Patient-derived explants, xenografts and organoids: 3-dimensional patient-relevant pre-clinical models in endometrial cancer.

The majority of endometrial cancers are detected early with a favourable prognosis. However, for patients with advanced disease, chemotherapy response rates and overall survival remains poor. The endometrial cancer population is typically elderly with multiple co-morbidities and aggressive cytotoxic therapy may be hazardous. Therefore, there is an urgent need to define optimal treatment strategies for advanced and recurrent disease and personalise therapy based on individual tumour and patient characteristics. Three-dimensional (3D) models that preserve the tumour microenvironment and tumour-stromal interactions are increasingly important for translational research with the advent of immunotherapy and molecularly targeted agents. 3D patient-relevant pre-clinical models in endometrial cancer include spheroids, patient-derived organoids, microfluidic systems, patient-derived xenografts and patient-derived explants. Here we present a review of available 3D modelling systems in endometrial cancers, highlighting their current use, advantages, disadvantages and applications to translational research with a focus on the power of the patient-derived explant platform.

Identification of tubular injury microRNA biomarkers in urine: comparison of next-generation sequencing and qPCR-based profiling platforms.

BACKGROUND: MicroRNAs (miRNAs) are small, non-coding RNAs that regulate protein levels post-transcriptionally. miRNAs play important regulatory roles in many cellular processes and have been implicated in several diseases. Recent studies have reported significant levels of miRNAs in a variety of body fluids, raising the possibility that miRNAs could serve as useful biomarkers. Next-generation sequencing (NGS) is increasingly employed in biomedical investigations. Although concordance between this platform and qRT-PCR based assays has been reported in high quality specimens, information is lacking on comparisons in biofluids especially urine. Here we describe the changes in miRNA expression patterns in a rodent model of renal tubular injury (gentamicin). Our aim is to compare RNA sequencing and qPCR based miRNA profiling in urine specimen from control and rats with confirmed tubular injury. RESULTS: Our preliminary examination of the concordance between miRNA-seq and qRT-PCR in urine specimen suggests minimal agreement between platforms probably due to the differences in sensitivity. Our results suggest that although miRNA-seq has superior specificity, it may not detect low abundant miRNAs in urine samples. Specifically, miRNA-seq did not detect some sequences which were identified by qRT-PCR. On the other hand, the qRT-PCR analysis was not able to detect the miRNA isoforms, which made up the majority of miRNA changes detected by NGS. CONCLUSIONS: To our knowledge, this is the first time that miRNA profiling platforms including NGS have been compared in urine specimen. miRNAs identified by both platforms, let-7d, miR-203, and miR-320, may potentially serve as promising novel urinary biomarkers for drug induced renal tubular epithelial injury.

A feasibility study of the use of saliva as an alternative to leukocytes as a source of DNA for the study of Pt-DNA adducts in cancer patients receiving platinum-based chemotherapy.

This note presents a comparison of the use of saliva versus leukocytes for the determination of Pt-DNA adducts obtained from patients undergoing platinum-based chemotherapy. Samples of both blood and saliva were taken pre- and post-treatment and were analysed via sector-field inductively coupled plasma mass spectrometry (SF-ICP-MS) to determine the level of Pt-DNA adducts formed. As expected, significant inter-patient variability was seen; however, a lack of correlation between the levels of adducts observed in saliva and blood samples was also observed (Pearson correlation coefficient r = -0.2598). A high yield of DNA was obtained from saliva samples, but significant difficulties were experienced in obtaining patient adherence to the saliva sampling procedure. In both leukocyte and saliva samples, not only was Pt from previous chemotherapy cycles detected, but the rapid appearance of Pt in the DNA was noted in both sample types 1 h after treatment.

Accounting for uncertainty in model-based prevalence estimation: paratuberculosis control in dairy herds.

BACKGROUND: A common approach to the application of epidemiological models is to determine a single (point estimate) parameterisation using the information available in the literature. However, in many cases there is considerable uncertainty about parameter values, reflecting both the incomplete nature of current knowledge and natural variation, for example between farms. Furthermore model outcomes may be highly sensitive to different parameter values. Paratuberculosis is an infection for which many of the key parameter values are poorly understood and highly variable, and for such infections there is a need to develop and apply statistical techniques which make maximal use of available data. RESULTS: A technique based on Latin hypercube sampling combined with a novel reweighting method was developed which enables parameter uncertainty and variability to be incorporated into a model-based framework for estimation of prevalence. The method was evaluated by applying it to a simulation of paratuberculosis in dairy herds which combines a continuous time stochastic algorithm with model features such as within herd variability in disease development and shedding, which have not been previously explored in paratuberculosis models. Generated sample parameter combinations were assigned a weight, determined by quantifying the model's resultant ability to reproduce prevalence data. Once these weights are generated the model can be used to evaluate other scenarios such as control options. To illustrate the utility of this approach these reweighted model outputs were used to compare standard test and cull control strategies both individually and in combination with simple husbandry practices that aim to reduce infection rates. CONCLUSIONS: The technique developed has been shown to be applicable to a complex model incorporating realistic control options. For models where parameters are not well known or subject to significant variability, the reweighting scheme allowed estimated distributions of parameter values to be combined with additional sources of information, such as that available from prevalence distributions, resulting in outputs which implicitly handle variation and uncertainty. This methodology allows for more robust predictions from modelling approaches by allowing for parameter uncertainty and combining different sources of information, and is thus expected to be useful in application to a large number of disease systems.

Treatment patterns and frequency of key outcomes in acute severe asthma in children: a Paediatric Research in Emergency Departments International Collaborative (PREDICT) multicentre cohort study.

RATIONALE: Severe acute paediatric asthma may require treatment escalation beyond systemic corticosteroids, inhaled bronchodilators and low-flow oxygen. Current large asthma datasets report parenteral therapy only. OBJECTIVES: To identify the use and type of escalation of treatment in children presenting to hospital with acute severe asthma. METHODS: Retrospective cohort study of children with an emergency department diagnosis of asthma or wheeze at 18 Australian and New Zealand hospitals. The main outcomes were use and type of escalation treatment (defined as any of intensive care unit admission, nebulised magnesium, respiratory support or parenteral bronchodilator treatment) and hospital length of stay (LOS). MEASUREMENTS AND MAIN RESULTS: Of 14 029 children (median age 3 (IQR 1-3) years; 62.9% male), 1020 (7.3%, 95% CI 6.9% to 7.7%) had treatment escalation. Children with treatment escalation had a longer LOS (44.2 hours, IQR 27.3-63.2 hours) than children without escalation 6.7 hours, IQR 3.5-16.3 hours; p<0.001). The most common treatment escalations were respiratory support alone (400; 2.9%, 95% CI 2.6% to 3.1%), parenteral bronchodilator treatment alone (380; 2.7%, 95% CI 2.5% to 3.0%) and both respiratory support and parenteral bronchodilator treatment (209; 1.5%, 95% CI 1.3% to 1.7%). Respiratory support was predominantly nasal high-flow therapy (99.0%). The most common intravenous medication regimens were: magnesium alone (50.4%), magnesium and aminophylline (24.6%) and magnesium and salbutamol (10.0%). CONCLUSIONS: Overall, 7.3% children with acute severe asthma received some form of escalated treatment, with 4.2% receiving parenteral bronchodilators and 4.3% respiratory support. There is wide variation treatment escalation.

A paraneoplastic manifestation of metastatic breast cancer responding to endocrine therapy: a case report.

BACKGROUND: Many cancers are known to be associated with paraneoplastic syndromes. These syndromes are usually treated by chemotherapy with or without immunosupression but they often respond poorly. There are no published reviews on response to endocrine treatment. CASE PRESENTATION: We report a case of a patient presenting with papillitis, myositis and sensory peripheral neuropathy 18 months before a diagnosis of metastatic oestrogen receptor positive breast cancer was confirmed. The patient was treated with anastrozole which led not only to a decrease of her tumour burden but also to an improvement in her biochemical markers and amelioration of her clinical symptoms. CONCLUSION: This case is an example of breast cancer presenting with paraneoplastic manifestations. It took several months to establish the cause of symptoms in this patient thus illustrating the need for physicians to maintain a high index of suspicion for paraneoplastic syndromes in women presenting with unusual neurological symptoms with no obvious cause.It is a unique case as it illustrates how treatment with an aromatase inhibitor leading to cancer regression can result in an improvement in the paraneoplastic symptoms.

Assessing barriers to a rational chemoprevention trial design in young patients with familial adenomatous polyposis.

Familial adenomatous polyposis coli (FAP) is an autosomal dominant condition caused by a germline mutation in the adenomatous polyposis coli gene. Colonic adenomas form and almost all patients will develop colorectal cancer if they are not managed at an early stage. The safest preventive strategy is surgical resection of the colon, most commonly performed in late teenage years. There is a paucity of trials investigating the use of primary chemoprevention to delay polyp formation in paediatric FAP. There are extensive preclinical and early clinical data demonstrating that curcumin may be a safe and effective chemotherapeutic agent in reducing the polyp burden in this disease. We ultimately proposed to design and conduct a clinical study to assess whether curcumin treatment delays the need for surgery and/or prevents cancer in young patients with FAP. Research into clinical trial protocols has demonstrated that assessing patients' perceptions at the initial stage leads to better outcomes. We therefore conducted a questionnaire study of patients and parents of children affected by FAP to gain information to aid the protocol design. Results demonstrated that there are some FAP patients for whom this study is relevant and desirable. Those with a personal history of curcumin use reported that it was well tolerated. However, the response rate was poor (25%), indicating that there are potential difficulties ensuring adequate recruitment to the proposed trial. This report draws on lessons learnt from prior trials and the findings from the questionnaire to outline the challenges faced in designing such a study.

Susceptibility of glomerular filtration rate estimations to variations in creatinine methodology: a study in older patients.

BACKGROUND: It is recommended that measurement of serum creatinine should be supplemented with a creatinine-based estimation of glomerular filtration rate (GFR). The influence of creatinine methodology on these estimates is not always appreciated. We have studied differences in creatinine methods and their influence on GFR estimation specifically in older people. METHODS: In all, 46 older patients (mean age 80 y, range 69-92 y) with predominantly mild or moderate kidney disease were studied. Serum creatinine was measured using a rate Jaffe method and two different enzymatic methods. Isotope dilution mass spectrometry served as the reference creatinine method. GFR was estimated using both the Modification of Diet in Renal Disease (MDRD) and Cockcroft and Gault formulae: a 51Cr-EDTA GFR estimation served as the reference GFR method. RESULTS: Both enzymatic methods produced creatinine results that were significantly different (P<0.001) from the reference method. The Jaffe method over- and underestimated creatinine at low and high concentrations, respectively. The most likely explanation for these differences relates to standardization of the assays. Irrespective of creatinine method, the Cockroft and Gault formula tended to underestimate GFR, and the MDRD formula to overestimate GFR. Use of the differing creatinine methods to estimate GFR produced predictable biases of the estimate, with mean GFR estimates varying by 14% across the creatinine methods. CONCLUSION: Estimates of GFR depend critically upon the accuracy and precision of the creatinine measurement used in their calculation.

Life, survival, and behavioral health in small closed communities: 10 years of studying isolated Antarctic groups.

In the late 1980s the Australian Antarctic Division collaborated with NASA to use the Australian National Antarctic Research Expeditions' (ANARE) stations to pursue research of benefit to both programs. This article outlines the data collection efforts, the development of analyses, and selected results, and describes some of the benefits for the aerospace, health, and environmental psychology communities. The Behavior and Performance Laboratory at Johnson Space Center developed a questionnaire to sample broadly the many aspects of life in extreme environments analogous to space missions. Data were collected from volunteers involved in various ANAREs conducted from 1994 to 2003. Pool-timed series regression, hierarchical models, and content analysis have all enhanced the understanding of the kinds of psychosocial variables relevant in extreme environments, and how these variables relate to each other; examples are given. Observations gathered over the last 10 yr comprise a unique, comprehensive, and advanced representation of psychosocial factors in this extreme environment and provide a strong base for future research and application.

Gender differences in leader and follower perceptions of social support in Antarctica.

The purpose of this study was to methodologically explore the links among social support, gender, age, prior experience, leader/follower status, and leadership effectiveness noted in previous accounts from Antarctic stations. Data for this study were collected from volunteers involved in Australian National Antarctic Research Expeditions conducted from 1996 to 2001. Multilevel analysis revealed that most of the variance in perceptions of social support was at the individual level (71%). Perceptions of social support had less variance at the group level (29%) and little variance at the weekly level. At the group level, the explanatory variables we examined included leadership effectiveness, gender similarity, and age similarity. At the individual level, the explanatory variables we examined included age, gender, prior experience, and leader/follower status. An interaction between gender and leader/follower status contributed to a significant model of variation in perceptions of social support.

Comet assay measures of DNA damage as biomarkers of irinotecan response in colorectal cancer in vitro and in vivo.

The use of irinotecan to treat metastatic colorectal cancer (CRC) is limited by unpredictable response and variable toxicity; however, no reliable clinical biomarkers are available. Here, we report a study to ascertain whether irinotecan-induced DNA damage measures are suitable/superior biomarkers of irinotecan effect. CRC-cell lines (HCT-116 and HT-29) were treated in vitro with irinotecan and peripheral blood lymphocytes (PBL) were isolated from patients before and after receiving irinotecan-based chemotherapy. Levels of in vitro-, in vivo-, and ex vivo-induced DNA damage were measured using the Comet assay; correlations between damage levels with in vitro cell survival and follow-up clinical data were investigated. Irinotecan-induced DNA damage was detectable in both CRC cell-lines in vitro, with higher levels of immediate and residual damage noted for the more sensitive HT-29 cells. DNA damage was not detected in vivo, but was measurable in PBLs upon mitogenic stimulation prior to ex vivo SN-38 treatment. Results showed that, following corrections for experimental error, those patients whose PBLs demonstrated higher levels of DNA damage following 10 h of SN-38 exposure ex vivo had significantly longer times to progression than those with lower damage levels (median 291 vs. 173 days, P = 0.014). To conclude, higher levels of irinotecan-induced initial and residual damage correlated with greater cell kill in vitro and a better clinical response. Consequently, DNA damage measures may represent superior biomarkers of irinotecan effect compared to the more often-studied genetic assays for differential drug metabolism.

Team climate at Antarctic research stations 1996-2000: leadership matters.

INTRODUCTION: The popular assumption is that extreme environments induce a climate of hostility, incompatibility, and tension by intensifying differences and disagreements among team members. Team members' perceptions of team climate are likely to change over time in an extreme environment, and thus team climate should be considered as a dynamic outcome variable resulting from multiple factors. In order to explore team climate as a dynamic outcome, we explored whether variables at multiple levels of analysis contributed to team climate over time for teams living and working in Antarctica. METHOD: Data for this study were collected from volunteers involved in Australian National Antarctic Research Expeditions conducted from 1996 to 2000. Multilevel analysis was used to partition and estimate the variance in team climate and to explore factors explaining variance at the group/team, individual, and weekly levels. RESULTS: Most of the variance in perceptions of team climate was at the individual level (57%). Team climate had less variance at the group level (16%) and at the weekly level (26%). Results indicated that perceived leadership effectiveness was significantly related to team climate. Perceived leadership effectiveness accounted for an estimated 77% of the group level variance, which equated to 14% of the overall variance in team climate. DISCUSSION: Our results suggest that exploring the characteristics and behaviors that constitute effective leadership would contribute to a more complete and useful picture of team climate, as well as guide selection research.

Speciation of oxaliplatin adducts with DNA nucleotides.

This paper describes a set of fast and selective high performance liquid chromatography (HPLC) methods coupled to electro-spray ionisation linear ion trap mass spectrometry (ESI-MS), sector-field inductively coupled plasma mass spectrometry (SF-ICP-MS) and UV detection for in vitro studies of the bifunctional adducts of oxaliplatin with mono-nucleotides, di-nucleotides and cellular DNA. The stationary phases and the optimised conditions used for each separation are discussed. Interaction of oxaliplatin with A and G mono-nucleotides resulted in the formation of five bifunctional platinum diaminocyclohexane (DACHPt) adducts. These were two isomers of the A-DACHPt-A and A-DACHPt-G adducts, and one G-DACHPt-G adduct, as confirmed by MS/MS spectra obtained by collision induced dissociation. These adducts were also characterised by UV absorption data and SF-ICP-MS elemental (195)Pt and (31)P signals. Further, interaction of oxaliplatin with AG and GG di-nucleotides resulted in the formation of three adducts: DACHPt-GG and two isomers of the DACHPt-AG adduct, as confirmed by ESI-MS and the complementary data obtained by UV and SF-ICP-MS. Finally, a very sensitive LC-ICP-MS method for the quantification of oxaliplatin GG intra-strand adducts (DACHPt-GG) was developed and used for monitoring the in vitro formation and repair of these adducts in human colorectal cancer cells. The method detection limit was 0.14 ppb Pt which was equivalent to 0.22 Pt adduct per 10(6) nucleotides based on a 10 µg DNA sample. This detection limit makes this method suitable for in vivo assessment of DACHPt-GG adducts in patients undergoing oxaliplatin chemotherapy.

Intrahepatic sarcomatoid cholangiocarcinoma.

Intrahepatic sarcomatoid cholangiocarcinoma is a rare but an aggressive variant of cholangiocarcinoma with a very poor prognosis. We report the first caucasian patient who presented with a rapidly enlarging liver mass requiring hepatic resection. Detailed histopathological analyses including immunohistochemistry and electron microscopy confirmed sarcomatoid cholangiocarcinoma. The patient had early onset disease recurrence within 5 weeks of surgery. Here we demonstrate that combination chemotherapy with gemcitabine and cisplatin is a potential treatment option in patients with advanced sarcomatous cholangiocarcinoma. The patient achieved sustained partial remission with combination chemotherapy and remains alive and well more than 29 months since initial surgery.

Novel VEGF signalling inhibitors: how helpful are biomarkers in their early development?

BACKGROUND: The development of vascular endothelial growth factor (VEGF) inhibitors of tumour angiogenesis can only be described as prolific. It is therefore interesting to speculate which will reach the clinic. Of course, the most effective agents will succeed, but how is effectiveness measured? When presented with a summary of competitive compounds, it can be difficult to discriminate between their potency on target, toxicity and response rates. OBJECTIVES: A comparison was undertaken between new small-molecule tyrosine kinase inhibitors with vascular endothelial growth factor receptor as one of their targets. Factors considered included mode of action (targets), toxicity and usefulness of biomarker data. METHODOLOGY: We carried out a systematic review using PubMed, MEDLINE and American Society of Clinical Oncologist (ASCO) databases for articles (including abstracts) presented in 2007 - 2009. Search terms included 'angiogenesis inhibitors', 'tyrosine kinase inhibitors', 'VEGF' and 'biomarkers'. Nine compounds were selected for detailed comparison. RESULTS AND CONCLUSIONS: The toxicity profiles of the compounds were similar. Many exposure biomarkers have been identified that have informed the dose and scheduling of these compounds in clinical trials. Progress has also been made in identifying potential efficacy and predictive biomarkers for these new agents; however, these are yet to be validated.