Abstract 4205: The role of non-muscle myosin IIA in HER2+ breast cancers

HER2 is amplified in about 20% of breast cancers. HER3 plays a critical role in HER2 mediated tumorigenesis. It is now clear that inhibition of HER2 tyrosine kinase activity results in upregulation of HER3 transcription and phosphorylation. We sought to identify HER3 binding partners upon pharmacological inhibition of HER2 using the irreversible pan HER inhibitor neratinib.

We immunoaffinity-purified HER3 from HER2+ BT474 cells treated ± neratinib. Following immunoprecipitation using a HER3 antibody, binding partners were released under reducing conditions. Mass spectrometry experiments identified non-muscle myosin IIA (NMMIIA) increased upon inhibition of HER2 with neratinib and decreased under DMSO control treatment from HER3 immunoprecipitates.

To confirm the presence of NMMIIA, we performed immunoprecipitation experiments in BT474 and MDA-MB-453 cells using a HER3 antibody. Immunoblots showed increased NMMIIA levels upon treatment with 200nM neratinib for 24 hours in both cell lines. Myosin heavy chain 9 (MYH9) gene encodes the protein nonmuscle myosin of class II, isoform A (NMMIIA). NMMIIA localizes to actin stress fibers and has been implicated in regulation of cell contractility and stress fiber organization

To further investigate the role of NMMIIA, we used blebbistatin, a myosin IIa inhibitor, in growth assays using BT474 and MDA-MB-453 breast cancer cells in vitro. The combination of blebbistatin and neratinib significantly decreased the proliferation in both cell lines compared to neratinib or blebbistatin treatment alone.

Additionally, we knocked out myosin IIa in BT474 cells using myosin IIa specific siRNA to examine the effect of myosin IIa silencing on HER3 and Myosin IIa protein levels in the presence or absence of neratinib treatment. Results indicated that in BT474 cells knockdown of NMMIIA resulted in both decreased HER3 and Myosin IIa protein expression and that neratinib treatment rescued this effect.

We next examined long term overall survival of primary breast cancer patients who have high and low levels of MYH9 gene expression from the METABRIC cohort. We observed that patients with high levels of MYH9 have a statistically significant worse overall survival versus patients who express low levels of MYH9.

Currently, further experiments are ongoing to determine the mechanism of action of the Myosin IIA/HER3 complex, which could be an adaptive response to HER2 inhibitors in HER2+ breast cancers and to evaluate the role of myosin IIa on proliferation, migration, and invasion of HER2+ breast cancer cells.

In conclusion, we have identified that neratinib treatment results in increased NMMIIA bound to HER3. Further studies to determine if NMMIIA could play a role in invasion of HER2+ breast cancer cells and/or resistance to HER2 inhibitors are ongoing.

Citation Format: Samar M. Alanazi, Rosalin Mishra, Long Yuan, Hima Patel, Joan Garrett. The role of non-muscle myosin IIA in HER2+ breast cancers [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 4205.

Credentialing for robotic lobectomy: what is the learning curve? A retrospective analysis of 272 consecutive cases by a single surgeon

Credentialing processes for surgeons seeking robotic thoracic surgical privileges are not evidence-based, and the learning curve has not been reported. The goal of this study is to review our experience with robotic lobectomies and provide evidence for the development of a more uniform credentialing process. We performed a retrospective review of the first 272 consecutive robotic lobectomies performed between 2011 and 2017 by a single surgeon with prior video-assisted thoracoscopic (VATS) experience. Primary outcomes were operative duration, blood loss, chest tube duration, length of hospital stay, intraoperative complication, and conversion to thoracotomy. The patients were subdivided by surgical date into two cohorts of 120 consecutive patients to compare differences in outcomes, thereby illustrating the learning curve. Between 2011 and 2017, 272 patients (median age 67.5 years) underwent a robotic lobectomy by a single surgeon. The majority of patients (157/272) had early stage (T1N0) adenocarcinoma. For the entire cohort, median operative time was 160 min (83-317 min). The median blood loss was 75 mL (10-4000 mL). Median chest tube duration was 2 days (1-23 days) and median hospital stay was 3 days (1-25 days). Intraoperative complications occurred in seven patients. Only six patients required conversion to thoracotomy. Using multivariable logistic regression, it was found that the age, gender, and stage do not factor into conversion to thoracotomy, but BMI was found to be a significant covariate (p 0.043). As the surgeon performs more surgeries, there is a significantly shorter operative time (p < 0.001), decreased blood loss (p < 0.001), and shorter hospital stay (p < 0.014). When the first 120 and last 120 surgeries were compared, there was significantly less blood loss (234.6 vs 78.69 cc, p < 0.001), shorter operative time (181.9 vs 147.4 min, p < 0.001), shorter tube duration (3.49 vs 3.11 days, p 0.007), and shorter length of stay (4.03 vs 3.48 days, p < 0.001), respectively. More intraoperative complications were observed during the first 120 surgeries (6/120) compared to the last 120 surgeries (0/120; Fischer exact p = 0.029). Regression model plots did not show any apparent and significant change points, but rather a steady improvement. The more cases the surgeon does, the better is the outcome in terms of operative duration, blood loss, post-operative length of stay and intraoperative complications. The learning curve for robotic surgery for a surgeon with prior VATS experience is that of a continuous improvement with experience instead of a particular change point. Since most thoracic surgeons who perform robotic-assisted surgery have already gotten past their VATS learning curves, they no longer have a definable learning curve for robotic surgery. Hence, if a surgeon is already proficient and credentialed to perform VATS lung resections, he or she is no longer faced with a significant learning curve for robotic lung resections, and should be credentialed to do so once he or she has undergone the appropriate training with the equipment and technology.

Abstract 4900: Reactive oxygen species scavenger extends the efficacy of BRAF inhibitors in BRAF-mutant melanoma

We aim to identify whether reactive oxygen species (ROS) targeted therapy using a ROS scavenger, A100, will inhibit tumor growth and evade BRAF inhibitor induced resistance in melanoma cells harboring the endogenous BRAFV600E mutation. We also propose to investigate the mechanism by which A100 sensitizes the dabrafenib-mediated resistance. Dabrafenib-resistant (DR) melanoma cells (WM-115DR, SK-MEL-24DR and A375DR) were generated using increasing doses of dabrafenib. We conducted flow cytometry experiments to measure ROS levels before and after acquisition of resistance. DCF-DA assay indicated upregulation of hydrogen peroxide levels in dabrafenib resistant cell lines versus parental cell lines. Furthermore, dabrafenib resistant cell lines demonstrated elevated superoxide levels as analyzed by MitoSOX. Crystal violet and three-dimensional matrigel assays were performed to analyze the effect of A100 and dabrafenib on cell growth of dabrafenib resistant and parental melanoma cell lines. We observed a statistically significant decrease in cell proliferation and colony formation of dabrafenib resistant cells when subjected to the combination of A100 and dabrafenib compared to single agent dabrafenib or A100. We also noted a trend of inhibition of cell proliferation in response to combined treatment of A100 and dabrafenib in parental cell lines versus the single agent. There was significant reduction in colony formation under similar condition in parental cells. Dabrafenib as a single agent had similar effect in reducing phosphorylated ERK1/2 as compared to co-treatment with A100 in A375, SK-MEL-24 and WM-115 parental cells. As expected, there was no alteration of MAPK signaling in resistant WM-115DR, SK-MEL-24DR and A375DR cells upon treatment with dabrafenib. A100 has been reported to cause DNA damage in leukemia cells. We analyzed the effect of A100 in the presence or absence of dabrafenib on markers of DNA damage. The data suggested that DNA damage is induced by A100 as assessed by increased levels of p-ATM, p-ATR and γ-H2AX. Further, A100 in combination with dabrafenib increased levels of p-ATM, p-ATR and γ-H2AX in parental and dabrafenib resistant cell lines. Proteomics analysis on WM-115 versus WM-115DR cell line was performed to determine alterations in mitochondrial protein expression upon resistance to BRAF inhibitors. The data indicated upregulation of proteins with antioxidant functions including SOD2 (superoxide dismutase [Mn]) and Peroxiredoxin-1 (PRDX1) in WM-115DR cells compared to WM-115 parental which was confirmed by immunoblotting analysis. Overall, this study suggested that the combination of ROS quenching agent (A100) with BRAF inhibitor (dabrafenib) could be a potential strategy to treat BRAF-mutant melanoma patients.

Citation Format: Long Yuan, Rosalin Mishra, Hima Patel, Samar Alanazi, Joan Garrett. Reactive oxygen species scavenger extends the efficacy of BRAF inhibitors in BRAF-mutant melanoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 4900.

Can we predict sputum eosinophilia from clinical assessment in patients referred to an adult asthma clinic?

BACKGROUND

There is overwhelming evidence that asthma guidelines aimed at reducing airway inflammation are superior to those based on clinical symptoms alone. This involves targeting eosinophilic inflammation with inhaled corticosteroids.

AIM

Because induced sputum is not readily available, our study set out to investigate whether the collective or singular use of routine asthma investigations can predict sputum eosinophilia.

METHODS

Eighty patients underwent skin prick testing, blood tests (IgE, full blood count), spirometry, exhaled fraction nitric oxide (FeNO), PD15 to hypertonic saline, and induced sputum testing at first assessment. A predictive model for sputum eosinophilia (defined as ≥3% eosinophils) was sought using routinely available tests.

RESULTS

Fifty-four subjects underwent both induced sputum and FeNO testing. Seventeen (30%) revealed eosinophilic inflammation, nine (16%) neutrophilic, four (7%) mixed granulocytic and 26 (46%) paucigranulocytic. Positive predictors for sputum eosinophilia included low forced expiratory volume in 1 s (FEV(1))% predicted, raised serum eosinophil, positive smoking history, Polynesian ethnicity and negative asthma family history. There was a non-statistically significant trend for FeNO predicting sputum eosinophilia. The best combination of predictors was low FEV(1)% predicted, raised serum eosinophil, positive smoking history and negative family history of asthma.

CONCLUSION

This study demonstrates that the serum eosinophil count and FEV(1) combined with aspects of a clinical history may provide a simple and practical alternative to assessment of airway (sputum) eosinophilia in the clinical setting. A full blood count can be performed at a substantially lesser cost and with greater accessibility than induced sputum. We feel the time has come for the clinical utility of the serum eosinophil count to be revisited.

Pregnancy intention and postpartum depression: secondary data analysis from a prospective cohort

OBJECTIVE

To assess the relationship between unintended pregnancy and postpartum depression.

DESIGN

Secondary analysis of data from a prospective pregnancy cohort.

SETTING

The study was performed at the University of North Carolina prenatal care clinics.

POPULATION/SAMPLE

Pregnant women enrolled for prenatal care at the University of North Carolina Hospital Center.

METHODS

Participants were questioned about pregnancy intention at 15-19 weeks of gestation, and classified as having an intended, mistimed or unwanted pregnancy. They were evaluated for postpartum depression at 3 and 12 months postpartum. Log binomial regression was used to assess the relationship between unintended pregnancy and depression, controlling for confounding by demographic factors and reproductive history.

MAIN OUTCOME MEASURES

Depression at 3 and 12 months postpartum, defined as Edinburgh Postpartum Depression Scale score >13.

RESULTS

Data were analysed for 688 women at 3 months and 550 women at 12 months. Depression was more likely in women with unintended pregnancies at both 3 months (risk ratio [RR] 2.1, 95% confidence interval [95% CI] 1.2-3.6) and 12 months (RR 3.6, 95% CI 1.8-7.1). Using multivariable analysis adjusting for confounding by age, poverty and education level, women with unintended pregnancies were twice as likely to have postpartum depression at 12 months (RR 2.0, 95% CI 0.96-4.0).

CONCLUSION

While many elements may contribute to postpartum depression, unintended pregnancy could also be a contributing factor. Women with unintended pregnancy may have an increased risk of depression up to 1 year postpartum.

Abstract 231: Upregulation of HER3 (ErbB3) levels and function counteracts the antitumor effect of HER2 and PI3K inhibitors

We examined HER3 by immunohistochemistry in formalin-fixed tumor blocks of patients with HER2-overexpressing breast cancer treated with the HER2 tyrosine kinase inhibitor (TKI) lapatinib. HER3 levels increased 135% after 2 weeks of lapatinib therapy compared to pre-therapy levels (n=8; p=0.03). Treatment of mice bearing BT474 xenografts with lapatinib also increased levels of both HER3 mRNA and protein. Treatment with lapatinib of HER2-overexpressing BT474, SKBR3, and SUM225 cells also induced upregulation of HER3 RNA and protein. There was recovery of HER3 phosphorylation that correlated with recovery of P-Akt when P-HER2 was still inhibited. Inhibition of PI3K or Akt with small molecule inhibitors or with Akt1, Akt2, and Akt3 siRNA resulted in upregulation of HER3 mRNA/protein. Expression of myristoylated Akt reduced basal and lapatinib-induced HER3 mRNA and protein, suggesting that PI3K/Akt signaling downstream of HER2 represses HER3 expression.

We identified three putative FoxO3a sites in the ERRB3 promoter. The transcription factor FoxO3a is negatively regulated by AKT-induced phosphorylation. FoxO3a knockdown with siRNA reduced basal and lapatinib-induced increase in HER3 mRNA. We next conducted chromatin immunoprecipitation (ChIP) with FoxO antibodies. There was an increase in the HER3 PCR product using all three sets of primers specific to the FoxO binding sites upon treatment of BT474 cells with lapatinib, supporting direct FoxO protein binding to the HER3 promoter.

We hypothesized that sustained inhibition of HER3 and its output to PI3K/Akt is required for the optimal antitumor effect of HER2 inhibitors. Indeed, transfection with HER3 siRNA sensitized HER2+ cancer cells 3-fold to lapatinib-induced apoptosis. Similarly, the HER3 monoclonal antibody AMG-888 sensitized cells to lapatinib both in vitro and in vivo. Combined treatment with lapatinib and AMG-888 of mice bearing BT474 xenografts inhibited [18F]-FDG-PET uptake, P-HER3, and P-Akt and increased nuclear FoxO3a, all pharmacodynamic biomarkers of PI3K/Akt activity, more effectively than each inhibitor alone. The recovery of P-HER3 following lapatinib-induced inhibition of HER2 was not blocked by MET, FGFR2, EGFR, Src, and IGF-IR inhibitors, nor by pertuzumab. However, trastuzumab prevented recovery of P-HER3, suggesting that a ligand-independent HER2-HER3 interaction was involved in partial maintenance of P-HER3. Finally, treatment of mice bearing BT474 xenografts with lapatinib and trastuzumab eliminated 16/16 tumors within ≪3 weeks. Therefore, in HER2+ cancers, inhibition of HER2 with TKIs will inhibit PI3K/Akt and relieve suppression of HER3 expression. In turn, FoxO-induced upregulation of HER3 counteracts the full response to HER2 TKIs. These data suggest that current inhibitors of HER2 and PI3K/Akt will not block the PI3K pathway in sustained fashion unless combined with HER3 antagonists.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 231. doi:10.1158/1538-7445.AM2011-231

Abstract P5-06-10: ErbB Signaling Is Required for Activation of Phosphatidylinositol-3 Kinase and Transformation of Mammary Epithelial Cells by Polyomavirus Middle T Antigen

Summary

Polyomavirus middle T (PyVmT) transforms cells through phosphatidylinositol 3-kinase (PI3K). Overexpression of ErbB2/ErbB3 heterodimers, potent activators of PI3K, occurs in PyVmT-driven mouse mammary tumors, but without known cause and consequence. Inhibition of ErbB2 with lapatinib, or genetically engineered loss of ErbB3, decreased PI3K signaling and tumor growth in mice, suggesting ErbB2/ErbB3 is required by PyVmT. ErbB2/ErbB3 formed signaling complexes containing PyVmT, p85 and Src. EZN-3920, a novel high-affinity oligonucleotide targeting ErbB3 transcripts, impaired ErbB3 expression in vivo, decreased PI3K signaling, cell survival, and growth of tumors, and improved response to lapatinib. Therefore, PyVmT utilizes ErbB2/ErbB3 overexpression to drive PI3K signaling. Furthermore, the challenge of ErbB3 as a kinase-inactive therapeutic target can be overcome by targeting ErbB3 mRNA transcripts in vivo. Significance

Given the widespread use of, and knowledge gained from the MMTV-PyVmT transgenic mouse breast cancer model, understanding how PyVmT utilizes existing cell signaling programs is necessary to interpret how results impact our understanding/treatment of human breast cancers. We found that ErbB2/ErbB3 heterodimers were a necessary part of PyVmT signaling complexes involving Src and PI3K, and that PyVmT depends on ErbB3 in the breast epithelium for PI3K activity and tumor growth. Because ErbB3 harbors a weak/inactive tyrosine kinase, therapeutic anti-ErbB3 interventions present with challenges. Further, anti-ErbB3 antibodies that block ligand interaction with ErbB3 do not alter ligand-independent ErbB3 signaling. However. these challenges were overcome using high-affinity oligonucleotides targeting ErbB3 mRNA. Use of the oligonucleotide EZN-3920 effectively reduced ErbB3 expression, inhibited PyVmT tumor growth, and improved the response of tumors to lapatinib. These results support oligonucleotide knock-down of targets as potential therapeutic strategy.

Citation Information: Cancer Res 2010;70(24 Suppl):Abstract nr P5-06-10.

Transcriptional and Post-Translational Upregulation of HER3 (ErbB3) Counteracts Antitumor Effect of HER2 Tyrosine Kinase Inhibitors

We hypothesized that sustained inhibition of HER3 and its output to PI3K/Akt is required for the optimal antitumor effect of HER2 inhibitors. Therefore, we examined the temporal effect of the HER2 tyrosine kinase inhibitor (TKI) lapatinib (lap) on feedback upregulation of active HER3 in HER2-overexpressing breast cancer cells. A time course with lap-treated cells showed 3 to 5-fold upregulation of HER3 RNA and protein, beginning at 4 h and increasing through 48 h. P-Tyr immunoblot of HER3 immunoprecipitates revealed recovery of HER3 phosphorylation at and beyond 13 h of treatment. Site-specific antibodies revealed HER3 phosphorylation at Y1197 and Y1289, two of the six p85 binding sites in HER3. Recovery of P-HER3 correlated temporally with recovery of T308 P-Akt. The upregulation of HER3 RNA upon treatment with lap suggested that inhibition of active HER2 and PI3K/Akt derepresses the transcription factor FoxO3a. Putative FoxO3a binding sites were identified within the 5' flanking region upstream of the HER3 transcription start site. Transfection with FoxO3a siRNA reduced basal and lap-induced HER3 RNA levels 2 to 5-fold compared to control cells. Conversely, overexpression of FoxO3a increased HER3 RNA 2.5-fold, which could be further enhanced by lap treatment. In addition to these transcriptional mechanisms, the recovery of P-HER3 upon lap-induced inhibition of HER2 suggested engagement of another tyrosine kinase transactivating HER3 and/or that HER2 had been incompletely inhibited by the TKI. However, IGF-IR, Src, and MET TKIs did not inhibit the recovery of P-HER3. On the other hand, the addition of trastuzumab (tz) to lap-treated cells prevented recovery of P-HER3, suggesting that disruption of a ligand-independent HER2-HER3 interaction was involved in partial maintenance of HER3 phosphorylation.The upregulation of HER3 RNA and partial maintenance of P-HER3 and P-Akt suggested that combined inhibition of HER2 and HER3 will synergistically inhibit tumor cell viability. Transfection with HER3 siRNA sensitized HER2+ breast cancer cells to each lap and tz as assessed by Apo-BrdU (apoptosis) and 3D-Matrigel growth assays. Further, treatment with AMG-888, a HER3 monoclonal antibody (AMGEN-U3), sensitized cells to each lap and tz. Ongoing studies include the treatment of BT474 xenografts in athymic mice with lap ± AMG-888 using [18F]-FDG-PET as a non-invasive imaging biomarker to predict treatment outcome. Finally, we examined HER3 levels by immunohistochemistry in sections from tumor blocks of patients enrolled in a neoadjuvant trial where lap was given alone during the first 6 weeks of therapy. The percent and intensity of tumor cell staining was calculated as a histoscore (Human Pathol. 26:291, 1995). On week 2 of therapy, HER3 levels increased 135% above pre-therapy levels (n=8; p=0.03, Mann-Whitney). These data suggest that upon inhibition of the HER2 tyrosine kinase, HER2+ breast cancers 1) upregulate HER3 by transcriptional mechanisms and partially maintain HER3 function by post-translational mechanisms; 2) this compensatory phosphorylation of HER3 partially maintains PI3K/Akt; and 3) inhibition of HER3 sensitizes HER2-dependent breast cancer cells to HER2 inhibitors.

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 63.

Phase I active immunotherapy with combination of two chimeric, human epidermal growth factor receptor 2, B-cell epitopes fused to a promiscuous T-cell epitope in patients with metastatic and/or recurrent solid tumors

PURPOSE To evaluate the maximum-tolerated dose (MTD), safety profile, and immunogenicity of two chimeric, B-cell epitopes derived from the human epidermal growth factor receptor (HER2) extracellular domain in a combination vaccine with a promiscuous T-cell epitope (ie, MVF) and nor-muramyl-dipeptide as adjuvant emulsified in SEPPIC ISA 720. PATIENTS AND METHODS Eligible patients with metastatic and/or recurrent solid tumors received three inoculations on days 1, 22, and 43 at doses of total peptide that ranged from 0.5 to 3.0 mg. Immunogenicity was evaluated by enzyme-linked immunosorbent assay, flow cytometry, and HER2 signaling assays. Results Twenty-four patients received three inoculations at the intended dose levels, which elicited antibodies able to recognize native HER2 receptor and inhibited both the proliferation of HER2-expressing cell lines and phosphorylation of the HER2 protein. The MTD was determined to be the highest dose level of 3.0 mg of the combination vaccine. There was a significant increase from dose level 1 (0.5 mg) to dose level 4 (3.0 mg) in HER2-specific antibodies. Four patients (one each with adrenal, colon, ovarian, and squamous cell carcinoma of unknown primary) were judged to have stable disease; two patients (one each with endometrial and ovarian cancer) had partial responses; and 11 patients had progressive disease. Patients with stable disease received 6-month boosts, and one patient received a 20-month boost. CONCLUSION The combination vaccines were safe and effective in eliciting antibody responses in a subset of patients (62.5%) and were associated with no serious adverse events, autoimmune disease, or cardiotoxicity. There was preliminary evidence of clinical activity in several patients.

Characterization of formulated microbial products by denaturing gradient gel electrophoresis, total cellular fatty acid analysis, and DNA microarray analysis

Two commercial products, Biotize and Cycle, containing bacteria as an active ingredient were characterized for species identification and batch-to-batch variation by denaturing gradient gel electrophoresis (DGGE), total cellular fatty acid analysis (FAA), and a taxonomic DNA microarray. DGGE was useful at assessing the stability of consortia in different batches, and cluster analysis differentiated each batch even when only slight differences in species composition were observed. DGGE, FAA, and DNA microarray results indicated little batch-to-batch variation in Biotize and some batch variation in Cycle. The 3 methods agreed well with species identification in Biotize but generated conflicting results in the species composition of Cycle. This multi-method approach was useful in determining if the observed bacterial species present in the products matched the expected species composition.

Prevalence of Giardia in symptomatic dogs and cats throughout the United States as determined by the IDEXX SNAP Giardia test

National prevalence of Giardia infection in dogs and cats presenting to clinics with vomiting and/or diarrhea was examined using the IDEXX SNAP Giardia test kit. Veterinary practices across the United States were sent an invitation to participate in the survey and asked to use the test on fecal samples from the target population. The survey requested that the clinics report the results of 20 or more tests. A total of 21,092 results were reported, comprised of 16,114 dogs and 4,978 cats. Analysis of the data (excluding the handful of results reported from Puerto Rico) showed a Giardia prevalence of 15.6% among dogs tested, and 10.8% among cats. This difference was statistically significant (p < 0.001). Regional categorization into Northeast, Southeast, West, and Midwest drew out significant (p < 0.001) differences in prevalence in most cases for dogs; the differences were not significant for cats. These differences and other variables are currently being examined with this and additional data sets. We conclude on the basis of the SNAP test diagnostic that Giardia is a common enteric agent among dogs and cats with gastrointestinal signs.

Management of solitary pulmonary nodules: how do thoracic computed tomography and guided fine needle biopsy influence clinical decisions?

BACKGROUND

Computed tomography (CT) and fine needle guided biopsy (FNB) are often used in the assessment of patients with lung nodules. The influence of these techniques on clinical decision making has not been quantified, especially for small solitary pulmonary nodules (SPN) where the probability of malignancy is lower. A study was undertaken to determine the effect of CT and FNB derived information on clinical decision making in patients with a solitary pulmonary nodule < or = 3 cm in diameter on initial chest radiography.

METHODS

Clinical, physiological, and outcome data on 114 patients with an SPN < or = 3 cm who had subsequent thoracic CT and FNB were extracted from the records of a specialist cardiorespiratory hospital in Auckland, New Zealand. Chest radiographs and CT scans were reported according to specified criteria by a thoracic radiologist. Computer generated summary sheets were used to present cases to each of six clinicians. Each case was presented three times: (1) with clinical data and chest radiograph only; (2) with the addition of the CT report; and (3) with all data including the result of the FNB. Clinicians were asked to specify their management on each occasion and to estimate the probability of the lesion being malignant. Reproducibility was assessed by re-evaluating 24 cases 1 month later.

RESULTS

33 (29%) nodules were benign, 35 (31%) nodules (malignant) were resected with negative node sampling, and 46 (40%) had a non-curative outcome (radiotherapy, incomplete resection, refused therapy). Intra-clinician decision making was consistent for all three levels of clinical data (median kappa values 0.79-0.89). Agreement between clinicians on the need for surgery was lowest with chest radiography alone (kappa=0.33), rose with CT information (kappa=0.44), and increased further with the addition of the FNB data (kappa=0.57). The proportion of successful decisions on surgical intervention (against the known outcome) increased with the addition of CT reports and further with FNB reports (p=0.006, Friedman's test). The major benefit of the information added by CT and FNB reports was a reduction in unnecessary surgery, especially when the clinical perception of pre-test probability of malignancy was intermediate (31-70%). FNB data contributed most to the benefit (p<0.001). The addition of CT and FNB was cost efficient and can be applied specifically to patients with a low or intermediate probability of malignancy.

CONCLUSION

Both CT and FNB make cost effective contributions to the clinical management of SPN < or = 3 cm in diameter by reducing unnecessary operations and increasing agreement between physicians on the need for surgery.

Management of solitary pulmonary nodules: how do thoracic computed tomography and guided fine needle biopsy influence clinical decisions?

BACKGROUND

Computed tomography (CT) and fine needle guided biopsy (FNB) are often used in the assessment of patients with lung nodules. The influence of these techniques on clinical decision making has not been quantified, especially for small solitary pulmonary nodules (SPN) where the probability of malignancy is lower. A study was undertaken to determine the effect of CT and FNB derived information on clinical decision making in patients with a solitary pulmonary nodule < or = 3 cm in diameter on initial chest radiography.

METHODS

Clinical, physiological, and outcome data on 114 patients with an SPN < or = 3 cm who had subsequent thoracic CT and FNB were extracted from the records of a specialist cardiorespiratory hospital in Auckland, New Zealand. Chest radiographs and CT scans were reported according to specified criteria by a thoracic radiologist. Computer generated summary sheets were used to present cases to each of six clinicians. Each case was presented three times: (1) with clinical data and chest radiograph only; (2) with the addition of the CT report; and (3) with all data including the result of the FNB. Clinicians were asked to specify their management on each occasion and to estimate the probability of the lesion being malignant. Reproducibility was assessed by re-evaluating 24 cases 1 month later.

RESULTS

33 (29%) nodules were benign, 35 (31%) nodules (malignant) were resected with negative node sampling, and 46 (40%) had a non-curative outcome (radiotherapy, incomplete resection, refused therapy). Intra-clinician decision making was consistent for all three levels of clinical data (median kappa values 0.79-0.89). Agreement between clinicians on the need for surgery was lowest with chest radiography alone (kappa=0.33), rose with CT information (kappa=0.44), and increased further with the addition of the FNB data (kappa=0.57). The proportion of successful decisions on surgical intervention (against the known outcome) increased with the addition of CT reports and further with FNB reports (p=0.006, Friedman's test). The major benefit of the information added by CT and FNB reports was a reduction in unnecessary surgery, especially when the clinical perception of pre-test probability of malignancy was intermediate (31-70%). FNB data contributed most to the benefit (p<0.001). The addition of CT and FNB was cost efficient and can be applied specifically to patients with a low or intermediate probability of malignancy.

CONCLUSION

Both CT and FNB make cost effective contributions to the clinical management of SPN < or = 3 cm in diameter by reducing unnecessary operations and increasing agreement between physicians on the need for surgery.

A child with Miller Fisher syndrome

We describe the case of a six-year-old girl who presented with a 3-day history of diplopia and gait disturbance following a febrile flu-like illness. On examination she was found to have ataxia, areflexia and ophthalmoplegia, and a diagnosis of Miller Fisher syndrome was made after the exclusion of other conditions. This report outlines the frequency of Miller Fisher syndrome and lists the differential diagnoses that should be considered in Australia. In addition, the occurrence of pupillary dysfunction is discussed.

Case-control study of severe life threatening asthma (SLTA) in adults: psychological factors

BACKGROUND

Severe life threatening asthma (SLTA) is important in its own right and as a proxy for asthma death. In order to target hospital based intervention strategies to those most likely to benefit, risk factors for SLTA among those admitted to hospital need to be identified. Adverse psychological factors are purported risk factors for asthma death and SLTA /near fatal asthma. A study was undertaken to determine whether, in comparison with patients admitted to hospital with acute asthma, those with SLTA have specific adverse psychological factors.

METHODS

A case-control study was undertaken. Cases (n=77) were admitted to the intensive care unit with SLTA (mean (SD) pH 7.17 (0.15), PaCO(2) 10.7 (5.0) kPa). Controls (n=239) were admitted to general wards with acute asthma and were matched only by date of index attack. An interviewer administered questionnaire was undertaken 24-48 hours after admission. A random sample of community based asthmatics was recruited to provide normative data on asthmatics for comparison with cases and hospital controls.

RESULTS

The risk of SLTA increased with age (OR 1.04/year, 95% CI 1.01 to 1.07) and was less for women (OR 0.36, 95% CI 0.20 to 0.68). These variables were controlled for in all further analyses. There was a high prevalence of psychological disorder in both cases and matched controls, but there was no difference in prevalence of caseness for anxiety or depression, total (or individual) life events in last 12 months, availability of general or disease specific social support, nor in any of the domains of the Attitudes and Beliefs about Asthma Questionnaire (emotional (mal) adjustment, doctor-patient relationship, stigma, self-efficacy). Cases (SLTA) were less likely to have had previous emotional counselling (25% v. 35%, p<0.05). However, when comparison was made with a community based group of asthmatic patients, those admitted to hospital with acute asthma (SLTA and hospital controls) had a higher prevalence of anxiety and depression, higher total life events, and higher prevalence of certain specific life events.

CONCLUSIONS

There was considerable psychological morbidity generally (and anxiety specifically) in those admitted with acute asthma. Specific adverse psychological factors were not risk factors for SLTA, when comparison was made with those admitted to hospital with acute asthma, but adverse psychological factors were a risk factor for hospitalisation for acute asthma (including SLTA). Psychological risk factors for adverse events in asthma are dependent both on the type of event under study and the comparison group used.

Normal midtrimester (17-20 weeks) genetic sonogram decreases amniocentesis rate in a high-risk population

OBJECTIVE

To evaluate a screening protocol using advanced maternal age, triple-marker screening, and genetic sonography.

METHODS

We compared adverse chromosomal outcomes of pregnancy in 1556 women referred for increased risk of aneuploidy because of either advanced maternal age or triple-marker test results. Patients were counseled about the results of the triple-marker test and subsequent sonography, which led to a patient decision of whether to pursue amniocentesis. Fetal measurements and structural abnormalities were compared with chromosomal findings. When patients elected amniocentesis, karyotypes were obtained.

RESULTS

Genetic sonography reduced the rate of amniocentesis by 61% overall and by 40% when compared with an alpha-fetoprotein profile alone. The sensitivity of sonography combined with the triple-marker screen for the detection of trisomy 21 was 87% compared with 91% for the triple-marker screen alone.

CONCLUSIONS

This study confirmed that sonographic findings in a targeted population, in combination with other risk markers (advanced maternal age and triple-marker screening), can be used to assess the risk of aneuploidy. Biometry provides additional information for assessing the risk of aneuploidy. Combining advanced maternal age, serum triple-marker screening, and sonographic screening may provide better risk prediction for use in clinical counseling.

Synthesis, anticonvulsant properties and pharmacokinetic profile of novel 10,11-dihydro-10-oxo-5H-dibenz/b,f/azepine-5-carboxamide derivatives

A series of novel derivatives of oxcarbazepine (5), 10,11-dihydro-10-oxo-5H-dibenz/b,f/azepine-5-carboxamide was synthesised and evaluated for their anticonvulsant activity and sodium channel blocking properties. The oxime 8 was found to be the most active compound from this series, displaying greater potency than its geometric isomer 9 and exhibiting also the highest protective index value. Importantly, the metabolic profile of 8 differs from the already established dibenz/b,f/azepine-5-carboxamide drugs such as 1 and 5 which undergo rapid and complete conversion in vivo to several biologically active metabolites. In contrast 8 is metabolised to only a very minor extent leading to the conclusion that the observed anti-convulsant effect is solely attributable to 8. It is concluded that 8 may be as effective as 1 and 5 at controlling seizures and that the low toxicity and consequently high protective index should provide the compound with an improved side-effect profile.

Lung volume reduction surgery: the Thoracic Society of Australia and New Zealand

Lung volume reduction surgery involves the removal of emphysematous lung tissue with the aim of palliating symptoms in selected patients with severe emphysema. This form of surgery is being practised in Australia with favourable short-term outcomes, similar to those reported in the literature. Large multicentre trials are currently underway in North America and the United Kingdom to clarify issues of safety and long-term efficacy. As a result, it is too early to apply an evidence-based approach to this procedure. In the meantime, local audits of practice need to be undertaken to define patient subgroups at higher risk of morbidity and mortality.

Case-control study of severe life threatening asthma (SLTA) in adults: demographics, health care, and management of the acute attack

BACKGROUND

Severe life threatening asthma (SLTA) is important in its own right and as a proxy for asthma death. In order to target hospital based intervention strategies to those most likely to benefit, risk factors for SLTA among those admitted to hospital need to be identified. A case-control study was undertaken to determine whether, in comparison with patients admitted to hospital with acute asthma, those with SLTA have different sociodemographic and clinical characteristics, evidence of inadequate ongoing medical care, barriers to health care, or deficiencies in management of the acute attack.

METHODS

Seventy seven patients with SLTA were admitted to an intensive care unit (pH 7.17 (0.15), PaCO(2) 10.7 (5.0) kPa) and 239 matched controls (by date of index attack) with acute asthma were admitted to general medical wards. A questionnaire was administered 24-48 hours after admission.

RESULTS

The risk of SLTA in comparison with other patients admitted with acute asthma increased with age (odds ratio (OR) 1.04/year, 95% CI 1.01 to 1.07) and was less for women (OR 0.36, 95% CI 0.20 to 0.68). These variables were controlled for in all subsequent analyses. There were no differences in other sociodemographic features. Cases were more likely to have experienced a previous SLTA (OR 2.04, 95% CI 1.20 to 3.45) and to have had a hospital admission in the last year (OR 1.86, 95% CI 1.09 to 3.18). There were no differences between cases and controls in terms of indicators of quality of ongoing asthma specific medical care, nor was there evidence of disproportionate barriers to health care. During the index attack cases had more severe asthma at the time of presentation, were less likely to have presented to general practitioners, and were more likely to have called an ambulance or presented to an emergency department. In terms of pharmacological management, those with SLTA were more likely to have been using oral theophylline (OR 2.14, 95% CI 1.35 to 3.68) and less likely to have been using inhaled corticosteroids in the two weeks before the index attack (OR 0.69, 95% CI 0.47 to 0.99). While there was no difference in self-management knowledge or behaviour scores, those with SLTA were more likely to have inappropriately used oral corticosteroids during the acute attack (OR 2.09, 95% CI 1.02 to 4.47).

CONCLUSIONS

In comparison with those admitted to hospital with acute severe asthma, patients with SLTA were indistinguishable on sociodemographic criteria (apart from male predominance), were more likely to have had a previous SLTA or hospital admission in the previous year, had similar quality ongoing asthma care, had no evidence of increased physical, economic or other barriers to health care, but had demonstrable deficiencies in the management of the acute index attack. Educational interventions, while not losing sight of the need for good quality ongoing care, should focus on providing individual patients with better advice on self-management of acute exacerbations.

Training in back care to improve outcome and patient satisfaction. Teaching old docs new tricks

BACKGROUND

We examined clinical outcomes and patient perceptions of back care given by physicians before and after an intensive course of training in back care and limited manual therapy techniques.

METHODS

From a prospective observational cohort study of low back pain involving 208 physicians (115 primary care) and their patients and a subsequent clinical trial of treatment of low back pain given by 31 physicians specially trained in manual therapy and enhanced back care, outcome data from the patients of 13 physicians participating in both studies were compared. In the observational study, the 13 physicians cared for 120 patients. In the manual therapy trial (191 patients) a control group of 94 patients received enhanced back care and an intervention group of 97 patients received enhanced back care plus manual therapy. Pearson's chi-square comparisons and linear and Cox proportional hazard modeling were used to examine effects of variables and recovery time.

RESULTS

Characteristics of the 13 physicians' patients in the cohort group and the manual therapy trial showed some differences in income, workers' compensation, previous employment, and baseline dysfunction. Both control and intervention patients in the manual therapy trial showed more rapid improvement in functional status over time and greater satisfaction with their care than those in the previous cohort study. However, there was no difference between the studies in patient-reported time to return to performing usual daily activities.

CONCLUSIONS

A structured clinical approach to low back care may bring modestly improved clinical outcomes and patient satisfaction.