Offshore pelagic subsidies dominate carbon inputs to coral reef predators

Coral reefs were traditionally perceived as productive hot spots in oligotrophic waters. While modern evidence indicates that many coral reef food webs are heavily subsidized by planktonic production, the pathways through which this occurs remain unresolved. We used the analytical power of carbon isotope analysis of essential amino acids to distinguish between alternative carbon pathways supporting four key reef predators across an oceanic atoll. This technique separates benthic versus planktonic inputs, further identifying two distinct planktonic pathways (nearshore reef-associated plankton and offshore pelagic plankton), and revealing that these reef predators are overwhelmingly sustained by offshore pelagic sources rather than by reef sources (including reef-associated plankton). Notably, pelagic reliance did not vary between species or reef habitats, emphasizing that allochthonous energetic subsidies may have system-wide importance. These results help explain how coral reefs maintain exceptional productivity in apparently nutrient-poor tropical settings, but also emphasize their susceptibility to future ocean productivity fluctuations.

Novel tri-isotope ellipsoid approach reveals dietary variation in sympatric predators

Sympatric species may partition resources to reduce competition and facilitate co-existence. While spatial variation and specialization in feeding strategies may be prevalent among large marine predators, studies have focussed on sharks, birds, and marine mammals. We consider for the first time the isotopic niche partitioning of co-occurring, teleost reef predators spanning multiple families. Using a novel tri-isotope ellipsoid approach, we investigate the feeding strategies of seven of these species across an atoll seascape in the Maldives. We demonstrate substantial spatial variation in resource use of all predator populations. Furthermore, within each area, there was evidence of intraspecific variation in feeding behaviors that could not wholly be attributed to individual body size. Assessing species at the population level will mask these intraspecific differences in resource use. Knowledge of resource use is important for predicting how species will respond to environmental change and spatial variation should be considered when investigating trophic diversity.

Prevalence of pelagic dependence among coral reef predators across an atoll seascape

Coral reef food webs are complex, vary spatially and remain poorly understood. Certain large predators, notably sharks, are subsidized by pelagic production on outer reef slopes, but how widespread this dependence is across all teleost fishery target species and within atolls is unclear.

North Malé Atoll (Maldives) includes oceanic barrier as well as lagoonal reefs. Nine fishery target predators constituting ca. 55% of the local fishery target species biomass at assumed trophic levels 3–5 were selected for analysis. Data were derived from carbon (δ¹³C), nitrogen (δ¹⁵N) and sulphur (δ³⁴S) stable isotopes from predator white dorsal muscle samples, and primary consumer species representing production source end‐members.

Three‐source Bayesian stable isotope mixing models showed that uptake of pelagic production extends throughout the atoll, with predatory fishes showing equal planktonic reliance between inner and outer edge reefs. Median plankton contribution was 65%–80% for all groupers and 68%–88% for an emperor, a jack and snappers.

Lagoonal and atoll edge predators are equally at risk from anthropogenic and climate‐induced changes, which may impact the linkages they construct, highlighting the need for management plans that transcend the boundaries of this threatened ecosystem.

Chronic spearfishing may indirectly affect reef health through reductions in parrotfish bite rates

The grazing behaviour of two Caribbean parrotfish, a fished species, the stoplight parrotfish Sparisoma viride and a non-fished species, the striped parrotfish Scarus iseri, were studied in the presence (fished site) and absence (marine reserve) of chronic spearfishing activity. Diurnal feeding periodicity did not differ between the sites in either species: roving individuals had significantly higher bite rates in the afternoon, while territorial individuals foraged consistently throughout the day. Mean bite rate varied between sites in both species. Abundance, biomass and bite rates of S. viride were all significantly higher within the reserve, except for roving S. viride which had a higher mean bite rate in the afternoon outside the reserve compared with within it, attributable to maximisation of feeding in the afternoon when fishing risk was lower. Scarus iseri mean abundance and bite rate were greater outside the reserve, potentially because reduction in large territorial herbivores allowed S. iseri to feed more rapidly. By reducing the grazing potential of the remaining S. viride individuals the effect of fishing is greater than would be predicted from biomass changes alone. Less grazing by S. viride would not be compensated for by the increase in grazing by S. iseri because the latter feeds on different algae. Spearfishing of key parrotfish species reduces grazing potential directly by extraction and indirectly by changing behaviour.

Simple Instructions for using Pressurized Aerosol Bronchodilators1

Although the manufacturers of pressurized aerosol bonchodilators issue instructions for using the inhalers, little or no experimental verification exists. Bronchodilatation has been measured after controlled inhalations of 500 μg terbutaline sulphate given in a systematic series of investigations to 8 patients with reversible airways obstruction at 2 different inhalation flow rates (25 1/min and 80 1/min), 3 different lung volumes (20%, 50% and 80% vital capacity) and followed by 2 different breath-holding pauses (4 and 10 seconds). The results indicate that patients may release the aerosol at any time during the course of a slow deep inhalation which should be followed by 10 seconds of breath-holding. This will ensure an optimal bronchodilator response.

Reef flattening effects on total richness and species responses in the Caribbean

There has been ongoing flattening of Caribbean coral reefs with the loss of habitat having severe implications for these systems. Complexity and its structural components are important to fish species richness and community composition, but little is known about its role for other taxa or species-specific responses. This study reveals the importance of reef habitat complexity and structural components to different taxa of macrofauna, total species richness, and individual coral and fish species in the Caribbean. Species presence and richness of different taxa were visually quantified in one hundred 25-m(2) plots in three marine reserves in the Caribbean. Sampling was evenly distributed across five levels of visually estimated reef complexity, with five structural components also recorded: the number of corals, number of large corals, slope angle, maximum sponge and maximum octocoral height. Taking advantage of natural heterogeneity in structural complexity within a particular coral reef habitat (Orbicella reefs) and discrete environmental envelope, thus minimizing other sources of variability, the relative importance of reef complexity and structural components was quantified for different taxa and individual fish and coral species on Caribbean coral reefs using boosted regression trees (BRTs). Boosted regression tree models performed very well when explaining variability in total (82·3%), coral (80·6%) and fish species richness (77·3%), for which the greatest declines in richness occurred below intermediate reef complexity levels. Complexity accounted for very little of the variability in octocorals, sponges, arthropods, annelids or anemones. BRTs revealed species-specific variability and importance for reef complexity and structural components. Coral and fish species occupancy generally declined at low complexity levels, with the exception of two coral species (Pseudodiploria strigosa and Porites divaricata) and four fish species (Halichoeres bivittatus, H. maculipinna, Malacoctenus triangulatus and Stegastes partitus) more common at lower reef complexity levels. A significant interaction between country and reef complexity revealed a non-additive decline in species richness in areas of low complexity and the reserve in Puerto Rico. Flattening of Caribbean coral reefs will result in substantial species losses, with few winners. Individual structural components have considerable value to different species, and their loss may have profound impacts on population responses of coral and fish due to identity effects of key species, which underpin population richness and resilience and may affect essential ecosystem processes and services.

Which factors are associated with quality of life in patients with Graves' orbitopathy presenting for orbital decompression surgery?

PURPOSE

Graves' orbitopathy (GO) is associated with changes in the appearance of the eyes and visual dysfunction. Patients report feeling socially isolated and unable to continue with day-to-day activities. This study aimed at investigating the demographic, clinical, and psychosocial factors associated with quality of life in patients presenting for orbital decompression surgery.

METHODS

One-hundred and twenty-three adults with GO due for orbital decompression at Moorfields Eye Hospital London were recruited prospectively. Clinical measures including treatment history, exophthalmos, optic neuropathy, and diplopia were taken by an ophthalmologist. Participants completed psychosocial questionnaires, including the Graves' Ophthalmopathy Quality of Life Scale (GO-QOL), the Hospital Anxiety and Depression Scale, and the Derriford Appearance Scale. Hierarchical multiple regression analyses were used to identify predictors of quality of life.

RESULTS

Higher levels of potential cases of clinical anxiety (37%) and depression (26%) were found in this study sample than in patients with other chronic diseases or facial disfigurements. A total of 55% of the variance in GO-QOL visual function scores was explained by the regression model; age, asymmetrical GO and depressed mood were significant unique contributors. In all, 75% of the variance in GO-QOL appearance scores was explained by the regression model; gender, appearance-related cognitions and depressed mood were significant unique contributors.

CONCLUSION

Appearance-related quality of life and mood were particularly affected in this sample. Predominantly psychosocial characteristics were associated with quality of life. It is important when planning surgery for patients that clinicians be aware of factors that could potentially influence outcomes.

Health-related quality of life of Asian patients with end-stage renal disease (ESRD) in Singapore

BACKGROUND

This study aimed to identify factors associated with the health-related quality of life (HRQOL) of multiethnic Asian end-stage renal disease (ESRD) patients treated with dialysis. The role of dialysis modality was also explored.

METHODS

Data used in this study were from two cross-sectional surveys of Singaporean ESRD patients on haemodialysis (HD) or peritoneal dialysis (PD). In both surveys, participants were assessed using the kidney disease quality of life (KDQOL) instrument and questions assessing socio-demographic characteristics. Clinical data including co-morbidity (measured by Charlson comorbidity index [CCI]), albumin level, haemoglobin level, and dialysis-related variables (e.g. dialysis vintage and dialysis adequacy) were retrieved from medical records. The 36-item KDQOL (KDQOL-36) was used to generate three summary scores (physical component summary [PCS], mental component summary [MCS] and kidney disease component summary [KDCS]) and two health utility scores (Short Form 6-dimension [SF-6D] and EuroQol 5-dimension [EQ-5D]). Linear regression analysis was performed to examine the association of factors with each of the HRQOL scale scores.

RESULTS

Five hundred and two patients were included in the study (mean age 57.1 years; male 52.4 %; HD 236, PD 266). Mean [standard deviation (SD)] PCS, MCS and KDCS scores were 37.9 (9.7), 46.4 (10.8) and 57.6 (18.1), respectively. Mean (SD) health utility score was 0.66 (0.12) for SF-6D and 0.60 (0.21) for EQ-5D. In multivariate regression analysis, factors found to be significantly associated with better HRQOL included: young (<45 years) or old age (>60 years), low CCI (<5), high albumin (≥37 g/l) and high haemoglobin (≥11 g/dl) with PCS; long dialysis vintage (≥3.5 years) with MCS; old age, Malay ethnicity and PD modality with KDCS; low CCI, high albumin and high haemoglobin with EQ-5D and high albumin with SF-6D.

CONCLUSIONS

Clinical characteristics are better predictors of HRQOL in ESRD patients than socio-demographics in Singapore. Dialysis modality has no impact on the health utility of those patients.

In vivo and in vitro properties of STX2484: a novel non-steroidal anti-cancer compound active in taxane-resistant breast cancer

BACKGROUND

STX2484 is a novel non-steroidal compound with potent anti-proliferative activity. These studies aimed to identify STX2484's mechanism of action, in vivo efficacy and activity in taxane-resistant breast cancer models.

METHODS

Effects of STX2484 and paclitaxel on proliferation, cell cycle and apoptosis were assessed in vitro in drug-resistant (MCF-7(DOX)) and non-resistant cells (MCF-7(WT)). STX2484 efficacy in βIII tubulin overexpression in MCF-7 cells was also determined. Anti-angiogenic activity was quantified in vitro by a co-culture model and in vivo using a Matrigel plug assay. An MDA-MB-231 xenograft model was used to determine STX2484 efficacy in vivo.

RESULTS

STX2484 is a tubulin disruptor, which induces p53 expression, Bcl2 phosphorylation, caspase-3 cleavage, cell cycle arrest and apoptosis. In addition, STX2484 is a potent anti-angiogenic agent in vitro and in vivo. In breast cancer xenografts, STX2484 (20 mg kg(-1) p.o.) suppressed tumour growth by 84% after 35 days of daily dosing, with limited toxicity. In contrast to paclitaxel, STX2484 efficacy was unchanged in two clinically relevant drug-resistant models.

CONCLUSIONS

STX2484 is an orally bioavailable microtubule-disrupting agent with in vivo anti-angiogenic activity and excellent in vivo efficacy with no apparent toxicity. Crucially, STX2484 has superior efficacy to paclitaxel in models of clinical drug resistance.

Managing treatment for end-stage renal disease--a qualitative study exploring cultural perspectives on facilitators and barriers to treatment adherence

Although adherence to hemodialysis (HD) regimes is important to maximise good clinical outcomes, it remains suboptimal and not well understood, particularly for those in non-Western settings and patients from Asian cultures. This qualitative study sought to explore cultural perspectives on facilitators and barriers to treatment adherence in HD patients. A descriptive exploratory design was used for the study, incorporating individual semi-structured interviews (n = 17) and three focus groups (n = 20). Each interview/focus group was audio-taped and transcribed verbatim, and coding was conducted by two coders using an iterative process. Study participants identified personal and social/contextual factors as major barriers or facilitators of treatment adherence. Barriers include time consumption, forgetfulness, concerns about safety, poor knowledge/understanding, poor communication and lack of control/social pressure. Participants also identified facilitators, both internal (self-initiated) and external (initiated by family, health care professional and peers) to ensure treatment adherence. These included support from family members and social obligation towards others, risk perception, establishment of routines and peer support. Internal and external factors can hinder or facilitate adherence to diet, fluid and medications in the context of dialysis. Several of these barriers/facilitators can be effectively addressed in the context of interventions and psycho-educational programmes.

What do we know about self-reported fatigue in systemic lupus erythematosus?

Fatigue is one of the most complex and ill understood symptoms of chronic illness often reported as the number one complaint by patients with systemic lupus erythematosus (SLE). This paper aims to provide a comprehensive review of the literature on fatigue in SLE. A pool of 55 relevant articles was retrieved via electronic searches of six databases including MEDLINE, EMBASE, CINAHL, AMED, PsychINFO and PubMed. Fatigue in the studies reviewed was assessed by a range of self-report instruments, the content of which is varied. The results displayed a consensus on the high prevalence of fatigue in SLE, which is significantly higher when compared with controls. The aetiology of fatigue appears to be multifactorial. Disease activity is not always significantly associated with fatigue, in comparison with other secondary features of SLE and psychological variables. The literature is limited by the cross-sectional nature of most of the studies, which does not permit for any firm conclusion regarding the direction of causal relationships to be made. The high prevalence of fatigue in SLE emphasizes the need for further detailed prospective research to inform the understanding of its aetiology, course and management.

The impact of a breast cancer diagnosis on religious/spiritual beliefs and practices in the UK

The use of religious/spiritual resources may increase when dealing with the stress of a cancer diagnosis. However, there has been very little research conducted into changes in religious/spiritual beliefs and practices as a result of a cancer diagnosis outside the USA. The aim of this study was to examine the impact of a breast cancer diagnosis on patients' religious/spiritual beliefs and practices in the UK where religious practice is different. The study used two methods. One compared the religious/spiritual beliefs and practices of 202 patients newly diagnosed with breast cancer with those of a control group of healthy women (n = 110). The other examined patients' perceived change in religious/spiritual beliefs and practices at the time of surgery with those in the year prior to surgery. The aspects of religiousness/spirituality assessed were: levels of religiosity/spirituality, strength of faith, belief in God as well as private and public practices. Patient's perceived their belief in God, strength of faith and private religious/spiritual practices to have significantly increased shortly after surgery compared with the year prior to surgery. However, there were no significant differences in religious/spiritual beliefs and practices between patients and healthy participants. Change scores demonstrated both a reduction and an increase in religious/spiritual beliefs and practices. Although belief in God, strength of faith and private religious/spiritual practices were perceived by patients to be significantly higher after their cancer diagnosis, no significant differences in religious/spiritual beliefs and practices were found between the cancer group at the time of surgery and the control group. Different methodologies appear to produce different results and may explain contradictions in past US studies. Limitations of this study are discussed and suggestions for future research are made.

A randomised controlled trial to compare minimally invasive glucose monitoring devices with conventional monitoring in the management of insulin-treated diabetes mellitus (MITRE)

OBJECTIVES

To evaluate whether the additional information provided by minimally invasive glucose monitors results in improved glycaemic control in people with poorly controlled insulin-requiring diabetes, and to assess the acceptability and health economic impact of the devices.

DESIGN

A four-arm randomised controlled trial was undertaken.

SETTING

Participants were recruited from secondary care diabetes clinics in four hospitals in England.

PARTICIPANTS

404 people aged over 18 years with insulin-treated diabetes mellitus (types 1 or 2) for at least 6 months who were receiving two or more injections of insulin daily were eligible. Participants had to have had two glycosylated haemoglobin (HbA1c) values > or = 7.5% in the last 15 months.

INTERVENTIONS

Participants were randomised to one of four groups. Two groups received minimally invasive glucose monitoring devices [GlucoWatch Biographer or MiniMed Continuous Glucose Monitoring System (CGMS)]. These groups were compared with an attention control group (standard treatment with nurse feedback sessions at the same frequency as those in the device groups) and a standard control group (reflecting common practice in the clinical management of diabetes in the UK).

MAIN OUTCOME MEASURES

Change in HbA1c from baseline to 3, 6, 12 and 18 months was the primary indicator of short- to long-term efficacy in this study. Perceived acceptability of the devices was assessed by use and a self-report questionnaire. A health economic analysis was also performed.

RESULTS

At 18 months all groups demonstrated a decline in HbA1c levels from baseline. Mean percentage changes in HbA1c were -1.4 for the GlucoWatch group, -4.2 for the CGMS group, -5.1 for the attention control group and -4.9 for the standard care control group. At 18 months the relative percentage reduction in HbA1c in each of the intervention arms was less than that in the standard care control group. In the intention to treat analysis no significant differences were found between any of the groups at any of the assessment times. There was no evidence that the additional information provided by the devices resulted in any change in the number or nature of treatment recommendations offered by the nurses. The health economics analysis indicated no advantage in the groups who received the devices; a lower cost and higher benefit were found for the attention control arm. Assessment of device use and acceptability indicated a decline in use of both devices, which was most marked in the GlucoWatch group by 18 months (20% still using GlucoWatch versus 57% still using the CGMS). The GlucoWatch group reported more side effects, greater interference with daily activities and more difficulty in using the device than the CGMS group.

CONCLUSIONS

Continuous glucose monitors do not lead to improved clinical outcomes and are not cost-effective for improving HbA1c in unselected individuals with poorly controlled insulin-requiring diabetes. On acceptability grounds the data suggest that the GlucoWatch will not be frequently used by individuals with diabetes because of the large number of side effects.

Randomized controlled trial to assess the impact of continuous glucose monitoring on HbA(1c) in insulin-treated diabetes (MITRE Study)

AIMS

To determine whether continuous glucose information provided through use of either the GlucoWatch G2 Biographer or the MiniMed continuous glucose monitoring system (CGMS) results in improved glycated haemoglobin (HbA(1c)) for insulin-treated adults with diabetes mellitus, relative to an attention control and standard care group.

METHODS

Four hundred and four adults taking at least two daily insulin injections and with two consecutive HbA(1c) values > or = 7.5% were recruited to this randomized controlled trial (RCT). All were trained at baseline to use the same monitor for traditional capillary glucose testing throughout the 18-month study. The CGMS group were asked to wear the device three times during the first 3 months of the trial and on another three occasions thereafter. The GlucoWatch group wore the device a minimum of four times per month and a maximum of four times per week during the first 3 months and as desired for the remainder of the trial. Trained diabetes research nurses used downloaded data to guide therapy adjustments. Proportional reduction in HbA(1c) from baseline to 18 months was the primary outcome measure.

RESULTS

Neither an intention-to-treat nor per-protocol analysis showed improvement in HbA(1c) in the device groups compared with standard care. For the intention-to-treat analysis, when the standard care group was compared with each of the other groups, this equated to differences in mean relative HbA(1c) reduction (95% confidence interval) from baseline to 18 months of 3.5% (-1.3 to 8.3; GlucoWatch), 0.7% (-4.1 to 5.5; CGMS), and -0.1% (-4.6 to 4.3; attention control).

CONCLUSIONS

The additional information provided by these devices did not result in improvements in HbA(1c) in this population.

Temporal effective size estimates of a managed walleye Sander vitreus population and implications for genetic-based management

The goal of this research was to use the long-term fishery data set and DNA from archived scales of walleye Sander vitreus in Escanaba Lake, WI, U.S.A., to improve the understanding of the underlying mechanism(s) influencing genetic diversity in naturally recruiting populations. The introduced population of S. vitreus in Escanaba Lake has a low mean effective population size (N(E)) between 124.6 and 185.5 despite a mean census size (N(C)) of 4659 (N(E)/N(C)c. 0.04), suggesting an accelerated rate of genetic drift between 1952 and 2002. These values are smaller than the median N(E) range of several studies suggesting typical N(E)/N(C) ratios of 0.11-0.16 in a wide range of taxa. N(E) increased steadily during the past two sampled decades (1992 and 2002) and was consistent with a lowering of the variance in S. vitreus reproductive success, possibly linked to a large, sustained exploitation (mean 28%) rate. Variance in reproductive success is one of the most important factors influencing N(E) in species, like S. vitreus, which have a potential for large fecundities and large juvenile mortalities (type III survivorship). The N(B) estimates across six sequential cohorts (age classes of S. vitreus, assayed from 1994 to 1999) was consistent with estimates of N(E) reported for 1992-2002. These results, coupled with in-depth census and exploitation data, show that the genetic characteristics of Escanaba Lake S. vitreus have changed substantially and that management activities, such as supplemental stocking and harvest practices, have profoundly influenced the genetic dynamics of S. vitreus in this lake.

BCRP expression does not result in resistance to STX140 in vivo, despite the increased expression of BCRP in A2780 cells in vitro after long-term STX140 exposure

The anti-proliferative and anti-angiogenic properties of the endogenous oestrogen metabolite, 2-methoxyoestradiol (2-MeOE2), are enhanced in a series of sulphamoylated derivatives of 2-MeOE2. To investigate possible mechanisms of resistance to these compounds, a cell line, A2780.140, eightfold less sensitive to the 3,17-O,O-bis-sulphamoylated derivative, STX140, was derived from the A2780 ovarian cancer cell line by dose escalation. Other cell lines tested did not develop STX140 resistance. RT-PCR and immunoblot analysis demonstrated that breast cancer resistance protein (BCRP) expression is dramatically increased in A2780.140 cells. The cells are cross-resistant to the most structurally similar bis-sulphamates, and to BCRP substrates, mitoxantrone and doxorubicin; but they remain sensitive to taxol, an MDR1 substrate, and to all other sulphamates tested. Sensitivity can be restored using a BCRP inhibitor, and this pattern of resistance is also seen in a BCRP-expressing MCF-7-derived cell line, MCF-7.MR. In mice bearing wild-type (wt) and BCRP-expressing tumours on either flank, both STX140 and mitoxantrone inhibited the growth of the MCF-7wt xenografts, but only STX140 inhibited growth of the MCF-7.MR tumours. In conclusion, STX140, a promising orally bioavailable anti-cancer agent in pre-clinical development, is highly efficacious in BCRP-expressing xenografts. This is despite an increase in BCRP expression in A2780 cells in vitro after chronic dosing with STX140.

The in vivo properties of STX243: a potent angiogenesis inhibitor in breast cancer

The steroidal-based drug 2-ethyloestradiol-3,17-O,O-bis-sulphamate (STX243) has been developed as a potent antiangiogenic and antitumour compound. The objective of this study was to ascertain whether STX243 is more active in vivo than the clinically relevant drug 2-methoxyoestradiol (2-MeOE2) and the structurally similar compound 2-MeOE2-3,17-O,O-bis-sulphamate (STX140). The tumour growth inhibition efficacy, antiangiogenic potential and pharmacokinetics of STX243 were examined using four in vivo models. Both STX243 and STX140 were capable of retarding the growth of MDA-MB-231 xenograft tumours (72 and 63%, respectively), whereas no inhibition was observed for animals treated with 2-MeOE2. Further tumour inhibition studies showed that STX243 was also active against MCF-7 paclitaxel-resistant tumours. Using a Matrigel plug-based model, in vivo angiogenesis was restricted with STX243 and STX140 (50 and 72%, respectively, using a 10 mg kg(-1) oral dose), thereby showing the antiangiogenic activity of both compounds. The pharmacokinetics of STX243 were examined at two different doses using adult female rats. The compound was orally bioavailable (31% after a single 10 mg kg(-1) dose) and resistant to metabolism. These results show that STX243 is a potent in vivo drug and could be clinically effective at treating a number of oncological conditions.

2-Methoxyoestradiol-3,17-O,O-bis-sulphamate and 2-deoxy-D-glucose in combination: a potential treatment for breast and prostate cancer

Drug combination therapy is a key strategy to improve treatment efficacy and survival of cancer patients. In this study the effects of combining 2-methoxyoestradiol-3,17-O,O-bis-sulphamate (STX140), a microtubule disruptor, with 2-deoxy-D-glucose (2DG) were assessed in MCF-7 (breast) and LNCaP (prostate) xenograft models in vivo. In mice bearing MCF-7 xenografts, daily p.o. administration of STX140 (5 mg kg⁻¹) resulted in a 46% (P<0.05) reduction of tumour volume. However, the combination of STX140 (5 mg kg⁻¹ p.o.) and 2DG (2 g kg⁻¹ i.p.) reduced tumour volume by 76% (P<0.001). 2-Methoxyoestradiol-3,17-O,O-bis-sulphamate also reduced tumour vessel density. 2-Deoxy-D-glucose alone had no significant effect on tumour volume or vessel density. A similar benefit of the combination treatment was observed in the LNCaP prostate xenograft model. In vitro the degree of inhibition of cell proliferation by STX140 was unaffected by oxygen concentrations. In contrast, the inhibition of proliferation by 2DG was enhanced under hypoxia by 20 and 25% in MCF-7 and LNCaP cells, respectively. The combination of STX140 and 2DG in LNCaP cells under normoxia or hypoxia inhibited proliferation to a greater extent than either compound alone. These results suggest that the antiangiogenic and microtubule disruption activities of STX140 may make tumours more susceptible to inhibition of glycolysis by 2DG. This is the first study to show the benefit of combining a microtubule disruptor with 2DG in the two most common solid tumours.

Development and piloting of an acceptability questionnaire for continuous glucose monitoring devices

BACKGROUND

User acceptability of new health technologies is important in determining their widespread use and adoption. The aim of this current study was twofold: first, to investigate the acceptability of two continuous glucose monitoring devices for people with diabetes; and second, to develop a valid questionnaire measure to assess the acceptability of continuous glucose monitoring devices.

METHODS

Semi-structured interviews were conducted with six people with diabetes who had previously used the GlucoWatchBiographer (Animas Corp., West Chester, PA) or the CGMS continuous glucose monitoring system (Medtronic MiniMed, Northridge, CA) in order to increase understanding of the issues relating to acceptability of, and satisfaction with, the devices. Interview transcripts were analyzed qualitatively using framework analysis. These analyses, together with consultation with researchers and health professionals in the field, provided the foundation for development of a questionnaire measure that was piloted with 19 individuals.

RESULTS

Six broad themes were elicited from the framework analysis: interference with daily activities; reliability and accuracy of the devices; practicality and ease of use; improvements in glycemic control; side effects; and self-consciousness and disclosure. Piloting of the questionnaire arising from this analysis demonstrated face validity. Further psychometric testing of the questionnaire will be conducted as part of a randomized controlled trial evaluating the clinical efficacy and cost-effectiveness of the CGMS and GlucoWatch G2 Biographer.

CONCLUSIONS

Ultimately it is the user's preferences and his or her assessment of acceptability that will determine uptake and use of continuous glucose monitoring devices. It is therefore essential to consider and evaluate this alongside clinical efficacy and cost-effectiveness.

Evaluation of an alternative S100b assay for use in cardiac surgery: relationship with microemboli and neuropsychological outcome

INTRODUCTION

The aim of the study was to investigate the relationship between S100b release, neuropsychological outcome and cerebral microemboli. Peri-operative assay of the astroglial cell protein S100b has been used as a marker of cerebral damage after cardiac surgery but potential assay cross-reactivity has limited its specificity. The present study uses an alternative enzyme-linked immunoabsorbant assay (ELISA) for serum S100b that has documented sensitivity and specificity data in patients undergoing coronary artery bypass grafting (CABG).

METHODS

Fifty-five consecutive patients undergoing routine CABG surgery received serial venous S100b sampling at five time points: i) Pre-operative, ii) At the end of cardiopulmonary bypass (CPB), iii) 6 hrs, iv) 24 hrs and v) 48 hrs post skin closure. A previously described sandwich ELISA with monoclonal anti- S100b was used. This assay has a lower limit of detection of 0.04 microg/L and < 0.006% reactivity with S100a at a concentration of 100 microg/L S100a. Cerebral microemboli during surgery were recorded by transcranial Doppler monitor over the right middle cerebral artery. Evidence of cerebral impairment was obtained by comparing patients' performance in a neuropsychological battery of 9 tests administered 6-8 weeks post-operatively with their pre-operative scores.

RESULTS

There was a significant increase in S100b only at the end of bypass (mean 0.30 microg/L, SD +/- 0.33 and range .00 to 1.57). S100b levels at the end of bypass did not correlate with neuropsychological outcome or microemboli counts.

CONCLUSIONS

The low levels of S100b detected using the present assay, despite its high sensitivity and despite the routine use of cardiotomy suction, suggest that the assay may have higher specificity for cerebral S100b than previously used assays. There was no evidence that this assay is related to neuropsychological change or cerebral microemboli in cardiac surgery.

Aerosol delivery of ergotamine tartrate via a breath-synchronized plume-control inhaler in humans

OBJECTIVE

To compare systemic delivery of ergotamine tartrate (ET) via a breath-synchronized, plume-control inhaler (BSPCI) (Tempo ET) with a sublingual ergot preparation and a commercial inhaler.

METHODS

Study 1 determined plasma ET concentrations in seven healthy subjects after administration of ET by a 2 mg tablet (Lingraine) and a BSPCI delivering 258 microg of ET. Study 2 determined plasma ET concentrations in 16 healthy subjects after administration via an ET metered dose inhaler (ME) (Medihaler) delivering 2052 microg of ET and a BSPCI delivering 129 microg of ET. Gamma scintigraphy with (99m)Tc validation was used to quantify lung deposition.

RESULTS

For both studies, ET C(max) was higher with the BSPCI (study 1: sublingual ET 134 pg/mL at 37 min; BSPCI 3743 pg/mL at 3 min; study 2: metered-dose inhaler 1109 pg/mL at 4 min; BSPCI 1210 pg/mL at 2.5 min). Mean dose normalized AUC was several-fold higher with the BSPCI compared with sublingual ET and ME dosing. Lung deposition of ET with the BSPCI was 33.5, 8.9, 11.4, and 13.2% for whole, central, intermediate, and peripheral lung, respectively, with a 1.5 peripheral : central ratio.

CONCLUSION

Based on these open-label studies, the BSPCI allows rapid delivery of potentially therapeutic plasma concentrations of ET at approximately 1/15th the dose of comparators.

The therapeutic potential of a series of orally bioavailable anti-angiogenic microtubule disruptors as therapy for hormone-independent prostate and breast cancers

Therapies for hormone-independent prostate and breast cancer are limited, with the effectiveness of the taxanes compromised by toxicity, lack of oral bioavailability and drug resistance. This study aims to identify and characterise new microtubule disruptors, which may have improved efficacy relative to the taxanes in hormone-independent cancer. 2-Methoxy-3-O-sulphamoyl-17β-cyanomethyl-oestra-1,3,5(10)-triene (STX641), 2-methoxy-3-hydroxy-17β-cyanomethyl-oestra-1,3,5(10)-triene (STX640) and 2-methoxyoestradiol-3,17-O,O-bis-sulphamate (STX140) were all potent inhibitors of cell proliferation in a panel of prostate and breast cancer cell lines. STX641 and STX640 significantly inhibited tumour growth in the MDA-MB-231 xenograft model. STX641 inhibited both in vitro and in vivo angiogenesis. Despite good in vivo activity, STX641 was not as potent in vivo as STX140. Therefore, STX140 was evaluated in the prostate hormone-independent PC-3 xenograft model. STX140 had superior efficacy to docetaxel, 2-MeOE2 and bevacizumab. In contrast to vinorelbine, no significant toxicity was observed. Furthermore, STX140 could be dosed daily over a 60-day period leading to tumour regression and complete responses, which were maintained after the cessation of dosing. This study demonstrates that STX641 and STX140 have considerable potential for the treatment of hormone-independent breast and prostate cancer. In contrast to the taxanes, STX140 can be dosed orally, with no toxicity being observed even after prolonged daily dosing.

In vivo inhibition of angiogenesis by sulphamoylated derivatives of 2-methoxyoestradiol

Drugs that inhibit growth of tumours and their blood supply could have considerable therapeutic potential. 2-Methoxyoestradiol-3,17-O,O-bis-sulphamate (2-MeOE2bisMATE) has been shown to inhibit the proliferation of MCF-7 (ER+) breast cancer cells and angiogenesis in vitro. 2-MeOE2bisMATE and its analogue, 17-Cym-2-MeOE2MATE, were investigated for their ability to inhibit in vivo angiogenesis and tumour growth. The mouse Matrigel plug assay for angiogenesis was used to investigate the effect of compounds on neovascularisation and was quantified using a FITC-dextran injection technique. Nude mice bearing tumours derived from MCF-7 cells were used to assess efficacy on tumour growth. Tumour sections were stained for VEGFR-2 and Ki67 to assess tumour angiogenesis and cell proliferation respectively. Matrigel plugs supplemented with basic fibroblast growth factor resulted in increased neovascularisation over 7 days. Oral administration of 2-MeOE2bisMATE for 7 days at 10 or 50 mg kg(-1) significantly reduced neovascularisation to or below control levels respectively. 17-Cym-2-MeOE2MATE at 20 mg kg(-1) was equally effective. 2-MeOE2bisMATE, dosed daily for 21 days, caused a 52% reduction in tumour growth at 5 mg kg(-1) and 38% regression at 20 mg kg(-1). 17-Cym-2-MeOE2MATE (20 mg kg(-1)) reduced tumour growth by 92%. Immunohistochemistry revealed a reduction in angiogenesis and proliferation. Matrigel plug and tumour imaging after FITC-dextran injection indicated that 2-MeOE2bisMATE caused a marked disruption of vasculature. These sulphamoylated oestrogen derivatives have been shown to be potent inhibitors of angiogenesis in vivo. This, together with their ability to inhibit tumour growth, indicates the potential of this new class of drugs for further development for cancer therapy.

Carers Assessment of Difficulties Index (CADI): psychometric properties for use with carers of people with dementia

Burden is a commonly recognised phenomenon in family caring. The Carers Assessment of Difficulties Index (CADI) was developed as a clinical tool for assessing the multiple dimensions of carer burden. It has been used with a number of caring cohorts, but its psychometric properties have not been explored specifically with carers of people with dementia. The 30-item CADI was administered to 232 carers of people with dementia with the aim of assessing the suitability of the frequency scale for clinical and research use with this population. The psychometric properties were examined, including descriptive data, a principal components analysis (PCA), and a reliability analysis on the resultant components. All items were experienced by some participants, but no item was experienced by all. An 8- factor solution from the PCA explained 59% of the variance. Eight subscales were established with good internal consistency. It is concluded that the CADI is suitable for both clinical and research use with carers of people with dementia.

The regulation and inhibition of 17beta-hydroxysteroid dehydrogenase in breast cancer

17Beta-hydroxysteroid dehydrogenase Type 1 (17beta-HSD1) has a pivotal role in regulating the synthesis of oestradiol (E2) within breast tumours. In whole body studies in postmenopausal women with breast cancer the conversion of oestrone (E1) to E2 (4.4+/-1.1%) was much lower than the inactivation of E2 to E1 (17.3+/-5.0%). In contrast, an examination of in vivo oestrogen metabolism within breast tumours revealed that whereas little metabolism of E2 occurred, E1 was converted to E2 to a much greater extent in malignant (48+/-14%) than in normal (19+/-6%) breast tissue. Findings from these studies originally suggested that oestrogen metabolism within breast tumours may differ from the mainly oxidative direction found in most other body tissues and that the activity of 17beta-HSD1 might be regulated by tumour-derived factors. Several growth factors (e.g. IGF-I, IGF-II) and cytokines (e.g. IL-6, TNFalpha) have now been identified which can markedly stimulate the activity of 17beta-HSD1 and such a mechanism may account for the high concentrations of E2 found in most breast tumours. Cells of the immune system, which can infiltrate breast tumours, are thought to be a major source of the growth factors and cytokines which can modulate 17beta-HSD1 activity. Given the central role that 17beta-HSD1 has in regulating breast tumour E2 concentrations the development of potent inhibitors of this enzyme has recently attracted considerable attention. Our initial studies in this area explored the use of derivatives of E1 as inhibitors, with 2-ethyl- and 2-methoxy E1 being found to inhibit 17beta-HSD1 activity in T-47D breast cancer cells by 96+/-2 and 91+/-1% respectively at 10 microM, but with a lack of specificity. Using the E1 scaffold a number of potent, selective 17beta-HSD1 inhibitors have now been identified including E1- and 2-ethyl-E1 containing a side chain with a m-pyridylmethylamidomethyl functionality extending from the 16beta position of the steroid nucleus. At 10 microM these compounds both inhibited 17beta-HSD1 activity by >90%, however some inhibition of 17beta-HSD2 activity was exhibited by the E1 derivative (25%) but not the 2-ethyl analogue. It is now apparent that 17beta-HSD1 activity contributes to the high E2 concentrations found in most breast tumours. The identification of potent, selective novel 17beta-HSD1 inhibitors will allow their efficacy to be tested in in vitro and in vivo studies.

Steroid sulfatase: molecular biology, regulation, and inhibition

Steroid sulfatase (STS) is responsible for the hydrolysis of aryl and alkyl steroid sulfates and therefore has a pivotal role in regulating the formation of biologically active steroids. The enzyme is widely distributed throughout the body, and its action is implicated in physiological processes and pathological conditions. The crystal structure of the enzyme has been resolved, but relatively little is known about what regulates its expression or activity. Research into the control and inhibition of this enzyme has been stimulated by its important role in supporting the growth of hormone-dependent tumors of the breast and prostate. STS is responsible for the hydrolysis of estrone sulfate and dehydroepiandrosterone sulfate to estrone and dehydroepiandrosterone, respectively, both of which can be converted to steroids with estrogenic properties (i.e., estradiol and androstenediol) that can stimulate tumor growth. STS expression is increased in breast tumors and has prognostic significance. The role of STS in supporting tumor growth prompted the development of potent STS inhibitors. Several steroidal and nonsteroidal STS inhibitors are now available, with the irreversible type of inhibitor having a phenol sulfamate ester as its active pharmacophore. One such inhibitor, 667 COUMATE, has now entered a phase I trial in postmenopausal women with breast cancer. The skin is also an important site of STS activity, and deficiency of this enzyme is associated with X-linked ichthyosis. STS may also be involved in regulating part of the immune response and some aspects of cognitive function. The development of potent STS inhibitors will allow investigation of the role of this enzyme in physiological and pathological processes.

The effects of 2-methoxyoestrogen sulphamates on the in vitro and in vivo proliferation of breast cancer cells

2-Methoxyoestrogen sulphamates are a new class of compounds, which inhibit breast cancer cell proliferation and are also potent inhibitors of steroid sulphatase (STS) activity. In the present study, we have used two cell proliferation assays (MTS and AB) to identify potent new compounds in this class. Similar IC(50) values were obtained using these assays with two of the most potent compounds identified being 2-methoxyoestradiol-bis-sulphamate (2-MeOE2bisMATE) and 2-methoxyoestradiol-17beta-cyanomethyl-3-O-sulphamate (2-MeOE2CyMATE). Both compounds inhibited the proliferation of MCF-7 (ER+) and MDA-MB-231 (ER-) breast cancer cells. Using the AB assay, which allows repeat measurements of cell proliferation without killing cells, both compounds were shown to inhibit cell proliferation in an irreversible manner. As STS may be involved in the removal of the sulphamoyl moiety of these compounds, which could reduce their potency, their ability to inhibit the proliferation of MCF-7 cells transfected with the cDNA for STS was also examined. Although the STS activity was 20-fold higher in these cells than in non-transfected MCF-7 cells, no decrease in the ability of these compounds to inhibit cell proliferation was detected. To test the efficacy of these compounds in vivo, nude mice were inoculated with MCF-7 cells in Matrigel and stimulated to grow with oestradiol. Three weeks after the oral administration of 2-MeOE2bisMATE or 2-MeOE2CyMATE (20mg/kg/day, 5 days/week) tumour volumes had regressed by 52% and 22%, respectively. Both compounds also inhibited liver and tumour STS activity by >90%. The potent anti-proliferative effects of these compounds, and their ability to inhibit tumour growth and STS activity in vivo, indicates that they are suitable for development as novel therapeutic agents, which should be active against a wide range of cancers.

NEGATIVE MATERNAL OR PATERNAL EFFECTS ON TACTIC INHERITANCE UNDER A CONDITIONAL STRATEGY

Alternative behavioral and life-history tactics are common in animal populations. The conditional strategy model provides a powerful explanation for the evolution and persistence of such tactics, as it allows alternative tactics to be perpetuated even if there is tactic inheritance and tactics yield unequal mean fitness. In many biological systems negative maternal or paternal effects complicate the inheritance of condition and, hence, the inheritance of alternative tactics. Indeed, the inheritance of condition may result in the alternation of tactics across generations. In this paper, we show that the conditional strategy is robust to these effects on progeny condition. There is a unique and stable proportion of tactics under standard inheritance and unequal tactic fitness, and these two important properties of the conditional strategy hold even if negative maternal or paternal effects on progeny condition cause tactics to alternate across generations. However, the dynamics of tactic proportions pursuant to a perturbation of the equilibrium tactic proportions depend on the form of tactic inheritance. An application of our theoretical results to data from a population of smallmouth bass (Micropterus dolomieu) in which negative paternal effects dictate progeny condition reveals that age at first reproduction in males alternates regularly across generations. Furthermore, the model indicates that the population would return rapidly to equilibrium if the proportions of males that mature early or late in life were perturbed from the equilibrium within the system. This example shows how the model of the conditional strategy can be used to gain insight into tactic dynamics in situations where some of the model parameters are difficult or impossible to measure empirically.

Pharmacokinetics and efficacy of 2-methoxyoestradiol and 2-methoxyoestradiol-bis-sulphamate in vivo in rodents

2-Methoxyoestradiol (2-MeOE2) is an endogenous oestrogen metabolite that inhibits the proliferation of cancer cells in vitro, and it is also antiangiogenic. In vivo 2-MeOE2, when administered at relatively high doses, inhibits the growth of tumours derived from breast cancer cells, sarcomas and melanomas. Sulphamoylated derivatives of 2-MeOE2 are more potent inhibitors of in vitro breast cancer cell growth than 2-MeOE2. In the present study, we have compared the pharmacokinetic profiles and metabolism of 2-MeOE2 and its sulphamoylated derivative, 2-methoxyoestradiol-bis-sulphamate (2-MeOE2bisMATE), in adult female rats. Their ability to inhibit tumour growth was compared in nude mice bearing xenografts derived from MDA-MB-435 (oestrogen receptor negative) melanoma cancer cells. After a single oral 10 mg kg⁻¹ dose of 2-MeOE2bisMATE, significant concentrations of this compound were still detectable at 24 h. In contrast, no 2-MeOE2 or metabolites were detected in plasma at any time after a 10 mg kg⁻¹ oral dose. Thus, the bioavailability of 2-MeOE2 is very low, whereas for 2-MeOE2bisMATE it was 85%. No significant metabolites of 2-MeOE2bisMATE were detected in plasma after oral or intravenous dosing, showing that this drug is resistant to metabolism. In the tumour efficacy model, oral administration of 2-MeOE2bisMATE, at 20 mg kg⁻¹ day⁻¹ daily for 28 days, almost completely inhibited tumour growth. Inhibition of tumour growth was maintained for a further 28 days after the cessation of dosing. At this dose level, 2-MeOE2 did not inhibit tumour growth. The resistance to metabolism shown by 2-MeOE2bisMATE and its ability to inhibit tumour growth in vivo suggest that this compound should have considerable potential for development as a novel anticancer drug.

Steroid sulphatase inhibitors for breast cancer therapy

In contrast to aromatase inhibitors, which are now in clinical use, the development of steroid sulphatase (STS) inhibitors for breast cancer therapy is still at an early stage. STS regulates the formation of oestrone from oestrone sulphate (E1S) but also controls the hydrolysis of dehydroepiandrosterone sulphate (DHEA-S). DHEA can be reduced to 5-androstenediol (Adiol), a steroid with potent oestrogenic properties. The active pharmacophore for potent STS inhibitors has now been identified, i.e. a sulphamate ester group linked to an aryl ring. This has led to the development of a number of STS inhibitors, some of which are due to enter Phase I trials in the near future. Such first generation inhibitors include the tricyclic coumarin-based 667 COUMATE. Aryl sulphamates, such as 667 COUMATE, are taken up by red blood cells (rbc), binding to carbonic anhydrase II (CA II), and transit the liver without undergoing first-pass inactivation. 667 COUMATE is also a potent inhibitor of CA II activity with an IC50 of 17 nM. Second generation STS inhibitors, such as 2-methoxyoestradiol bis-sulphamate (2-MeOE2bisMATE), in addition to inhibiting STS activity, also inhibit the growth of oestrogen receptor negative (ER-) tumours in mice and are anti-angiogenic. As the active pharmacaphores for the inhibition of aromatase and STS are now known it may be possible to develop third generation inhibitors that are capable of inhibiting the activities of both enzymes. Whilst exploring the potential of such a strategy it was discovered that 667 COUMATE possessed weak aromatase inhibitory properties with an IC50 of 300 nM in JEG-3 cells. The identification of potent STS inhibitors will allow the therapeutic potential of this new class of drug to be explored in post-menopausal women with hormone-dependent breast cancer. Second generation inhibitors, such as 2-MeOE2bisMATE, which also inhibit the growth of ER- tumours should be active against a wide range of cancers.

The effects of 2-methoxy oestrogens and their sulphamoylated derivatives in conjunction with TNF-alpha on endothelial and fibroblast cell growth, morphology and apoptosis

2-methoxyoestradiol (2-MeOE2) is a potent anti-angiogenic agent. Its 3- and 17-sulphamoylated derivatives have been demonstrated to induce G2-M cell cycle arrest and apoptosis in breast cancer cells in vitro as well as tumour regression in rats in vivo with greater potency than the parent oestrogen. To determine whether the anti-cancer properties of these derivatives can be synergistically enhanced with low-dose TNF-alpha co-treatment, we investigated the effects of these treatments in adult human fibroblasts and human umbilical vein endothelial cells (HUVECs). Treatment of fibroblasts with 0.1 microM 2-methoxyoestradiol-3,17-bis sulphamate (2-MeOE2bisMATE) but not 2-MeOE2 caused a reversible morphology change and induced G2-M arrest (from 12 to 33%) but not subsequent apoptosis. In contrast, treatment of HUVECs did not induce morphology change or G2-M arrest. Using a nucleosomal ELISA assay, we showed that TNF-alpha (20 ng/ml) combination treatment synergistically increases 0.1 microM 2-MeOE2bisMATE-induced but not 0.1 microM 2-MeOE2-induced apoptosis in HUVECs. These results suggest that TNF-alpha co-treatment may be a beneficial method of increasing the potency of 2-substituted oestrogens as anti-angiogenic agents through synergistic induction of apoptosis in endothelial cells while maintaining low cytotoxicity to fibroblasts.

Inhibition of carbonic anhydrase II by steroidal and non-steroidal sulphamates

Carbonic anhydrases (CAs) are expressed by many solid tumours where they may act to confer a growth advantage on malignant tissues. In this study we have examined the ability of a series of steroidal and non-steroidal sulphamates (originally developed as steroid sulphatase inhibitors) and related compounds to inhibit human CAII (hCAII) activity in vitro. Using a 96-well plate assay, oestrone-3-O-sulphamate (EMATE) and two coumarin-based sulphamate drugs (667 COUMATE and STX 118) were found to have IC(50) values of 25-59 nM for the inhibition of hCAII activity. These compounds therefore have a similar CAII inhibitory potency to that of acetazolamide (IC(50)=25 nM), a known hCAII inhibitor. Docking studies have been performed with selected compounds to the crystal structure of hCAII and excellent correlation of scores with biological activity was observed. This agrees with our recent observations when we were the first to report the inhibition of hCAII by STS inhibitors. These studies and initial results with docking to the crystal structure of the extracellular domain of hCAXII indicate that the STS sulphamate ester inhibitors should also be interesting candidates to pursue as inhibitors of CA isozymes that are over-expressed in human tumours.

Growth inhibition of multi-drug-resistant breast cancer cells by 2-methoxyoestradiol-bis-sulphamate and 2-ethyloestradiol-bis-sulphamate

There is currently considerable interest in the use of the endogenous oestrogen metabolite, 2-methoxyoestradiol (2-MeOE2) for the treatment and prevention of breast cancer. We have previously shown that sulphamoylation of 2-MeOE2 and related derivatives greatly enhances their ability to inhibit the proliferation of ER+ and ER- breast cancer cells. In this study, we have compared the abilities of 2-methoxyoestradiol-bis-sulphamate (2-MeOE2bisMATE) and 2-ethyloestradiol-bis-sulphamate (2-EtE2bisMATE) with that of 2-MeOE2 to inhibit the proliferation of breast cancer cells when grown on three different substrata: plastic, collagen I and Matrigel. The human breast cell line MCF-7 was utilised for these studies together with its doxorubicin resistant variant, MCF-7 DOX40 and mitoxantrone resistant variant, MCF-7 MR, as a longitudinal model of in vitro drug resistance. On a plastic substratum all three cell lines were sensitive to the effects of 2-MeOE2bisMATE and 2-EtE2bisMATE whereas MCF-7 cells and the MCF-MR variant cells were resistant to the effects of 2-MeOE2 at 1 microM. The sensitivity of the cell lines to those compounds also remained significant when grown on more physiological substrata. All of the drugs tested arrested cells in the G2/M phase of the cell cycle. The finding that breast cancer cells that are resistant to conventional chemotherapeutic agents remain sensitive to 2-substituted oestrogen sulphamates offers considerable potential for the treatment of women with drug-resistant breast cancer.

Genetic screening for Alzheimer's disease: what factors predict intentions to take a test?

The authors investigated factors that predict intention to take a genetic test for Alzheimer's disease (AD). The 449 men and women were surveyed in two groups: (a) those told that a positive result meant a 90% chance of developing AD (increased certainty) and (b) those told that a positive result meant a 50% chance of developing AD (decreased certainty). Participants completed measures of the Theory of Planned Behavior (TPB), anticipated regret, risk perception, likelihood of taking a genetic test for cancer, and AD risk factors. Just over 50% of the variance in intentions was related to TPB variables, likelihood of taking a genetic test for cancer, number of people the participants knew who had AD, experimental condition, and anticipated regret. The subjective norm was the strongest predictor of intention in the increased certainty group, whereas positive belief was the strongest predictor in the decreased certainty group.

Evolution of dry powder inhaler design, formulation, and performance

Many companies are now prioritizing the development of dry powder inhalers (DPIs) above pressurized formulations of asthma drugs. A well-designed DPI and an appropriate powder formulation can optimize the effectiveness of inhaled drug therapy. A DPI must be able to deliver medications effectively for most patients, and an ideal inhaler would provide a dose that does not vary with inspiratory flow rate. Recent regulatory guidelines, among which the U.S. FDA draft guidance is the most stringent, demand consistent dose delivery from an inhaler throughout its life and consistency of doses from one inhaler to another. However, the properties of free micronized powders often interfere with drug handling and with drug delivery reducing dose consistency. Recent advances in formulation technology can increase lung dose and reduce its variability. While a perfect DPI may never exist, both device and formulation technology are evolving to rectify perceived deficiencies in earlier systems.

Neuroprotection during cardiac surgery: strategies to reduce cognitive decline

Although the population receiving cardiac surgery is older and therefore more prone to cognitive deterioration, these difficulties have declined over the last ten years. It is likely that the multiple changes introduced to cardiac surgery over time have had a cumulative benefit in protecting the brain. The most likely causes of cognitive difficulties are microemboli delivered to the brain during surgery, altered cerebral perfusion and an inflammatory response. The interventions that have been implemented can be divided into those which have attempted to reduce the potential causes of damage and those aimed at reducing the impact by attempting to protect the brain. The evidence for three main types of intervention (equipment, techniques and drugs) is reviewed in this paper. Although many interventions are available only a few have shown a clear benefit. Progress in the future will require larger studies to address this multifactorial problem.

A brief history of gamma scintigraphy

Gamma scintigraphy involves the radiolabeling of inhaled drug formulations, followed by in vivo imaging of deposition in two dimensions. This permits whole lung deposition to be quantified as mass of drug or percentage of the dose, and regional deposition patterns to be assessed. Gamma scintigraphy is the method by which the majority of inhaled drug deposition data have been obtained, and scintigraphic studies have become viewed as milestone assessments in the development of new pulmonary drug products. Lung deposition data are used to show "proof of concept" in vivo for these products, and act as a bridge between in vitro laboratory testing and a clinical trials program. Gamma scintigraphy is likely to remain the method of choice for assessing inhaled drug deposition for some time to come.

Deposition and pharmacokinetics of an HFA formulation of triamcinolone acetonide delivered by pressurized metered dose inhaler

Novel formulations of asthma drugs contained in pressurized metered dose inhalers (pMDIs) are being developed containing hydrofluoroalkane (HFA) propellants. The objectives of this study were to assess the deposition in the lungs and oropharynx of triamcinolone acetonide (TAA; Azmacort, Aventis Pharma, Collegeville, PA) delivered by pMDI formulated with HFA-134a, together with the pharmacokinetic profile of TAA, and to determine the extent to which the Azmacort spacer improves targeting of TAA to the lungs. The deposition of TAA, labelled with 99mTc, was assessed by gamma scintigraphy in 10 patients with mild to moderate asthma (mean forced expiratory volume in one second [FEV1] 76% predicted), who received in randomized order three delivered (ex-device) doses of 75 microg TAA via pMDI coupled to an Azmacort spacer (TAA-spacer), and three delivered doses of 230 microg TAA via the same device, but with the spacer removed (TAA-no spacer). Mean lung deposition expressed as mass of drug was similar for each regimen (TAA-no spacer 175 microg; TAA-spacer 188 microg), but when expressed as percentage delivered dose, lung deposition was higher for TAA-spacer (53.8%) versus TAA-no spacer (26.0%), indicating superior drug targeting for TAA-spacer. The spacer reduced oropharyngeal deposition. The pharmacokinetic data showed higher plasma levels of drug for TAA-no spacer, resulting from higher oropharyngeal deposition. "Pharmacoscintigraphic" data showed proof of concept for a novel HFA delivery system for an inhaled corticosteroid based on pulmonary targeting of drug.

Comparison of beclomethasone dipropionate delivery by easyhaler dry powder inhaler and pMDI plus large volume spacer

Dry powder inhalers (DPIs) provide a means of delivering inhaled asthma drugs without the use of propellants. Easyhaler is a multidose DPI, delivering 200 doses of beclomethasone dipropionate (BDP), 200 microg/dose. A gamma scintigraphic study has been carried out in 10 healthy volunteers to compare the deposition of BDP from Easyhaler with that from a pressurized metered dose inhaler (pMDI) coupled to a Volumatic spacer device delivering 250 microg BDP per dose. The spacer was used without any pretreatment to reduce static charge on the spacer walls. The study was conducted according to an open, randomized, crossover design. The volunteers inhaled the study drug using optimal inhalation technique for both devices. Lung deposition of 99mTc-labeled BDP averaged 18.9% (SD 9.5%) of the metered dose for Easyhaler, and 11.2% (SD 5.3%) for pMDI plus spacer (p < 0.05); when the data were expressed as mass of BDP deposited in the lungs, the difference in lung deposition just failed to reach statistical significance (Easyhaler 37.8 microg; pMDI plus spacer 28.0 microg). Oropharyngeal deposition was significantly reduced by use of the spacer. The results of this study show that Easyhaler delivers drug more efficiently to the lungs than pMDI plus Volumatic spacer when no measures are taken to eliminate static charge on the spacer walls.

Deposition and pharmacokinetics of flunisolide delivered from pressurized inhalers containing non-CFC and CFC propellants

Our objective was to assess the deposition and pharmacokinetics of a novel formulation of flunisolide (Aerobid, Forest Laboratories) in hydrofluoroalkane (HFA) 134a delivered by pressurized metered dose inhaler (pMDI). The design was a two-way crossover investigation in 12 healthy male subjects comparing HFA-134a flunisolide by pMDI versus pMDI plus 50 mL spacer device. Four of these subjects also took part in a two-way crossover investigation comparing chlorofluorocarbon (CFC) flunisolide pMDI versus pMDI plus Aerochamber holding chamber. The imaging technique of gamma scintigraphy was used to quantify total and regional lung deposition of flunisolide. Plasma levels of flunisolide and its major metabolite (6beta-OH flunisolide) were also determined. The spacer and Aerochamber reduced oropharyngeal deposition dramatically for both the HFA and CFC products (mean 59.8 to 14.9% (p < 0.01) of ex-valve (metered) dose for HFA product; 66.3 to 12.3% (p < 0.01) of ex-valve dose for CFC product) owing to deposition of part of the dose on the walls of the add-on devices themselves. Lung deposition averaged 22.6 and 40.4% (p < 0.01) of the ex-valve dose for the HFA formulation used with pMDI alone and with pMDI plus spacer. Mean lung deposition of the CFC formulation delivered via the Aerochamber (mean 23.4%) was higher than that for the CFC pMDI alone (mean 17.0%), but this difference was not statistically significant. Lung deposition expressed as percentage ex-device (delivered) dose averaged 68.3% for HFA pMDI plus spacer and 19.7% for CFC pMDI. Plasma levels of flunisolide were higher for the pMDI plus spacer than for pMDI alone, reflecting higher lung deposition via the spacer, but plasma levels of the 6beta-OH flunisolide metabolite were higher for the pMDI alone as a consequence of higher oropharyngeal deposition. When delivered via the spacer, pulmonary targeting of the flunisolide HFA formulation was improved compared with the CFC formulation, which should benefit patients by providing satisfactory asthma therapy from a much-reduced delivered dose of flunisolide.

Inhibition of oestrone sulphatase activity by tibolone and its metabolites

Tibolone is a 19-nortestosterone derivative commonly used in hormone replacement therapy. Although tibolone and its 3alpha/beta-hydroxy metabolites exert oestrogenic effects on bone and the vasomotor system, they do not appear to stimulate breast tissue proliferation. It has been proposed that the lack of an oestrogenic effect on breast tissues may result from the inhibition of oestrone sulphatase (E1-STS) in this tissue by tibolone and its metabolites. In this study we have examined the ability of tibolone and its metabolites to inhibit E1-STS activity in intact breast cancer cells, its effect on E1-STS activity in placental microsomes and also the expression of E1-STS mRNA in more detail. As the major proportion of hydroxytibolone metabolites circulate in a sulphated form, the ability of the 3alpha-sulphate and 3alpha,17beta-disulphate metabolites to inhibit E1-STS activity was also examined. In MCF-7 cells, tibolone and its 3beta-hydroxylated metabolite were relatively potent inhibitors; they inhibited activity by 48 % and 46 %, respectively. In these cells, the 3alpha-sulphate and 3alpha,17beta-disulphate metabolites of tibolone inhibited E1-STS activity by 95% and 79% at 10 microM, respectively. No effects of tibolone or its metabolites on the expression of E1-STS mRNA in MCF-7 cells were detected. Using T-47D breast cancer cells, evidence was obtained that the sulphated metabolites of tibolone could continue to inhibit E1-STS activity after removal of the drugs and extensive washing of cells. In placental microsomes, however, the 3beta-hydroxy metabolite was the most potent inhibitor with an IC50 of 20.5 microM; the sulphated metabolites were less potent. Neither tibolone nor its metabolites had any inhibitory effect on the conversion of oestrone to oestradiol in breast cancer cells. Results from this study have confirmed that tibolone and its metabolites can inhibit E1-STS activity. This may explain the absence of breast stimulation as observed in clinical studies.