Random numbers certified by Bell's theorem.

Randomness is a fundamental feature of nature and a valuable resource for applications ranging from cryptography and gambling to numerical simulation of physical and biological systems. Random numbers, however, are difficult to characterize mathematically, and their generation must rely on an unpredictable physical process. Inaccuracies in the theoretical modelling of such processes or failures of the devices, possibly due to adversarial attacks, limit the reliability of random number generators in ways that are difficult to control and detect. Here, inspired by earlier work on non-locality-based and device-independent quantum information processing, we show that the non-local correlations of entangled quantum particles can be used to certify the presence of genuine randomness. It is thereby possible to design a cryptographically secure random number generator that does not require any assumption about the internal working of the device. Such a strong form of randomness generation is impossible classically and possible in quantum systems only if certified by a Bell inequality violation. We carry out a proof-of-concept demonstration of this proposal in a system of two entangled atoms separated by approximately one metre. The observed Bell inequality violation, featuring near perfect detection efficiency, guarantees that 42 new random numbers are generated with 99 per cent confidence. Our results lay the groundwork for future device-independent quantum information experiments and for addressing fundamental issues raised by the intrinsic randomness of quantum theory.

Beat note stabilization of mode-locked lasers for quantum information processing.

We stabilize a chosen radio frequency beat note between two optical fields derived from the same mode-locked laser pulse train in order to coherently manipulate quantum information. This scheme does not require access or active stabilization of the laser repetition rate. We implement and characterize this external lock, in the context of two-photon stimulated Raman transitions between the hyperfine ground states of trapped 171Yb(+) quantum bits.

Optimal quantum control of multimode couplings between trapped ion qubits for scalable entanglement.

We demonstrate entangling quantum gates within a chain of five trapped ion qubits by optimally shaping optical fields that couple to multiple collective modes of motion. We individually address qubits with segmented optical pulses to construct multipartite entangled states in a programmable way. This approach enables high-fidelity gates that can be scaled to larger qubit registers for quantum computation and simulation.

Dietary potassium intake and renal handling, and their impact on the cardiovascular health of normotensive afro-caribbeans.

OBJECTIVE: Recent nutritional profiles of dietary intake have indicated a shift from the ancient diet to the Western diet. The ancient diet provided a high potassium and low sodium intake, which in turn leads to sodium conservation and potassium excretion. This change in the dietary intake is expected to affect potassium and sodium handling in the kidneys. Numerous studies have been done to emphasize the importance of sodium handling by the kidneys and its impact on cardiovascular health. This study will investigate potassium intake and handling, and its impact on the cardiovascular health of a sample of normotensive Afro-Caribbeans by the possible modulation of the renin angiotensin aldosterone system (RAAS). METHODS: A sample of 51 normotensive Afro-Caribbean participants was recruited for the study. Participants were observed over a two-day period in which they were given a 24-hour ambulatory blood pressure monitor and a container to collect blood pressure data and a 24-hour urine sample. Anthropometric measurements were noted. Urinary electrolytes and supine plasma renin activity (PRA) were determined from the 24-hour urine collection and a blood sample. Dietary potassium intake was estimated based on dietary intake observations and calculated based on the urinary potassium excretion. SPSS version 19 was used to analyse the data to make inferences. RESULTS: The daily potassium intake was observed to be 2.95 g/day and measured intake from the urinary potassium was between 4.95 and 7.32 g/day. Urinary potassium excretion was 3.66 (± 1.40) g/day. The urinary potassium excretion in the Afro-Caribbean sample in Barbados was higher than the other population samples. The averaged PRA of the participants (supine) was 0.778 (± 1.072) ng/mL/hour. The averaged nocturnal systolic blood pressure dip of the participants was 5.97 (± 4.324) %. There was no significant correlation between urinary potassium excretion, blood pressure, nocturnal systolic blood pressure dip and PRA. CONCLUSIONS: The Afro-Caribbean sample has an inadequate daily potassium intake based on the observed intake and recommended values, with a high urinary excretion of the electrolyte compared to other values in the literature. This high potassium excretion could have been partly due to low plasma renin activity levels in the study participants. As a possible consequence, an increase in the nocturnal peripheral resistance is a likely cause for the diminished systolic dip. The lack of correlations between dietary potassium excretion and the blood pressure parameters does not allow any firm inference of the electrolyte's handling and its impact on cardiovascular health in the normotensive Afro-Caribbean participants. However, further research is needed to get a more accurate daily potassium intake value, and a more statistically robust sample to assess whether potassium handling and blood pressure would be affected by a change in potassium intake.

Shape selectivity by guest-driven restructuring of a porous material.

A flexible metal-organic framework selectively sorbs para- (pX) over meta-xylene (mX) by synergic restructuring around pX coupled with generation of unused void space upon mX loading. The nature of the structural change suggests more generally that flexible structures which are initially mismatched in terms of fit and capacity to the preferred guest are strong candidates for effective molecular separations.

Predicting 24-hour urinary protein excretion in Afro-Caribbean Barbadians by comparing urine protein excretion over different durations versus spot collection.

AIM: The gold standard for the determination of proteinuria, an independent risk factor for cardiovascular and renal disease, is the measurement of protein in a 24-hour urine collection. However this method has been shown to be unreliable mainly due to poor compliance of sampling by patients. This study investigates other appropriate means of predicting 24-hour urinary protein excretion in a sample of Afro-Caribbeans in Barbados by assessing the correlation of actual and estimated urinary protein excretion between a 24-hour urine collection sample, 12-hour (AM and PM) and spot (AM and PM) urine collections. SUBJECTS AND METHOD: A convenient sample of 30 healthy participants of Afro-Caribbean origin between the ages of21 and 55 years was recruited for the study The 24-hour urine samples and anthropometric data were collected as documented in the study s standard clinical procedure. A 24-hour urine sample was collected as two separate 12-hour AM and PM samples. In addition, two spot samples (AM and PM) were taken during each 12-hour sample collection period. Analysis of the urinary protein and creatinine was done with a Roche/Hitachi Modular System (Roche Diagnostics, IN, USA). SPSS version 19 was used to analyse the data to make inferences. RESULTS: Thirty Afro-Caribbean persons participated in the study: 16 females and 14 males. The average age and body mass index (BMI) were 38 +/- 17 years and 25.32+/- 5.98 kg/m2, respectively. The Spearman Rho 's correlation was used to interpret associations of the urinary parameters in 24-hour collected sample and the other samples. The strongest correlation of the protein:creatinine ratio in the 24-hour collected sample to the other samples was observed with the 12-hour AM sample (r = + 0.743, p < O.01)followed by the 12-hour PM sample (r = +0.672, p < 0.01). On analysing gender, the more significant correlations found were among the males for the 12-hour timed samples with r = +0.945, p < 0.01 and r = +0.736, p < 0.01 for the AM and PM samples, respectively. There were very strong correlations between the 24-hour urinary protein excretion and the estimated 24-hour protein excretion from the 12-hour AM and PM samples (r = +0.846, p < 0.01 and r = +0.637, p < 0.01, respectively). Both males and females had the strongest correlation for the estimation of 24-hour protein excretion in the 12-hour AM sample (r = +0.795, p < 0.01 and r = +0.965, p < 0.01, respectively). CONCLUSION: The use ofa 12-hour timed sample, specifically the morning sample, may be a more convenient way to assess proteinuria in the Afro-Caribbean population. This method allows for a quicker assessment of proteinuria which not only allows earlier diagnosis of renal disease but may also reduce the clinical cost of the disease s management.

Predicting 24-hour urinary sodium excretion in Afro-Caribbean Barbadians by comparing urine sodium excretion over different durations versus spot collection.

AIM: Urinary sodium excretion is used as an assessment tool for salt intake and salt handling. Even though cumbersome, the most reliable and readily used method in clinical and epidemiological studies is the 24-hour urine collection. This study investigates other appropriate means ofpredicting 24-hour urinary sodium excretion in a sample of Afro-Caribbeans in Barbados by assessing the correlation of actual and estimated urinary sodium excretion between a 24-hour urine collection sample, 12-hour (AM and PM), and spot (AM and PM) urine collections. METHOD: A convenient sample of 30 healthy participants of Afro-Caribbean origin between the ages of 21 and 55 years was recruited for the study. The 24-hour urine samples and anthropometric data were collected as documented in the study's standard clinical procedure. A 24-hour urine sample was collected as two separate 12-hour AM and PM samples. In addition, two spot samples (AM and PM) were taken during each 12-hour sample collection period. Analysis of the urinary sodium and creatinine was done with a Roche/Hitachi Modular System (Roche Diagnostics, IN, USA). SPSS version 19 was used to analyse the data to make inferences. RESULTS: Thirty Afro-Caribbean subjects participated in this study: 16 females and 14 males. The average age and body mass index (BMI) were 38 +/- 17 years and 25.32 +/- 5.98 kg/m2, respectively. The greatest correlation of the estimated 24-hour sodium excretion to the measured 24-hour sodium excretion was observed in the 12-hour PM sample (Pearson's correlation, r = 0.786, p < 0.001) followed by the 12-hour AM sample (Pearson's correlation, r = 0.774, p < 0.001). The PM spot sample showed a weaker, but still statistically significant correlation to the 24-hour timed sample (Pearson 's correlation, r = 0.404, p < 0.045). The AM spot sample showed a very weak and insignificant correlation (Pearson 's correlation, r = 0.05, p = 0.807) to the 24-hour timed sample. Similarly to the whole sample, the gender analysis demonstrated that estimated 24-hour sodium excretion in the female's 12-hour PM sample had the greatest correlation (r = 0.819, p < 0.001) to the measured 24-hour sodium excretion, followed by the 12-hour AM (r = 0.793, p = 0.001) and the PM spot samples (r = 0.741, p = 0.02). The correlation between variables is weaker in males compared to the females. CONCLUSION: Overall, this study shows a clear correlation between the estimated 24-hour sodium excretion from the 12-hour timed PM sample and the measured 24-hour sodium excretion. Such findings support the thought of using other alternatives to determine sodium excretion, in view of replacing the cumbersome 24-hour urinary collection with a smaller timed sample. Nonetheless, a more robust and randomized population sample as well as a method to correct for high creatinine variability is required to further enhance the significance of the obtained results.

Healthcare costs of methicillin resistant Staphylococcus aureus and Pseudomonas aeruginosa infections in veterans: role of vitamin D deficiency.

Methicillin resistant Staphylococcus aureus (MRSA) and Pseudomonas aeruginosa (P. aeruginosa) infections are frequently associated with hospitalization and increased healthcare costs. Vitamin D deficiency may contribute to increased costs for patients with these infections and there is evidence that vitamin D may have an antimicrobial role. To evaluate the role of vitamin D deficiency in the costs incurred with these infections, we studied the relationship of serum 25(OH)D levels to healthcare costs in veterans in the southeastern United States. Patients with both infections were vitamin D deficient to a similar extent and so were combined for further analysis. Vitamin D deficient patients had higher costs and service utilization than those who were not vitamin D deficient. Those with vitamin D deficiency had higher inpatient costs compared to the non-deficient group, and this difference was across most categories except for the number of inpatient hospitalizations or total number of days as an inpatient. Vitamin D deficiency was not significantly related to outpatient cost or service utilization parameters. We conclude that vitamin D deficiency is intimately linked to adverse healthcare costs in veterans with MRSA and P. aeruginosa infections. Vitamin D status should be assayed in patients with these infections.

The impact of the healthcare system in Barbados (provision of health insurance and the benefit service scheme) on the use of herbal remedies by Christian churchgoers.

AIM: To determine the impact of health insurance and the government's Benefit Service Scheme, a system that provides free drugs to treat mostly chronic illnesses to persons aged 16 to 65 years, on the use of herbal remedies by Christian churchgoers in Barbados. METHODS: The eleven parishes of Barbados were sampled over a six-week period using a survey instrument developed and tested over a four-week period prior to administration. Persons were asked to participate and after written informed consent, they were interviewed by the research team. The data were analysed by the use of IBM SPSS version 19. The data were all nominal, so descriptive statistics including counts, the frequencies, odds ratios and percentages were calculated. RESULTS: More than half of the participants (59.2%) were female, a little less than a third (29.9%) were male, and one tenth of the participants (10.9%) did not indicate their gender The majority of the participants were between the ages of 41 and 70 years, with the age range of 51-60 years comprising 26.1% of the sample interviewed. Almost all of the participants were born in Barbados (92.5%). Approximately 33% of the respondents indicated that they used herbal remedies to treat various ailments including chronic conditions. The odds ratio of persons using herbal remedies and having health insurance to persons not using herbal remedies and having health insurance is 1.01 (95% CI 0.621, 1.632). There was an increase in the numbers of respondents using herbal remedies as age increased. This trend continued until the age group 71-80 years which showed a reduction in the use of herbal remedies, 32.6% of respondents compared with 38.3% of respondents in the 61-70-year category. CONCLUSIONS: The data demonstrated that only a third of the study population is using herbal remedies for ailments. Health insurance was not an indicator neither did it influence the use of herbal remedies by respondents. The use of herbal remedies may not be associated with affluence. The reduction in the use of herbal remedies in the age group 71-80 years could be due to primarily a lower response rate from this age group, and secondarily due to the Benefit Service Scheme offering free medication to persons who have passed the age of 65 years.

Taxonomic annotation of 16S rRNA sequences of pig intestinal samples using MG-RAST and QIIME2 generated different microbiota compositions.

Environmental microbiome studies rely on fast and accurate bioinformatics tools to characterize the taxonomic composition of samples based on the 16S rRNA gene. MetaGenome Rapid Annotation using Subsystem Technology (MG-RAST) and Quantitative Insights Into Microbial Ecology 2 (QIIME2) are two of the most popular tools available to perform this task. Their underlying algorithms differ in many aspects, and therefore the comparison of the pipelines provides insights into their best use and interpretation of the outcomes. Both of these bioinformatics tools are based on several specialized algorithms pipelined together, but whereas MG-RAST is a user-friendly webserver that clusters rRNA sequences based on their similarity to create Operational Taxonomic Units (OTU), QIIME2 employs DADA2 in the construction of Amplicon Sequence Variants (ASV) by applying an error model that considers the abundance of each sequence and its similarity to other sequences. Taxonomic compositions obtained from the analyses of amplicon sequences of DNA from swine intestinal gut and faecal microbiota samples using MG-RAST and QIIME2 were compared at domain-, phylum-, family- and genus-levels in terms of richness, relative abundance and diversity. We found significant differences between the microbiota profiles obtained from each pipeline. At domain level, bacteria were relatively more abundant using QIIME2 than MG-RAST; at phylum level, seven taxa were identified exclusively by QIIME2; at family level, samples processed in QIIME2 showed higher evenness and richness (assessed by Shannon and Simpson indices). The genus-level compositions obtained from each pipeline were used in partial least squares-discriminant analyses (PLS-DA) to discriminate between sample collection sites (caecum, colon and faeces). The results showed that different genera were found to be significant for the models, based on the Variable Importance in Projection, e.g. when using sequencing data processed by MG-RAST, the three most important genera were Acetitomaculum, Ruminococcus and Methanosphaera, whereas when data was processed using QIIME2, these were Candidatus Methanomethylophilus, Sphaerochaeta and Anaerorhabdus. Furthermore, the application of differential filtering procedures before the PLS-DA revealed higher accuracy when using non-restricted datasets obtained from MG-RAST, whereas datasets obtained from QIIME2 resulted in more accurate discrimination of sample collection sites after removing genera with low relative abundances (<1%) from the datasets. Our results highlight the differences in taxonomic compositions of samples obtained from the two separate pipelines, while underlining the impact on downstream analyses, such as biomarkers identification.

Establishing an SEIR-based framework for local modelling of COVID-19 infections, hospitalisations and deaths.

Without timely assessments of the number of COVID-19 cases requiring hospitalisation, healthcare providers will struggle to ensure an appropriate number of beds are made available. Too few could cause excess deaths while too many could result in additional waits for elective treatment. As well as supporting capacity considerations, reliably projecting future "waves" is important to inform the nature, timing and magnitude of any localised restrictions to reduce transmission. In making the case for locally owned and locally configurable models, this paper details the approach taken by one major healthcare system in founding a multi-disciplinary "Scenario Review Working Group", comprising commissioners, public health officials and academic epidemiologists. The role of this group, which met weekly during the pandemic, was to define and maintain an evolving library of plausible scenarios to underpin projections obtained through an SEIR-based compartmental model. Outputs have informed decision-making at the system's major incident Bronze, Silver and Gold Commands. This paper presents illustrated examples of use and offers practical considerations for other healthcare systems that may benefit from such a framework.

Viral metagenomics reveals the presence of novel Zika virus variants in Aedes mosquitoes from Barbados.

BACKGROUND: The Zika virus (ZIKV) epidemic of 2015/2016 spread throughout numerous countries. It emerged in mainland Latin America and spread to neighboring islands, including the Caribbean island of Barbados. Recent studies have indicated that the virus must have already been circulating in local mosquito populations in Brazil for almost 2 years before it was identified by the World Health Organization in 2015. Metagenomic detection assays have the potential to detect emerging pathogens without prior knowledge of their genomic nucleic acid sequence. Yet their applicability as vector surveillance tools has been widely limited by the complexity of DNA populations from field-collected mosquito preparations. The aim of this study was to investigate local vector biology and characterize metagenomic arbovirus diversity in Aedes mosquitoes during the ongoing 2015/2016 ZIKV epidemic. METHODS: We performed a short-term vector screening study on the island of Barbados during the ongoing 2015/2016 ZIKV epidemic, where we sampled local Aedes mosquitoes. We reanalyzed mosquito viral microbiome data derived from standard Illumina MiSeq sequencing to detect arbovirus sequences. Additionally, we employed deep sequencing techniques (Illumina HiSeq) and designed a novel bait capture enrichment assay to increase sequencing efficiency for arbovirus sequences from complex DNA samples. RESULTS: We found that Aedes aegypti seemed to be the most likely vector of ZIKV, although it prevailed at a low density during the observed time period. The number of detected viruses increased with sequencing depth. Arbovirus sequence enrichment of metagenomic DNA preparations allowed the detection of arbovirus sequences of two different ZIKV genotypes, including a novel one. To our knowledge, this is the first report of the S3116W mutation in the NS5 gene region of ZIKV polyprotein. CONCLUSIONS: The metagenomic arbovirus detection approach presented here may serve as a useful tool for the identification of epidemic-causing arboviruses with the additional benefit of enabling the collection of phylogenetic information on the source. Apart from detecting more than 88 viruses using this approach, we also found evidence of novel ZIKV variants circulating in the local mosquito population during the observed time period.

Effects of complementarity determining region mutations on the affinity of an alpha/beta T cell receptor: measuring the energy associated with CD4/CD8 repertoire skewing.

It has been proposed that the generally low affinities of T cell receptors (TCRs) for their peptide-major histocompatibility complex (pMHC) ligands (Kd approximately 10(-4) to 10(-7) M) are the result of biological selection rather than an intrinsic affinity limitation imposed by the TCR framework. Using a soluble version of the 2C TCR, we have used complementarity determining region (CDR)-directed mutagenesis to investigate whether the affinity of this receptor for its allogeneic pMHC ligand can be improved upon. We report that several mutants at positions lying within CDR3alpha and CDR2beta showed increased affinities for pMHC compared with the wild-type receptor. Additionally, we have investigated whether Valpha mutations that have been implicated in the phenomenon of CD8(+) repertoire skewing achieve this skewing by means of generalized increases in affinity for MHC-I molecules. Two mutants (S27F and S51P), which each promote skewing toward a CD8(+) phenotype, exhibited significantly reduced affinity for pMHC-I, consistent with a quantitative-instructional model of CD4/CD8 lineage commitment. This model predicts that CD8 is downregulated on thymocytes that have TCR-ligand interactions above a minimal energy threshold. Together, the results (a) demonstrate that engineering higher affinity TCRs is feasible, and (b) provide TCR-pMHC energy values associated with CD4/CD8 repertoire skewing.

Healthcare costs of Staphylococcus aureus and Clostridium difficile infections in veterans: role of vitamin D deficiency.

Clostridium difficile and staphylococcal infections are associated with increased morbidity, mortality and healthcare costs. Vitamin D deficiency may also contribute to increased healthcare costs. There is increasing evidence that vitamin D may have an antimicrobial role. We examined the relationship of serum 25(OH)D levels to staphylococcal and C. difficile infections to determine if vitamin D deficiency was associated with adverse outcomes. In the outpatient setting, vitamin D deficiency in patients with C. difficile and staphylococcal infections were associated with significantly increased total outpatients costs and fee-based consultation. Laboratory expenses had a trend towards higher costs in the vitamin D-deficient group but did not reach statistical significance. The differences were most clearly seen in the in-patient group with enhanced laboratory, pharmacy and radiology costs. These differences resulted in vitamin D-deficient patients with C. difficile or staphylococcal infections having costs more than five times higher than the non-deficient patients. The total length of hospital stay was four times greater in the vitamin D-deficient group. In addition, the total number of hospitalizations was also significantly greater in the vitamin D-deficient group. Surgery costs demonstrated a tendency to be higher in the vitamin D-deficient group but failed to reach statistical significance. Vitamin D deficiency is intimately linked to adverse health outcomes and costs in Veterans with staphylococcal and C. difficile infections in North East Tennessee. We recommend that vitamin D status be checked in patients with these infections and appropriate therapy be instituted to restore vitamin D level to normal in an expeditious manner.

Drug-herb interaction: database of medicinal plants of the Caribbean, their indications, toxicities and possible interactions with conventional medication.

OBJECTIVE: Healthcare professionals in the Caribbean today know very little about these drug-herb interactions of the popular West Indian medicinal herb practices linked to the immigrants from West Africa and India, and to the indigenous Amerindians. It is the intent of this project to produce a database which comprehensively summarizes indications and possible drug-herb interactions of these plants. METHOD: Using the database programme Epi Info 3.5.1, one hundred and eighty-three herbs used in the Caribbean as medicine by locals have been entered into the West Indian Drug Herb Interaction Database version 0.06 (WIDHID 0.06). RESULTS: A range of one to three common names have been entered with the family and scientific name of each herb, in addition to a range of one to six conditions/illnesses for which a particular plant was to be used as a medicinal herb. One to four bioactive compounds have been made to correlate with the typical herbal preparation methods and toxicity. Thirty of the most common and popular herbs have been researched for their drug herb interactions. CONCLUSION: West Indian Drug Herb Interaction Database version 0.06 for the first time allows easy access to Caribbean ethno-medicinal plant cures with their possible drug-herb interactions reference sources, a feature often absent although so important. In addition, WIDHID 0.06 will support pharmaco-epidemiological studies in the field. It will also ensure future public access to ethno-medicinal information through developed web pages or programmes.

Complete Genome Sequences of Nine Mycobacteriophages from New Zealand, Beatrix, Carthage, Daegal, Dulcie, Fancypants, Fenn, Inca, Naira, and Robyn.

Beatrix, Carthage, Daegal, Dulcie, Fancypants, Fenn, Inca, Naira, and Robyn are newly isolated bacteriophages capable of infecting Mycolicibacterium smegmatis mc2 155. We discovered, sequenced, and annotated these New Zealand bacteriophages. These phages illustrate that New Zealand harbors a selection of the highly diverse and distributed mycobacteriophage clusters found globally.

A multi-centre cohort study evaluating the role of inflammatory markers in patient's presenting with acute ureteric colic (MIMIC).

BACKGROUND: Spontaneous Stone Passage (SSP) rates in acute ureteric colic range from 47 to 75%. There is conflicting evidence on the role of raised inflammatory markers in acute ureteric colic. The use of an easily applicable biomarker that could predict SSP or need for intervention would improve the management of obstructing ureteric stones. Thus, there is a need to determine in an appropriately powered study, in patients who are initially managed conservatively, which factors at the time of acute admission can predict subsequent patient outcome such as SSP and the need for intervention. Particularly, establishing whether levels of white cell count (WBC) at presentation are associated with likelihood of SSP or intervention may guide clinicians on the management of these patients' stones. DESIGN: Multi-center cohort study disseminated via the UK British Urology Researchers in Surgical Training (BURST) and Australian Young Urology Researchers Organisation (YURO). PRIMARY RESEARCH QUESTION: What is the association between WBC and SSP in patients discharged from emergency department after initial conservative management? PATIENT POPULATION: Patients who have presented with acute renal colic with CT KUB evidence of a solitary ureteric stone. A minimum sample size of 720 patients across 15 centres will be needed. HYPOTHESIS: A raised WBC is associated with decreased odds of spontaneous stone passage. PRIMARY OUTCOME: The occurrence of SSP within six months of presentation with acute ureteric colic (YES/NO). SSP was defined as absence of need for intervention to assist stone passage. STATISTICAL ANALYSIS PLAN: A multivariable logistic regression model will be constructed, where the outcome of interest is SSP using data from patients who do not undergo intervention at presentation. A random effect will be used to account for clustering of patients within hospitals/institutions. The model will include adjustments for gender, age as control variables.

Glioma migration can be blocked by nontoxic inhibitors of myosin II.

Anaplastic gliomas are infiltrative tumors, and their ability to migrate through normal brain contributes to their highly malignant behavior. Invasion of brain requires cell motility, which in turn depends on the activity of the cytoskeleton. A cytoskeletal component central to this process is myosin II, the cytoplasmic analogue of smooth and skeletal muscle myosin. Myosin II activity is regulated by the enzyme myosin light chain kinase, which activates myosin II by phosphorylating it on its regulatory light chain. We have investigated the role of myosin II in glioma motility and invasiveness by examining the effects of two inhibitors of myosin light chain kinase, ML7 and KT5926. Both drugs are potent inhibitors of both glioma motility, as measured by a scrape motility assay, and an in vitro haptotaxis assay. The inhibition of in vitro haptotaxis follows the dose-response relationship expected for competitive inhibition of myosin light chain kinase by these drugs and is seen at drug concentrations that are nontoxic. These results highlight the important role that myosin II contributes to glioma invasiveness and suggest that it may serve as a target in future strategies at blocking invasion by these tumors.

Modulation of glioma cell migration and invasion using Cl(-) and K(+) ion channel blockers.

Human malignant gliomas are highly invasive tumors. Mechanisms that allow glioma cells to disseminate, migrating through the narrow extracellular brain spaces are poorly understood. We recently demonstrated expression of large voltage-dependent chloride (Cl(-)) currents, selectively expressed by human glioma cells in vitro and in situ (Ullrich et al., 1998). Currents are sensitive to several Cl(-) channel blockers, including chlorotoxin (Ctx), (Ullrich and Sontheimer; 1996; Ullrich et al; 1996), tetraethylammonium chloride (TEA), and tamoxifen (Ransom and Sontheimer, 1998). Using Transwell migration assays, we show that blockade of glioma Cl(-) channels specifically inhibits tumor cell migration in a dose-dependent manner. Ctx (5 microM), tamoxifen (10 microM), and TEA (1 mM) also prevented invasion of human glioma cells into fetal rat brain aggregates, used as an in vitro model to assess tumor invasiveness. Anion replacement studies suggest that permeation of chloride ions through glioma chloride channel is obligatory for cell migration. Osmotically induced cell swelling and subsequent regulatory volume decrease (RVD) in cultured glioma cells were reversibly prevented by 1 mM TEA, 10 microM tamoxifen, and irreversibly blocked by 5 microM Ctx added to the hypotonic media. Cl(-) fluxes associated with adaptive shape changes elicited by cell swelling and RVD in glioma cells were inhibited by 5 microM Ctx, 10 microM tamoxifen, and 1 mM TEA, as determined using the Cl(-)-sensitive fluorescent dye 6-methoxy-N-ethylquinolinium iodide. Collectively, these data suggest that chloride channels in glioma cells may enable tumor invasiveness, presumably by facilitating cell shape and cell volume changes that are more conducive to migration and invasion.

Role of extracellular signal-regulated kinase and phosphatidylinositol-3 kinase in chemoattractant and LPS delay of constitutive neutrophil apoptosis.

The present study examined the role of mitogen-activated protein kinases (MAPKs) and phosphatidylinositol-3 kinase-stimulated Akt (PI-3K/Akt) in the regulation of constitutive human neutrophil apoptosis by bacterial lipopolysaccharide (LPS) and two chemoattractants, fMLP and leukotriene B(4) (LTB(4)). LPS and LTB(4) inhibited apoptosis, while fMLP had no effect. Inhibition of extracellular signal-regulated kinase (ERK) with PD098059 significantly inhibited the anti-apoptotic effect of both LPS and LTB(4), while inhibition of p38 kinase with SB203580 had no effect. Inhibition of PI-3K with wortmannin and LY294002 significantly attenuated the anti-apoptotic effect of LTB(4), but not LPS. LPS, fMLP, and LTB(4) stimulated similar levels of ERK and Akt activation. LTB(4) and LPS inhibited neutrophil apoptosis when added simultaneously with fMLP, and LTB(4) and LPS demonstrated an additive effect. We conclude that the ERK and/or PI-3K/Akt pathways are necessary, but not sufficient, for LPS and LTB(4) to delay apoptosis, but other anti-apoptotic pathways remain to be identified.