Distinguishing viruses responsible for influenza-like illness.

The many respiratory viruses that cause influenza-like illness (ILI) are reported and tracked as one entity, defined by the CDC as a group of symptoms that include a fever of 100 degrees Fahrenheit, a cough, and/or a sore throat. In the United States alone, ILI impacts 9-49 million people every year. While tracking ILI as a single clinical syndrome is informative in many respects, the underlying viruses differ in parameters and outbreak properties.

Updated distribution maps of predominant Culex mosquitoes across the Americas.

Background: Estimates of the geographical distribution of Culex mosquitoes in the Americas have been limited to state and provincial levels in the United States and Canada and based on data from the 1980s. Since these estimates were made, there have been many more documented observations of mosquitoes and new methods have been developed for species distribution modeling. Moreover, mosquito distributions are affected by environmental conditions, which have changed since the 1980s.

Estimating the reproductive number, total outbreak size, and reporting rates for Zika epidemics in South and Central America.

As South and Central American countries prepare for increased birth defects from Zika virus outbreaks and plan for mitigation strategies to minimize ongoing and future outbreaks, understanding important characteristics of Zika outbreaks and how they vary across regions is a challenging and important problem. We developed a mathematical model for the 2015/2016 Zika virus outbreak dynamics in Colombia, El Salvador, and Suriname. We fit the model to publicly available data provided by the Pan American Health Organization, using Approximate Bayesian Computation to estimate parameter distributions and provide uncertainty quantification.

Characterization of intestinal and pancreatic dysfunction in VPAC1-null mutant mouse.

Objectives: These studies examined the effect of homozygous deletion of vasoactive intestinal peptide receptor type 1 (VPAC1) on development and function of intestines and pancreas.

Methods: Genetically engineered VPAC1-null mutant mice were monitored for growth, development, and glucose homeostasis. Expression of VPAC1 was examined during embryonic development using VPAC1 promoter-driven β-galactosidase transgenic mice.

2-deoxy-D-glucose induces oxidative stress and cell killing in human neuroblastoma cells.

Malignant cells have a demonstrably greater sensitivity to glucose deprivation-induced cytotoxicity than normal cells. This has been hypothesized to be due to a higher level of reactive oxygen species (ROS) production in cancer cells leading to the increased need for reducing equivalents, produced by glucose metabolism, to detoxify hydroperoxides. Because complete glucose deprivation cannot be achieved in vivo, it has been proposed that agents that antagonize glucose metabolism, such as 2-deoxy-D-glucose (2DG), can mimic in vitro glucose deprivation that selectively kills cancer cells by oxidative stress.

Functional coupling of cleavage and polyadenylation with transcription of mRNA.

Cleavage and polyadenylation define the 3' ends of almost all eukaryotic mRNAs and are thought to occur during transcription. We describe a human in vitro system utilizing an immobilized template, in which transcripts in RNA polymerase II elongation complexes are efficiently cleaved and polyadenylated. Because the cleavage rate of free RNA is much slower, we conclude that cleavage is functionally coupled to transcription.

Changes in the motility, morphology, and F-actin architecture of human dendritic cells in an in vitro model of dendritic cell development.

An in vitro model has been developed for analyzing the two developmental phases of human dendritic cell (DC) migration. Employing the age of the culture and the addition of GM-CSF, IL-4, and serum to regulate cellular phenotype, and glass coated with acid-precipitated human plasma proteins to facilitate persistent DC translocation, the model produces three sequential in vitro phenotypes with the following suggested in vivo counterparts: (1) DCs recently isolated from blood, which are highly polar and motile, and reflect the behavior of "undifferentiated" DCs that must extravasate from the blood stream and migrate into peripheral tissue; (2) large, nonmotile, stellate DCs, which reflect the highly "differentiated" signature phenotype of DCs in peripheral tissue, whose function is to capture foreign antigens; and (3) the large, motile "dedifferentiated" DCs, which reflect the behavior of "veiled cells" that have captured an antigen, retracted dendritic processes, migrated out of peripheral tissue, and are in the process of transporting a captured antigen to a proximal draining lymph node for presentation to T cells. Computer-assisted motion analysis of the three sequential phenotypes and fluorescent staining of F-actin reveal three unique behavioral states and unique cellular architecture consistent with inferred in vivo function.

HIV-induced T-cell syncytia release a two component T-helper cell chemoattractant composed of Nef and Tat.

Using a newly developed gradient chamber to provide independent measurements of chemokinesis (stimulated motility) and chemotaxis (stimulated motility up a concentration gradient) of individual T-helper cells, it was recently demonstrated that HIV-induced T-cell syncytia release two distinct chemotactic activities that are separable by their rates of diffusion. The molecular masses of the two chemoattractant activities were estimated to be 30 and 120 kDa. The higher molecular mass activity was demonstrated to be the viral glycoprotein gp120.

T cell syncytia induced by HIV release. T cell chemoattractants: demonstration with a newly developed single cell chemotaxis chamber.

A chemotaxis chamber has been developed to analyze both the velocity and the directionality of individual T cells in gradients of high molecular mass molecules over long periods of time. Employing this chamber, it is demonstrated that syncytia induced by HIV in SUP-T1 cell cultures release two T cell chemoattractants with approximate molecular masses of 30 and 120 kDa. Neither uninfected single cells nor polyethylene glycol-induced syncytia release detectable chemoattractant, suggesting that these chemoattractants are linked to HIV infection.

Phosphorylation of the Dictyostelium myosin II heavy chain is necessary for maintaining cellular polarity and suppressing turning during chemotaxis.

Conversion of the three mapped threonine phosphorylation sites in the myosin II heavy chain tail to alanines results in a mutant (3XALA) in Dictyostelium discoideum, which displays constitutive myosin overassembly in the cytoskeleton and increased cortical tension. To assess the importance of myosin phosphorylation in cellular translocation and chemotaxis, 3XALA mutant cells have been analyzed by 2D and 3D computer-assisted methods in buffer, in a spatial gradient of cAMP, and after the rapid addition of cAMP. 3XALA cells crawling in buffer exhibit distinct abnormalities in cellular shape, the maintenance of polarity and the complexity of the pseudopod perimeter.

HIV-induced T cell syncytia are self-perpetuating and the primary cause of T cell death in culture.

Prior studies suggested that induced fusion in T cell cultures infected with syncytium-inducing HIV was not the primary cause of T cell death. However, these studies failed to assess the contribution of fusion in terms of syncytium volume, rather than syncytium frequency. This question has been reassessed by monitoring the frequency, volume, rate of growth, longevity, p24 production, viral budding, and self-propagating ability of syncytia in HIV-infected SUP-T1 cell cultures and individually isolated syncytia seeded in uninfected SUP-T1 cell cultures.

Overexpression of microfilament-stabilizing human caldesmon fragment, CaD39, affects cell attachment, spreading, and cytokinesis.

Previous studies have demonstrated that overexpression of the carboxyl-terminal fragment, CaD39, of human fibroblast caldesmon in Chinese hamster ovary cells protected endogenous tropomyosin from turnover and stabilized actin microfilament bundles [Warren et al., 1994: J. Cell Biol.

Ponticulin plays a role in the positional stabilization of pseudopods.

Ponticulin is a 17-kD glycoprotein that represents a major high affinity link between the plasma membrane and the cortical actin network of Dictyostelium. To assess the role of ponticulin in pseudopod extension and retraction, the motile behavior of two independently generated mutants lacking ponticulin was analyzed using computer-assisted two- and three-dimensional motion analysis systems. More than half of the lateral pseudopods formed off the substratum by ponticulin-minus cells slipped relative to the substratum during extension and retraction.

HIV-induced syncytia in peripheral blood cell cultures crawl by extending giant pseudopods.

It was previously demonstrated that HIV-induced syncytia of the immortalized T cell line SupT1 reorganize their cytoskeleton and form a spherical supernuclear complex, thus mimicking the organization, polarity, and morphology of a single SupT1 cell. Then, through extension of a single, giant pseudopod, these syncytia, which grow to more than 100 times the volume of a single SupT1 cell, translocate along a substratum. To verify that syncytium motility is not peculiar to the SupT1 cell line, we have analyzed the cytoskeletal organization and motile capabilities of HIV-induced syncytia formed in peripheral blood cell cultures containing more than 90% CD4-positive cells.

T cells and HIV-induced T cell syncytia exhibit the same motility cycle.

Ameboid cells ranging in complexity from Dictyostelium amebas to human polymorphonuclear leukocytes (PMNs) translocate in a cyclical fashion. Using computer-assisted motion analysis, we have analyzed the motility of human lymphocytes of the immortal SupT1 cell line and of a peripheral blood mononuclear cell population highly enriched for CD4-positive cells (CD4-enriched PBMCs) on four substrates--plastic, dehydrated rat tail collagen, hydrated rat tail collagen, and bovine aortic endothelium. In addition, we have analyzed the motility on these substrates of syncytia induced by human immunodeficiency virus (HIV) in cultures of both cell types.

A comparison of stress in surgically and non-surgically mulesed sheep.

A comparison has been made in 9- to 10-month-old castrated male Merino sheep of the changes in plasma total cortisol concentration and behaviour after being treated by either the modified Mules operation or by topical application of a quaternary ammonium compound to achieve non-surgical mulesing. After surgical mulesing, plasma total cortisol concentration increased immediately and rapidly and reached a peak value in 15 minutes, whereas after non-surgical treatment an immediate rise did not occur, but a similar peak value was observed in blood samples collected 24 hours after treatment. The concentrations were lower in both groups at 48 hours.

HIV-induced syncytia of a T cell line form single giant pseudopods and are motile.

The human immunodeficiency virus, HIV, induces syncytium formation in cultures of many T cell lines. These syncytia have previously been viewed as disorganized fusion products in the throes of death. Evidence is presented that in HIV1-infected SupT1 cultures, syncytia five times to over one hundred times larger than single cells organize their many nuclei into blastula-like balls, reorganize their cytoskeleton to mimic that of a single cell, and extend single, giant pseudopods in a polar fashion.

Salivary and plasma cortisol as an index of stress in goats.

Total assayable cortisol in plasma was highly correlated (r = 0.97) with physiologically active free cortisol in plasma after routine management procedures in 1- to 3-weeks-old goats. Transport of adult goats caused significant increases (P less than 0.

Effects of ovine corticotropin-releasing factor and vasopressin on plasma beta-endorphin, cortisol and behavior after minor surgery in sheep.

The evidence for an analgesic effect arising from increased peripheral concentrations of beta-endorphin (beta-EP) in various animal species is controversial, and has not been fully evaluated in the sheep. To stimulate beta-EP release, ovine corticotropin-releasing factor (oCRF) and arginine vasopressin (AVP) were injected intravenously (iv) into a group of 12 out of 24 sheep, 15 min prior to minor surgery on all sheep. This brought about significant increases (P less than 0.

Stress responses in lambs docked and castrated surgically or by the application of rubber rings.

A comparative study has been made in lambs 3 to 6 weeks of age of the behavioural responses and changes in plasma immunoreactive beta-endorphin (ir beta-endorphin) and cortisol after docking or docking plus castration by the application of rubber rings or by surgery. The use of rubber rings on lambs at this age was characterised by very agitated behaviour indicative of considerable distress for a period of up to 1 h. In contrast, surgery was accompanied by some post-operative shock exhibited by reduced exploratory and social behaviour, at least in the lambs exposed to docking plus castration.