Filling in the Gaps. Making Sense of Living with Temporomandibular Disorders: A Reflexive Thematic Analysis

INTRODUCTION

Persistent, painful temporomandibular disorders (TMDs) are challenging to manage and usually require the active engagement of patients. To achieve this, it is necessary to understand the complex and multifactorial nature of persistent pain. Many dental professionals have little education about persistent pain and may prefer to offer structural management and advice. This research aims to explore how people understand their persistent TMD and how this understanding has been influenced by their treatment providers.

METHODS

Twenty-one people were recruited to represent a diversity of experience with persistent TMD. Interviews followed a semistructured topic guide. Themes were constructed through reflexive thematic analysis to represent how people made sense of their symptoms and the messages that they had picked up through their treatment journey.

RESULTS

Participants described examples of conflicting opinions and inconsistent management recommendations. They rarely recalled collaborative discussions about the nature and complexity of their symptoms and different options for treatment. This experience is represented by a single theme, "a medical merry-go-round." Subthemes of "a medical journey to nowhere-participants' frustrated attempts to find medical management that will end their pain" and "is it me?-participants' questioning their role in persisting pain" kept participants on the merry-go-round, while symptom resolution and participants' emerging development of a holistic understanding of their TMD pain provided exit points. Understanding pain holistically tended to be helpful and typically occurred despite rather than because of the advice given in routine treatment settings.

CONCLUSION

Participants in this study had not typically found their pain management within dental and medical settings to have helped them to construct meaning and understand their experiences of painful TMD. However, understanding symptoms holistically was experienced as beneficial. This study suggests that improved communication and signposting within services for persistent TMD may be beneficial to patients with TMD pain.

KNOWLEDGE TRANSFER STATEMENT

Results of this study confirm that being offered a series of anatomically based, singular-cause explanations for persisting pain symptoms had been experienced as unhelpful by the participants who had sought help for their TMD. Participants highlighted the importance of accurate and collaborative communication and of dental professionals explicitly adopting and communicating a biopsychosocial understanding of pain to their patients who have TMD. Results highlight that some people can struggle to manage persisting pain with minimal support. Signposting patients to appropriate services and resources may help them to understand more about the nature of persistent pain and methods of managing it.

Abstract P6-17-11: The small molecule inhibitor of HER2, tucatinib, has potent and highly selective activity in preclinical modes of HER2-driven cancer

Background: Pharmacologically targeting the HER2 oncoprotein provides clinical benefit for patients with HER2-amplified cancers. However, a significant number of patients do not respond to the currently approved HER2-targeted therapies, despite carrying the HER2-alteration. Small molecule inhibitors of HER2, that target other receptor tyrosine kinases such as EGFR (i.e. lapatinib), are approved and provide some clinical benefit but are often associated with increased toxicity. Tucatinib (ARRY-380) is an orally available, potent, highly selective small molecule inhibitor of the HER2 kinase. In this study, we assessed the in vitroand in vivoactivity of tucatinib, relative to approved HER2-targeting molecules, in a panel of molecularly characterized breast cancer cell lines.

Materials and Methods:The growth inhibitory activity of tucatinib, trastuzumab and lapatinib were evaluated in a panel of 48 breast cancer cell lines molecularly characterized at baselineby genomic (array-CGH) and proteomic (Reverse Phase Protein Array; RPPA) profiling. IC50values for tucatinib and lapatinibwere determined from direct cell counts using a Cellavista Cell Imaging System. Trastuzumab activity was measured as % inhibition of cell growth at fixed concentrations. In vivoefficacy of tucatinib was assessed in cell line xenograft models of HER2+/ER- and HER2+/ER+ breast cancers as a single agent or in combination with targeted therapies for breast cancer.

Results: A broad range of IC50values (3.2nM to >10μM), was seen for tucatinib with a high degree of selectivity for the HER2-amplfied sub-type. High levels of total and phosphorylated HER2 (pHER2) accompanied by high levels of pEGFR and pHER3 enriched for sensitivity to tucatinib, confirming that HER2-driven cancers may be uniquely sensitive to tucatinib. The response profile for lapatinib was less clean, with responses also observed in HER2-low/EGFR-high cell lines. Sensitivity to tucatinib was also observed in HER2-amplified cell lines that were either de novoor acquired resistant to trastuzumab. Single agent tucatinib induced tumor regressions in a xenograft model of HER2+/ER+ breast cancer. Tumor regressions were further enhanced by combination with trastuzumab. The combination of tucatinib plus trastuzumab was as efficacious and better tolerated than trastuzumab plus docetaxel or trastuzumab plus pertuzumab plus docetaxel. The triple combination of tucatinib plus hormonal blockade (fulvestrant) and CDK4/6 inhibition (abemaciclib) also induced robust tumor regressions, without significant body weight loss.

Discussion: These preclinical data highlight the potential of the HER2-selective small molecule inhibitor, tucatinib, to provide benefit to patients with HER2-amplifed cancers. Furthermore, our biomarker analysis of response to tucatinib has identified a HER2-driven signature within the HER2-amplfied sub-type that selects for sensitivity to tucatinib. Selecting patients based on this profile may further enrich for individuals most likely to benefit from tucatinib-based therapies.

Citation Format: O'Brien NA, Conklin D, McDermott M, Luo T, Ayala R, Issakhanian S, Salgar S, Hurvitz S, Slamon DJ. The small molecule inhibitor of HER2, tucatinib, has potent and highly selective activity in preclinical modes of HER2-driven cancer [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P6-17-11.

Abstract P4-06-07: Activity of nivolumab alone or in combination with targeted therapies in a humanized BLT-mouse model of human breast cancer

Background: Recent advances in the field of cancer immunotherapy have increased demand for reliable preclinical models to inform patient selection and rational drug combination strategies. The development of the bone marrow-liver-thymus (BLT) mouse may provide the opportunity to study the complex interactions of human tumor and host immune systems in vivo. Other models are limited by the rapid onset of graft versus host disease (GVHD) and a lack of orderly maturation and trafficking of human T and B cells. In BLT mice, implantation of human fetal liver and thymus fragments beneath the kidney capsule of NSG (NOD/SCID/IL-2RΥ-/-) mice followed by engraftment of matched ex vivoexpanded CD34+ cells supports the production of an almost complete human immune system. In this study, we used this model to assess the efficacy of the anti-PD-1 therapeutic antibody, nivolumab, in combination with targeted therapeutics in specific breast cancer sub-types.

Materials and Methods: For triple negative breast cancer (TNBC), the activity of nivolumab was assessed in combination with the PARP1/2 inhibitor, talazoparib, in humanized BLT mice. Xenografts were established by subcutaneous injection of 5.0x106MDA-231 (TNBC) cells. Mice (n=5) were randomized into treatment groups as follows; 1) Vehicle control (PBS), 2) nivolumab (10mg/kg QW), 3) talazoparib (0.33mg/kg Q5/2D) and 4) nivolumab+talazoparib. After 21 days of treatment, tumor tissue, serum and PBMCs were collected for biomarker analysis.

Results: Successful reconstitution of mature human T and B cells was confirmed in BLT mice 12-weeks post engraftment of donor tissue and CD34+ hematopoietic stem cells. MDA-231 cells injected subcutaneously into the flank of these mice formed palpable tumors (150-200mm3) within 9 days of injection. For vehicle control treated mice, tumors grew (2.5-fold) throughout the 21-day study. Single agent nivolumab induced significant tumor growth inhibition (TGI) relative to vehicle control treated mice at Day 21. Single agent talazoparib also induced comparable levels of TGI as did the combination of nivolumab plus talazoparib. Nivolumab treated mice continued to gain weight throughout the study without overt signs of toxicity. Reversible weight loss was observed in the talazoparib and combination treated arms. Overt signs of GVHD were not observed in any of these animals. Preliminary tissue analysis identified high levels of cell surface PD-L1 protein in control treated MDA-231 xenografts. Further analysis of the treated tumors will provide valuable insight into the mechanism of action of this class of molecule. We are establishing xenograft models of hormone receptor (ER+) positive breast cancer to measure the activity of nivolumab+/-CDK4/6-inhibition in humanized BLT mice and these data will also be presented.

Discussion: The data presented here highlight the potential of the PD-1 antibody nivolumab to have activity in TNBC. Furthermore, these findings illustrate the potential of the humanized BLT-mouse to model responses to immune check-point in the preclinical setting. Expanded use of this model may help to identify response biomarkers and inform design of combination therapies using immune oncology molecules and approved targeted therapies.

Citation Format: O'Brien NA, Luo T, Ayala R, Salgar S, Conklin D, McDermott M, Kitchen S, Rezek V, Horak C, Dugan U, Slamon DJ. Activity of nivolumab alone or in combination with targeted therapies in a humanized BLT-mouse model of human breast cancer [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P4-06-07.

Abstract P4-03-15: Targeting Src kinase blocks development of afatinib resistance in HER2-positive breast cancer

Background: Afatinib is an irreversible pan-HER inhibitor approved for non-small cell lung cancer. We have previously shown that afatinib inhibits growth of HER2-positive breast cancer cells and enhances response to trastuzumab. However, we have also shown that long-term exposure to tyrosine kinase inhibitors leads to the development of acquired resistance. To determine if acquired afatinib resistance develops in HER2-positive breast cancer cells, we exposed a HER2-positive breast cancer cell line to afatinib for 6 months and investigated alterations in the cells following long-term exposure.

Methods: SKBR3 cells were treated with 150 nM afatinib twice-weekly for 6 months. Growth response to drug inhibitors was assessed by acid phosphatase assay. Drug sensitivity was examined in four HER2-positive cell lines (SKBR3, EFM192A, BT474 and HCC1954) and three acquired trastuzumab resistant cell lines (SKBR3-T, BT474-T and EFM192A-T). Reverse phase protein array (RPPA) was used to determine alterations in key signaling pathways. Src, p-Src, EGFR, p-EGFR, ERK1/2, p-ERK 1/2 levels were examined by Western blotting. To examine the prevention of the development of afatinib resistance, cells were treated twice weekly with afatinib, dasatinib, or the combination and stained with crystal violet when confluent.

Results: Following 6 months of afatinib treatment, the SKBR3-A cells were more resistant to afatinib compared to parental cells (IC50 SKBR3-A 284 ± 28.2 nM vs SKBR3-Par 10.9 ± 3.4 nM). Furthermore, the resistant cells were cross-resistant to lapatinib, neratinib and trastuzumab. RPPA interrogation of the SKBR3-A cells showed alterations in several pathways, including significantly increased levels of p-Src (Y416). SKBR3-A cells were more sensitive to Src inhibition with dasatinib compared to SKBR3-Par cells and the combination of afatinib and dasatinib was highly synergistic in SKBR3-A cells (CI value = 0.09 ± 0.06). The combination of afatinib and dasatinib was also synergistic in the trastuzumab resistant SKBR3-T cells (Table). Afatinib and dasatinib inhibited EGFR and Src activation and ERK 1/2 signalling in SKBR3-A cells.

Short-term resistance assays showed that the addition of dasatinib to afatinib blocks the emergence of resistant cells in three of four HER2 positive cell lines tested and two of the three acquired trastuzumab resistant cell lines tetsed.

Conclusion: HER2-positive breast cancer cells that are highly sensitive to afatinib can develop acquired resistance to afatinib within six months. Src is a potential target to prevent the development of afatinib resistance and thus combined treatment with afatinib and dasatinib may be beneficial in patients with HER2-positive breast cancer.

Percentage growth in HER2-positive cells treated with afatinib and/or dasatinib for 5 days. 20 nM Afatinib40 nM Dasatinib20 nM Afatinib + 40 nM DasatinibSKBR325.2 ± 6.1109.9 ± 6.222.6 ± 6.2SKBR3-A62.1 ± 0.787.3 ± 11.036.3 ± 0.3*SKBR3-T42.6 ± 4.9107.4 ± 9.729.3 ± 3.5*BT47418.2 ± 3.079.5 ± 5.213.3 ± 1.1BT474-T6.9 ± 2.795.3 ± 2.06.2 ± 2.3EFM192A39.1 ± 4.7105.7 ± 3.135.3 ± 2.7EFM192A-T30.4 ± 5.299.8 ± 2.528.5 ± 4.4HCC195461.8 ± 8.180.5 ± 8.219.4 ± 3.6** indicates enhanced anti-proliferative response for the combination compared to the single agents.

Citation Format: Conlon N, Canonici A, Morgan C, Cremona M, Hennessey BT, Eustace A, O'Brien N, Slamon D, Crown J, O'Donovan N. Targeting Src kinase blocks development of afatinib resistance in HER2-positive breast cancer [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr P4-03-15.

A novel strategy to reduce very late HIV diagnosis in high-prevalence areas in South-West England: serious incident audit

Background

Very late diagnosis of HIV is a serious public health issue. We used serious incident reporting (SIR) to identify and address reasons for late diagnoses across the patient pathway.

Methods

Cases of very late HIV diagnosis were reported via SIR in two 6-month batches between 2011 and 2012 in Bournemouth, Poole and Bristol. Case notes were reviewed for missed opportunities for earlier diagnosis using a root-cause analysis tool.

Results

A total of 33 patients (aged 30-67 years, 66% male) were diagnosed very late. Although the majority were white British (n = 17), Black African (n = 9) and Eastern European (n = 4) ethnicities were over-represented. Twenty-four (73%) patients had clinical indicator conditions for HIV, 30 (91%) had a risk factor for HIV acquisition, with 13 (39%) having 2 or more (men-who-have-sex-with-men (n = 11), partner HIV positive (n = 11), from high-prevalence area (n = 12)). Actions resulting from SIR included increasing awareness of indicator conditions, HIV education days within primary care, and initiatives to increase testing within hospital specialities.

Conclusions

SIR allowed identification of reasons for very late HIV diagnosis and provided an impetus for initiatives to address them. SIR may be part of an effective strategy to prevent late diagnosis of HIV which would have important benefits for individual and population health.

Abstract P3-04-15: The PI3K-inhibitor, copanlisib, has selective activity in luminal breast cancer cell lines and shows robust combined activity with hormonal blockade and CDK-4/6 inhibition in ER+ breast cancer cell line xenografts

Background: Genetic and epigenetic alterations in the PI3K/mTOR and cyclin D:CDK-4/6:Rb signaling axes occur frequently in breast cancer and have been attributed to resistance to both ER- and HER2-directed therapeutics. Pharmacologically targeting CDK-4/6 in combination with hormonal blockade provides clinical benefit in patients with advanced ER+ breast cancer. In this study, we evaluated the activity of the pan-class I PI3K inhibitor, copanlisib (BAY-80-6946), with potent alpha and delta activity as a single agent or in combination with CDK-4/6 inhibition and hormonal blockade in a panel of breast cancer cell lines.

Methods: The growth inhibitory activity of copanlisib was evaluated against a large panel of 48 breast cancer cell lines molecularly characterized by genomic, transcriptomic and proteomic profiling. IC50 values were determined from direct cell counts using a Z1-particle counter. The activity of copanlisib in combination with hormone blockade and CDK-4/6 inhibition, by palbociclib, was assessed in two cell line xenograft models of ER+ breast cancer; MCF7(PIK3CA-E545K) and ZR751(PIK3CA WT). For xenograft studies, tumor bearing mice were treated once weekly (BID) by intravenous injection with clinically achievable doses of copanlisib (10 mg/kg) as single agent or in combination with tamoxifen or fulvestrant with or without 75 mg/kg daily palbociclib for 21 days.

Results: A broad range of IC50 values (0.491-895 nM), with a high degree of separation between sensitive and resistant histologically defined subgroups were determined for copanlisib, indicating the potential for a wide therapeutic window. Luminal subtype, the presence of activating mutations in PIK3CA, high levels of ER, HER2, HER3 and EGFR protein enriched for sensitivity to copanlisib. Activating mutations of KRAS and BRAF were associated with resistance to copanlisib. Single agent copanlisib induced significant tumor growth inhibition (TGI) relative to vehicle control in each of the xenograft models. Modest increases in anti-tumor activity were achieved when copanlisib was combined with hormonal blockade by either tamoxifen or fulvestrant. However, robust tumor regressions were observed with the triple combinations of copanlisib-palbociclib-tamoxifen and copanlisib-palbociclib-fulvestrant. Furthermore, these triple combinations achieved a statistically significant improvement in anti-tumor activity over the standard of care combination of palbociclib plus fulvestrant. Each of the single agent and treatment combinations tested were well tolerated in animals.

Discussion: These preclinical data illustrate the potent and selective activity of the pan class I PI3K inhibitor copanlisib in luminal breast cancers and support the clinical investigation of copanlisib in combination with CDK-4/6 inhibition and hormonal blockade in ER+ breast cancer.

Citation Format: O'Brien NA, Conklin D, Luo T, Ayala R, Issakhanian S, Kalous O, Von Euw E, Politz O, Wilhelm S, Childs BH, Hurvitz SA, Slamon DJ. The PI3K-inhibitor, copanlisib, has selective activity in luminal breast cancer cell lines and shows robust combined activity with hormonal blockade and CDK-4/6 inhibition in ER+ breast cancer cell line xenografts [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr P3-04-15.

Whole-exome sequencing of individuals from an isolated population implicates rare risk variants in bipolar disorder

Bipolar disorder affects about 1% of the world's population, and its estimated heritability is about 75%. Only few whole genome or whole-exome sequencing studies in bipolar disorder have been reported, and no rare coding variants have yet been robustly identified. The use of isolated populations might help finding variants with a recent origin, more likely to have drifted to higher frequency by chance. Following this approach, we investigated 28 bipolar cases and 214 controls from the Faroe Islands by whole exome sequencing, and the results were followed-up in a British sample of 2025 cases and 1358 controls. Seventeen variants in 16 genes in the single-variant analysis, and 3 genes in the gene-based statistics surpassed exome-wide significance in the discovery phase. The discovery findings were supported by enrichment analysis of common variants from genome-wide association studies (GWAS) data and interrogation of protein-protein interaction networks. The replication in the British sample confirmed the association with NOS1 (missense variant rs79487279) and NCL (gene-based test). A number of variants from the discovery set were not present in the replication sample, including a novel PITPNM2 missense variant, which is located in a highly significant schizophrenia GWAS locus. Likewise, PIK3C2A identified in the gene-based analysis is located in a combined bipolar and schizophrenia GWAS locus. Our results show support both for existing findings in the literature, as well as for new risk genes, and identify rare variants that might provide additional information on the underlying biology of bipolar disorder.

Abstract P4-14-25: Single agent and combined targeting of PI3K, mTOR, HER2 and ER signaling in a panel of HER2+/ER+ versus HER2+/ER- breast cancer cell lines

Background: Altered PI3K/mTOR signaling, through activating mutations in PIK3CA and/or PTEN loss, has been implicated in resistance to both hormonal and HER2-directed therapeutics for breast cancer. Recent data from the BOLERO-1 phase III clinical trials demonstrate an improvement in progression free survival (PFS) of 7.2 months in patients with HER2+/estrogen receptor negative (HER2+/ER-) advanced breast cancer when treated with trastuzumab and paclitaxel plus the mTORC1 inhibitor, everolimus (Afinitor ®). However, improvement in PFS was not observed in patients with HER2+/ER+ positive disease. These data suggest that hormone receptor levels may influence the response of HER2-amplifed cells to both HER2 and PI3K/mTOR directed therapies in the absence of hormonally directed therapies. In this study, we investigated the role of ER in HER2+ breast cancer by screening a large panel of HER2+/ER- and HER2+/ER+ breast cancer cell lines for responses to single agent and combined treatment with PI3K, mTOR, HER2 and ER-directed therapeutics.

Materials and Methods: The anti-proliferative activity of BKM120 (pan-PI3K inhibitor), BYL719 (p110α-specific) and everolimus were assessed as single agents or in combination with trastuzumab and/or tamoxifen in a panel of six HER2+/ER+ versus six HER2+/ER- breast cancer cell lines in two-dimensional culture. Drug response IC50s were generated from actual cell counts as measured by Z2-particle counting. Biomarker analyses were conducted using baseline mRNA microarray (Agilent) and reverse phase protein array (RPPA) profiling of each of the cell lines to determine associations with response or resistance data.

Results: RPPA analysis confirmed the presence of higher levels of ER protein in the cell lines designated as ER+ and significantly higher levels of PTEN protein were detected in those cell lines. Interestingly, each of the PI3K/mTOR pathway inhibitors tended to have increased single agent activity in the ER+ relative to the ER- lines. Combined activity with trastuzumab and either BKM120 or BYL719 was observed in 6 of the 12 cell lines tested and occurred independent of ER status. Similarly, combined activity of everolimus and trastuzumab was also observed in both HER2+/ER+ and HER2+/ER- cell lines. In 3/6 HER2+/ER+ cell lines the addition of tamoxifen provided no benefit to the combination of trastuzumab and PI3K/mTOR pathway inhibitor, whereas in two cell lines mild antagonism was observed with the triple combination. Finally, one cell line did show significant potentiation from the addition of endocrine therapy on top of HER2/PI3K/mTOR targeting.

Discussion: These data confirm levels of estrogen receptor are likely playing a role in response to single agent PI3K/mTOR pathway inhibition and highlight the potential utility of combining endocrine therapy with HER2/PI3K/mTOR-directed therapeutics in a sub-group of HER2-amplified breast cancers. Further in depth biomarker analyses may reveal additional molecular alterations responsible for this differential sensitivity to the double and triple combinations and is underway.

Citation Format: O'Brien NA, Nichols CM, Thomas J, Conklin D, Kalous O, Linnartz R, Di Tomasso E, Hurvitz SA, Hirawat S, Slamon DJ. Single agent and combined targeting of PI3K, mTOR, HER2 and ER signaling in a panel of HER2+/ER+ versus HER2+/ER- breast cancer cell lines. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P4-14-25.

Targeting ErbB-2 nuclear localization and function inhibits breast cancer growth and overcomes trastuzumab resistance

Membrane overexpression of ErbB-2/HER2 receptor tyrosine kinase (membrane ErbB-2 (MErbB-2)) has a critical role in breast cancer (BC). We and others have also shown the role of nuclear ErbB-2 (NErbB-2) in BC, whose presence we identified as a poor prognostic factor in MErbB-2-positive tumors. Current anti-ErbB-2 therapies, as with the antibody trastuzumab (Ttzm), target only MErbB-2. Here, we found that blockade of NErbB-2 action abrogates growth of BC cells, sensitive and resistant to Ttzm, in a scenario in which ErbB-2, ErbB-3 and Akt are phosphorylated, and ErbB-2/ErbB-3 dimers are formed. Also, inhibition of NErbB-2 presence suppresses growth of a preclinical BC model resistant to Ttzm. We showed that at the cyclin D1 promoter, ErbB-2 assembles a transcriptional complex with Stat3 (signal transducer and activator of transcription 3) and ErbB-3, another member of the ErbB family, which reveals the first nuclear function of ErbB-2/ErbB-3 dimer. We identified NErbB-2 as the major proliferation driver in Ttzm-resistant BC, and demonstrated that Ttzm inability to disrupt the Stat3/ErbB-2/ErbB-3 complex underlies its failure to inhibit growth. Furthermore, our results in the clinic revealed that nuclear interaction between ErbB-2 and Stat3 correlates with poor overall survival in primary breast tumors. Our findings challenge the paradigm of anti-ErbB-2 drug design and highlight NErbB-2 as a novel target to overcome Ttzm resistance.

Is the NHS best practice tariff for type 1 diabetes applicable in the Irish context?

The National Health Service in the UK has identified thirteen key standards of paediatric diabetes care. Funding depends on services meeting these standards. The aim of this study was to determine if these standards are applicable in an Irish setting. All patients attending the diabetes service during 2012 were included. Patient charts, electronic appointments, nursing notes and computerised results were used to ascertain relevant information for comparison with the NHS standards. Patients attended a mean 2.97 (SD 0.7) medical and 2.2 (SD 2.9) nursing appointments per year, with a median additional contacts of 8 nurse phone calls (range 0 - 125). Most standards were met by this service. In comparing our service to the NHS standard, we have identified a number of areas for improving our service provision. Limited resources and staff shortages make a number of these standards unachievable, namely annual dietetic review and three monthly outpatient appointments.

Abstract PD1-5: Targeting PI3K overcomes in vivo resistance to everolimus in estrogen receptor (ER+) breast cancer

Background: The selective mTORC1 inhibitor everolimus (RAD001/Affinitor®) has recently been approved, in combination with exemestane, for treatment of advanced hormone receptor positive breast cancer after demonstrating significantly improved progression free survival for patients having progressed on a previous non-steroidal aromatase inhibitor. However, despite these improved outcomes many tumors go on to develop resistance to everolimus. Alterations in PI3K/AKT signaling, either through activating mutations in PIK3CA or loss of PTEN, have been shown to influence responses to everolimus treatment in vitro (Weigelt et al., 2011). In this study we used cell line xenograft models of everolimus resistance to assess the potential of a pan-PI3K inhibitor (BKM120) or a p110a-specific inhibitor (BYL719) to reverse resistance either as single agents or in combination with anti-ER therapy (Fulvestrant).

Materials and Methods: Everolimus resistant xenografts were developed from three originally everolimus sensitive ER+ cell lines carrying distinct genetic alterations that confer aberrant PI3K/AKT signaling; ZR75-1 (PTEN null), MCF7 (PIK3CA mutant) and KPL1 (wild-type). Mice were treated by daily oral everolimus (10 mg/kg) until tumors began to progress on treatment (∼ 35 days of daily treatment). Mice that developed everolimus resistant tumors were randomized into six treatment groups (n = 6) as follows: continued on everolimus (10 mg/kg), fulvestrant (5 mg/wk), BKM120 (35 mg/kg), BYL719 (50 mg/kg), fulvestrant + BKM120 or BYL719.

Results: All three cell line xenografts were initially responsive to everolimus. ZR75-1 xenografts were allowed to progress on everolimus until they reached a mean tumor volume greater than that on day zero, at which point mice were randomized into treatment groups. Tumor selected to continue on everolimus gained a mean tumor volume of 550 mm3 over the six-week duration of study, demonstrating resistance to everolimus. These tumors showed a partial response to Fulvestrant (28% TGI), BYL719 alone (40% TGI) and BYL719 combined with fulvestrant (61% TGI). In contrast, over 100% tumor growth inhibition (tumor regression) was observed with both single agent BKM120 or BKM120 plus fulvestrant. This is consistent with our in vitro findings that PTEN null tumor cells might be less sensitive to inhibition by BYL719 yet sensitive to BKM120. Data from the ongoing PIK3CA mutant and wild-type KPL1 models will inform whether these molecular subtypes of ER+ breast cancer are more sensitive to the pan-PI3K inhibitor or the p110α-specific inhibitor. Comprehensive pharmacodynamic analyses of these tumor tissues may identify the additional molecular determinants responsible for resistance to everolimus and help guide the design of future clinical studies.

Discussion: These pre-clinical data indicate that targeting PI3K either alone or in combination with fulvestrant overcomes resistance to everolimus in ER+ breast cancer.

Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr PD1-5.

Abstract P4-08-01: PI3K/mTOR inhibition overcomes in vitro and in vivo trastuzumab resistance independent of feedback activation of pAKT

Background: Aberrant activity of the PI3K/mTOR pathway has been implicated in resistance to trastuzumab and anti-hormonal therapy for HER2-amplified and ER-positive breast cancer, respectively. Previous studies in our laboratory and others have shown that increased PI3K/mTOR signaling, either through PTEN loss or activating PIK3CA mutations, can confer resistance to trastuzumab therapy. In this study, we assessed the potential of targeting the PI3K/mTOR pathway in overcoming both de novo and acquired trastuzumab resistance.

Materials and Methods: The in vitro activity of the pan-PI3K inhibitor BKM120, the mTORC1 inhibitor RAD001 and the dual PI3K/mTORC1/2 inhibitor BEZ235 were evaluated in a panel of 49 human breast cancer and immortalized cell lines. The in vivo activity of these molecules was assessed in six cell line xenografts models representing, ER+/HER2− (KPL-1, ZR75-1), ER+/HER2+ (UACC812, MDA361), ER−/HER2+ (SUM190), PIK3CA mutant (SUM190, MDA361), PTEN-null (ZR75-1) and trastuzumab resistant (BT-TR) breast cancer. Finally, the effect of PI3K/mTOR inhibition on feedback activation of PI3K signaling and compensatory pathways was measured by Western blot, immunohistochemistry (IHC) and reverse phase protein analysis (RPPA) of control and treated cell lysates/tumors.

Results: Using a sensitivity cut-off of an IC50 of < 1 µmol/L, 16 of the 18 HER2-amplified breast cancer cell lines and 8 of 10 cell lines with activating mutations in PIK3CA were sensitive to the pan-PI3K inhibitor BKM120. BEZ235 showed the most potent efficacy across the panel with IC50s < 100 nmol/L for each of the 49 cell lines tested. The HER2-amplified/PIK3CA mutant cell lines were also unexpectedly sensitive to the mTORC1 inhibitor RAD001, this was despite the silencing of mTORC1 signaling being followed by a feedback increase in phospho-AKT signaling. Furthermore, each of these molecules showed remarkable in vivo activity across the panel of xenografts models. BKM120, RAD001 and BEZ235 induced both tumor stabilization and regression independent of PTEN, PI3K, ER and HER2 status. Pharmacodynamic analysis of tumor tissue revealed that BEZ235 and RAD001 both inhibited mTORC1 signaling as indicated by a reduction in the levels of phosphorylated ribosomal protein S6 (pS6). However, in contrast to BKM120 and BEZ235, RAD001 did not induce a reduction in the levels of pAKT (S473 or TH308) yet showed comparable in vivo efficacy to each of these molecules. Finally, combined targeting of HER2 and PI3K/mTOR in vitro increased the anti-proliferative activity of the molecules and led to an increased induction of apoptosis. The efficacy of these molecules (alone or in combination with trastuzumab) was assessed in a model of in vivo trastuzumab resistance generated through long-term treatment of the trastuzumab sensitive BT474 cells (BT-TR). All PI3Ki induced complete inhibition of tumor proliferation in monotherapy, while the combination of trastuzumab and each of these molecules induced tumor regression in the trastuzumab resistant tumors.

Discussion: These pre-clinical data indicate that targeting the PI3K/mTOR pathway either alone or in combination with trastuzumab is effective strategy for overcoming trastuzumab resistance.

Citation Information: Cancer Res 2012;72(24 Suppl):Abstract nr P4-08-01.

P1-12-06: The Role of MAPK and PI3K/AKT/mTOR Signaling in Innate Lapatinib Resistance

Background: Lapatinib is a tyrosine kinase inhibitor which blocks downstream MAPK and P13K/AKT/mTOR proliferation and survival signaling pathways in HER2 positive breast cancer cell lines, tumor xenografts and HER2 positive breast cancer patients. However, pre-clinical and clinical studies have shown that not all HER2 positive patients respond to lapatinib and thus innate resistance to lapatinib exists. The identification of biomarkers of lapatinib response is therefore critical and would enable individual therapeutic decisions to be based on tumor biology rather than basic histopathology data alone. The aim of this study was to examine the role of MAPK and PI3K/AKT/mTOR signaling in a panel of lapatinib sensitive and resistant HER2−amplified breast cancer cell lines to identify pharmacodynamic markers of response to lapatinib treatment.

Methods: Dose response curves were generated to determine sensitivity to lapatinib in a panel of 17 HER2−amplified breast cancer cell lines. Total and phosphorylated levels of HER2, HER3, EGFR, AKT, ERK, S6K and eEF2 were determined following 24 hours lapatinib treatment in each of the cell lines.

Results: Twelve of the cell lines were sensitive to lapatinib with IC50g < 1 μM while 5 of the cell lines were innately resistant to lapatinib with IC50g > 1 μM. Levels of pHER2 and pHER3 were decreased in response to lapatinib in all cell lines independent of sensitivity to lapatinib. This suggests that inhibition of HER2/HER3 activation is not indicative of response to lapatinib treatment. There was also no correlation between the levels of HER2, HER3, and EGFR and sensitivity to lapatinib in the cell line panel.

In lapatinib sensitive cell lines, lapatinib decreased PI3K (pAKT), mTOR (pS6K) and MAPK (pERK) signaling and increased peEF2 levels. In contrast the levels of pAKT, pS6K, peEF2 and pERK were maintained following lapatinib treatment in lapatinib resistant cells. The continued activation of these proteins in the presence of lapatinib suggests a possible feedback mechanism that warrants further investigation. These data confirm that maintained signaling through either the P13K/AKT/mTOR pathway or the MAPK pathways in the presence of lapatinib can be an early pharmacodynamic biomarker of response.

Conclusions: Maintenance of pAKT, pS6K, peEF2 and pERK levels, in response to lapatinib treatment correlates with lapatinib resistance. These data suggest that alterations in the P13K/AKT/mTOR and MAPK pathways play an important role in innate lapatinib resistance and pharmacologically targeting these pathways is a rational therapeutic approach for overcoming innate lapatinib resistance.

Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr P1-12-06.

P1-12-03: Combined Targeting of the PI3K Pathway and HER2 Overcomes Acquired and De Novo Trastuzumab Resistance

Background: Although trastuzumab and lapatinib provide clinical benefit for women with HER2−positive breast cancer, both de novo and acquired resistance to these agents exist. There is increasing evidence to suggest that aberrant activity of the PI3K/AKT/mTOR signaling pathway is one of the key mechanisms responsible for resistance. Thus, pharmacologically targeting the PI3K pathway is a rational approach for overcoming resistance to HER2−targeted therapy. However, specifically targeting individual elements of the PI3K pathway may result in feedback activation or in activation of compensatory pathways, whereas targeting the pathway at multiple points may be more effective in permanently shutting down proliferation and inducing cell death.

Materials and Methods: In this study we evaluated the activity of three small molecule tyrosine kinase inhibitors that target specific critical portions of the PI3K pathway; BKM120 (pan-PI3K), RAD001 (mTORC1 specific) and BEZ235 (dual PI3K & mTOR) both individually and in combination with trastuzumab in a panel of HER2−amplified breast cancer cell lines that have previously been characterized for trastuzumab response/resistance.

Results: In the trastuzumab sensitive BT-474 and SKBR3 cell lines, 72 hours of trastuzumab treatment efficiently inhibited cell proliferation and deactivated AKT (S473 & Th308), PS6K and ERK signaling. In contrast, in the trastuzumab-resistant MDA453 and SUM225 cell lines, as well as the BT-474 cells conditioned to acquire trastuzumab resistance (BT-TR), trastuzumab treatment did not inhibit pAKT, pS6K and pERK levels. RAD001 had significant antiproliferative activity in both trastuzumab sensitive and resistant cell lines and resulted in rapid down regulation of pPS6K (mTOR) activity (15 min). However, this deactivation was followed by a reactivation of AKT and ERK signaling (24 to 72 hours). BKM120 also demonstrated anti-proliferative activity independent of trastuzumab sensitivity.

Specifically targeting PI3K with BKM120 directly decreased pAKT/pS6K/pERK signaling and feedback activation was less pronounced than that observed with RAD001. Of the three molecules tested, BEZ235 was the most efficacious in the cell line panel (all IC50gs < 20 nM). BEZ235 rapidly (15 min) decreased pAKT/pS6K/pERK signaling in both trastuzumab sensitive and resistant cells lines and this inhibition was maintained at 72 hours. Thus, BEZ235 is effective in shutting down PI3K feedback activation and efficiently shuts down PI3K signaling in trastuzumab resistant HER2−amplified breast cancer cell lines. The combined treatment of trastuzumab and each of the PI3K/mTOR targeting agents resulted in greater inhibition of proliferation and induction of cell death in the HER2−amplified cell lines than each agent used alone. No increase in activity was observed in the HER2−normal control cell lines, MCF-7 and KPL-1. Discussion: Together, these data indicate that targeting the PI3K/AKT/mTOR pathway either alone or in combination with trastuzumab is effective in overcoming trastuzumab resistance. These findings are currently being validated in in vivo models of trastuzumab resistance.

Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr P1-12-03.

Hyperlactataemia in HIV-infected subjects initiating antiretroviral therapy in a large randomized study (a substudy of the INITIO trial)

OBJECTIVE

The aim of the study was to evaluate the predictive value of clinical and molecular risk factors, including peripheral blood mononuclear cell (PBMC) mitochondrial DNA (mtDNA) and mitochondrial RNA (mtRNA), for the development of lactic acidosis (LA) and symptomatic hyperlactataemia (SHL).

METHODS

In a substudy of a large multicentre, randomized trial of three antiretroviral regimens, all containing didanosine (ddI) and stavudine (d4T), in antiretroviralnaïve, HIV-1-infected patients, patients with LA/SHL ('cases') were compared with those without LA/SHL in a univariate analysis, with significant parameters analysed in a multivariate model. In a molecular substudy, PBMC mtDNA and mtRNA from cases and matched controls at baseline and time of event were examined.

RESULTS

In 911 subjects followed for a median of 192 weeks, 24 cases were identified (14 SHL and 10 LA). In univariate analysis, cases were more likely to be female (P=0.05) and to have a high body mass index (BMI) (P=0.02). In multivariate analyses, only BMI remained an independent predictor of the development of LA/SHL (P=0.03). Between cases and controls there was no significant difference in mtDNA copy number at baseline (389 vs. 411 copies/cell, respectively; P=0.60) or at time of event (329 vs. 474 copies/cell, respectively; P=0.21), in the change in mtDNA copy number from baseline to event (-65 vs. +113 copies/cell, respectively; P=0.12), in mtRNA expression at baseline or time of event, or in the change in mtRNA expression from baseline to event.

CONCLUSION

The development of LA/SHL was associated with increased BMI, but PBMC mtDNA and mtRNA did not predict LA/SHL. This demonstrates the ineffectiveness of routine measurement of PBMC mtDNA in patients on ddI and d4T as a means of predicting development of LA/SHL.

Abstract P4-01-06: The Role of the PI3K/AKT, RAS/MAPK and Novel Signaling Pathways in Resistance to HER2-Targeted Therapy

Despite the proven clinical benefits of HER2-targeted therapy, resistance to trastuzumab and lapatinib exists. Understanding the molecular mechanisms responsible for resistance is critical to improving the survival rates of patients with this aggressive subtype of breast cancer. Currently, there are no clinically validated biomarkers of resistance to therapy. To address this issue, we measured the responses of a panel of 18 HER2-amplified breast cancer cell lines to both trastuzumab and lapatinib and evaluated the activity of PI3K/AKT/mTOR and RAS/MAPK/ERK signaling in resistance. Eight of the cell lines were identified as resistant to trastuzumab and seven as resistant to lapatinib by both two and three dimensional response assays. Five of the trastuzumab resistant cell lines remained sensitive to lapatinib (IC50 < 1 μM), indicating that these two agents have at least partially non-overlapping mechanisms of resistance. The combination of low PTEN or the presence of activating mutations of PI3K, and thus increased activity of PI3K/AKT signaling, is a strong predictor of resistance to trastuzumab. However, this is not the case with lapatinib, two of the cell lines with activating mutations of PI3K (MDA-361 and HCC-202) were resistant to lapatinib whereas two other PI3K mutant cells lines (SUM-190 and HCC-1954) were lapatinib sensitive, indicating that lapatinib resistance can occurindependently of increased PI3K/AKT signaling. To further investigate these mechanisms, we measured the effects of trastuzumab and lapatinib treatment on AKT/mTOR and ERK activation. Cell lines sensitive to trastuzumab or lapatinib showed a marked reduction in pAKT, pS6K and pERK in response to either agent, whereas the resistant cells maintained high pAKT, pS6K and pERK levels in the presence of trastuzumab and lapatinib. In cell lines resistant to trastuzumab yet sensitive to lapatinib, treatment with lapatinib significantly reduced the phosphorylation of AKT, S6K and ERK. Thus in a subpopulation of cell lines lapatinib can overcome trastuzumab resistance via continued deactivation of PI3K/AKT/mTOR and MAPK/ERK signaling. However, there still remains a subgroup of HER2-positive cells that are resistant to both trastuzumab and lapatinib. We used global expression analysis by both mRNA microarray and proteomic screening to identify a set of genes and proteins that are consistently altered in these innately resistant cells relative to the sensitive cell lines. In vitro validation of these targets will reveal which are playing a functional role in resistance and are thus potentially druggable targets to be used in improving the survival of patients with HER2-positive disease.

Citation Information: Cancer Res 2010;70(24 Suppl):Abstract nr P4-01-06.

Hepatorenal bypass allowing fenestrated endovascular repair of juxtarenal abdominal aortic aneurysm: a case report

A 61-year-old man presented with a 66-mm juxtarenal aortic aneurysm. He was unfit for open repair. The anatomical proximity of his right renal artery (RRA) and his superior mesenteric artery (SMA) precluded fabrication of an endograft allowing perfusion of both vessels. He underwent a hepato-renal bypass to his RRA and subsequent fenestrated endovascular aneurysm repair (EVAR) using an endoprosthesis with fenestrations for the SMA and the left renal artery (LRA), and a scallop for the coeliac trunk. Follow-up imaging showed all visceral vessels to be perfused. The use of this limited hybrid approach allows endovascular treatment of aneurysms that are initially unsuitable for such an approach.

Second trimester hepatic rupture in a 35 year old nulliparous woman with HELLP syndrome: a case report

The HELLP syndrome (haemolysis, elevated liver blood tests and low platelets) is a serious complication in pregnancy characterized by haemolysis, elevated liver enzymes and low platelet count occurring in 0.5 to 0.9% of all pregnancies and in 10–20% of cases with severe preeclampsia. Hepatic capsular rupture is a rare yet dramatic complication of HELLP syndrome. The majority of cases occur in multiparous women over the age of 30. Classically it presents with acute onset right upper quadrant pain in the presence of constitutional symptoms such as vomiting and pyrexia. However, symptoms and signs are usually non specific. Spontaneous hepatic rupture can be preceded by signs of hypovolaemic shock; yet the diagnosis is infrequently made prior to emergent laparotomy. We present the case of a 35 year old nulliparous woman with a second trimester gestational hepatic rupture associated with HELLP syndrome. We briefly discuss the aetiology, diagnostic difficulties and treatment options associated with this rare presentation.

HER-2 signaling and inhibition in breast cancer

Amplification of the HER-2 gene occurs in approximately 25% of breast cancers, causing up-regulation of key signaling pathways which control cell growth and survival. In breast cancer patients, HER-2 overexpression correlates with an aggressive phenotype and poor prognosis. HER-2, therefore, has become the focus of many anti-cancer therapeutic approaches. Trastuzumab (Herceptin), a humanized monoclonal antibody directed against the extracellular domain of HER-2, was the first FDA-approved HER-2-targeted therapy for the treatment of metastatic breast cancer. However, not all HER-2-overexpressing patients respond to trastuzumab and most that initially respond develop resistance within one year of treatment. Trastuzumab resistance has been studied in cell line models of resistance and several mechanisms of resistance have been proposed. More recent anti-HER-2 strategies involve targeting its tyrosine kinase domain; for example, lapatinib (Tykerb) is a dual HER-2 and EGFR tyrosine kinase inhibitor and has shown efficacy as a single agent and in combination with other therapeutics. A number of novel HER-2 antagonists are currently in preclinical or clinical development, including both monoclonal antibodies and small molecule inhibitors. Increased understanding of HER-2 signaling in breast cancer, and of response and resistance to HER-2 antagonists, will aid the development of strategies to overcome resistance to HER-2 targeted therapies.

Optical Vectorial Vortex Coronagraphs using Liquid Crystal Polymers: theory, manufacturing and laboratory demonstration

In this paper, after briefly reviewing the theory of vectorial vortices, we describe our technological approach to generating the necessary phase helix, and report results obtained with the first optical vectorial vortex coronagraph (OVVC) in the laboratory. To implement the geometrical phase ramp, we make use of Liquid Crystal Polymers (LCP), which we believe to be the most efficient technological path to quickly synthesize optical vectorial vortices of virtually any topological charge. With the first prototype device of topological charge 2, a maximum peak-to-peak attenuation of 1.4x10(-2) and a residual light level of 3x10(-5) at an angular separation of 3.5 lambda/d (at which point our current noise floor is reached) have been obtained at a wavelength of 1.55 microm. These results demonstrate the validity of using space-variant birefringence distributions to generate a new family of coronagraphs usable in natural unpolarized light, opening a path to high performance coronagraphs that are achromatic and have low-sensitivity to low-order wavefront aberrations.

Roles for the calcium sensing receptor in primary and metastatic cancer

AIM

To review the role of the calcium sensing receptor (CASR) in colorectal, breast and parathyroid cancers and related cell lines, and to discuss the effects of CASR in the setting of bone metastases from breast cancer.

METHODS

We performed a literature search of the PubMed database of the National Library of Medicine (NLM) to identify articles concerning the CASR's involvement in different cancers. Further relevant papers were obtained from the references of those identified in the original search.

RESULTS

Loss of CASR expression is understood to be associated with abnormal differentiation and progression of colorectal carcinoma. It is expressed in both normal and malignant breast tissues and has been implicated in the vicious cycle of bone metastases through its interactions with the parathyroid hormone related peptide (PTHrP). In parathyroid tissue, CASR expression has been linked to proliferation of both parathyroid adenomas and carcinomas.

CONCLUSION

Apart from its role in calcium homeostasis, the CASR has many diverse functions in a variety of tissue types throughout the body, and is involved in various signalling pathways relating to cell proliferation and differentiation. CASR has been shown to be involved in the progression and spread of a variety of cancers such as colorectal, breast and parathyroid, and is likely to be the focus of much research to further elucidate its precise role.

The issue of anti-D: an integrated seamless approach from recognition of need to bedside administration

BACKGROUND

The appropriate and timely administration of Anti-D immunoglobulin to Rhesus (D) negative women who have delivered Rhesus (D) positive babies is a vital part of obstetric care. Anti-D has an especially high profile in Ireland because of the tragic inadvertent transmission of Hepatitis C to Irish women in past decades.

AUDIT

We have reviewed our policy and procedures pertaining to the administration of Anti-D for sensitising events during pregnancy and postnatally, in the Mid-Western Health Board in 1999/2000. As a result, major changes were made in the storage, issue, recording and administration of Anti-D. New procedures in the transfusion laboratory and in the maternity hospital have been accepted by scientists and midwives and supported by haematology and obstetric medical staff. The pharmacy and haematology laboratory no longer have a role in this programme. IMPLEMENTATION OF MULTI-DISCIPLINARY CHANGE MANAGEMENT: As a result of these changes, the storage, issuing and tracking of Anti-D has become the responsibility of the hospital blood bank. Measurement offoeto-maternal haemorrhage (FMH) is now the responsibility of bio medical scientists in blood bank, utilising both flow cytometry (increasingly recognised as the gold standard method) and the Kleihauer method (Kleihauer-Betke). The programme has moved from a doctor-administered IV Anti-D Ig, to a midwife-administered IM preparation. Prescription remains the responsibility of the doctor. These changes are facilitated by the protocol guided issue of the appropriate dose of Anti-D Ig by bio medical scientists to midwives. The issue of the Anti-D Ig occurs simultaneously with issue of results of mother and baby's serology testing and estimation of volume of FMH. These major changes have been guided by audit and needs assessment and require close liaison between medical, nursing and laboratory scientific staff in haematology, transfusion and obstetrics. CRITICAL INCIDENT AUDIT-CASE REPORT: Before new procedures became official policy, a critical incident audit allowed us to pilot our protocol and to revise it using draft new procedures. In this critical incident we describe successful management of a patient with a large foeto-maternal haemorrhage. This incident supported the need for the procedural enhancements already underway. This critical incident re-emphasised the need for the planned systems improvements to be introduced quickly.

A comparative study on attitudes, towards the provision of out-of-hours care, of the spouses of general practitioners participating, or not, in a rural out-of-hours co-op

Qualitative research has suggested that the stress of general practice, and that of out-of-hours care in particular, has an impact on general practitioners' (GPs') spouses. The effects on the families of practitioners, of the introduction of out-of-hours co-operatives has not been extensively studied. Our objective was to compare, between the spouses of GPs participating or not in a rural co-op, the effects of out-of-hours commitments on personal and family life. The spouses of all 125 GPs in a rural region in Ireland were sent questionnaires; 59 GPs were members of an out-of-hours co-op, 66 were engaged in traditional on-call rotas. Most questions were in statement form, to which participants were required to respond on a five point Likert rating scale. The response rate was 67%. Non-co-op spouses were significantly older than co-op spouses (48.3 years versus 42.6, t(68)=-3.02, p=0.04). 80% of the co-op group favoured a co-op for on-call cover as compared to 46% of the non-co-op group. The majority of respondents from both groups agreed that they dislike when their spouse is on call and that time spent on-call placed a strain on family life and was detrimental to their spouse's health. Spouses of non-co-op general practitioners were more likely to agree that their home life was interrupted by patients telephoning the house (z=-3.06, p=0.002) and by patients calling to the door without a prior appointment (z=2.9, p=0.004). They were also more likely to worry about the safety of their spouse on call (z=-2.07, p=0.038). The general provision of out-of-hours care has a significant impact on the spouses and families of GPs participating, or not, in a rural co-op. Spouses of participants in co-ops had significantly less interruptions to their home life from patients and worried less about the safety of their spouse. The implications of these findings on the recruitment and retention of rural practitioners merits further discussion.

A comparative study on attitudes, mental health and job stress amongst GPs participating, or not, in a rural out-of-hours co-operative

OBJECTIVES

To test the study hypothesis that GPs participating in co-operatives will have more positive attitudes towards co-operatives, better mental health and less stress than GPs using traditional out-of-hours arrangements.

METHODS

A comparative questionnaire study was conducted amongst GPs, participating, or not, in an out-of-hours, largely rural, co-operative ('NoWDOC') which had been established one year previously. The general attitudes of GPs towards out-of-hours work were obtained together with responses to the General Health Questionnaire-12 (mental health) and Stress Arousal Checklist (job stress).

RESULTS

Eighty-nine of 120 eligible practitioners responded (74%). The mean GHQ scores for GPs in NoWDOC was 10.2 [standard deviation (SD) 3.9] compared to a score of 11.3 (SD 4.5) for those not participating (t = -1.18; P = 0.24). The overall mean stress score for members of NoWDOC was 3.8 (SD 2.6) compared to 3.4 (SD 2.7) for non-NoWDOC (t = 0.59; P = 0.55). The overall mean arousal score for NoWDOC GPs was 5.2 (SD 2.0) compared to 5.5 (SD 2.9) for non-NoWDOC GPs (t = -0.68; P = 0.50). Multiple regression analyses suggested that the independent variables (partnership arrangements, age, working hours and membership of NoWDOC) did not account for any of the variability in the GHQ score but a significant amount of variability in stress and arousal scores.

CONCLUSIONS

The anticipated differences in mental health and job stress among participating GPs were not shown. As the new generation of GPs resemble the NoWDOC participants in their preferences for multi-partner practices with limited out-of-hours care provision, clarification of these findings is important.

Continuous crossover femoropopliteal bypass in a 68-year-old gentleman with rest pain

Patients who have had multiple previous attempts at limb salvaging surgery frequently go on to have an amputation. This, however, results both in psychological perturbation for the patient and high rehabilitation costs for the community. Successful limb salvage surgery therefore has an important role in vascular surgery. We describe the management of a patient with critical limb ischemia that had previously undergone multiple limb salvage procedures and whose limb was saved by the use of a continuous femoropopliteal crossover bypass graft. The patient, who may have been deemed by some as a candidate for amputation, has full use of his limb 6 months after surgery with ankle brachial pressure index readings of 0.6. Continuous femoropopliteal crossover bypass grafting is a poorly described surgical technique that may be appropriate in a subgroup of patients and may allow salvage of a limb that otherwise may have been deemed fit for amputation.

Electro-optic spectral tuning in a continuous-wave, asymmetric-duty-cycle, periodically poled LiNbO(3) optical parametric oscillator

We demonstrate electro-optic spectral tuning in a continuous-wave periodically poled LiNbO(3) (PPLN) optical parametric oscillator (OPO). We achieve 8.91 cm(-1) of rapid spectral tuning, with a linear tuning rate of 2.89 cm(-1) /(kV/mm), by applying electric fields up to +/-1.5 kV/mm across the crystal while it is operating within the OPO. Intentionally poling the PPLN crystal with an asymmetric domain structure enables tuning, and numerical predictions closely match the experimental observations. The tuning is considerably larger than the typical operational bandwidth of the OPO, indicating that we are in fact shifting the gain curve of the PPLN crystal.

Current use of the TORCH screen in the diagnosis of congenital infection

The aim of the study was to determine the number of congenital infections detected in Dublin with the current use of the TORCH screen. A review of all laboratory results was undertaken with subsequent review of relevant medical charts. A total of nine cases were documented in a 5-year period from January 1991 to December 1995. Six of these had already been suspected. There was a failure to follow up 47% of positive screens. TORCH screening in Ireland has an unacceptably low yield, and in the opinion of the authors should be abolished.

Modulation of UVA light-induced oxidative stress by beta-carotene, lutein and astaxanthin in cultured fibroblasts

The ability of beta-carotene, lutein or astaxanthin to protect against UVA-induced oxidative stress in rat kidney fibroblasts (NRK) was assessed. Activities of the antioxidant enzymes catalase (CAT) and superoxide dismutase (SOD), and changes in thiobarbituric acid reactive substances (TBARS) were measured as indices of oxidative stress. Exposure to UVA light at a dose intensity of 5.6 mW/cm2 for 4 h resulted in a significant decrease in CAT and SOD activities and a significant increase in TBARS. No cytotoxicity, as indicated by lactate dehydrogenase (LDH) release, was observed. beta-Carotene (1 microM), lutein (1 microM) and astaxanthin (10 nM) protect against UVA light-induced oxidative stress in vitro with astaxanthin exhibiting superior protective properties.

The Dublin outcome for low birth-weight infants

This report describes outcomes for all infants with birth weight 501-1750 grams born in the three major maternity hospitals in Dublin between 1.1.90 to 31.12.91. 37,958 mothers delivered 38,498 infants during this period, consisting of approximately 36% of all deliveries in Ireland. 633 (1.6%) of all infants born weighed 501-1750 grms. 102 (16%) were stillborn and 28 of the 531 live born infants had lethal malformations. 30% of women received two or more doses of antenatal steroids before delivery and a highly significant negative correlation occurred between the need for ventilation after birth and antenatal steroids. 56.4% of babies were delivered by caesarean section as compared with 10.8% of the hospital population. Of 503 liveborn infants without lethal malformation. 426 (85%) survived to 28 days and 419 (83%) to discharge home. 15% were growth retarded. 46% of infants were ventilated, mean duration of ventilation was 7 days. 25% of infants had an intraventricular haemorrhage, 10% necrotising enterocolitis and 19% culture proven sepsis. 15% of survivors developed broncho pulmonary dysplasia and 12% retinopathy of prematurity. This paper describes important information for mortality, morbidity and interventions among a large population of low birth weight infants in Ireland and can be used as a basis against which to compare future alterations in practice. It demonstrates a clear benefit for antenatal steroids in decreasing the need for ventilation and the importance of ensuring their utilisation antenatally where possible.