The impacts of geometry and binding on CaMKII diffusion and retention in dendritic spines.

We used a particle-based Monte Carlo simulation to dissect the regulatory mechanism of molecular translocation of CaMKII, a key regulator of neuronal synaptic function. Geometry was based upon measurements from EM reconstructions of dendrites in CA1 hippocampal pyramidal neurons. Three types of simulations were performed to investigate the effects of geometry and other mechanisms that control CaMKII translocation in and out of dendritic spines. First, the diffusional escape rate of CaMKII from model spines of varied morphologies was examined. Second, a postsynaptic density (PSD) was added to study the impact of binding sites on this escape rate. Third, translocation of CaMKII from dendrites and trapping in spines was investigated using a simulated dendrite. Based on diffusion alone, a spine of average dimensions had the ability to retain CaMKII for duration of ~4 s. However, binding sites mimicking those in the PSD controlled the residence time of CaMKII in a highly nonlinear manner. In addition, we observed that F-actin at the spine head/neck junction had a significant impact on CaMKII trapping in dendritic spines. We discuss these results in the context of possible mechanisms that may explain the experimental results that have shown extended accumulation of CaMKII in dendritic spines during synaptic plasticity and LTP induction.

Dissecting cooperative calmodulin binding to CaM kinase II: a detailed stochastic model.

Calmodulin (CaM) is a major Ca(2+) binding protein involved in two opposing processes of synaptic plasticity of CA1 pyramidal neurons: long-term potentiation (LTP) and depression (LTD). The N- and C-terminal lobes of CaM bind to its target separately but cooperatively and introduce complex dynamics that cannot be well understood by experimental measurement. Using a detailed stochastic model constructed upon experimental data, we have studied the interaction between CaM and Ca(2+)-CaM-dependent protein kinase II (CaMKII), a key enzyme underlying LTP. The model suggests that the accelerated binding of one lobe of CaM to CaMKII, when the opposing lobe is already bound to CaMKII, is a critical determinant of the cooperative interaction between Ca(2+), CaM, and CaMKII. The model indicates that the target-bound Ca(2+) free N-lobe has an extended lifetime and may regulate the Ca(2+) response of CaMKII during LTP induction. The model also reveals multiple kinetic pathways which have not been previously predicted for CaM-dissociation from CaMKII.

Early prediction of response to chemotherapy and survival in malignant pleural mesothelioma using a novel semiautomated 3-dimensional volume-based analysis of serial 18F-FDG PET scans.

UNLABELLED: The aim of chemotherapy for mesothelioma is to palliate symptoms and improve survival. Measuring response using CT is challenging because of the circumferential tumor growth pattern. This study aims to evaluate the role of serial (18)F-FDG PET in the assessment of response to chemotherapy in patients with mesothelioma. METHODS: Patients were prospectively recruited and underwent both (18)F-FDG PET and conventional radiological response assessment before and after 1 cycle of chemotherapy. Quantitative volume-based (18)F-FDG PET analysis was performed to obtain the total glycolytic volume (TGV) of the tumor. Survival outcomes were measured. RESULTS: Twenty-three patients were suitable for both radiological and (18)F-FDG PET analysis, of whom 20 had CT measurable disease. After 1 cycle of chemotherapy, 7 patients attained a partial response and 13 had stable disease on CT assessment by modified RECIST (Response Evaluation Criteria in Solid Tumors) criteria. In the 7 patients with radiological partial response, the median TGV on quantitative PET analysis fell to 30% of baseline (range, 11%-71%). After 1 cycle of chemotherapy, Cox regression analysis demonstrated a statistically significant relationship between a fall in TGV and improved patient survival (P = 0.015). Neither a reduction in the maximum standardized uptake value (P = 0.097) nor CT (P = 0.131) demonstrated a statistically significant association with patient survival. CONCLUSION: Semiquantitative (18)F-FDG PET using the volume-based parameter of TGV is feasible in mesothelioma and may predict response to chemotherapy and patient survival after 1 cycle of treatment. Therefore, metabolic imaging has the potential to improve the care of patients receiving chemotherapy for mesothelioma by the early identification of responding patients. This technology may also be useful in the assessment of new systemic treatments for mesothelioma.

Assessing quality of life during chemotherapy for pleural mesothelioma: feasibility, validity, and results of using the European Organization for Research and Treatment of Cancer Core Quality of Life Questionnaire and Lung Cancer Module.

PURPOSE: To assess the feasibility and validity of using the European Organization for Research and Treatment of Cancer (EORTC) Core Quality of Life Questionnaire (QLQ-C30) and Lung Cancer Module (QLQ-LC13) to describe health-related quality of life (HRQL) in patients with pleural mesothelioma undergoing combination chemotherapy, to identify the most impaired aspects of HRQL, and to assess the impact of chemotherapy on HRQL. PATIENTS AND METHODS: Fifty-three patients received cisplatin on day 1 and gemcitabine on days 1, 8, and 15 of a 28-day cycle for a maximum of six cycles. HRQL was assessed using the EORTC QLQ-C30 and QLQ-LC13. RESULTS: Compliance was 100% at baseline but subsequently decreased. At baseline, role function and social function were the most impaired domains, and the worst-rated symptoms were fatigue, dyspnea, pain, insomnia, appetite loss, and cough. Dyspnea, pain, insomnia, and cough improved with chemotherapy, although functional domains and chemotherapy-related symptoms deteriorated. Fatigue remained unchanged. Few patients reported hemoptysis. Functional domains and symptoms scales from the QLQ-C30 demonstrated predictive validity for survival. The predictive value of QLQ-LC13 pain scores was improved by combining three pain items into a single score. Dyspnea scores were correlated strongly with lung function as measured by forced vital capacity. CONCLUSION: This study supports the validity of the EORTC QLQ-C30 and LC13 as outcome measures for trials of chemotherapy in mesothelioma. Although the most prominent symptoms reported were concordant with clinical experience, impairments in role and social function and insomnia were worse than expected. Future research should focus on how best to apply, analyze, and interpret existing, validated HRQL instruments in mesothelioma research and practice, not on the development of new ones.

Assessing the effectiveness of a mammography screening service.

BACKGROUND: Trials have shown that mammography screening reduces mortality and probably decreases morbidity related to breast cancer. METHODS: We assessed whether the major mammography service in Western Australia (BreastScreen WA) is likely to reduce mortality by comparing prognostic variables between screen-detected and other cases of breast cancer diagnosed in 1999. We assessed likely reductions in morbidity by comparing treatments received by these two groups. To confirm mortality and morbidity reduction, we also compared prognostic variables and treatments with targets. Information on demographic variables, tumour characteristics at presentation and treatments were collected from medical records for all incident cases of breast cancer in Western Australia in 1999. We matched cases with the Western Australian Cancer Registry records to determine which cases had been detected by BreastScreen WA. RESULTS: BreastScreen WA achieved the targets for mortality reduction. Tumours detected by BreastScreen WA were smaller in size, less likely to have vascular invasion, of lower histological grade and were more likely to be ductal carcinoma in situ alone without invasive carcinoma. Oestrogen receptor status was more likely to be positive, the difference in progesterone status was not significant, and lymph node involvement tended to be lower. BreastScreen WA patients were treated more often with local therapy and less often with systemic therapy, and the proportion of patients treated with breast-conserving surgery was close to the target for minimizing morbidity in breast cancer. CONCLUSION: Mammographic detection of breast cancer by BreastScreen WA is associated with reduced breast cancer morbidity and a more favourable prognosis.

Surgical management of lung cancer in Western Australia in 1996 and its outcomes.

BACKGROUND: All cases of lung cancer diagnosed in Western Australia in 1996 in which surgery was the primary treatment, were reviewed. Reported herein are the characteristics of the patients, the treatment outcomes and a comparison of the management undertaken with that recommended by international guidelines. METHODS: All patients with a new diagnosis of lung cancer in Western Australia in the calendar year of 1996 were identified using two different population-based registration systems: the Western Australian (WA) Cancer Registry and the WA Hospital Morbidity Data System. A structured questionnaire on the diagnosis and management was completed for each case. Date of death was determined through the WA Cancer Registry. RESULTS: Six hundred and sixty-eight patients with lung cancer were identified; 132 (20%) were treated with surgery. Lobectomy was the most frequently performed procedure (71%), followed by pneumonectomy (19%). Major complications affected 23% of patients. Postoperative mortality was 6% (3% lobectomy, 12% pneumonectomy). At 5 years the absolute survival was as follows for stage I, II, IIIA, IIIB, respectively: 51%, 45%, 12%, 5%. CONCLUSIONS: Investigations and choice of surgery in WA in 1996 reflect current international guidelines. The survival of patients with resectable lung cancer remains unsatisfactory.

Observer variability in mesothelioma tumor thickness measurements: defining minimally measurable lesions.

INTRODUCTION: Single time-point unidimensional tumor thickness measurements define measurable disease for clinical trial inclusion and also constitute a field in the International Association for the Study of Lung Cancer prospective mesothelioma staging database. The modified Response Evaluation Criteria in Solid Tumors (RECIST) guidelines for mesothelioma did not alter the 10-mm minimum tumor measurement recommendation. However, as computed tomography technology has advanced, we sought to examine whether interobserver agreement was acceptable at smaller tumor thickness in mesothelioma. METHODS: The primary observer selected 170 discrete measurement sites from 105 thoracic computed tomography scans from 50 consenting patients with pleural mesothelioma. Sites represented a range of tumor thickness, lesion morphology, and location. The outer (parietal) tumor margin was marked at each site and presented to five additional observers, who then selected the visceral margin of the tumor to create a line segment that captured tumor thickness. Relative differences among the observer measurements were estimated using a random-effects analysis of variance model to identify the smallest tumor thickness at which linear measurements could be made reliably. RESULTS: Systematic bias was observed, with some observers consistently measuring larger or smaller thicknesses than the thickness measured by others. The mean range across all 170 sites was 15.1% of the mean per-site measurement (SD = 9.1%; median range, 13.1%). Measurements acquired at sites with mean tumor thickness less than 7.5 mm demonstrated interobserver variability with a 75th percentile included 20% of the tumor thickness. The 95% confidence interval for relative interobserver measurement differences obtained for mean measurement lengths in the range 5 to 7.5 mm does not exceed the RECIST thresholds. CONCLUSIONS: This study has implications for the definition of minimally measurable tumor adopted by clinical trial and staging protocols. Although the statistical findings suggest that a reduction in "minimally measurable disease" from 10 mm to 5 or 7.5 mm might be warranted, clinical factors may ultimately dictate the most appropriate definition.

A benchmark comparison of deterministic and probabilistic methods for defining manual review datasets in duplicate records reconciliation.

INTRODUCTION: Clinical databases require accurate entity resolution (ER). One approach is to use algorithms that assign questionable cases to manual review. Few studies have compared the performance of common algorithms for such a task. Furthermore, previous work has been limited by a lack of objective methods for setting algorithm parameters. We compared the performance of common ER algorithms: using algorithmic optimization, rather than manual parameter tuning, and on two-threshold classification (match/manual review/non-match) as well as single-threshold (match/non-match). METHODS: We manually reviewed 20,000 randomly selected, potential duplicate record-pairs to identify matches (10,000 training set, 10,000 test set). We evaluated the probabilistic expectation maximization, simple deterministic and fuzzy inference engine (FIE) algorithms. We used particle swarm to optimize algorithm parameters for a single and for two thresholds. We ran 10 iterations of optimization using the training set and report averaged performance against the test set. RESULTS: The overall estimated duplicate rate was 6%. FIE and simple deterministic algorithms allowed a lower manual review set compared to the probabilistic method (FIE 1.9%, simple deterministic 2.5%, probabilistic 3.6%; p<0.001). For a single threshold, the simple deterministic algorithm performed better than the probabilistic method (positive predictive value 0.956 vs 0.887, sensitivity 0.985 vs 0.887, p<0.001). ER with FIE classifies 98.1% of record-pairs correctly (1/10,000 error rate), assigning the remainder to manual review. CONCLUSIONS: Optimized deterministic algorithms outperform the probabilistic method. There is a strong case for considering optimized deterministic methods for ER.

Optimized dual threshold entity resolution for electronic health record databases--training set size and active learning.

Clinical databases may contain several records for a single patient. Multiple general entity-resolution algorithms have been developed to identify such duplicate records. To achieve optimal accuracy, algorithm parameters must be tuned to a particular dataset. The purpose of this study was to determine the required training set size for probabilistic, deterministic and Fuzzy Inference Engine (FIE) algorithms with parameters optimized using the particle swarm approach. Each algorithm classified potential duplicates into: definite match, non-match and indeterminate (i.e., requires manual review). Training sets size ranged from 2,000-10,000 randomly selected record-pairs. We also evaluated marginal uncertainty sampling for active learning. Optimization reduced manual review size (Deterministic 11.6% vs. 2.5%; FIE 49.6% vs. 1.9%; and Probabilistic 10.5% vs. 3.5%). FIE classified 98.1% of the records correctly (precision=1.0). Best performance required training on all 10,000 randomly-selected record-pairs. Active learning achieved comparable results with 3,000 records. Automated optimization is effective and targeted sampling can reduce the required training set size.

Trade-offs in quality of life and survival with chemotherapy for advanced breast cancer: mature results of a randomized trial comparing single-agent mitoxantrone with combination cyclophosphamide, methotrexate, 5-fluorouracil and prednisone.

BACKGROUND: We evaluate trade-offs between quality of life (QoL) and survival improvement for two chemotherapy regimens in advanced breast cancer. We also report on the long-term survival of patients in the ANZ 8614 clinical trial. METHODS: A total of 391 patients were randomized to mitoxantrone (14 mg/m(2) intravenously every 21 days) or a combination of cyclophosphamide 100 mg/m(2) and prednisone 40 mg/m(2) orally days 1 to 14 plus methotrexate 40 mg/m(2) and 5-fluorouracil 600 mg/m(2) intravenously days 1 and 8 every 28 days (CMFP). QoL was self-assessed on 14 linear analog scales. We computed the mean differences between the two treatments as products of the mean differences in global QoL, progression-free survival and overall survival. RESULTS: CMFP led to a higher overall tumor response (39% vs. 25%, P=0.004) and longer progression-free survival (PFS) (median 5.6 vs 3.9 months, P=0.02) but with significantly more toxicity from alopecia, mucositis, diarrhea, anemia and lethargy. Overall survival (OS) was similar in the two groups (median 10.1 vs 11.6 months, P=0.81). QoL over the first 12 weeks was rated better by patients on CMFP for mood (P=0.04), nausea and vomiting (P=0.01), and feeling sick (P=0.02) but worse for hair loss (P<0.0001). A weighted combination of individual QoL items favoured CMFP (subset score mean difference 2.4, P=0.03). A global QoL score tended to favour CMFP (global score mean difference 1.7, P=0.18). Quality-adjusted PFS was significantly longer with CMFP (mean 7.208 vs 5.965 months, P=0.04), but quality-adjusted OS was not significantly different (mean 11.832 vs 11.315 months, P=0.57). CONCLUSION: Despite the greater toxicity, the superior antitumor activity of CMFP led to an overall improvement in quality-adjusted PFS. In advanced breast cancer, in clinical decision making about treatment for palliative intent, the principle used to assess trade-offs between antitumor efficacy and toxicity remains relevant and applicable to all modern therapeutic agents.

A phase II clinical trial of the vascular disrupting agent BNC105P as second line chemotherapy for advanced Malignant Pleural Mesothelioma.

BNC105P is a tubulin polymerisation inhibitor that selectively disrupts tumour vasculature and suppresses cancer cell proliferation. This agent has exhibited preclinical and phase I activity in Malignant Pleural Mesothelioma (MPM). This phase II, single arm trial investigated the efficacy and safety of BNC105P as second line therapy in MPM. Participants had progressive MPM after first line pemetrexed/platinum chemotherapy, ECOG PS 0-1, adequate organ function, and measurable disease. BNC105P 16 mg/m(2) was administered intravenously on day 1 and 8 every 21 days until progression or undue toxicity. The primary endpoint was centrally reviewed objective response rate (RR). Tumour response was assessed every two cycles using modified RECIST. 30 patients were enrolled in 10 months, predominantly male (90%), ECOG PS 1 (77%), epithelioid histology (67%), and non-metastatic disease (67%). All patients received at least one dose of study drug, with a median of 2 cycles. No significant haematologic, biochemical, or cardiac adverse events (AEs) were observed. Grade 3 or 4 AEs occurred in 10 patients (33%). There were 2 deaths on study: 1 cardiorespiratory, the other to pneumonia. We observed 1 partial response (3%); 13 patients had stable disease (43%). Median progression free survival was 1.5 months (95% CI 1.4-2.4); median overall survival was 8.2 months (95% CI 3.8-11.9). BNC105P was safe and tolerable. The sole response was insufficient to warrant further research as a single agent.

Duplicate patient records--implication for missed laboratory results.

INTRODUCTION: Although duplicate records are a potential patient safety hazard, the actual clinical harm associated with these records has never been studied. We hypothesized that duplicate records will be associated with missed abnormal laboratory results. METHODS: A retrospective, matched, cohort study of 904 events of abnormal laboratory result (HgbA1c, TSH, Vitamin B(12), LDL). We compared the rates of missed laboratory results between patients with duplicate and non-duplicate records from the ambulatory clinics. Cases were matched according to test and ordering physician. RESULTS: Duplicate records were associated with a higher rate of missed laboratory results (OR=1.44, 95% CI 1.1-1.9). Other factors associated with missed lab results were tests performed as screening (OR=2.22, 95% CI 1.4-3.4), and older age (OR=1.15 for every decade, 95% CI 1.01-1.2). In most cases test results were reported into the main patient record. DISCUSSION: Duplicate records were associated with a higher risk of missing important laboratory results.

A phase II study of intermittent sunitinib malate as second-line therapy in progressive malignant pleural mesothelioma.

INTRODUCTION: There is no accepted second-line therapy for patients with advanced malignant pleural mesothelioma (MPM), whose disease has progressed after first-line chemotherapy. The multitargeted tyrosine kinase inhibitor sunitinib malate targets several pathways overexpressed in mesothelioma. This phase II study assessed objective response to sunitinib and correlative biomarkers in patients with progressive pretreated MPM. METHODS: Eligible patients had confirmed MPM, radiological progression after chemotherapy, Eastern Cooperative Oncology Group performance status 0 to 1, and measurable disease. Patients received oral sunitinib 50 mg daily for 28 of every 42 days. The primary endpoint was objective radiological response. Patients without prior pleurodesis had fluorodeoxyglucose positron emission tomographic response assessed by total glycolytic volume criteria. Correlative biomarkers included serum mesothelin, vascular endothelial growth factor (VEGF)-A, VEGF-C, interleukin-8, sVEGFR-2, sVEGFR-3, and s-kit. RESULTS: Fifty-three patients received sunitinib between July 2006 and December 2009; 51 were assessable for response. Patients received a median of two cycles (range, 1-12); 40% required dose reduction. Fatigue was the most prominent toxicity. Six patients (12%) had a confirmed radiological partial response, 34 (65%) had stable disease, and 11 (22%) had progressive disease as best response. Six of 20 patients had a decrease in fluorodeoxyglucose positron emission tomographic total glycolytic volume of 15% or more. Median overall survival was 6.1 months, and median time to progression was 3.5 months. Correlative biomarkers did not predict treatment response. CONCLUSIONS: Sunitinib has activity in a subset of patients with pretreated MPM. Consideration should be given to different treatment schedules and examination of other biomarkers for further study of sunitinib in MPM.

Serum soluble mesothelin concentrations in malignant pleural mesothelioma: relationship to tumor volume, clinical stage and changes in tumor burden.

PURPOSE: To examine the clinical utility of soluble mesothelin in patients with malignant pleural mesothelioma. EXPERIMENTAL DESIGN: A total of 97 patients (female: 11; male: 86) were prospectively enrolled, longitudinal serum samples collected, and mesothelin concentrations determined. Baseline mesothelin levels were analyzed relative to tumor stage, presence of metastatic disease, the positron emission tomography (PET) parameters maximum standardized uptake value, tumor volume, total glycolytic volume, and survival. Changes in mesothelin level were correlated to objective response to chemotherapy, as assessed radiologically and by PET imaging, and with patient survival. RESULTS: Baseline mesothelin levels greater than 5 nmol/L were a significant negative prognostic indicator (HR = 2.25; 95% CI, 1.20-4.21) and correlated with tumor stage and volume. In 55 patients who received chemotherapy, change in mesothelin correlated with radiological response (χ(2) = 11.32; P = 0.023) and change in metabolically active tumor volume (r = 0.58; P < 0.01). Median survival for patients with a reduction in mesothelin following chemotherapy (19 months) was significantly longer than for patients with increased mesothelin (5 months; P < 0.001). CONCLUSION: These findings show the potential value of changes in mesothelin levels for prognostication and monitoring of treatment response in mesothelioma.

Capecitabine versus classical cyclophosphamide, methotrexate, and fluorouracil as first-line chemotherapy for advanced breast cancer.

PURPOSE: We compared oral capecitabine, administered intermittently or continuously, versus classical cyclophosphamide, methotrexate, and fluorouracil (CMF) as first-line chemotherapy for women with advanced breast cancer unsuited to more intensive regimens. PATIENTS AND METHODS: Three hundred twenty-three eligible women were randomly assigned to capecitabine administered intermittently (1,000 mg/m(2) twice daily for 14 of every 21 days; n = 107) or continuously (650 mg/m(2) twice daily for 21 of every 21 days; n = 107), or to classical CMF (oral cyclophosphamide 100 mg/m(2) days 1 to 14 with intravenous methotrexate 40 mg/m(2) and fluorouracil 600 mg/m(2) on days 1 and 8 every 28 days; n = 109). The primary end point was quality-adjusted progression-free survival (PFS); secondary end points included PFS, overall survival (OS), objective tumor response, and adverse events. Intermittent and continuous capecitabine were to be compared first and, if similar (P > .05), combined for definitive comparisons versus CMF. RESULTS: Quality-adjusted PFS (P = .2), objective tumor response rate (20%; P = .8), and PFS (median, 6 months; hazard ratio [HR], 0.86; 95% CI, 0.67 to 1.10; P = .2) were similar in women assigned capecitabine versus CMF. OS was longer in women assigned capecitabine rather than CMF (median, 22 v 18 months; HR, 0.72; 95% CI, 0.55 to 0.94; P = .02). Febrile neutropenia, infection, stomatitis, and serious adverse events were more common with CMF; hand-foot syndrome was more common with capecitabine. CONCLUSION: Capecitabine improved OS by being similarly active, less toxic, and more tolerable than CMF. Capecitabine is a good first-line chemotherapy option for women with advanced breast cancer who are unsuited to more intensive regimens.

Cellular dynamic simulator: an event driven molecular simulation environment for cellular physiology.

In this paper, we present the Cellular Dynamic Simulator (CDS) for simulating diffusion and chemical reactions within crowded molecular environments. CDS is based on a novel event driven algorithm specifically designed for precise calculation of the timing of collisions, reactions and other events for each individual molecule in the environment. Generic mesh based compartments allow the creation / importation of very simple or detailed cellular structures that exist in a 3D environment. Multiple levels of compartments and static obstacles can be used to create a dense environment to mimic cellular boundaries and the intracellular space. The CDS algorithm takes into account volume exclusion and molecular crowding that may impact signaling cascades in small sub-cellular compartments such as dendritic spines. With the CDS, we can simulate simple enzyme reactions; aggregation, channel transport, as well as highly complicated chemical reaction networks of both freely diffusing and membrane bound multi-protein complexes. Components of the CDS are generally defined such that the simulator can be applied to a wide range of environments in terms of scale and level of detail. Through an initialization GUI, a simple simulation environment can be created and populated within minutes yet is powerful enough to design complex 3D cellular architecture. The initialization tool allows visual confirmation of the environment construction prior to execution by the simulator. This paper describes the CDS algorithm, design implementation, and provides an overview of the types of features available and the utility of those features are highlighted in demonstrations.

A novel prognostic model for malignant mesothelioma incorporating quantitative FDG-PET imaging with clinical parameters.

PURPOSE: Existing prognostic systems for malignant pleural mesothelioma do not incorporate imaging information. We aimed to identify the contribution of quantitative fluorodeoxyglucose positron emission tomography (FDG-PET) analysis to other prognostic variables in this disease. EXPERIMENTAL DESIGN: Patients with malignant pleural mesothelioma underwent helical thoracoabdominal computed tomography and FDG-PET scans at baseline. Patients were treated as clinically indicated and followed for survival. FDG-PET variables derived included total glycolytic volume, a composite of tumor volume and glycolytic activity. RESULTS: Ninety-three patients were accrued from 2003 to 2006. Of 89 eligible assessable patients, 28 had undergone pleurodesis before enrolment. Seventeen patients remained alive at analysis; median survival is 15.4 months. On univariate analysis, significant prognostic factors were: total glycolytic volume on FDG-PET (P = 0.003), sarcomatoid histology (P < 0.0005), weight loss (P = 0.031), computed tomography stage (P = 0.015), and European Organization for Research and Treatment of Cancer good prognostic score (P = 0.049). In patients with epithelioid or biphasic histology, baseline total glycolytic volume remained predictive of survival in patients with (P = 0.01) or without (P = 0.018) previous pleurodesis. In multivariate analysis, no variable other than histology contributed to the model in patients with sarcomatoid histology; total glycolytic volume and weight loss contributed to the models in patients with nonsarcomatoid histology. computed tomography-assessed tumor-node-metastasis stage did not contribute to the model. A nomogram, which incorporates quantitative PET parameters and pleurodesis into prognostic information, is presented. CONCLUSIONS: Sarcomatoid histology remains the strongest prognostic factor. In patients with non sarcomatoid disease, volumetric FDG-PET parameters are more predictive of survival than tumor-node-metastasis staging, suggesting that tumor volume and glycolytic activity may be more important determinants of prognosis in malignant pleural mesothelioma than anatomic extent of disease.

MicroRNA expression in preimplantation mouse embryos from Ped gene positive compared to Ped gene negative mice.

PURPOSE: The mouse preimplantation embryo development (Ped) gene product, Qa-2, influences the rate of preimplantation embryonic development and overall reproductive success. Here we investigated the expression pattern of two microRNAs, miR-125a and miR-125b, known to be involved in development in lower organisms, in preimplantation embryos from the two-cell, four-cell, eight-cell, morula, and blastocyst stages of development from the congenic B6.K1 (Ped negative) and B6.K2 (Ped positive) strains of mice. METHOD: B6.K1 and B6.K2 congenic mice differ only in the absence (B6.K1) or presence (B6.K2) of the genes encoding Qa-2 protein. We analyzed the expression of miR-125a and miR-125b in B6.K1 and B6.K2 preimplantation embryos by using real-time PCR. RESULT: We found no variability in miR-125b expression at any developmental stage in both strains. However, miR-125a expression increased during development in both strains and was ten times higher in Ped negative (B6.K1) embryos than in Ped positive (B6.K2) embryos by the blastocyst stage of development. CONCLUSION: Our results show that the absence of the Ped gene profoundly affects the level of a miRNA (miR-125a) known to regulate early development. The implication is that miR-125a is likely involved in the regulation of timing of early development in mice.

Preimplantation embryo development (Ped) gene copy number varies from 0 to 85 in a population of wild mice identified as Mus musculus domesticus.

The preimplantation embryo development (Ped) gene regulates the rate of preimplantation embryonic cleavage division and subsequent embryo survival. In the mouse, the Ped gene product is Qa-2 protein, a nonclassical MHC class I molecule encoded by four tandem genes, Q6/Q7/Q8/Q9. Most inbred strains of mice have all four genes on each allelic chromosome, making a total of eight Qa-2 encoding genes, but there are a few strains that are missing all eight genes, defining a null allele. Mouse strains with the presence of the Qa-2 encoding genes express Qa-2 protein and produce embryos with a faster rate of preimplantation embryonic development and a greater chance of embryo survival compared to mouse strains with the null allele. There is extensive evidence that the human homolog of Qa-2 is HLA-G. HLA-G in humans, like Qa-2 in mice, is associated with enhanced reproductive success. The human population is an outbred population. Therefore, for a better comparison to the human population, we undertook an investigation of the presence of the genes encoding Qa-2 in an outbred population of mice. We used Real-Time Quantitative PCR to quantify the number of Qa-2 encoding genes in a population of 32 wild mice identified as Mus musculus domesticus both by morphologic assessment and by PCR analysis of their DNA. We found great variability in the number of Qa-2 encoding genes in the wild mice tested. The wild mouse with the highest number of Qa-2 encoding genes had 85 such genes, whereas we discovered one wild mouse without any Qa-2 encoding genes. Evolutionary implications of a range of Qa-2 encoding gene numbers in the wild mouse population are discussed, as well as the relevance of our findings to humans.

Analysis of the sex ratio in preimplantation embryos from B6.K1 and B6.K2 Ped gene congenic mice.

PURPOSE: The mouse preimplantation embryo development (Ped) gene product, Qa-2, which is the homolog of human HLA-G, influences the rate of preimplantation embryonic development and overall reproductive success. The sex ratio in preimplantation embryos from Ped gene congenic mice was examined in order to determine whether embryo sex is a confounding factor in the control of the rate of preimplantation development. METHODS: B6.K1 (Ped slow) and B6.K2 (Ped fast) congenic mice differ only in the absence (B6.K1) or presence (B6.K2) of the genes encoding Qa-2 protein. We analyzed the sex of B6.K1 (n=221) and B6.K2 (n=260) preimplantation embryos by using Real-Time PCR with primers specific for the X and Y chromosomes. RESULTS: We found that there was no statistically significant difference in the ratio of male to female preimplantation embryos in either strain. CONCLUSIONS: We conclude that the sex of the embryos is not a confounding factor that affects the Ped gene control of the rate of preimplantation development. Therefore, the Ped gene is entirely responsible for mediating the faster development of B6.K2 embryos compared to B6.K1 embryos.