Relationship between Glioblastoma Heterogeneity and Survival Time: An MR Imaging Texture Analysis

BACKGROUND AND PURPOSE

The heterogeneity of glioblastoma contributes to the poor and variant prognosis. The aim of this retrospective study was to assess the glioblastoma heterogeneity with MR imaging textures and to evaluate its impact on survival time.

MATERIALS AND METHODS

A total of 133 patients with primary glioblastoma who underwent postcontrast T1-weighted imaging (acquired before treatment) and whose data were filed with the survival times were selected from the Cancer Genome Atlas. On the basis of overall survival, the patients were divided into 2 groups: long-term (≥12 months, n = 67) and short-term (<12 months, n = 66) survival. To measure heterogeneity, we extracted 3 types of textures, co-occurrence matrix, run-length matrix, and histogram, reflecting local, regional, and global spatial variations, respectively. Then the support vector machine classification was used to determine how different texture types perform in differentiating the 2 groups, both alone and in combination. Finally, a recursive feature-elimination method was used to find an optimal feature subset with the best differentiation performance.

RESULTS

When used alone, the co-occurrence matrix performed best, while all the features combined obtained the best survival stratification. According to feature selection and ranking, 43 top-ranked features were selected as the optimal subset. Among them, the top 10 features included 7 run-length matrix and 3 co-occurrence matrix features, in which all 6 regional run-length matrix features emphasizing high gray-levels ranked in the top 7.

CONCLUSIONS

The results suggest that local and regional heterogeneity may play an important role in the survival stratification of patients with glioblastoma.

InGaN µLEDs integrated onto colloidal quantum dot functionalized ultra-thin glass

Red-, orange-, and green-emitting integrated optoelectronic sources are demonstrated by transfer printing blue InGaN µLEDs onto ultra-thin glass platforms functionally enhanced with II-VI colloidal quantum dots (CQDs). The forward optical power conversion efficiency of these heterogeneously integrated devices is, respectively, 9%, 15%, and 14% for a blue light absorption over 95%. The sources are demonstrated in an orthogonal frequency division multiplexed (OFDM) visible light communication link reaching respective data transmission rates of 46 Mbps, 44 Mbps and 61 Mbps.

[Association between the time of sedentary behaviors and risk of type 2 diabetes]

Objective: To explore the relationship between the time of sedentary behaviors and the risk of type 2 diabetes mellitus (T2DM) among rural adults in Henan Province. Methods: A total of 1 227 adults from Houzhai village in Zhengzhou City and Qiaomiao village in Jiaozuo City in Henan Province were randomly selected to participate in the survey; each of them finished a questionnaire and accepted physical examination and test of biochemical indicators. The participants were divided into case and control groups according to whether suffering from T2DM. A Pearson linear correlation and linear regression model analysis were used to investigate the relevance between the time of sedentary behaviors and fasting plasma glucose (FPG); meanwhile, a multi factor logistic regression model was used to analyze the relationship between the time of sedentary behaviors and T2DM. Results: The average FPG level among the participants was (5.4±2.5) mmol/L, and the average time of sedentary behaviors was (234.5±156.5) min per day. The prevalence rate of T2DM in subgroups whose time of sedentary behaviors were separately 0-<2.5, 2.5-<4.5, 4.5-<6.5 and ≥6.5 h/day were 15.8% (72/457), 19.3% (73/379), 16.7% (35/210) and 20.4% (37/181), respectively. There was a linear regression relationship between the time of sedentary behaviors(x) and FPG(y), the regression equation was: y=5.081+0.001x (t=3.01, P=0.003). Logistic regression model analysis showed that participants whose time of sedentary behaviors ≥6.5 h/day had significantly higher risk of T2DM than those whose time of sedentary behaviors between 0-2.4 h/day (OR=1.77, 95%CI: 1.11-2.81) after age and gender adjusted. However, the associations only exist in males and adults ≥50 years old according to sex and age stratification. It showed that participants with sedentary time ≥6.5 h/day had significantly higher risk of T2DM than those with sedentary time between 0-<2.5 h/d, with the corresponding OR (95%CI) at 2.34 (1.21-4.52) and 2.22 (1.19-4.16), respectively. Conclusion: The prolonged sedentary time is a risk factor of type 2 diabetes. After stratification by gender and age, the correlation only found in males and adults aged ≥50 years old.

Utilizing Electronic Medical Records to Discover Changing Trends of Medical Behaviors Over Time

Objectives

Medical behaviors are playing significant roles in the delivery of high quality and cost-effective health services. Timely discovery of changing frequencies of medical behaviors is beneficial for the improvement of health services. The main objective of this work is to discover the changing trends of medical behaviors over time.

Methods

This study proposes a two-steps approach to detect essential changing patterns of medical behaviors from Electronic Medical Records (EMRs). In detail, a probabilistic topic model, i.e., Latent Dirichlet allocation (LDA), is firstly applied to disclose yearly treatment patterns in regard to the risk stratification of patients from a large volume of EMRs. After that, the changing trends by comparing essential/critical medical behaviors in a specific time period are detected and analyzed, including changes of significant patient features with their values, and changes of critical treatment interventions with their occurring time stamps.

Results

We verify the effectiveness of the proposed approach on a clinical dataset containing 12,152 patient cases with a time range of 10 years. Totally, 135 patients features and 234 treatment interventions in three treatment patterns were selected to detect their changing trends. In particular, evolving trends of yearly occurring probabilities of the selected medical behaviors were categorized into six content changing patterns (i.e, 112 growing, 123 declining, 43 up-down, 16 down-up, 35 steady, and 40 jumping), using the proposed approach. Besides, changing trends of execution time of treatment interventions were classified into three occurring time changing patterns (i.e., 175 early-implemented, 50 steady-implemented and 9 delay-implemented).

Conclusions

Experimental results show that our approach has an ability to utilize EMRs to discover essential evolving trends of medical behaviors, and thus provide significant potential to be further explored for health services redesign and improvement.

Dysfunction of the WT1-MEG3 signaling promotes AML leukemogenesis via p53-dependent and -independent pathways

Long non-coding RNAs (lncRNAs) play a pivotal role in tumorigenesis, exemplified by the recent finding that lncRNA maternally expressed gene 3 (MEG3) inhibits tumor growth in a p53-dependent manner. Acute myeloid leukemia (AML) is the most common malignant myeloid disorder in adults, and TP53 mutations or loss are frequently detected in patients with therapy-related AML or AML with complex karyotype. Here, we reveal that MEG3 is significantly downregulated in AML and suppresses leukemogenesis not only in a p53-dependent, but also a p53-independent manner. In addition, MEG3 is proven to be transcriptionally activated by Wilms’ tumor 1 (WT1), dysregulation of which by epigenetic silencing or mutations is causally involved in AML. Therefore MEG3 is identified as a novel target of the WT1 molecule. Ten–eleven translocation-2 (TET2) mutations frequently occur in AML and significantly promote leukemogenesis of this disorder. In our study, TET2, acting as a cofactor of WT1, increases MEG3 expression. Taken together, our work demonstrates that TET2 dysregulated WT1-MEG3 axis significantly promotes AML leukemogenesis, paving a new avenue for diagnosis and treatment of AML patients.

A liquid thermal gradient refractive index lens and using it to trap single living cell in flowing environments

A gradient refractive index (GRIN) lens has a great potential for on-chip imaging and detection systems because of its flat surface with reduced defects. This paper reports a liquid thermal GRIN lens prepared using heat conduction between only one liquid, and uses it as a tunable optical tweezer for single living cell trapping in a flowing environment. This liquid GRIN lens consists of a trapezoidal region in the upper layer which is used to establish a GRIN profile by the heat conduction between three streams of benzyl alcohol with different temperatures, and subsequently a rhombus region in the lower layer with compensation liquids to form a steady square-law parabolic refractive index profile only in transverse direction. Simulations and experiments successfully show the real-time tunability of the focusing properties. The focal length can be modulated in the range of 500 μm with the minimum focal length of 430 μm. A considerable high enhancement factor achieves 5.4 whereas the full width at half maximum is 4 μm. The response time of the GRIN lens is about 20 ms. Based on this enhancement, tunable optical trapping for single human embryonic kidney 293 cell in the range of 280 μm is demonstrated by varying the focal length and working distance which is difficult for solid optical tweezers. The considerable quality of this liquid GRIN lens indicates on-chip applications especially in high quality optical imaging, detection and cells' handling.

The versatility and paradox of GDF 11

In addition to its roles in embryonic development, Growth and Differentiation Factor 11 (GDF 11) has recently drawn much interest about its roles in other processes, such as aging. GDF 11 has been shown to play pivotal roles in the rescue of the proliferative and regenerative capabilities of skeletal muscle, neural stem cells and cardiomyocytes. We would be remiss not to point that some controversy exists regarding the role of GDF 11 in biological processes and whether it will serve as a therapeutic agent. The latest studies have shown that the level of circulating GDF 11 correlates with the outcomes of patients with cardiovascular diseases, cancer and uremia. Based on these studies, GDF 11 is a promising candidate to serve as a novel biomarker of diseases. This brief review gives a detailed and concise view of the regulation and functions of GDF 11 and its roles in development, neurogenesis and erythropoiesis as well as the prospect of using this protein as an indicator of cardiac health and aging.

[Body mass index, waist circumference and waist-to-height ratio associated with the incidence of type 2 diabetes mellitus: a cohort study]

OBJECTIVE

To investigate the association between body mass index (BMI), waist circumference (WC), waist-to-height ratio (WHtR), and the incidence risk of type 2 diabetes mellitus (T2DM).

METHODS

In total, 20 194 participants ≥18 years old were selected randomly by cluster sampling from two township (town) of the county in Henan province from July to August of 2007 and July to August of 2008 and the investigation included questionnaires, anthropometric measurements, fasting plasma glucose, and lipid profile examination were performed at baseline; 17 236 participants were enrolled in this cohort study. 14 720 (85.4%) were followed up from July to August 2013 and July to October 2014. Finally, 11 643 participants (4 301 males and 7 342 females) were included in this study. Incidence density and Cox proportional hazards regression models were used to evaluate the risk of T2DM associated with baseline BMI, WC, WHtR, and their dynamic changes.

RESULTS

After average of 6.01 years following up for 11 643 participants, 613 developed T2DM and the incidence density was 0.89 per 100 person-years. After adjusted for baseline sex, age, smoking, drinking, family history of diabetes, as well as the difference of fasting plasma-glucose (FPG), total cholesterol (TC), triglyceride (TG), high density lipoprotein cholesterol (HDL-C), systolic blood pressure (SBP), diastolic blood pressure (DBP) between baseline and follow-up, Cox Proportional-Hazards regression analysis indicated that T2DM risk of baseline BMI overweight group, BMI obesity group, abnormal WC group and abnormal WHtR group were significantly higher than that of the corresponding baseline normal groups , and the incidence risk of T2DM reached the highest for those whose baseline BMI, WC and WHtR were all abnormal, the corresponding HR (95%CI) were 2.05 (1.62-2.59), 3.01 (2.33-3.90), 2.34 (1.89-2.90), 2.88 (2.21-3.74), 3.32 (2.50-4.40), respectively. Whether baseline BMI/WC was normal or not, T2DM risk increased if baseline WHtR was abnormal, and the HR (95%CI) of baseline normal BMI/abnormal WHtR group, baseline abnormal BMI/abnormal WHtR group, baseline normal WC/abnormal WHtR group, baseline abnormal WC/abnormal WHtR group were 1.88 (1.29-2.74), 3.08 (2.34-4.05), 2.15(1.53-3.00), 3.22 (2.45-4.23), respectively. The analysis for dynamic changes of BMI, WC, and WHtR indicated that in baseline normal WC or WHtR group, T2DM risk increased when baseline normal WC or WHtR developed abnormal at follow-up, and the corresponding HR (95%CI) were 1.79 (1.26-2.55), 2.12(1.32-3.39), respectively. In baseline abnormal WC or WHtR group, T2DM risk decresed when baseline abnormal WC or WHtR reversed to normal at follow-up, and the corresponding HR (95%CI) were 2.16 (1.42-3.29), 2.62 (1.63-4.20), respectively.

CONCLUSION

BMI, WC, and WHtR were associated with increased T2DM risk. The more abnormal aggregation of BMI, WC, and WHtR presents, the higher T2DM risk was. T2DM risk could be decreased when abnormal WC or WHtR reversed to normal.

First Liquid Layer Inertial Confinement Fusion Implosions at the National Ignition Facility

The first cryogenic deuterium and deuterium-tritium liquid layer implosions at the National Ignition Facility (NIF) demonstrate D_{2} and DT layer inertial confinement fusion (ICF) implosions that can access a low-to-moderate hot-spot convergence ratio (12<CR<25). Previous ICF experiments at the NIF utilized high convergence (CR>30) DT ice layer implosions. Although high CR is desirable in an idealized 1D sense, it amplifies the deleterious effects of asymmetries. To date, these asymmetries prevented the achievement of ignition at the NIF and are the major cause of simulation-experiment disagreement. In the initial liquid layer experiments, high neutron yields were achieved with CRs of 12-17, and the hot-spot formation is well understood, demonstrated by a good agreement between the experimental data and the radiation hydrodynamic simulations. These initial experiments open a new NIF experimental capability that provides an opportunity to explore the relationship between hot-spot convergence ratio and the robustness of hot-spot formation during ICF implosions.

The cost-effectiveness of bevacizumab for the treatment of advanced ovarian cancer in Canada

BACKGROUND

The overall survival (os) analysis of the icon7 trial demonstrated that frontline ovarian cancer patients with a high risk of progression (stage iii suboptimally debulked, and stage iii or iv with unresectable disease) benefited from the addition of bevacizumab to standard chemotherapy compared with standard chemotherapy alone. The objective of the present study was to investigate the cost-effectiveness, from a Canadian publicly funded perspective, of adding bevacizumab to frontline treatment of ovarian cancer at high risk of progression.

METHODS

An area-under-the-curve, Markov-structured model was used to estimate the cost-effectiveness of the treatments. Long-term progression-free survival (pfs) and os were extracted from the icon7 trial (subgroup at high risk of relapse) and extrapolated by parametric time-to-event functions over a time horizon of 10 years. Canadian pfs health state utility values were obtained from the EQ-5D (EuroQoL Group, Rotterdam, Netherlands) questionnaires in the icon7 high-risk patient population. Canadian post-progression utility values were consistent with those for other gynecologic cancers. Cost inputs were informed by public sources. An annual 5% efficacy and cost discount rate was applied. A probabilistic sensitivity analysis and one-way sensitivity analyses were conducted.

RESULTS

Ovarian cancer patients at high risk of progression receiving bevacizumab plus standard chemotherapy experienced a mean incremental quality-adjusted life year (qaly) gain of 0.374 years. At an additional cost of $35,901.54, the incremental cost-effectiveness ratio (icer) for the addition of bevacizumab to standard chemotherapy, relative to standard chemotherapy alone, was $95,942 per qaly.

CONCLUSIONS

No formal health technology assessment willingness-to-pay threshold exists in Canada. However, at a threshold of $100,000 per qaly, bevacizumab in addition to chemotherapy is a cost-effective alternative for ovarian cancer patients who are at high risk of progression (stage iii suboptimally debulked, and stage iii or iv with unresectable disease). Using the $100,000 per qaly threshold in a probabilistic sensitivity analysis, it was determined that, compared with standard chemotherapy, the addition of bevacizumab to chemotherapy is cost-effective in 56% of tested scenarios.