent predicted large and small airway function). Our findings support the hypothesis that DeltaVD is a physiologic test that is reflective of airway remodeling.

Pharmacokinetics and absolute bioavailability of sitafloxacin, a new fluoroquinolone antibiotic, in healthy male and female Caucasian subjects

1. The aim was to compare the pharmacokinetics of sitafloxacin from a capsule formulation (dose of 500 mg sitafloxacin) and an intravenous (i.v.) formulation infused over 1 h (dose of 400 mg sitafloxacin) in healthy male and female subjects and to estimate the absolute bioavailability of sitafloxacin from the capsule formulation. 2. Following oral administration, sitafloxacin was rapidly absorbed, with a mean maximum concentration in plasma of 4.65 microgml(-1) occuring at median tmax = 1.25 h giving a mean AUC(0-infinity) = 28.1 microg h ml(-1). For the i.v. administration, a mean Cmax = 5.53 microm(-1) occurred at the end of the 1-h infusion with a mean AUC(0-infinity) = 25.4 microg h ml(-1). The mean terminal elimination half-life was 7.0 h (oral) and 6.6 h (i.v.). For the oral and i.v. formulations, the mean total plasma clearance was 296 and 263 mlmin(-1), respectively and the mean volume of distribution was 180 and 150 litres, respectively. 3. Within 48 h post-dose, approximately 61% (range 22-86%) of the administered dose was excreted unchanged in urine following capsule administration, compared with approximately 75% (range 42-101%) following the i.v. formulation. For both formulations, the renal clearance of sitafloxacin (means of 181 and 198 ml min(-1) for the capsule and i.v. doses, respectively) implies active tubular secretion of the drug. 4. The absolute bioavailability of sitafloxacin from the capsule formulation was high at 89%, with a 95% CI of 84-94%. The intersubject variability (CV%) in the sitafloxacin AUC(0-infinity) for the capsule was low at 18.6%. 5. Gender differences in the pharmacokinetics of sitafloxacin were small and would not warrant dose adjustment. 6. The findings show that the capsule formulation offers good oral bioavailability and merits further clinical evaluation of sitafloxacin as an orally effective fluoroquinolone antibacterial.

Bronchoalveolar lavage macrophage and lymphocyte phenotypes in lung transplant recipients

Recent publications have demonstrated potentially pathologic changes in bronchoalveolar lavage (BAL) from clinically stable lung transplant recipients (SLTRs), but there are few available data on alveolar macrophages (AMs). We formulated the hypothesis that changes in BAL AM and lymphocyte phenotypes would be apparent even in SLTRs.A cross-sectional study using a standardized 3 x 60 ml BAL, investigating lymphocyte and AM phenotypes in 19 SLTRs, 5 subjects with bronchiolitis obliterans syndrome (BOS) and 18 normal control volunteers. BAL lymphocyte and AM markers were assessed using flow cytometry. We confirmed a significant elevation of neutrophils in all lung transplant recipients with a more marked elevation in the BOS subjects. Flow-cytometric analysis showed increased numbers of natural killer (NK; CD56/CD16-positive) cells, increased CD11b- and CD11c-positive CD3 lymphocytes, increased CD8-positive lymphocytes and increased HLA-DR expression in CD8 cells from the lung transplant recipients, when compared with normals (p <.005). In contrast, the expression of a number of AM surface markers, associated with a range of host defense functions against bacteria, fungi and viruses (CD11a, CD11b, CD11c, HLA-DR, CD14), was lower in both SLTRs and those with BOS (p <.05). These novel findings are consistent with complex lymphocyte and macrophage changes that may result from clinically silent infection, partially suppressed rejection, or both.

Iron overload and nitric oxide-derived oxidative stress following lung transplantation

BACKGROUND

Reactive oxygen species (ROS) may contribute to airway injury and the development of the bronchiolitis obliterans syndrome (BOS) following lung transplantation (LT). Chemically active iron released from ferritin stores and nitric oxide (NO)-derived radicals may add to the oxidative burden.

METHODS

We determined the concentrations of ferritin and the aqueous NO derivative nitrite (NO2(-)) within bronchoalveolar lavage fluid (BALF) of 14 stable LT recipients (ST) and 7 subjects with BOS and 21 normal controls. We also assessed the relationship between BALF ferritin and hemosiderin-laden macrophages (HLMs) using a hemosiderin score (HS) and determined BALF albumin concentration as a marker of microvascular leakage.

RESULTS

BALF ferritin concentrations and HSs were significantly elevated in LT recipients overall compared with normal controls (p < 0.05). BALF NO2(-) levels were elevated in BOS subjects and STs compared with normal controls (p = 0.002 and p = 0.09, respectively), but there was no difference between transplant groups. BALF albumin concentrations were elevated in BOS patients compared with normal controls (p = 0.02) and ST (p = 0.05), but there was no difference between STs and controls. There was a significant relationship between BALF ferritin concentration and HS in LT recipients overall (r(s) = 0.7, p < 0.001). In BOS subjects, but not ST, BALF ferritin was significantly related to BALF albumin (r(s) = 0.8, p = 0.05) and there was a weak relationship with NO2(-) concentration (r(s) = 0.6, p = 0.1). BALF NO2(-) was strongly related to BALF % neutrophils in BOS subjects (r(s) = 0.9, p < 0.01), but there was no such relationship in STs.

CONCLUSIONS

Our findings suggest that the allograft could be subject to significant iron-generated oxidative stress, which may be exacerbated by NO and neutrophil-derived ROS, particularly in BOS. Microvascular leakage may be a feature of established chronic rejection, which potentiates the iron overload and contributes to further airway damage and remodeling.

Intravenous safety and pharmacokinetics of a novel dimerizer drug, AP1903, in healthy volunteers

AP1903 is a novel gene-targeted drug that is being developed for use in drug-regulated cell therapies. An intravenous, single-blind, placebo- and saline-controlled, ascending-dose study was performed to evaluate the safety, tolerability, and pharmacokinetics of AP1903. Twenty-eight normal healthy male volunteers were randomized into five dosage groups of AP1903 (0.01, 0.05, 0.1, 0.5, and 1 mg/kg). Within each group, 4 volunteers received a single dose of AP1903, 1 volunteer received an equal volume of placebo, and 1 received an equal volume of normal saline. The only exception was in the 0.5 mg/kg group, in which 4 volunteers were dosed: 3 received AP1903 and 1 received normal saline. All dosages were administered as intravenous infusions over 2 hours. Clinical safety parameters were monitored, and serial blood and urine samples were collected for analysis of AP1903. No drug-related adverse events were observed at any of the dose levels with the possible exception of facial flushing in 1 volunteer at the 1.0 mg/kg dose level. AP1903 plasma levels were directly proportional to the administered dose, with mean Cmax values ranging from approximately 10 to 1,275 ng/mL over the 0.01 to 1.0 mg/kg dose range. Following the infusion period, blood concentrations revealed a rapid distribution phase, with plasma levels being reduced to approximately 18%, 7%, and 1% of the maximal concentration at 0.5, 2, and 10 hours postdose, respectively. AP1903 was shown to be safe and well tolerated at all dose levels and demonstrated a favorable pharmacokinetic profile at doses well above the anticipated therapeutic dose.

The concerns of patients under palliative care and a heart failure clinic are not being met

Patients with a terminal illness, identified by palliative care teams working in Manchester, and patients attending a heart failure clinic, were asked to participate in a prospective survey to determine their main concerns. Data were collected from 213 palliative care (PC) patients (mostly with cancer) and 66 patients with heart failure (HF). The median ages of the two patient groups were similar, but the HF patients were more likely to be male and living with a partner; 13% of PC and 7% of HF patients reported that they had no carer. The PC patients had more district nurse, hospice, social work and physiotherapy input. The most frequently reported troublesome problems for PC patients were pain (49%), loss of independence (30%) and difficulty walking (27%). HF patients reported dyspnoea (55%), angina (32%) and tiredness (27%) as the most troublesome problems. From a checklist of symptoms, the frequency of tiredness (PC = 77%, HF = 82%) and difficulty getting about (PC = 71%, HF = 65%) were high in each group. Psychological problems were reported by 61% of PC and 41% of HF patients. Cardiac patients reported more breathlessness and cough than PC patients (83% vs 49% and 44% vs 26%, respectively). Reduced libido was more common in cardiac patients (42% vs 21%). Patient disclosure of troublesome problems to professional carers was high (>87% in both PC and HF patients). Documented action was greater for physical than social or psychological problems. For PC patients, documented action was recorded for 83% physical, 43% social/functional and 52% psychological problems. For HF patients documented action was recorded for 74% cardiac, 60% physical - non-cardiac, 30% social/functional and 28% psychological problems. Clearly many patients' troublesome problems were not being addressed. As a result of this study, specific action by health care professionals was taken in 50% of PC patients and 71% of HF patients. We plan to target specific educational events on the treatment of physical problems, psychological assessment and social service provision.

Effect of a long-acting beta2-agonist over three months on airway wall vascular remodeling in asthma

There are few data regarding the potential effects of antiasthma treatment on indices of airway remodeling, such as the increased subepithelial airway vascularity in patients with asthma. We studied 45 symptomatic subjects with asthma who were receiving treatment with low dose inhaled corticosteroids (ICS) (range 200-500 microg twice a day) and 28 normal subjects without asthma as a control population. Subjects underwent bronchoscopy with airway biopsy and subjects with asthma were then randomized to receive supplementary inhaled salmeterol 50 microg twice a day, fluticasone propionate 100 microg twice a day, or placebo for 3 mo in addition to their baseline ICS. Biopsy of the airway was then repeated. The biopsies were analyzed for vascular structures in the subepithelial lamina propria. Sufficient biopsy material was available for analysis of vascularity in 34 of the subjects with asthma and 28 of the normal subjects. We confirmed that airways of subjects with asthma had a significant increase in the number of vessels/mm2 of lamina propria compared with airways of normal subjects (524 +/- 137 vessels/mm2, n = 34 versus 425 +/- 130 vessels/mm2, n = 28; p = 0.004). There was a decrease in the density of vessels of lamina propria after treatment only in the salmeterol group compared with baseline (before, 535 +/- 153 vessels/mm2 versus after, 400 +/- 142 vessels/mm2; n = 12; p = 0.04). There was no significant change within the fluticasone (n = 11) or placebo (n = 11) treatment groups, but also no significant differences between the groups. Notably, no treatment was associated with increased airway wall vascularity. The demonstrated fall in vessel number within the salmeterol-treated group may suggest an advantageous effect of long-acting beta2-agonists on this manifestation of airway remodeling over the 3-mo time scale of this study, which is complementary to the action of ICS on airway vascularity.

Environmental enrichment: effects on spatial memory and hippocampal CREB immunoreactivity

Environmental enrichment has been shown to improve performance in tests of spatial memory, induce neurogenesis in the hippocampus, enhance survival of newly formed granule cells, and inhibit spontaneous apoptosis. Although neuroplasticity of the mammalian brain declines with age, recent evidence suggests that the adult brain exhibits significant plasticity in response to environmental stimulation. The present study was designed to evaluate the effect of environmental enrichment on spatial memory and on immunoreactivity to cAMP response element binding protein (CREB) from the hippocampus. C57/BL/6 mice were trained in a Morris water maze after exposure to an enriched environment, either from 35 to 94 days or from 100 to 159 days of age. Hippocampal tissue from representative animals was later analyzed by Western blot for CREB immunoreactivity. Results indicate that environmental enrichment (particularly during the earlier period) improved performance on the Morris water maze and tended to increase immunoreactivity to CREB in the hippocampus. Social interaction by itself did not result in significant differences in navigational performance. Results with regard to social interaction and CREB immunoreactivity were mixed. Results are discussed in terms of evaluating the construct of enrichment, the correlation of CREB transcription and behavior change, and the importance of the developmental period for enrichment.

Hormone replacement therapy. Knowledge, attitudes and practices of women attending a gynaecology outpatient clinic in Trinidad

A questionnaire was used to assess the knowledge, attitudes, and practices of a sample of 218 outpatients attending the Port of Spain General Hospital Gynaecology Outpatient Clinic. The questionnaire investigated women's knowledge of menopause, risks and benefits of Hormone Replacement Therapy (HRT), their attitudes concerning HRT and menopause as well as practices of postmenopausal women with respect to HRT. Comparisons were made between women of differing menopausal status, educational background and ethnicity. The results showed that overall knowledge was lacking regardless of menopausal status, ethnicity or educational background. Less educated women were more inclined to believe that HRT was inappropriate principally because they regarded the menopause as a natural process (p = 0.023). Only 24% of postmenopausal women were practicing some form of HRT. A minority (7%) had previously been undergoing the therapy but had stopped. Most postmenopausal women (69%) simply never considered treatment because the majority had never heard about HRT. The main source of patient information was from the clinic they were attending. This study reveals low awareness of menopausal information and therapeutic options in a Trinidadian population. A targeted education programme may substantially fill this void.

Normally suppressing CD40 coregulatory signals delivered by airway macrophages to TH2 lymphocytes are defective in patients with atopic asthma

BACKGROUND

We have previously shown that airway macrophages (AMs) from atopic nonasthmatic subjects, but not atopic asthmatic subjects, inhibit T-cell IL-5 production during an allergen-dependent interaction. However, the mechanisms responsible for the IL-5-modulating effect of the AMs are less clear.

OBJECTIVES

The aim of the present study was to define the roles of B7 and CD40 costimulatory signals delivered by AMs in regulating T-cell IL-5 responses in an allergen-stimulated coculture system.

METHODS

Peripheral blood CD4(+) T cells and AMs were cocultured under different conditions.

RESULTS

Compared with those from well-matched atopic nonasthmatic subjects, AMs from atopic asthmatic subjects demonstrated a significantly lower expression of B7-1 and CD40, but not B7-2 and HLA-DR, after either fresh isolation or coculture with allergen-reactive CD4(+) T cells. Lower IL-12 production by the AMs from asthmatic subjects was also observed under the same conditions. Allergen-related T-cell IFN-gamma and IL-5 production was inhibited by the addition of either neutralizing B7-1 or B7-2 antibody to the cocultures in both atopic groups. In contrast, IL-5 production was significantly increased by the addition of blocking CD40 antibody, whereas IL-12 production by the AMs was inhibited. Anti-IL-12 mAb enhanced IL-5 production in the cocultures from atopic nonasthmatic subjects, whereas a dose-dependent suppressive effect of recombinant human IL-12 on IL-5 production was seen in atopic asthmatic subjects.

CONCLUSION

In this coculture model system, lower IL-12 production by AMs and higher IL-5 production by CD4(+) T cells in atopic asthmatic subjects compared with that found in atopic nonasthmatic subjects are related to the lower expression of CD40 rather than B7-1 signals on the AMs from these patients.

Continuous-wave bistatic laser Doppler wind sensor

A coherent laser radar has been built by use of a master-oscillator power-amplifier arrangement in which the master oscillator is an external-cavity semiconductor laser and the power amplifier is an erbium-doped fiber amplifier with approximately 1-W output at a wavelength of 1.55 microm. The beams are routed within single-mode optical fiber, allowing modular construction of the optical layout with standard components. The system employs separate transmit and receive optics (a bistatic configuration) and has sufficient sensitivity for reliable Doppler wind-speed detection in moderate scattering conditions at short range (to as much as approximately 200 m). The bistatic arrangement leads to a well-defined probe volume formed by the intersection of the transmitted laser beam with the virtual backpropagated local-oscillator beam. This could be advantageous for applications in which the precise localization of wind speed is required (e.g., wind tunnel studies) or in which smoke, low cloud, or solid objects can lead to spurious signals. The confinement of the probe volume also leads to a reduction in the signal power. A theoretical study has been carried out on the reduction in wind signal strength compared with the monostatic arrangement, and the results are compared with experimental observation.

Bronchoalveolar lavage cellular profiles in lung transplantation: the effect of inhaled corticosteroids

Bronchiolitis Obliterans Syndrome (BOS) remains a major cause of long term morbidity and mortality in lung transplantation, and occurs despite significant immunosuppression. Airway inflammation is thought to precede the development of BOS.

OBJECTIVES

To examine the effect of inhaled corticosteroids on airway inflammation and the development of BOS in lung transplant recipients.

METHODS

30 patients were recruited and randomised in a double blind fashion to receive either 750 micrograms Fluticasone propionate (FP) twice daily or an identical appearing placebo for 3 months. BAL cell counts and differentials were performed at time 0 and after 3 months treatment. Lung function was assessed at each time point using spirometry.

RESULTS

24 patients were felt to be stable and free from infection at both time points and thus included in the analysis. There was a significant reduction in total cell count in BAL fluid after treatment with 3 months FP compared to 3 months placebo, however no change in cell differentials nor lung function was found.

DISCUSSION

Despite a reduction in total cell numbers in BAL fluid, lung function was not altered over the 3 months of treatment. It may be that longer treatment is required to see an effect.

Epidemiology and molecular biology of early prostatic neoplasia

This paper provides our institutional data with respect to the prevalence of early neoplastic changes within the prostate gland and the age and race distribution of the patients. The changes examined were prostatic intraepithelial neoplasia (PIN) and preclinical (latent) cancers. The literature on the prevalence of these early lesions among different geographic and ethnic groups is summarized, and an abbreviated review of the more common molecular alterations reported at this early phase of prostatic neoplasia is offered.