Performance of the cobas EZH2 mutation test on clinical samples from non-Hodgkin lymphoma patients.

OBJECTIVE: To present the technical verification and clinical validation of the companion diagnostic assay, cobas® EZH2 Mutation Test (cobas EZH2 Test), targeting gain-of-function EZH2 mutations in follicular lymphoma (FL) and diffuse large B-cell lymphoma (DLBCL). The focus is on patient clinical samples proving that the test met the performance criteria required for FDA approval of a companion diagnostic test. DESIGN: Epizyme, Inc., Eisai Co., Ltd., and Roche Molecular Systems, Inc., collaborated to develop the cobas EZH2 Test on an RT-PCR platform. The assay design needed to detect the gain-of-function EZH2 mutations found in FL and DLBCL indications. Thus, the test was optimized for investigational purposes in a clinical trial setting. Part of its technical verification included testing of patient tumor samples with a documented diagnosis of FL and DLBCL procured from commercial vendors, and the clinical validation used patient samples from the Epizyme clinical study. Both the technical performance verification method correlation study (104 clinical commercially acquired samples) and the clinical validation accuracy study (341 patient samples from the therapeutic study) used next-generation sequencing as a reference method to establish true vs. false results by cobas EZH2 Test. The reproducibility study used a 15-member panel of DNA samples with varying EZH2 mutation status from procured clinical FL and DLBCL patient samples under multiple variables. RESULTS: Single and rare, infrequent double EZH2 mutations were detected in FL and DLBCL samples. Agreements between results from cobas EZH2 and sequencing were >98% from commercial clinical samples and from the therapeutic study clinical samples. The reproducibility study obtained 178 to 180 valid results for each panel member, with an overall invalid rate of 0.37%. The agreement for each per panel member was 100%. CONCLUSION: cobas EZH2 Test data demonstrated that the test is reliable and will perform well in a commercial customer environment.

Occupational symptoms due to exposure to volatile organic compounds among female Vietnamese nail salon workers in Danang city.

OBJECTIVES: Nail workers are exposed to many hazardous chemicals. Despite many warnings about health problems among nail workers in other countries, data concerning exposure to chemical hazards among nail workers is still limited in Vietnam. In this study, we aimed to identify exposure to volatile organic compounds and their relationship with occupational symptoms among Vietnamese female nail salon workers. METHODS: A cross-sectional study was conducted in Danang, Vietnam, from January 2019 to September 2019. Total 42 personal passive samplers were collected to evaluate 12 substances from 21 nail workers (15 salons) twice a week. We chose one representative worker from each of the nine salons with less than six workers and two representative workers from each of the six salons with over five workers for personal sampling based on the principle of similar exposure groups. We interviewed a total of 100 nail workers in 15 salons and 100 office workers in offices adjacent to the salons to compare occupational symptoms among them. RESULTS: The commonly detected compounds in nail salons were acetone (97.6%), butyl acetate (83.3%), and ethyl acetate and ethyl methacrylate (78%). The concentration of total target VOCs was related to the number of serviced customers, the concentration of CO2 , and general ventilation used. The subjective symptoms were significantly higher for the nail workers than for the comparison subjects, that is, headache, nausea, nose irritation, skin irritation, shortness of breath, and confusion. Among 100 nail workers, nose irritation was significantly higher for nail workers who were exposed to acetone at levels exceeding the Vietnam occupational exposure limit (VOEL) adjusted with the Brief-Scala model. CONCLUSIONS: Exposure to VOCs such as acetone in nail salons results in occupational symptoms among workers.

Publisher Correction: Toxoplasma Modulates Signature Pathways of Human Epilepsy, Neurodegeneration & Cancer.

A correction to this article has been published and is linked from the HTML and PDF versions of this paper. The error has been fixed in the paper.

CSGID Solves Structures and Identifies Phenotypes for Five Enzymes in Toxoplasma gondii.

Toxoplasma gondii, an Apicomplexan parasite, causes significant morbidity and mortality, including severe disease in immunocompromised hosts and devastating congenital disease, with no effective treatment for the bradyzoite stage. To address this, we used the Tropical Disease Research database, crystallography, molecular modeling, and antisense to identify and characterize a range of potential therapeutic targets for toxoplasmosis. Phosphoglycerate mutase II (PGMII), nucleoside diphosphate kinase (NDK), ribulose phosphate 3-epimerase (RPE), ribose-5-phosphate isomerase (RPI), and ornithine aminotransferase (OAT) were structurally characterized. Crystallography revealed insights into the overall structure, protein oligomeric states and molecular details of active sites important for ligand recognition. Literature and molecular modeling suggested potential inhibitors and druggability. The targets were further studied with vivoPMO to interrupt enzyme synthesis, identifying the targets as potentially important to parasitic replication and, therefore, of therapeutic interest. Targeted vivoPMO resulted in statistically significant perturbation of parasite replication without concomitant host cell toxicity, consistent with a previous CRISPR/Cas9 screen showing PGM, RPE, and RPI contribute to parasite fitness. PGM, RPE, and RPI have the greatest promise for affecting replication in tachyzoites. These targets are shared between other medically important parasites and may have wider therapeutic potential.

Toxoplasma Modulates Signature Pathways of Human Epilepsy, Neurodegeneration & Cancer.

One third of humans are infected lifelong with the brain-dwelling, protozoan parasite, Toxoplasma gondii. Approximately fifteen million of these have congenital toxoplasmosis. Although neurobehavioral disease is associated with seropositivity, causality is unproven. To better understand what this parasite does to human brains, we performed a comprehensive systems analysis of the infected brain: We identified susceptibility genes for congenital toxoplasmosis in our cohort of infected humans and found these genes are expressed in human brain. Transcriptomic and quantitative proteomic analyses of infected human, primary, neuronal stem and monocytic cells revealed effects on neurodevelopment and plasticity in neural, immune, and endocrine networks. These findings were supported by identification of protein and miRNA biomarkers in sera of ill children reflecting brain damage and T. gondii infection. These data were deconvoluted using three systems biology approaches: "Orbital-deconvolution" elucidated upstream, regulatory pathways interconnecting human susceptibility genes, biomarkers, proteomes, and transcriptomes. "Cluster-deconvolution" revealed visual protein-protein interaction clusters involved in processes affecting brain functions and circuitry, including lipid metabolism, leukocyte migration and olfaction. Finally, "disease-deconvolution" identified associations between the parasite-brain interactions and epilepsy, movement disorders, Alzheimer's disease, and cancer. This "reconstruction-deconvolution" logic provides templates of progenitor cells' potentiating effects, and components affecting human brain parasitism and diseases.

Membrane skeletal association and post-translational allosteric regulation of Toxoplasma gondii GAPDH1.

When Toxoplasma gondii egresses from the host cell, glyceraldehyde-3-phosphate dehydrogenase 1 (GAPDH1), which is primary a glycolysis enzyme but actually a quintessential multifunctional protein, translocates to the unique cortical membrane skeleton. Here, we report the 2.25 Å resolution crystal structure of the GAPDH1 holoenzyme in a quaternary complex providing the basis for the molecular dissection of GAPDH1 structure-function relationships Knockdown of GAPDH1 expression and catalytic site disruption validate the essentiality of GAPDH1 in intracellular replication but we confirmed that glycolysis is not strictly essential. We identify, for the first time, S-loop phosphorylation as a novel, critical regulator of enzymatic activity that is consistent with the notion that the S-loop is critical for cofactor binding, allosteric activation and oligomerization. We show that neither enzymatic activity nor phosphorylation state correlate with the ability to translocate to the cortex. However, we demonstrate that association of GAPDH1 with the cortex is mediated by the N-terminus, likely palmitoylation. Overall, glycolysis and cortical translocation are functionally decoupled by post-translational modifications.

The structure of bradyzoite-specific enolase from Toxoplasma gondii reveals insights into its dual cytoplasmic and nuclear functions.

In addition to catalyzing a central step in glycolysis, enolase assumes a remarkably diverse set of secondary functions in different organisms, including transcription regulation as documented for the oncogene c-Myc promoter-binding protein 1. The apicomplexan parasite Toxoplasma gondii differentially expresses two nuclear-localized, plant-like enolases: enolase 1 (TgENO1) in the latent bradyzoite cyst stage and enolase 2 (TgENO2) in the rapidly replicative tachyzoite stage. A 2.75 Šresolution crystal structure of bradyzoite enolase 1, the second structure to be reported of a bradyzoite-specific protein in Toxoplasma, captures an open conformational state and reveals that distinctive plant-like insertions are located on surface loops. The enolase 1 structure reveals that a unique residue, Glu164, in catalytic loop 2 may account for the lower activity of this cyst-stage isozyme. Recombinant TgENO1 specifically binds to a TTTTCT DNA motif present in the cyst matrix antigen 1 (TgMAG1) gene promoter as demonstrated by gel retardation. Furthermore, direct physical interactions of both nuclear TgENO1 and TgENO2 with the TgMAG1 gene promoter are demonstrated in vivo using chromatin immunoprecipitation (ChIP) assays. Structural and biochemical studies reveal that T. gondii enolase functions are multifaceted, including the coordination of gene regulation in parasitic stage development. Enolase 1 provides a potential lead in the design of drugs against Toxoplasma brain cysts.

Structural and functional divergence of the aldolase fold in Toxoplasma gondii.

Parasites of the phylum Apicomplexa are highly successful pathogens of humans and animals worldwide. As obligate intracellular parasites, they have significant energy requirements for invasion and gliding motility that are supplied by various metabolic pathways. Aldolases have emerged as key enzymes involved in these pathways, and all apicomplexans express one or both of fructose 1,6-bisphosphate (F16BP) aldolase and 2-deoxyribose 5-phosphate (dR5P) aldolase (DERA). Intriguingly, Toxoplasma gondii, a highly successful apicomplexan parasite, expresses F16BP aldolase (TgALD1), d5RP aldolase (TgDERA), and a divergent dR5P aldolase-like protein (TgDPA) exclusively in the latent bradyzoite stage. While the importance of TgALD1 in glycolysis is well established and TgDERA is also likely to be involved in parasite metabolism, the detailed function of TgDPA remains elusive. To gain mechanistic insight into the function of different T. gondii aldolases, we first determined the crystal structures of TgALD1 and TgDPA. Structural analysis revealed that both aldolases adopt a TIM barrel fold accessorized with divergent secondary structure elements. Structural comparison of TgALD1 and TgDPA with members of their respective enzyme families revealed that, while the active-site residues are conserved in TgALD1, key catalytic residues are absent in TgDPA. Consistent with this observation, biochemical assays showed that, while TgALD1 was active on F16BP, TgDPA was inactive on dR5P. Intriguingly, both aldolases are competent to bind polymerized actin in vitro. Altogether, structural and biochemical analyses of T. gondii aldolase and aldolase-like proteins reveal diverse functionalization of the classic TIM barrel aldolase fold.

Clevidipine for the treatment of severe hypertension in adults.

BACKGROUND: Intravenous antihypertensive agents are used when immediate control of blood pressure (BP) is required, including during the perioperative cardiac surgery period. Controlling postoperative BP is challenging because of the need to adequately reduce BP while maintaining appropriate end-organ perfusion. Clevidipine is an intravenous, ultra-short-acting, third-generation dihydropyridine calcium channel antagonist with selectivity for arteriolar vasodilatation. It is approved by the US Food and Drug Administration for the treatment of severe hypertension. OBJECTIVE: This paper reviews the clinical pharmacology, pharmacokinetic and pharmacodynamic properties, tolerability, and clinical efficacy of clevidipine. METHODS: To minimize selection bias, each author conducted an independent search for English-language publications indexed on MEDLINE and International Pharmaceutical Abstracts through January 2010 using the term clevidipine. All identified prospective, randomized and nonrandomized Phase III trials were included in the review. RESULTS: Seven Phase III trials were identified in which clevidipine was compared with baseline, placebo, or other intravenous antihypertensive agents in the settings of severe hypertension (1 study), preoperative cardiac surgery (1), perioperative cardiac surgery (1), and postoperative cardiac surgery (4). In a multicenter, randomized, double-blind, placebo-controlled study of the efficacy of clevidipine in treating preoperative hypertension, the mean reduction from baseline in mean arterial pressure was 31.2% with clevidipine and 11.2% with placebo (P < 0.001). In a randomized, open-label, prospective study involving separate comparisons of clevidipine with nitroglycerin, sodium nitroprusside, and nicardipine, the median total AUC for digression in systolic BP from the predetermined target range differed significantly between clevidipine and nitroglycerin (4.14 vs 8.87 mm Hg . min/h; respectively, P < 0.001) and between clevidipine and sodium nitroprusside (4.37 vs 10.5 mm Hg . min/h; P = 0.003), but not between clevidipine and nicardipine (1.76 and 1.69 mm Hg . min/h). Another study found no significant difference in efficacy in controlling BP during the 3-hour study period between clevidipine and sodium nitroprusside (AUC for mean [SD] arterial pressure, 106 [25] and 101 [28] mm Hg . min/h, respectively). Adverse events in these studies included atrial fibrillation (13.0%-36.1% clevidipine vs 12.0% placebo), nausea (5.0%-21.0% vs 12.0%, respectively), fever (19.0% vs 13.7%), insomnia (12.0% vs 6.1%), and acute renal failure (9.0% vs 2.0%). In the studies reviewed, only 1 case of chest discomfort in the setting of severe hypertension was considered a serious adverse event related to clevidipine therapy. CONCLUSION: In the Phase III trials reviewed, clevidipine was effective in controlling BP in the settings of perioperative cardiac surgery and severe hypertension and was associated with minimal adverse effects.

No effect of a traditional Chinese medicine, Hochu-ekki-to, on antibody titer after influenza vaccination in man: a randomized, placebo-controlled, double-blind trial.

BACKGROUND: It was shown that a traditional Chinese medicine, Hochu-ekki-to (HET), had adjuvant effects in influenza vaccination in an animal experiment. This, however, could not be assessed in a clinical study. METHODS: Thirty-two healthy subjects were randomly assigned to two groups (control and HET groups) in a double-blind manner. HET subjects (n=17) took 7.5 g of HET/day for two weeks; control subjects took the same amount of indistinguishable placebo. Then subjects were vaccinated against influenza (H1N1, H3N2 and B/Shandong). Hemagglutinin titers and natural killer (NK) activity were measured at weeks 0, 1, 2, 4, and 12. RESULTS: Antiinfluenza titers against the three viruses were increased continuously for the first two weeks and leveled off. However, there were no significant differences in any titers between the two groups. NK activity peaked at week 2 without any inter-group differences. CONCLUSION: We could not find any adjuvant effects of HET in this experimental condition.

Effect of nesiritide on renal function: a retrospective review.

OBJECTIVES: Recent meta-analysis has demonstrated that nesiritide may worsen renal function (RF) in patients with acute decompensated heart failure (ADHF). A nesiritide utilization evaluation (NUE) performed in our institution reflected that belief of RF preservation was one reason leading to nesiritide overuse. This study examined the effect of nesiritide on RF in patients evaluated in this NUE. RESEARCH DESIGN AND METHODS: Nesiritide patient records from October 1, 2003 to March 31, 2004 were reviewed (n = 162). Pertinent demographics, laboratory and medication utilization data were obtained. MAIN OUTCOME MEASURES: Changes in creatinine clearance (CrCl) and percentage of patients demonstrating worsening RF (decrease in CrCl > or = 25%) during diuretics therapy before nesiritide initiation and during nesiritide initiation and during nesiritide therapy were compared using Wilcoxon Signed-Ranks test and Chi-Square respectively. RESULTS: Overall, the addition of nesiritide to IV furosemide did not clinically change RF as compared to the use of IV furosemide alone (% change in CrCl: 0 vs. -2.13 mL/min, p = 0.023), although the difference was statistically significant. When categorized into different RF, there is no different in CrCl changes between the nesiritide group and the IV furosemide alone group. There is also no difference in terms of number of patients experiencing > or = 25% reduction in CrCl overall. Changes in RF were also not correlated to dose or duration of therapy. CONCLUSION: Nesiritide did not demonstrate significant impact in RF. Larger studies that examine RF in a more systematic and controlled manner and relate changes in RF to clinical outcomes are necessary to further elucidate the risk versus benefit profile of nesiritide.

Are rhoptries in Apicomplexan parasites secretory granules or secretory lysosomal granules?

The club-shaped rhoptries in Apicomplexan parasites are one of the most unusual secretory organelles among the eukaryotes, containing unusual lipid and protein cargo that is specialized for intracellular parasitism. Rhoptries have traditionally been viewed strictly as regulated secretory granules. We discuss in this article recent data on the cargo, function and biogenesis of rhoptries in two parasitic model systems, Toxoplasma and Plasmodium. Current findings suggest that rhoptries receive products from both biosynthetic and endocytic pathways and, therefore, they are most analogous to secretory lysosomal granules found in mammalian cells.

Pleiotropic effect due to targeted depletion of secretory rhoptry protein ROP2 in Toxoplasma gondii.

Long after their discovery, the function and biogenesis of rhoptries remain enigmatic. In Apicomplexan parasites, these organelles discharge and their contents are exocytosed at the time of host cell invasion, and are thus proposed to play an essential role in establishing the parasitophorous vacuole. In Toxoplasma gondii, ROP2 is suspected to serve as the molecular link between host cell mitochondria and parasitophorous vacuole membrane. In this study we addressed the function of ROP2. Targeted depletion of ROP2 using a ribozyme-modified antisense RNA strategy resulted in multiple effects on parasite morphology because of a disruption in the formation of mature rhoptries, and an arrest in cytokinesis. The association of host cell mitochondria with the parasitophorous vacuole membrane was abolished and the ROP2-deficient parasites had a reduced uptake of sterol from the host cell. Furthermore, these parasites invaded human fibroblasts poorly and had markedly attenuated virulence in mice. We conclude that rhoptry discharge, and in particular release of ROP2, are essential for parasite invasion, replication and host cell-parasite interaction.

AP-1 in Toxoplasma gondii mediates biogenesis of the rhoptry secretory organelle from a post-Golgi compartment.

We have previously demonstrated that Toxoplasma gondii has a tyrosine-based sorting system, which mediates protein targeting to the lysosome-like rhoptry secretory organelle. We now show that rhoptry protein targeting is also dependent on a dileucine motif and occurs from a post-Golgi endocytic organelle to mature rhoptries in an adaptin-dependent fashion. The T. gondii AP-1 adaptin complex is implicated in this transport because the micro1 chain of T. gondii AP-1 (a) was localized to multivesicular endosomes and the limiting and luminal membranes of the rhoptries; (b) bound to endocytic tyrosine motifs in rhoptry proteins, but not in proteins from dense granule secretory organelles; (c) when mutated in predicted tyrosine-binding motifs, led to accumulation of the rhoptry protein ROP2 in a post-Golgi multivesicular compartment; and (d) when depleted via antisense mRNA, resulted in accumulation of multivesicular endosomes and immature rhoptries. These are the first results to implicate AP-1 in transport from a post-Golgi compartment to a mature secretory organelle and substantially expand the role for AP-1 in anterograde protein transport.

Golgi biogenesis in Toxoplasma gondii.

Two models have been put forward to explain the growth of new Golgi during the cell cycle. The first suggests that a new Golgi grows out of the endoplasmic reticulum by de novo synthesis. The second suggests that a pre-existing Golgi is needed for the growth of a new one, that is, the Golgi is an autonomously replicating organelle. To resolve this issue, we have exploited the simplicity of the apicomplexan parasite Toxoplasma gondii, which has only a single Golgi stack. Here we show, by using video fluorescence microscopy and three-dimensional reconstructions of serial thin sections, that the Golgi grows by a process of lateral extension followed by medial fission. Further fission leads to the inheritance by each daughter of a pair of Golgi structures, which then coalesce to re-form a single Golgi. Our results indicate that new Golgi grow by autonomous duplication and raise the possibility that the Golgi is a paired structure that is analogous to centrioles.

Toxoplasma gondii Rab5 enhances cholesterol acquisition from host cells.

The role of endocytosis in nutrient uptake by Toxoplasma gondii is unknown. To explore this issue, we characterized an endosomal compartment by identifying a T. gondii Rab5 homologue, a molecular marker for early endosomes in eukaryotic cells. The deduced amino acid sequence of the T. gondii Rab5 gene encodes a protein of 240 amino acids, which we termed TgRab51. TgRab51 was epitope-tagged at the N-terminus, expressed in the parasite, and localized by immunofluorescence and immunoelectron microscopy to tubulovesicular structures anterior to the parasite nucleus and adjacent to, but distinct from the Golgi. By immunofluorescence analysis, TgRab51wt-HA staining partially overlapped with Golgi/TGN markers, but not with the T. gondii secretory organelles. A dominant positive mutant, TgRab51Q103L-HA, enhanced uptake of exogenous cholesterol analogues in intracellular parasites, augmented formation of lipid droplets and accelerated parasite growth. Brefeldin A disrupted the TgRab51 compartment, and altered the distribution of fluorescent exogenous cholesterol in cells expressing TgRab51Q103L-HA. These results suggest that TgRab51 facilitates sterol uptake, possibly through a Golgi-dependent pathway.