120. OXYGEN REGULATED GENE EXPRESSION IN MOUSE CUMULUS CELLS

Hypoxia inducible factors (HIFs) are heterodimeric transcription factors that mediate the expression of a range of genes in response to low oxygen. Previously we showed that subsequent developmental outcomes were influenced by oxygen levels during in vitro maturation. The aim of the current study was to examine the effects of varying oxygen concentration during in vitro maturation of mouse COCs on expression of HIF target genes in the cumulus cells. I mmature COCs were collected from the ovaries of eCG-stimulated CBAB6F1 females (21 d) and cultured for 17-18 h under 2, 5 or 20% O2. Hyaluronidase-treated and recovered cumulus cells were collected and mRNA extracted for analysis. A microarray approach (Affymetrix 430_2) was used to identify genes in cumulus cells that were differentially expressed under varying oxygen concentrations (2, 5, 10 and 20%). This revealed 218 differentially expressed probes, of which 34 were up-regulated with decreasing oxygen levels. The great majority of these were classified as HIF-regulated genes. Specific analysis from real time RT-PCR of HIF regulated target genes Slc2a1, Ldha, Pgk1, Eno1, Ndrg1, Bnip3 were all significantly up-regulated (by at least 5–fold) when cells were cultured at 2% or 5% oxygen, when compared to 20% oxygen. Hif-1a mRNA decreased when cumulus cells were cultured in 2%, compared to 20% oxygen. This study demonstrates that cumulus cell gene expression is influenced by oxygen concentration, and suggests that these effects are mediated by the HIF transcription factors.

Aspects of intracerebral hematomas--an update

BACKGROUND

In Norway, there are approximately 16000 strokes each year and 15% of these are caused by intracerebral hematomas. Intracerebral hemorrhage (ICH) results from the rupture of blood vessels within the brain parenchyma. ICH occurs as a complication of several diseases, the most prevalent of which is chronic hypertension. When hemorrhage develops in the absence of a pre-existing vascular malformation or brain parenchymal lesion, it is denoted primary ICH. Secondary ICH refers to hemorrhage complicating a pre-existing lesion. Primary ICH is the most common type of hemorrhagic stroke, accounting for approximately 10% of all strokes. Despite aggressive management strategies, the 30-day mortality remains high, at almost 50%, with the majority of deaths occurring within the first 2 days. At 6 months, only 20-30% achieve independent status.

MATERIAL AND METHODS

This article is based on clinical experience, modern therapeutic guidelines for the treatment of intracerebral hematomas and up-to-date medical literature found in Medline. The article discusses the pathophysiology, clinical aspects, treatment, and the prognosis of intracerebral hematomas.

RESULTS AND DISCUSSION

Advances in diagnosis, prognosis, pathophysiology, and treatment over the past few decades have significantly advanced our knowledge of ICH; however, much work still needs to be carried out. Future genetic and epidemiologic studies will help identify at-risk populations and hopefully allow for primary prevention. Randomized controlled studies focusing on novel therapeutics should help to minimize secondary injury and hopefully improve morbidity and mortality.

Needle-stick injuries in primary care in Wales

BACKGROUND

Accidental needle-stick injuries (NSIs) are a hazard for health-care workers and for the general public.

OBJECTIVES

To estimate the presentation rate of NSIs to general medical practices, their relation to practice characteristics, and review practice policies for managing NSIs.

METHOD

Descriptive study using logistic regression analysis.

RESULTS

Annual rates of 2.73 (95% CI 2.08, 3.50) occupational NSIs per 100 clinical practice staff and 2.14 (95% CI 1.39, 3.13) non-occupational NSIs per 100,000 practice population were recorded. Stepwise logistic regressions showed that chance of a practice reporting at least one occupational NSI in previous five years was best predicted by being a single-handed practice (decreased odds). In contrast, the chance of a practice reporting at least one non-occupational NSI was best predicted by being a rural practice (increased odds). About one in five practices possessed no written policy on managing NSIs. Stepwise logistic regressions showed that the chance of a practice owning a NSI policy was best predicted by being located in an LHB area with a coastline (increased odds).

CONCLUSION

NSIs are an important public health issue in Wales. We have tried to address the lack of guidance by developing new guidelines in Wales.

435. Follicle differentiation and luteinisation in the mouse is associated with hypoxia inducible factor activity

Hypoxia inducible factors (HIF) are transcription factors that mediate the response to hypoxic stress. Under hypoxic conditions, HIF is stabilised, translocates to the nucleus, and binds to the Hypoxia Response Elements (HRE) upstream of numerous target genes involved in angiogenesis and glycolysis, including Vegf, Glut-1 and Ldha. Little is known about the role of HIFs in regulating ovarian function. In rat granulosa cells, FSH stimulates HIF 1α via the PI3K/Akt pathway, demonstrating a role for HIFs during follicular development. In contrast, there is limited information regarding the role of HIFs during corpus luteum formation. In this study we investigated whether HIFs play a role in follicle differentiation and luteinisation. Prepubertal C57Bl6 females were stimulated with eCG (5 IU) followed 46 h later by hCG (5 IU). Mice were sacrificed at 0, 4, 8, 12, 16 and 24 h post hCG and granulosa cells were collected for Western analysis of HIF-1a protein. To investigate HIF activation in the ovary, a transgenic reporter mouse line was developed by lenti-viral incorporation of an HRE (4)-SV40-eGFP construct. Ovaries were collected from mice plugged day 1, 4 and 8 for CL analysis in vivo.A time- dependent increase of HIF 1α protein levels in granulosa cells, maximal around time of ovulation, was observed. Ovaries from cycling HRE-eGFP transgenic mice exhibited no eGFP in primordial, primary or preantral follicles. Upon antrum formation, eGFP was evident in occasional sections in antral follicles but HIF signalling was restricted within the theca. In contrast, corpora lutea on pregnancy day 1, 4 and 8 readily expressed eGFP and eGFP expression increases as luteinisation progresses.These results demonstrate that in vivo HIFs may play a role in folliculogenesis, but this is restricted to theca cells of antral follicles before hCG stimulation. Following hCG, maximal HIF activity is associated with the time of ovulation. In addition, HIF activity is maintained during luteinisation.

Akt-induced endocrine therapy resistance is reversed by inhibition of mTOR signaling

BACKGROUND

Resistance to endocrine therapy is a major impediment in breast cancer therapeutics. The Phosphatidylinositol-3-OH kinase (PI3K)/Protein kinase B (Akt/PKB) kinase signaling pathway has been implicated in altering breast cancer response to multiple therapies. How Akt modulates response is an area of significant clinical relevance.

METHODS

We have used an in vitro model to discern the effects of robust Akt activity on breast cancer cellular response to endocrine therapies.

RESULTS

High levels of Akt activity confer resistance to the aromatase inhibitor Letrozole (Let) and the selective estrogen receptor (ER) down-regulator Fulvestrant (ICI). Akt-induced resistance is not due to failure of these endocrine agents to inhibit estrogen receptor alpha activity. Instead, resistance is characterized by altered cell cycle and apoptotic response. Cotreatment with low concentrations of the mTOR inhibitor RAD-001 and either Let or ICI restores response of the resistant cells to levels observed in the responsive cells treated with either Let or ICI as a single agent.

CONCLUSIONS

Our preliminary findings in experiments with RAD-001 indicate that cotreatment with mTOR inhibitors and either Let or ICI reverses the Akt-mediated resistance and restores responsiveness to antiestrogens. Concurrent ER and mTOR inhibition is therefore an effective strategy to overcome growth factor-induced resistance and bears significant implications for optimal clinical development of these agents in breast cancer treatment.

In vitro abrogation of acquired tamoxifen resistance using histone deacetylase inhibitors

10607

Tamoxifen (TAM) is a highly effective therapy for breast cancer. However, only 60% of estrogen receptor expressing (ER+) breast cancers respond to TAM (40% de-novo resistance). Continuous TAM treatment causes emergence of acquired resistance in these initially- responsive cancers. Strategies that abrogate TAM-resistance are therefore of significant clinical importance. One approach being studied is the use of histone deacetylase (HDAC) inhibitors. These compounds impact tumor biology both at the level of gene transcription and protein stability. In our study, we developed an in vitro model of tamoxifen resistance to test the efficacy of a hydroxamic acid derivative, Trichostatin A (TSA) at modulating breast cancer cell growth both in TAM responsive as well as TAM resistant cells. Forty-eight MCF-7 breast cancer single-cell colonies were isolated from a heterogeneous population, with 16 of the 48 (33%) surviving 4 months of continual growth in charcoal-stripped media with 10-7 M tamoxifen. ER expression was lost in 9 (56%) and HER-2 expression was acquired in 7 (44%) of the 16 resistant clones. The ER-negative cells demonstrated a concomitant increase in p-Rb, p21 and p27 levels, as well as significant increase in activation of both the PI3K and MAP kinase pathways. These results suggest that alteration of parent cell phenotype is an adaptive event at the transcriptional level, and is a significant mechanism for mediating TAM resistance. Inhibition of growth, by TSA, was studied in both the ER+ and ER- cells, with and without cotreatment with TAM. Cotreatment with TSA effectively blocked the emergence of resistance and prolonged the duration of response to TAM. The molecular mechanisms mediating this enhanced response were studied and focused on the effects of TSA on ER and HER-2 activity and expression. Our results indicate that short term exposure to TSA induces suppression of ER gene transcription, as well as targets ER for protein degradation where as long term exposure shows paradoxical effects at the genomic level. The effects of TSA on acquired HER-2 expression are being studied. These data have important clinical ramifications for the clinical development of HDAC inhibitors for the treatment of breast cancer patients.

No significant financial relationships to disclose.

61. GP PERSPECTIVES ON PARTNER NOTIFICATION FOR CHLAMYDIA

As part of a larger, combined qualitative-quantitative study of partner notification, 40 semi-structured in-depth telephone interviews were conducted with General Practitioners (GPs), from Victoria, ACT and Queensland, who had diagnosed at least one case of chlamydia in the last year. Rural doctors and those who had experience working with Aboriginal patients were over-sampled to ensure their views were represented in the study. The interviews explored GPs' current practices with regard to partner notification for chlamydia, barriers they perceived to partner notification for chlamydia in the general practice setting and what resources/incentives they felt would improve partner notification for chlamydia. The GPs in our study primarily ask the index patient to carry out partner notification themselves. It was relatively rare for GPs to have experience of notifying partners on the patient's behalf. Half of the GPs report that they only encourage notification of the patient's current/immediate past partners. There was considerable confusion amongst the GPs interviewed as to the role of government partner notification officers. Many thought that support from a government agency would allow partner notification to occur more effectively. Some were under the impression that this process is automatically activated when they 'notify' that they have diagnosed someone with chlamydia. Some of the main barriers perceived include confusion about issues of privacy and confidentiality with regard to partner notification and the sense that there is a lack of clarity as to what is expected of them in terms of partner notification for chlamydia. Most GPs feel that access to decision support tools and clear guidelines would be helpful. Financial incentives for doing partner notification were seen as particularly important to fund allied health workers' time rather than to pay GPs themselves e.g. for practice nurses and Aboriginal health workers. GPs were enthusiastic about computer based resources to aid in partner notification

Design of trials with dying patients: a feasibility study of cluster randomisation versus randomised consent

There is little rigorous evidence to underpin clinical guidelines for palliative care. However, research in palliative care is difficult, especially with dying patients. Consent is a major issue, since staff do not wish to invite dying patients to participate in trials. We, therefore, conducted a feasibility study in two units within the North West Wales NHS Trust. We explored two novel approaches to research in palliative care -cluster randomisation and randomised consent. All patients admitted to the two units during the study were asked for permission to use their data for research. We allocated the two units, at random, to use cluster randomisation or randomised consent for three months, and then to crossover to the other design. Of 24 patients dying during cluster-randomised phases, 13 gave consent on admission to use their data and were, thus, eligible to enter the trial; however, defined eligibility criteria reduced these to six active participants. Of 29 patients dying during randomised consent phases, seven gave consent on admission to use their data; although two were eligible for randomisation, neither entered the trial. We judge that cluster randomisation is the more effective design for research with dying patients. Computer simulation, based on data from 1500 dying patients on the Welsh Integrated Care Pathway, shows that crossover cluster trials need much smaller samples than simple cluster trials. Furthermore, this study has shown that crossover cluster trials are entirely feasible. We recommend a 'definitive' trial to test the crossover design more widely.

Clinical management of casualties exposed to lung damaging agents: a critical review

There is no specific antidote for the treatment of casualties exposed to chlorine, phosgene, or mustards; therefore, management is largely supportive. Corticosteroid treatment has been given to casualties accidentally exposed to chlorine. Clinical data on efficacy are inconclusive as the numbers given steroids have been small and the indications for administration unclear. There have been no clinical controlled studies. There is a stronger evidence base from animal studies, particularly from porcine and rodent models. Lung injury induced by phosgene and mustard appears to be mediated by glutathione depletion, lipid peroxidation, free radical generation, and subsequent cellular toxicity. There is limited evidence to suggest that repletion of glutathione reduces and/or prevents lung damage by these agents. This may provide an opportunity for therapeutic intervention.

Improving the management and referral of patients with transient ischaemic attacks: a change strategy for a health community

PROBLEM

Rapid referral and management of patients with transient ischaemic attacks is a key component in the national strategy for stroke prevention. However, patients with transient ischaemic attacks are poorly identified and undertreated.

DESIGN AND SETTING

Before and after evaluation of quality improvement programme with controlled comparison in three primary care trusts reflecting diverse populations and organisational structures in an urban district in the North of England.

KEY MEASURES FOR IMPROVEMENT

The proportion of patients receiving antiplatelet drugs and safe driving advice on referral to a specialty clinic, and the numbers of referrals, adjusted for age, to the specialist clinic before and after the improvement programme.

STRATEGIES FOR CHANGE

Interviews with patient and professionals to identify gaps and barriers to good practice; development of evidence based guidelines for the management of patients with transient ischaemic attacks; interactive multidisciplinary workshops for each primary care trust with feedback of individual audit results of referral practice; outreach visits to teams who were unable to attend the workshops; referral templates and desktop summaries to provide reminders of the guidelines to clinicians; incorporation of standards into professional contracts.

EFFECTS OF CHANGE

A significant improvement occurred in identification and referral of patients with transient ischaemic attacks to specialist clinics, with a 41% increase in referrals from trained practices compared with control practices. There were also significant improvements in the early treatment and safety advice provided to patients before referral.

LESSONS LEARNT

A strategic approach to effective quality improvement across a diverse health community is feasible and achievable. Careful planning with patient and professional involvement to develop a tailored and multifaceted quality improvement programme to implement evidence based practice can work in very different primary care settings. Key components of the effectiveness of the model include contextual analysis, strong professional support, clear recommendations based on robust evidence, simplicity of adoption, good communication, and use of established networks and opinion leaders.

Deficits in the mid-brain raphe nuclei and striatum of the AS/AGU rat, a protein kinase C-γ mutant

The AS/AGU rat carries a recessive mutation (agu) in the gene coding for the gamma isoform of protein kinase C. The rat is characterized by disordered locomotion and progressive dysfunction of the nigrostriatal dopaminergic (DA) system. This dysfunction begins with a failure to release DA within the striatum and culminates in cell loss within the substantia nigra pars compacta. The present study examines another midbrain aminergic system with input to the basal ganglia, the serotonergic (5-HT) raphe-striatal system originating in the dorsal raphe nucleus. By 3 months after birth, there is a very substantial reduction in the extracellular levels of 5-HT in the dorsal caudate-putamen of the mutants compared with controls (c. 70%). This is accompanied by a proportional increase in the levels of the 5-HT metabolite 5-hydroxyindole acetic acid (5-HIAA). At a later age, there are reductions in whole tissue 5-HT (and increases in 5-HIAA) in both the striatum and the region containing the dorsal raphe nucleus, as well as numbers of 5-HT-immunoreactive cells in the dorsal raphe nucleus. The median raphe appears to be unaffected. The results are seen in terms of an initial dysfunction in transmitter release leading to cell death, perhaps through the formation of free radicals or neurotoxins.

Doppler ultrasound and clinical findings in patients with acute ischemic stroke treated with intravenous thrombolysis

The aim of this study was to assess cerebral hemodynamics in patients with acute ischemic stroke undergoing thrombolytic therapy and to assess the relationship between cerebral hemodynamics and outcome. Forty-one unselected patients admitted to hospital within 3 h received intravenous thrombolytic therapy and were examined by extracranial and transcranial Doppler ultrasound examinations. Their strokes were clinically graded with the National Institute of Health Stroke Scale. Outcome after 3 months was graded with the modified Rankin Scale. Amongst the 27 patients who had an additional ultrasound examination 24 h after treatment, favorable outcome was significantly more common amongst patients with recanalization than amongst those without (P < 0.004). Thirteen patients with middle cerebral artery occlusions were continuously monitored during thrombolysis and frequently up to 5 h after start of thrombolysis. Early recanalization occurred in nine (69%), at a median delay of 178 min (range 140-287) after stroke onset. All of these nine patients had a favorable outcome. Recanalization within 24 h was associated with favorable outcome. Subgroup analysis suggests that this effect is mostly related to early recanalization within the first 5 h after stroke. Transcranial Doppler may therefore help to identify those patients most probably to benefit from thrombolysis, especially in those patients with a higher potential risk of complications.

Bacterial resistance to silver in wound care

Ionic silver exhibits antimicrobial activity against a broad range of micro-organisms. As a consequence, silver is included in many commercially available healthcare products. The use of silver is increasing rapidly in the field of wound care, and a wide variety of silver-containing dressings are now commonplace (e.g. Hydrofiber dressing, polyurethane foams and gauzes). However, concerns associated with the overuse of silver and the consequent emergence of bacterial resistance are being raised. The current understanding of the biochemical and molecular basis behind silver resistance has been documented since 1998. Despite the sporadic evidence of bacterial resistance to silver, there have been very few studies undertaken and documented to ascertain its prevalence. The risks of antibacterial resistance developing from the use of biocides may well have been overstated. It is proposed that hygiene should be emphasized and targeted towards those applications that have demonstrable benefits in wound care. It is the purpose of this review to assess the likelihood of widespread resistance to silver and the potential for silver to induce cross-resistance to antibiotics, in light of its increasing usage within the healthcare setting.

Short report: encouraging GPs to complete postal questionnaires--one big prize or many small prizes? A randomized controlled trial

BACKGROUND

Low response rates to surveys are a problem in general practice. There is evidence that offering GPs incentives improves response rates to postal questionnaires. However, there is less evidence about the most effective form of incentive.

OBJECTIVE

Our trial aimed to maximize response to a postal questionnaire and to test the most effective form of incentive.

METHODS

The study involved a randomized controlled trial of a postal survey

RESULTS

The incentive of a lottery for six bottles of champagne generated a response rate of 79%. Furthermore, one chance of six bottles generated 9% more responses than six chances of one bottle.

CONCLUSIONS

This study has established that, among incentives for postal questionnaires, one big prize improves the yield more than many small prizes despite the lower odds of winning. It has also confirmed that offering a modest incentive to GPs generates good response rates for postal questionnaires.

Evaluating children's rehabilitation services: an application of a programme logic model

OBJECTIVES

To apply a programme logic model to evaluate the effectiveness of a new therapy service for children with special needs who were in transition from pre-school to kindergarten.

SETTING

A children's outpatient rehabilitation centre in Ontario, Canada.

MAIN OUTCOMES

The short-term outcomes included parents' perceptions of the transition process itself and the information they required, the children's skill development for the transition to kindergarten, and parents' perceptions of services and satisfaction with resources.

METHODS

A combination of quantitative methods [Goal Attainment Scaling (GAS), Measure of Processes of Care (MPOC), Client Satisfaction Questionnaire (CSQ)] and qualitative interviews were used to evaluate both the process ('Outputs') and outcomes ('Short-term objectives') of the new therapy service.

RESULTS

The children involved in the evaluation met or exceeded goals that were set by therapists and parents. Parents' perceptions of, and satisfaction with, the new service were higher than the provincial average. Qualitative data from interviews with parents and service providers supported the findings from standardized measures, and provided suggestions for future service delivery.

CONCLUSIONS

The programme logic model provided researchers and service providers a collaborative and systematic approach to conducting programme evaluation in a relatively short-time frame. It appears to be a useful option for evaluation of other children's services.

Eosinophil activation and cysteinyl leukotriene production in infants with respiratory syncytial virus bronchiolitis

BACKGROUND

It has been suggested that acute infantile bronchiolitis associated with respiratory syncytial virus (RSV) may share some pathogenic features with atopic asthma in that virus-specific IgE is produced and cysteinyl leukotrienes (cLTs) and eosinophil cationic protein (ECP) have been detected in airway secretions. ECP is a specific marker of eosinophil activation although leukotrienes can be released from a variety of cells including mast cells, eosinophils and monocytes.

OBJECTIVE

To test the association between eosinophil activation and cysteinyl leukotriene production in the upper airway secretions of infants with RSV positive (RSV+ve) bronchiolitis.

METHODS

Nasal lavage samples were performed in 78 infants (0.0-11.5 months) admitted to hospital with RSV+ve bronchiolitis soon after admission (0-48 h). Leukotriene C4 (LTC4) was assayed by enzyme immunoassay (EIA) and eosinophil cationic protein (ECP) by fluoroimmunoassay (FIA).

RESULTS

LTC4 was detectable in 51 and ECP in 57 of 78 samples with a significant positive relationship between LTC4 and ECP (r=0.557, P<0.001).

CONCLUSION

In the majority of our subjects with RSV+ve bronchiolitis ECP and LTC4 were detectable in upper airway secretions and were significantly associated with each other. In this clinical setting much of the detected LTC4 within upper airway secretions is likely to originate from the eosinophil, an observation that may have implications for clinical management and for delineation of the underlying mechanisms associated with this illness.

The formation of AFB1-macromolecular adducts in rats and humans at dietary levels of exposure

The levels of aflatoxin B(1)-DNA and aflatoxin B(1)-albumin adducts were investigated by accelerator mass spectrometry (AMS) in humans and rats following exposure to a known, dietary relevant amount of carbon-14 labeled aflatoxin B(1) ([(14)C]AFB(1)). The aims of the study were to: (a) investigate the dose-dependent formation of DNA and protein adducts at very low doses of AFB(1) (0.16 ng/kg-12.3 microg/kg) in the rat; (b) measure the levels of AFB(1)-albumin and AFB(1)-DNA adducts at known, relevant exposures in humans (c) study rat to human extrapolations of AFB(1)-albumin and DNA adduct levels. The results in the rat showed that both AFB(1)-albumin adduct and AFB(1)-DNA adduct formation were linear over this wide dose range. The order of adduct formation within the tissues studied was liver>kidney>colon>lung=spleen. Consenting volunteers received 1 microg ( approximately 15 ng/kg) of [(14)C]AFB(1) in a capsule approximately approximately 3.5-7 h prior to undergoing colon surgery. The mean level of human AFB(1)-albumin adducts was 38.8+/-19.55 pg [(14)C]AFB(1)/mg albumin/microg AFB(1)/kg body weight (b.w.), which was not statistically different to the equivalent dose in the rat (15 ng/kg) 42.29+/-7.13 pg [(14)C]AFB(1)/mg albumin/microg AFB(1)/kg b.w. There was evidence to suggest the formation of AFB(1)-DNA adducts in the human colon at very low doses. Comparison of the linear regressions of hepatic AFB(1)-DNA adduct and AFB(1)-albumin adduct levels in rat found them to be statistically similar suggesting that the level of AFB(1)-albumin adducts are useful biomarkers for AFB(1) dosimetry and may reflect the DNA adduct levels in the target tissue. [(14)C]AFB(1)-DNA and [(14)C]AFB(1)-albumin adducts were hydrolysed and analysed by HPLC to confirm that the [(14)C] measured by AMS was derived from the expected [(14)C]AFB(1) adducts.