18 results on '"Roberts, Paul C."'
Search Results
2. Membrane-bound IL-12 and IL-23 serve as potent mucosal adjuvants when co-presented on whole inactivated influenza vaccines
- Author
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Khan, Tila, Heffron, C. Lynn, High, Kevin P., Roberts, Paul C., Khan, Tila, Heffron, C. Lynn, High, Kevin P., and Roberts, Paul C.
- Abstract
Background Potent and safe adjuvants are needed to improve the efficacy of parenteral and mucosal vaccines. Cytokines, chemokines and growth factors have all proven to be effective immunomodulatory adjuvants when administered with a variety of antigens. We have previously evaluated the efficacy of membrane-anchored interleukins (IL) such as IL-2 and IL-4 co-presented as Cytokine-bearing Influenza Vaccines (CYT-IVACs) using a mouse model of influenza challenge. Findings Here, we describe studies evaluating the parenteral and mucosal adjuvanticity of membrane-bound IL-12 and IL-23 CYT-IVACs in young adult mice. Mucosal immunization using IL-12 and IL-23 bearing whole influenza virus vaccine (WIV) was more effective at eliciting virus-specific nasal IgA and reducing viral lung burden following challenge compared to control WIV vaccinated animals. Both IL-12 and IL-23 bearing WIV elicited the highest anti-viral IgA levels in serum and nasal washes. Conclusions This study highlights for the first time the mucosal adjuvant potential of IL-12 and IL-23 CYT-IVAC formulations in eliciting mucosal immune responses and reducing viral lung burden. The co-presentation of immunomodulators in direct context with viral antigen in whole inactivated viral vaccines may provide a means to significantly lower the dose of vaccine required for protection.
- Published
- 2014
- Full Text
- View/download PDF
3. The Parity-Associated Microenvironmental Niche in the Omental Fat Band Is Refractory to Ovarian Cancer Metastasis
- Author
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Cohen, Courtney A., Shea, Amanda A., Heffron, C. Lynn, Schmelz, Eva M., Roberts, Paul C., Cohen, Courtney A., Shea, Amanda A., Heffron, C. Lynn, Schmelz, Eva M., and Roberts, Paul C.
- Abstract
Ovarian cancer is an insidious and aggressive disease of older women, typically undiscovered prior to peritoneal metastasis due to its asymptomatic nature and lack of early detection tools. Epidemiological studies suggest that child-bearing (parity) is associated with decreased ovarian cancer risk, although the molecular mechanisms responsible for this phenomenon have not been delineated. Ovarian cancer preferentially metastasizes to the omental fat band (OFB), a secondary lymphoid organ that aids in filtration of the peritoneal serous fluid (PSF) and helps combat peritoneal infections. In the present study we assessed how parity and age impact the immune compositional profile in the OFB of mice, both in the homeostatic state and as a consequence of peritoneal implantation of ovarian cancer. Using fluorescence-activated cell sorting analysis and quantitative realtime PCR, we found that parity was associated with a significant reduction in omental monocytic subsets and B1-B lymphocytes, correlating with reduced homeostatic expression levels of key chemoattractants and polarization factors (Ccl1, Ccl2, Arg1, Cxcl13). Of note, parous animals exhibited significantly reduced tumor burden following intraperitoneal implantation compared to nulliparous animals. This was associated with a reduction in tumor-associated neutrophils and macrophages, as well as in the expression levels of their chemoattractants (Cxcl1, Cxcl5) in the OFB and PSF. These findings define a pre-existing "parity-associated microenvironmental niche" in the OFB that is refractory to metastatic tumor seeding and outgrowth. Future studies designed to manipulate this niche may provide a novel means to mitigate peritoneal dissemination of ovarian cancer.
- Published
- 2013
- Full Text
- View/download PDF
4. Investigating dielectric properties of different stages of syngeneic murine ovarian cancer cells
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Salmanzadeh, Alireza, Sano, Michael B., Gallo-Villanueva, R. C., Roberts, Paul C., Schmelz, Eva M., Davalos, Rafael V., Salmanzadeh, Alireza, Sano, Michael B., Gallo-Villanueva, R. C., Roberts, Paul C., Schmelz, Eva M., and Davalos, Rafael V.
- Abstract
In this study, the electrical properties of four different stages of mouse ovarian surface epithelial (MOSE) cells were investigated using contactless dielectrophoresis (cDEP). This study expands the work from our previous report describing for the first time the crossover frequency and cell specific membrane capacitance of different stages of cancer cells that are derived from the same cell line. The specific membrane capacitance increased as the stage of malignancy advanced from 15.39 +/- 1.54 mF m(-2) for a non-malignant benign stage to 26.42 +/- 1.22 mF m(-2) for the most aggressive stage. These differences could be the result of morphological variations due to changes in the cytoskeleton structure, specifically the decrease of the level of actin filaments in the cytoskeleton structure of the transformed MOSE cells. Studying the electrical properties of MOSE cells provides important information as a first step to develop cancer-treatment techniques which could partially reverse the cytoskeleton disorganization of malignant cells to a morphology more similar to that of benign cells. (C) 2013 American Institute of Physics. [http://dx.doi.org/10.1063/1.4788921] Actual pdf downloaded from NCBI.
- Published
- 2013
- Full Text
- View/download PDF
5. Regulation of Cytoskeleton Organization by Sphingosine in a Mouse Cell Model of Progressive Ovarian Cancer
- Author
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Creekmore, Amy L., Heffron, C. Lynn, Brayfield, Bradley P., Roberts, Paul C., Schmelz, Eva M., Creekmore, Amy L., Heffron, C. Lynn, Brayfield, Bradley P., Roberts, Paul C., and Schmelz, Eva M.
- Abstract
Ovarian cancer is a multigenic disease and molecular events driving ovarian cancer progression are not well established. We have previously reported the dysregulation of the cytoskeleton during ovarian cancer progression in a syngeneic mouse cell model for progressive ovarian cancer. In the present studies, we investigated if the cytoskeleton organization is a potential target for chemopreventive treatment with the bioactive sphingolipid metabolite sphingosine. Long-term treatment with non-toxic concentrations of sphingosine but not other sphingolipid metabolites led to a partial reversal of a cytoskeleton architecture commonly associated with aggressive cancer phenotypes towards an organization reminiscent of non-malignant cell phenotypes. This was evident by increased F-actin polymerization and organization, a reduced focal adhesion kinase expression, increased a-actinin and vinculin levels which together led to the assembly of more mature focal adhesions. Downstream focal adhesion signaling, the suppression of myosin light chain kinase expression and hypophosphorylation of its targets were observed after treatment with sphingosine. These results suggest that sphingosine modulate the assembly of actin stress fibers via regulation of focal adhesions and myosin light chain kinase. The impact of these events on suppression of ovarian cancer by exogenous sphingosine and their potential as molecular markers for treatment efficacy warrants further investigation.
- Published
- 2013
- Full Text
- View/download PDF
6. Sphingolipid Metabolites Modulate Dielectric Characteristics of Cells in a Mouse Ovarian Cancer Progression Model
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Salmanzadeh, Alireza, Elvington, Elizabeth S., Roberts, Paul C., Schmelz, Eva M., Davalos, Rafael V., Salmanzadeh, Alireza, Elvington, Elizabeth S., Roberts, Paul C., Schmelz, Eva M., and Davalos, Rafael V.
- Abstract
Currently, conventional cancer treatment regimens often rely upon highly toxic chemotherapeutics or target oncogenes that are variably expressed within the heterogeneous cell population of tumors. These challenges highlight the need for novel treatment strategies that (1) are non-toxic yet able to at least partially reverse the aggressive phenotype of the disease to a benign or very slow-growing state, and (2) act on the cells independently of variably expressed biomarkers. Using a label-independent rapid microfluidic cell manipulation strategy known as contactless dielectrophoresis (cDEP), we investigated the effect of non-toxic concentrations of two bioactive sphingolipidmetabolites, sphingosine (So), with potential anti-tumor properties, and sphingosine-1-phosphate (S1P), a tumor-promoting metabolite, on the intrinsic electrical properties of early and late stages of mouse ovarian surface epithelial (MOSE) cancer cells. Previously, we demonstrated that electrical properties change as cells progress from a benign early stage to late malignant stages. Here, we demonstrate an association between So treatment and a shift in the bioelectrical characteristics of late stage MOSE (MOSE-L) cells towards a profile similar to that of benign MOSE-E cells. Particularly, the specific membrane capacitance of MOSE-L cells shifted toward that of MOSE-E cells, decreasing from 23.94 ± 2.75 to 16.46 ± 0.62 mF m_2 after So treatment, associated with a decrease in membrane protrusions. In contrast, S1P did not reverse the electrical properties of MOSE-L cells. This work is the first to indicate that treatment with non-toxic doses of So correlates with changes in the electrical properties and surface roughness of cells. It also demonstrates the potential of cDEP to be used as a new, rapid technique for drug efficacy studies, and for eventually designing more personalized treatment regimens.
- Published
- 2013
- Full Text
- View/download PDF
7. Intra-Abdominal Fat Depots Represent Distinct Immunomodulatory Microenvironments: A Murine Model
- Author
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Cohen, Courtney A., Shea, Amanda A., Heffron, C. Lynn, Schmelz, Eva M., Roberts, Paul C., Cohen, Courtney A., Shea, Amanda A., Heffron, C. Lynn, Schmelz, Eva M., and Roberts, Paul C.
- Abstract
White adipose tissue (WAT) is a multi-faceted endocrine organ involved in energy storage, metabolism, immune function and disease pathogenesis. In contrast to subcutaneous fat, visceral fat (V-WAT) has been associated with numerous diseases and metabolic disorders, indicating specific functions related to anatomical location. Although visceral depots are often used interchangeably in V-WAT-associated disease studies, there has been a recent subdivision of V-WAT into “true visceral” and non-visceral intra-abdominal compartments. These were associated with distinct physiological roles, illustrating a need for depot-specific information. Here, we use FACS analysis to comparatively characterize the leukocyte and progenitor populations in the stromal vascular fraction (SVF) of peritoneal serous fluid (PSF), parametrial (pmWAT), retroperitoneal (rpWAT), and omental (omWAT) adipose tissue from seven-month old C57BL/6 female mice. We found significant differences in SVF composition between all four microenvironments. PSF SVF was comprised almost entirely of CD45+ leukocytes (>99%), while omWAT contained less, but still almost two-fold more leukocytes than pmWAT and rpWAT (75%, 38% and 38% respectively; p<0.01). PmWAT was composed primarily of macrophages, whereas rpWAT more closely resembled omWAT, denoted by high levels of B1 B-cell and monocyte populations. Further, omWAT harbored significantly higher proportions of T-cells than the other tissues, consistent with its role as a secondary lymphoid organ. These SVF changes were also reflected in the gene expression profiles of the respective tissues. Thus, intra-abdominal fat pads represent independent immunomodulatory microenvironments and should be evaluated as distinct entities with unique contributions to physiological and pathological processes.
- Published
- 2013
- Full Text
- View/download PDF
8. Investigating dielectric properties of different stages of syngeneic murine ovarian cancer cells
- Author
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Biomedical Engineering and Mechanics, Biomedical Sciences and Pathobiology, Human Nutrition, Foods, and Exercise, Institute for Critical Technology and Applied Science, School of Biomedical Engineering and Sciences, Salmanzadeh, Alireza, Sano, Michael B., Gallo-Villanueva, R. C., Roberts, Paul C., Schmelz, Eva M., Davalos, Rafael V., Biomedical Engineering and Mechanics, Biomedical Sciences and Pathobiology, Human Nutrition, Foods, and Exercise, Institute for Critical Technology and Applied Science, School of Biomedical Engineering and Sciences, Salmanzadeh, Alireza, Sano, Michael B., Gallo-Villanueva, R. C., Roberts, Paul C., Schmelz, Eva M., and Davalos, Rafael V.
- Abstract
In this study, the electrical properties of four different stages of mouse ovarian surface epithelial (MOSE) cells were investigated using contactless dielectrophoresis (cDEP). This study expands the work from our previous report describing for the first time the crossover frequency and cell specific membrane capacitance of different stages of cancer cells that are derived from the same cell line. The specific membrane capacitance increased as the stage of malignancy advanced from 15.39 +/- 1.54 mF m(-2) for a non-malignant benign stage to 26.42 +/- 1.22 mF m(-2) for the most aggressive stage. These differences could be the result of morphological variations due to changes in the cytoskeleton structure, specifically the decrease of the level of actin filaments in the cytoskeleton structure of the transformed MOSE cells. Studying the electrical properties of MOSE cells provides important information as a first step to develop cancer-treatment techniques which could partially reverse the cytoskeleton disorganization of malignant cells to a morphology more similar to that of benign cells. (C) 2013 American Institute of Physics. [http://dx.doi.org/10.1063/1.4788921] Actual pdf downloaded from NCBI.
- Published
- 2013
9. Regulation of Cytoskeleton Organization by Sphingosine in a Mouse Cell Model of Progressive Ovarian Cancer
- Author
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Biomedical Sciences and Pathobiology, Human Nutrition, Foods, and Exercise, Virginia-Maryland College of Veterinary Medicine, Creekmore, Amy L., Heffron, C. Lynn, Brayfield, Bradley P., Roberts, Paul C., Schmelz, Eva M., Biomedical Sciences and Pathobiology, Human Nutrition, Foods, and Exercise, Virginia-Maryland College of Veterinary Medicine, Creekmore, Amy L., Heffron, C. Lynn, Brayfield, Bradley P., Roberts, Paul C., and Schmelz, Eva M.
- Abstract
Ovarian cancer is a multigenic disease and molecular events driving ovarian cancer progression are not well established. We have previously reported the dysregulation of the cytoskeleton during ovarian cancer progression in a syngeneic mouse cell model for progressive ovarian cancer. In the present studies, we investigated if the cytoskeleton organization is a potential target for chemopreventive treatment with the bioactive sphingolipid metabolite sphingosine. Long-term treatment with non-toxic concentrations of sphingosine but not other sphingolipid metabolites led to a partial reversal of a cytoskeleton architecture commonly associated with aggressive cancer phenotypes towards an organization reminiscent of non-malignant cell phenotypes. This was evident by increased F-actin polymerization and organization, a reduced focal adhesion kinase expression, increased a-actinin and vinculin levels which together led to the assembly of more mature focal adhesions. Downstream focal adhesion signaling, the suppression of myosin light chain kinase expression and hypophosphorylation of its targets were observed after treatment with sphingosine. These results suggest that sphingosine modulate the assembly of actin stress fibers via regulation of focal adhesions and myosin light chain kinase. The impact of these events on suppression of ovarian cancer by exogenous sphingosine and their potential as molecular markers for treatment efficacy warrants further investigation.
- Published
- 2013
10. Sphingolipid Metabolites Modulate Dielectric Characteristics of Cells in a Mouse Ovarian Cancer Progression Model
- Author
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School of Biomedical Engineering and Sciences, Salmanzadeh, Alireza, Elvington, Elizabeth S., Roberts, Paul C., Schmelz, Eva M., Davalos, Rafael V., School of Biomedical Engineering and Sciences, Salmanzadeh, Alireza, Elvington, Elizabeth S., Roberts, Paul C., Schmelz, Eva M., and Davalos, Rafael V.
- Abstract
Currently, conventional cancer treatment regimens often rely upon highly toxic chemotherapeutics or target oncogenes that are variably expressed within the heterogeneous cell population of tumors. These challenges highlight the need for novel treatment strategies that (1) are non-toxic yet able to at least partially reverse the aggressive phenotype of the disease to a benign or very slow-growing state, and (2) act on the cells independently of variably expressed biomarkers. Using a label-independent rapid microfluidic cell manipulation strategy known as contactless dielectrophoresis (cDEP), we investigated the effect of non-toxic concentrations of two bioactive sphingolipidmetabolites, sphingosine (So), with potential anti-tumor properties, and sphingosine-1-phosphate (S1P), a tumor-promoting metabolite, on the intrinsic electrical properties of early and late stages of mouse ovarian surface epithelial (MOSE) cancer cells. Previously, we demonstrated that electrical properties change as cells progress from a benign early stage to late malignant stages. Here, we demonstrate an association between So treatment and a shift in the bioelectrical characteristics of late stage MOSE (MOSE-L) cells towards a profile similar to that of benign MOSE-E cells. Particularly, the specific membrane capacitance of MOSE-L cells shifted toward that of MOSE-E cells, decreasing from 23.94 ± 2.75 to 16.46 ± 0.62 mF m_2 after So treatment, associated with a decrease in membrane protrusions. In contrast, S1P did not reverse the electrical properties of MOSE-L cells. This work is the first to indicate that treatment with non-toxic doses of So correlates with changes in the electrical properties and surface roughness of cells. It also demonstrates the potential of cDEP to be used as a new, rapid technique for drug efficacy studies, and for eventually designing more personalized treatment regimens.
- Published
- 2013
11. Dielectrophoretic differentiation of mouse ovarian surface epithelial cells, macrophages, and fibroblasts using contactless dielectrophoresis
- Author
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Salmanzadeh, Alireza, Kittur, Harsha, Sano, Michael B., Roberts, Paul C., Schmelz, Eva M., Davalos, Rafael V., Salmanzadeh, Alireza, Kittur, Harsha, Sano, Michael B., Roberts, Paul C., Schmelz, Eva M., and Davalos, Rafael V.
- Abstract
Ovarian cancer is the leading cause of death from gynecological malignancies in women. The primary challenge is the detection of the cancer at an early stage, since this drastically increases the survival rate. In this study we investigated the dielectrophoretic responses of progressive stages of mouse ovarian surface epithelial (MOSE) cells, as well as mouse fibroblast and macrophage cell lines, utilizing contactless dielectrophoresis (cDEP). cDEP is a relatively new cell manipulation technique that has addressed some of the challenges of conventional dielectrophoretic methods. To evaluate our microfluidic device performance, we computationally studied the effects of altering various geometrical parameters, such as the size and arrangement of insulating structures, on dielectrophoretic and drag forces. We found that the trapping voltage of MOSE cells increases as the cells progress from a non-tumorigenic, benign cell to a tumorigenic, malignant phenotype. Additionally, all MOSE cells display unique behavior compared to fibroblasts and macrophages, representing normal and inflammatory cells found in the peritoneal fluid. Based on these findings, we predict that cDEP can be utilized for isolation of ovarian cancer cells from peritoneal fluid as an early cancer detection tool. (C) 2012 American Institute of Physics. [http://dx.doi.org/10.1063/1.3699973] Actual pdf downloaded from NCBI.
- Published
- 2012
- Full Text
- View/download PDF
12. Dielectrophoretic differentiation of mouse ovarian surface epithelial cells, macrophages, and fibroblasts using contactless dielectrophoresis
- Author
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Biomedical Engineering and Mechanics, Biomedical Sciences and Pathobiology, Human Nutrition, Foods, and Exercise, Institute for Critical Technology and Applied Science, School of Biomedical Engineering and Sciences, Salmanzadeh, Alireza, Kittur, Harsha, Sano, Michael B., Roberts, Paul C., Schmelz, Eva M., Davalos, Rafael V., Biomedical Engineering and Mechanics, Biomedical Sciences and Pathobiology, Human Nutrition, Foods, and Exercise, Institute for Critical Technology and Applied Science, School of Biomedical Engineering and Sciences, Salmanzadeh, Alireza, Kittur, Harsha, Sano, Michael B., Roberts, Paul C., Schmelz, Eva M., and Davalos, Rafael V.
- Abstract
Ovarian cancer is the leading cause of death from gynecological malignancies in women. The primary challenge is the detection of the cancer at an early stage, since this drastically increases the survival rate. In this study we investigated the dielectrophoretic responses of progressive stages of mouse ovarian surface epithelial (MOSE) cells, as well as mouse fibroblast and macrophage cell lines, utilizing contactless dielectrophoresis (cDEP). cDEP is a relatively new cell manipulation technique that has addressed some of the challenges of conventional dielectrophoretic methods. To evaluate our microfluidic device performance, we computationally studied the effects of altering various geometrical parameters, such as the size and arrangement of insulating structures, on dielectrophoretic and drag forces. We found that the trapping voltage of MOSE cells increases as the cells progress from a non-tumorigenic, benign cell to a tumorigenic, malignant phenotype. Additionally, all MOSE cells display unique behavior compared to fibroblasts and macrophages, representing normal and inflammatory cells found in the peritoneal fluid. Based on these findings, we predict that cDEP can be utilized for isolation of ovarian cancer cells from peritoneal fluid as an early cancer detection tool. (C) 2012 American Institute of Physics. [http://dx.doi.org/10.1063/1.3699973] Actual pdf downloaded from NCBI.
- Published
- 2012
13. Changes in Gene Expression and Cellular Architecture in an Ovarian Cancer Progression Model
- Author
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Creekmore, Amy L., Silkworth, William T., Cimini, Daniela, Jensen, Roderick V., Roberts, Paul C., Schmelz, Eva M., Creekmore, Amy L., Silkworth, William T., Cimini, Daniela, Jensen, Roderick V., Roberts, Paul C., and Schmelz, Eva M.
- Abstract
Background Ovarian cancer is the fifth leading cause of cancer deaths among women. Early stage disease often remains undetected due the lack of symptoms and reliable biomarkers. The identification of early genetic changes could provide insights into novel signaling pathways that may be exploited for early detection and treatment. Methodology/Principal Findings Mouse ovarian surface epithelial (MOSE) cells were used to identify stage-dependent changes in gene expression levels and signal transduction pathways by mouse whole genome microarray analyses and gene ontology. These cells have undergone spontaneous transformation in cell culture and transitioned from non-tumorigenic to intermediate and aggressive, malignant phenotypes. Significantly changed genes were overrepresented in a number of pathways, most notably the cytoskeleton functional category. Concurrent with gene expression changes, the cytoskeletal architecture became progressively disorganized, resulting in aberrant expression or subcellular distribution of key cytoskeletal regulatory proteins (focal adhesion kinase, α-actinin, and vinculin). The cytoskeletal disorganization was accompanied by altered patterns of serine and tyrosine phosphorylation as well as changed expression and subcellular localization of integral signaling intermediates APC and PKCβII. Conclusions/Significance Our studies have identified genes that are aberrantly expressed during MOSE cell neoplastic progression. We show that early stage dysregulation of actin microfilaments is followed by progressive disorganization of microtubules and intermediate filaments at later stages. These stage-specific, step-wise changes provide further insights into the time and spatial sequence of events that lead to the fully transformed state since these changes are also observed in aggressive human ovarian cancer cell lines independent of their histological type. Moreover, our studies support a link between aberrant cytoskeleton organization and regulat
- Published
- 2011
- Full Text
- View/download PDF
14. Incorporation of membrane-bound, mammalian-derived immunomodulatory proteins into influenza whole virus vaccines boosts immunogenicity and protection against lethal challenge
- Author
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Herbert, Andrew S., Heffron, C. Lynn, Sundick, Roy, Roberts, Paul C., Herbert, Andrew S., Heffron, C. Lynn, Sundick, Roy, and Roberts, Paul C.
- Abstract
Background Influenza epidemics continue to cause morbidity and mortality within the human population despite widespread vaccination efforts. This, along with the ominous threat of an avian influenza pandemic (H5N1), demonstrates the need for a much improved, more sophisticated influenza vaccine. We have developed an in vitro model system for producing a membrane-bound Cytokine-bearing Influenza Vaccine (CYT-IVAC). Numerous cytokines are involved in directing both innate and adaptive immunity and it is our goal to utilize the properties of individual cytokines and other immunomodulatory proteins to create a more immunogenic vaccine. Results We have evaluated the immunogenicity of inactivated cytokine-bearing influenza vaccines using a mouse model of lethal influenza virus challenge. CYT-IVACs were produced by stably transfecting MDCK cell lines with mouse-derived cytokines (GM-CSF, IL-2 and IL-4) fused to the membrane-anchoring domain of the viral hemagglutinin. Influenza virus replication in these cell lines resulted in the uptake of the bioactive membrane-bound cytokines during virus budding and release. In vivo efficacy studies revealed that a single low dose of IL-2 or IL-4-bearing CYT-IVAC is superior at providing protection against lethal influenza challenge in a mouse model and provides a more balanced Th1/Th2 humoral immune response, similar to live virus infections. Conclusion We have validated the protective efficacy of CYT-IVACs in a mammalian model of influenza virus infection. This technology has broad applications in current influenza virus vaccine development and may prove particularly useful in boosting immune responses in the elderly, where current vaccines are minimally effective.
- Published
- 2009
- Full Text
- View/download PDF
15. RECENT DEVELOPMENTS ON SERRE'S MULTIPLICITY CONJECTURES: GABBER'S PROOF OF THE NONNEGATIVITY CONJECTURE
- Author
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ROBERTS, Paul C. and ROBERTS, Paul C.
- Published
- 1998
- Full Text
- View/download PDF
16. Pressure Responsive Fluid Bag Ejector.
- Author
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DEPARTMENT OF THE NAVY WASHINGTON D C, Roberts,Paul C, DEPARTMENT OF THE NAVY WASHINGTON D C, and Roberts,Paul C
- Abstract
A pressure responsive fluid bag ejector including an elongated flexible bladder means which is capable of containing a fluid and which has an outlet end for expelling the fluid; and the bladder being progressively structurally stronger toward its outlet end so that upon application of the pressure the bladder will progressively eject the fluid toward the outlet. (Author), Supersedes PAT-APPL-43 256-70.
- Published
- 1978
17. STUDIES OF A VENTILATED SUPERCAVITATING PROPELLER ON A TORPEDO TEST VEHICLE. PART 1. PERFORMANCE RESULTS
- Author
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NAVAL ORDNANCE TEST STATION CHINA LAKE CA, ROBERTS, PAUL C., NAVAL ORDNANCE TEST STATION CHINA LAKE CA, and ROBERTS, PAUL C.
- Abstract
A torpedo test vehicle utilizing a ventilated supercavitating propeller was the subject of an experimental program carried out on the underwater cableway facility at Morris Dam. Vehicle runs, incorporating an 11-in.-diam ventilated supercavitating propeller (DTMB 3819), showed the propulsive efficiency to average 79%. As gas was passed through the blade-ventilation holes in increasing amounts, the advance ratio progressively decreased by 10% but it could not be concluded that the efficiency was directly affected. Propeller performance data obtained with the actual test torpedo agreed with water tunnel results reported by other laboratories.
- Published
- 1961
18. Fluid Velocity Indicator.
- Author
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DEPARTMENT OF THE NAVY WASHINGTON D C, Roberts,Paul C., DEPARTMENT OF THE NAVY WASHINGTON D C, and Roberts,Paul C.
- Abstract
The patent relates to a fluid velocity indicator which includes a casing having fore and aft ends. A propeller shaft is rotatably mounted through the fore end of the casing with portions of the shaft extending exterior and interior the casing. A propeller is mounted on the exterior portion of the shaft, and a light source and a light sensor are mounted within the casing in a spaced apart relationship. Means are mounted on the interior portion of the propeller shaft and movable through the space between the light source and the light sensor for coding the light transmitted to the light sensor when the propeller is rotated by the fluid. In this manner light sensed by the light sensor will enable indication of velocity and direction of fluid flow passed the propeller.
- Published
- 1973
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