Comparing Generalized Estimating Equation and Linear Mixed Effects Model for Estimating Marginal Association with Bivariate Continuous Outcomes

Both linear regression with generalized estimating equations (GEE) and linear mixed-effects models (LMEM) can be used to estimate the marginal association of an exposure with clustered continuous outcomes. This study compares their performance for bivariate continuous outcomes which are common in eye studies. Parametric and non-parametric simulations were used to compare the GEE models including independent, exchangeable, and unstructured working correlation structures and LMEM including random intercept only and random intercept and slope models in R and SAS. Data generation referenced the data distributions from a real-world study for estimating ocular structure-visual function relationships in patients with retinitis pigmentosa. From both parametric and non-parametric simulations, comparing the random intercept LMEM and GEE exchangeable model, bias was similar; coverage probability of the 95% confidence interval (CI) from the random intercept LMEM was often closer to 95%, especially when the sample size was small; the power for testing the association of the exposure was higher from the GEE exchangeable model, but its type-I error rate might be inflated especially when the sample size was small. The type-I error rate from the random intercept LMEM was closer to 0.05, but it might be under 0.05 and coverage probability might be over 95%. The GEE independent model performed worst and the LMEM with both random intercept and slope might not converge. To estimate marginal exposure-outcome association with bivariate continuous outcomes, the random intercept LMEM may be preferred. It has the best coverage probability of 95% CI and is the only model with correct type-I error rates in this study. However, it may have low power and overly wide CI in studies with small sample size or low inter-eye correlation.</p

Image_2_Nontoxic Targeting of Energy Metabolism in Preclinical VM-M3 Experimental Glioblastoma.TIFF

Introduction: Temozolomide (TMZ) is part of the standard of care for treating glioblastoma multiforme (GBM), an aggressive primary brain tumor. New approaches are needed to enhance therapeutic efficacy and reduce toxicity. GBM tumor cells are dependent on glucose and glutamine while relying heavily on aerobic fermentation for energy metabolism. Restricted availability of glucose and glutamine may therefore reduce disease progression. Calorically restricted ketogenic diets (KD-R), which reduce glucose and elevate ketone bodies, offer a promising alternative in targeting energy metabolism because cancer cells cannot effectively burn ketones due to defects in the number, structure, and function of mitochondria. Similarly, oxaloacetate, which participates in the deamination of glutamate, has the potential to reduce the negative effects of excess glutamate found in many brain tumors, while hyperbaric oxygen therapy can reverse the hypoxic phenotype of tumors and reduce growth. We hypothesize that the combinatorial therapy of KD-R, hyperbaric oxygen, and oxaloacetate, could reduce or eliminate the need for TMZ in GBM patients.Methods: Our proposed approach for inhibiting tumor metabolism involved various combinations of the KD-R, oxaloacetate (2 mg/g), hyperbaric oxygen, and TMZ (20 mg/kg). This combinatorial therapy was tested on adult VM/Dk mice bearing the VM-M3/Fluc preclinical GBM model grown orthotopically. After 14 days, tumor growth was quantified via bioluminescence. A survival study was performed and the data were analyzed and portrayed in a Kaplan Meier plot. Preliminary dosage studies were used and strict diet and drug administration was maintained throughout the study.Results: The therapeutic effect of all treatments was powerful when administered under KD-R. The most promising survival advantage was seen in the two groups receiving oxaloacetate without TMZ. The survival of mice receiving TMZ was diminished due to its apparent toxicity. Among all groups, those receiving TMZ had the most significant reduction in tumor growth. The most powerful therapeutic effect was evident with combinations of these therapies.Conclusion: This study provides evidence for a potentially novel therapeutic regimen of hyperbaric oxygen, oxaloacetate, and the KD-R for managing growth and progression of VM-M3/Fluc GBM.</p

Image_1_Nontoxic Targeting of Energy Metabolism in Preclinical VM-M3 Experimental Glioblastoma.TIFF

Introduction: Temozolomide (TMZ) is part of the standard of care for treating glioblastoma multiforme (GBM), an aggressive primary brain tumor. New approaches are needed to enhance therapeutic efficacy and reduce toxicity. GBM tumor cells are dependent on glucose and glutamine while relying heavily on aerobic fermentation for energy metabolism. Restricted availability of glucose and glutamine may therefore reduce disease progression. Calorically restricted ketogenic diets (KD-R), which reduce glucose and elevate ketone bodies, offer a promising alternative in targeting energy metabolism because cancer cells cannot effectively burn ketones due to defects in the number, structure, and function of mitochondria. Similarly, oxaloacetate, which participates in the deamination of glutamate, has the potential to reduce the negative effects of excess glutamate found in many brain tumors, while hyperbaric oxygen therapy can reverse the hypoxic phenotype of tumors and reduce growth. We hypothesize that the combinatorial therapy of KD-R, hyperbaric oxygen, and oxaloacetate, could reduce or eliminate the need for TMZ in GBM patients.Methods: Our proposed approach for inhibiting tumor metabolism involved various combinations of the KD-R, oxaloacetate (2 mg/g), hyperbaric oxygen, and TMZ (20 mg/kg). This combinatorial therapy was tested on adult VM/Dk mice bearing the VM-M3/Fluc preclinical GBM model grown orthotopically. After 14 days, tumor growth was quantified via bioluminescence. A survival study was performed and the data were analyzed and portrayed in a Kaplan Meier plot. Preliminary dosage studies were used and strict diet and drug administration was maintained throughout the study.Results: The therapeutic effect of all treatments was powerful when administered under KD-R. The most promising survival advantage was seen in the two groups receiving oxaloacetate without TMZ. The survival of mice receiving TMZ was diminished due to its apparent toxicity. Among all groups, those receiving TMZ had the most significant reduction in tumor growth. The most powerful therapeutic effect was evident with combinations of these therapies.Conclusion: This study provides evidence for a potentially novel therapeutic regimen of hyperbaric oxygen, oxaloacetate, and the KD-R for managing growth and progression of VM-M3/Fluc GBM.</p

Image_3_Nontoxic Targeting of Energy Metabolism in Preclinical VM-M3 Experimental Glioblastoma.TIFF

Introduction: Temozolomide (TMZ) is part of the standard of care for treating glioblastoma multiforme (GBM), an aggressive primary brain tumor. New approaches are needed to enhance therapeutic efficacy and reduce toxicity. GBM tumor cells are dependent on glucose and glutamine while relying heavily on aerobic fermentation for energy metabolism. Restricted availability of glucose and glutamine may therefore reduce disease progression. Calorically restricted ketogenic diets (KD-R), which reduce glucose and elevate ketone bodies, offer a promising alternative in targeting energy metabolism because cancer cells cannot effectively burn ketones due to defects in the number, structure, and function of mitochondria. Similarly, oxaloacetate, which participates in the deamination of glutamate, has the potential to reduce the negative effects of excess glutamate found in many brain tumors, while hyperbaric oxygen therapy can reverse the hypoxic phenotype of tumors and reduce growth. We hypothesize that the combinatorial therapy of KD-R, hyperbaric oxygen, and oxaloacetate, could reduce or eliminate the need for TMZ in GBM patients.Methods: Our proposed approach for inhibiting tumor metabolism involved various combinations of the KD-R, oxaloacetate (2 mg/g), hyperbaric oxygen, and TMZ (20 mg/kg). This combinatorial therapy was tested on adult VM/Dk mice bearing the VM-M3/Fluc preclinical GBM model grown orthotopically. After 14 days, tumor growth was quantified via bioluminescence. A survival study was performed and the data were analyzed and portrayed in a Kaplan Meier plot. Preliminary dosage studies were used and strict diet and drug administration was maintained throughout the study.Results: The therapeutic effect of all treatments was powerful when administered under KD-R. The most promising survival advantage was seen in the two groups receiving oxaloacetate without TMZ. The survival of mice receiving TMZ was diminished due to its apparent toxicity. Among all groups, those receiving TMZ had the most significant reduction in tumor growth. The most powerful therapeutic effect was evident with combinations of these therapies.Conclusion: This study provides evidence for a potentially novel therapeutic regimen of hyperbaric oxygen, oxaloacetate, and the KD-R for managing growth and progression of VM-M3/Fluc GBM.</p

Table_1_Nontoxic Targeting of Energy Metabolism in Preclinical VM-M3 Experimental Glioblastoma.DOCX

Introduction: Temozolomide (TMZ) is part of the standard of care for treating glioblastoma multiforme (GBM), an aggressive primary brain tumor. New approaches are needed to enhance therapeutic efficacy and reduce toxicity. GBM tumor cells are dependent on glucose and glutamine while relying heavily on aerobic fermentation for energy metabolism. Restricted availability of glucose and glutamine may therefore reduce disease progression. Calorically restricted ketogenic diets (KD-R), which reduce glucose and elevate ketone bodies, offer a promising alternative in targeting energy metabolism because cancer cells cannot effectively burn ketones due to defects in the number, structure, and function of mitochondria. Similarly, oxaloacetate, which participates in the deamination of glutamate, has the potential to reduce the negative effects of excess glutamate found in many brain tumors, while hyperbaric oxygen therapy can reverse the hypoxic phenotype of tumors and reduce growth. We hypothesize that the combinatorial therapy of KD-R, hyperbaric oxygen, and oxaloacetate, could reduce or eliminate the need for TMZ in GBM patients.Methods: Our proposed approach for inhibiting tumor metabolism involved various combinations of the KD-R, oxaloacetate (2 mg/g), hyperbaric oxygen, and TMZ (20 mg/kg). This combinatorial therapy was tested on adult VM/Dk mice bearing the VM-M3/Fluc preclinical GBM model grown orthotopically. After 14 days, tumor growth was quantified via bioluminescence. A survival study was performed and the data were analyzed and portrayed in a Kaplan Meier plot. Preliminary dosage studies were used and strict diet and drug administration was maintained throughout the study.Results: The therapeutic effect of all treatments was powerful when administered under KD-R. The most promising survival advantage was seen in the two groups receiving oxaloacetate without TMZ. The survival of mice receiving TMZ was diminished due to its apparent toxicity. Among all groups, those receiving TMZ had the most significant reduction in tumor growth. The most powerful therapeutic effect was evident with combinations of these therapies.Conclusion: This study provides evidence for a potentially novel therapeutic regimen of hyperbaric oxygen, oxaloacetate, and the KD-R for managing growth and progression of VM-M3/Fluc GBM.</p

Additional file 1: of miR-589 promotes gastric cancer aggressiveness by a LIFR-PI3K/AKT-c-Jun regulatory feedback loop

Supplementary materials and methods. (DOC 82 kb

DataSheet1_Immobilized Fe3O4-Polydopamine-Thermomyces lanuginosus Lipase-Catalyzed Acylation of Flavonoid Glycosides and Their Analogs: An Improved Insight Into Enzymic Substrate Recognition.PDF

The conversion of flavonoid glycosides and their analogs to their lipophilic ester derivatives was developed by nanobiocatalysts from immobilizing Thermomyces lanuginosus lipase (TLL) on polydopamine-functionalized magnetic Fe3O4 nanoparticles (Fe3O4-PDA-TLL). The behavior investigation revealed that Fe3O4-PDA-TLL exhibits a preference for long chain length fatty acids (i.e., C10 to C14) with higher reaction rates of 12.6–13.9 mM/h. Regarding the substrate specificity, Fe3O4-PDA-TLL showed good substrate spectrum and favorably functionalized the primary OH groups, suggesting that the steric hindrances impeded the secondary or phenolic hydroxyl groups of substrates into the bonding site of the active region of TLL to afford the product.</p

Identification of a Novel <i>Afipia</i> Species Isolated from an Indian Flying Fox

<div><p>An old world fruit bat <i>Pteropus giganteus</i>, held in captivity and suffering from necrosis of its wing digits, failed to respond to antibiotic therapy and succumbed to the infection. Samples submitted to the National Centre for Foreign Animal Disease were tested for viral infection. Vero E6 cells exhibited minor but unique cytopathic effects on second blind passage, and full CPE by passage four. Utilizing an unbiased random amplification technique from cell culture supernatant, we identified a bacterium belonging to the <i>Bradyrhizobiaceae</i>. Purification of cell culture supernatant on TY media revealed a slow growing bacterial isolate. In this study using electron microscopy, 16S rRNA gene analysis and whole genome sequencing, we identify a novel bacterial species associated with the site of infection belonging to the genus <i>Afipia</i>. This genus of bacteria is very diverse, with only a limited number of species characterized. <i>Afipia felis</i>, previously described as the etiological agent to cause cat scratch disease, and <i>Afipia septicemium</i>, most recently shown to cause disease in humans, highlight the potential for members of this genus to form a branch of opportunistic pathogens within the <i>Bradyrhizobiaceae</i>. Increased utilization of next generation sequencing and genomics will aid in classifying additional members of this intriguing bacterial genera.</p></div

Phylogenetic analysis of the 16S rRNA gene.

<p>A maximum likelihood tree was constructed for the bat bacterial isolate using sequence obtained from NCBI BLASTn. Bacterial bat isolate is shown in bold as <i>Afipia pteropus</i> (AZSJ00000000). Sequences were obtained from both fully sequenced and partially sequenced genomes. Phylogenetic tree was constructed using the MEGA5 software[<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0121274#pone.0121274.ref015" target="_blank">15</a>].</p

Oroxylin A increased probability of survival after a lethal dose of CCl₄ treatment (2.6 ml/kg body weight).

<p>(A) WT mice were respectively administered with or without oroxylin A once per day for 5 days after CCl₄ (2.6 ml/kg body weight) treatment (<i>P</i> = 0.0033). (B) After a lethal dose of CCl₄ (2.6 ml/kg body weight) treatment, the probalility of survival in IL-1RI−/− mice significantly decreased compared to the WT mice (<i>P</i><0.0001). (C) Oroxylin A administration could not improve survival of IL-1RI−/− mice after a lethal dose of CCl₄ (2.6 ml/kg body weight) performace, which indicated that oraoxylin A protects against CCl₄-induced acute liver failure directly through regulating IL-1Ra/IL-1RI pathway (<i>P</i> = 0.9141, non-significant). Survivals were scored twice per day, and the results were analyzed using the log-rank test and expressed as the Kaplan-Meier survival curves (n = 20).</p