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Dible SA, Flint JA, Lepper PA. On the role of periodic structures in the lower jaw of the atlantic bottlenose dolphin (Tursiops truncatus). Bioinspir Biomim 2009; 4:015005. [PMID: 19258687 DOI: 10.1088/1748-3182/4/1/015005] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
This paper proposes the application of band-gap theory to hearing in the atlantic bottlenose dolphin (Tursiops truncatus). Using the transmission line modelling (TLM) technique and published computed tomography (CT) data of an atlantic bottlenose dolphin (Tursiops truncatus), a series of sound propagation experiments have been carried out. It is shown that the teeth in the lower jaw can be viewed as a periodic array of scattering elements which result in the formation of an acoustic stop band (or band gap) that is angular dependent. It is shown through simple and complex geometry simulations that performance enhancements such as improved gain and isolation between the two receive paths can be achieved. This mechanism has the potential to be exploited in direction-finding sonar.
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Affiliation(s)
- S A Dible
- Electronic and Electrical Engineering, Loughborough University, Loughborough, UK
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2
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Jovanovic AV, Flint JA, Varshney M, Morey TE, Dennis DM, Duran RS. Surface Modification of Silica Core−Shell Nanocapsules: Biomedical Implications. Biomacromolecules 2006; 7:945-9. [PMID: 16529435 DOI: 10.1021/bm050820+] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
In this article we present the synthesis of oil core silica shell nanocapsules with different shell thicknesses. The surface of the nanocapsules was modified with polyethyleoxide (PEO) and succinic anhydride. Two biomedical tests were then used to study the biocompatibility properties of these nanocapsules with different surface treatments, hemolysis and thromboelastography (TEG). PEO surface modification greatly reduced the damaging interactions of nanocapsules with red blood cells (RBCs) and platelets and attenuated particle size effects. It was found that the blood toxicity of charged particles increased with the acid strength on the surface. Experiments toward the assessment of detoxification of these nanocapsules in model drug overdose concentrations are currently underway.
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Affiliation(s)
- Aleksa V Jovanovic
- George and Josephine Butler Polymer Laboratory, Department of Chemistry, University of Florida, P.O. Box 117200 Gainesville, 32611, USA
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Majowicz SE, Doré K, Flint JA, Edge VL, Read S, Buffett MC, McEwen S, McNab WB, Stacey D, Sockett P, Wilson JB. Magnitude and distribution of acute, self-reported gastrointestinal illness in a Canadian community. Epidemiol Infect 2004; 132:607-17. [PMID: 15310162 PMCID: PMC2870141 DOI: 10.1017/s0950268804002353] [Citation(s) in RCA: 80] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
To estimate the magnitude and distribution of self-reported, acute gastrointestinal illness in a Canadian-based population, we conducted a retrospective, cross-sectional telephone survey of approximately 3500 randomly selected residents of the city of Hamilton (Ontario, Canada) from February 2001 to February 2002. The observed monthly prevalence was 10% (95 % CI 9.94-10.14) and the incidence rate was 1.3 (95 % CI 1.1-1.4) episodes per person-year; this is within the range of estimates from other developed countries. The prevalence was higher in females and in those aged < 10 years and 20-24 years. Overall, prevalence peaked in April and October, but a different temporal distribution was observed for those aged < 10 years. Although these data were derived from one community, they demonstrate that the epidemiology of acute gastrointestinal illness in a Canadian-based population is similar to that reported for other developed countries.
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Affiliation(s)
- S E Majowicz
- Department of Population Medicine, University of Guelph, Guelph, Ontario, Canada
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Varshney M, Morey TE, Shah DO, Flint JA, Moudgil BM, Seubert CN, Dennis DM. Pluronic microemulsions as nanoreservoirs for extraction of bupivacaine from normal saline. J Am Chem Soc 2004; 126:5108-12. [PMID: 15099093 PMCID: PMC3606560 DOI: 10.1021/ja0394479] [Citation(s) in RCA: 85] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
We hypothesized that custom-designed microemulsions would effectively scavenge compounds from bulk media. Pluronic-based oil-in-water microemulsions were synthesized that efficiently reduced the free concentration of the local anesthetic bupivacaine in 0.9% NaCl. Both the molecular nature and concentration of the constituents in the microemulsions significantly affected extraction efficiencies. Pluronic F127-based microemulsions extracted bupivacaine more efficiently than microemulsions synthesized using other Pluronic surfactants (L44, L62, L64, F77, F87, F88, P104). Extraction was markedly increased by addition of fatty acid sodium salts due to greater oil/water interface area, increased columbic interaction between bupivacaine and fatty acids sodium salt, and greater surface activity. These data suggest that oil-in-water microemulsions may be an effective agent to treat cardiotoxicity caused by bupivacaine or other lipophilic drugs.
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Affiliation(s)
- Manoj Varshney
- Engineering Research Center for Particle Science and Technology, University of Florida, Gainesville, 32610 USA
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Morey TE, Varshney M, Flint JA, Rajasekaran S, Shah DO, Dennis DM. Treatment of Local Anesthetic-Induced Cardiotoxicity Using Drug Scavenging Nanoparticles. Nano Lett 2004; 4:757-759. [PMID: 26321882 PMCID: PMC4552340 DOI: 10.1021/nl049880w] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
Because of its ability to create structures of nanoscale dimension with large aggregate particle surface area-to-volume ratios, nanotechnology offers new opportunities to treat drug poisonings. Emulsion-based nanoparticles (diameter: 118.4 nm) extracted bupivacaine from the aqueous phase in a physiological salt solution and attenuated the drug's cardiotoxicity in guinea pig heart to a greater extent than did a macroemulsion (432.0 nm). Additionally, nanoparticles sequestered bupivacaine from the aqueous phase of human blood and merit further investigation in animal models of intoxication.
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Affiliation(s)
| | | | | | | | | | - Donn M. Dennis
- Corresponding author: Donn M. Dennis, M. D., Department of Anesthesiology, University of Florida, P.O. 100254, Gainesville, FL 32610-0254. Telephone: (352) 846-1355. Fax: (352) 392-4719.
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Choi AH, McNeal MM, Basu M, Flint JA, Stone SC, Clements JD, Bean JA, Poe SA, VanCott JL, Ward RL. Intranasal or oral immunization of inbred and outbred mice with murine or human rotavirus VP6 proteins protects against viral shedding after challenge with murine rotaviruses. Vaccine 2002; 20:3310-21. [PMID: 12213401 DOI: 10.1016/s0264-410x(02)00315-8] [Citation(s) in RCA: 62] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Intranasal (i.n.) administration of an Escherichia coli-expressed chimeric VP6 protein from the EDIM strain of murine rotavirus to adult BALB/c (H-2(d)) mice along with LT(R192G), an attenuated mutant of the mucosal adjuvant E. coli heat-labile toxin, has been found to consistently stimulate ca. 99% reductions in rotavirus shedding after subsequent EDIM challenge. This study was designed to determine the robustness of this protection, i.e. can VP6 immunization consistently protect against shedding in this model, thus, providing an indication of its potential as a vaccine. Intranasal immunization with two 8.8 microg doses of EDIM VP6 and 10 microg of LT(R192G) was found to stimulate 99% reductions in EDIM shedding in four additional strains of inbred mice belonging to three haplotypes, i.e. DBA/2 (H-2(d)), C57BL/6 (H-2(b)), 129 (H-2(b)) and C3H (H-2(k)). Protection stimulated against EDIM antigen shedding following i.n. immunization with VP6 from the human CJN strain was less (P=0.02) than induced by EDIM VP6 (86% versus 99%), but no further loss of protection was observed when the dose of CJN VP6 was reduced 100-fold. Protection against EDIM shedding was also maintained after i.n. immunization of three strains of outbred mice (CF-1, CD-1 and Swiss Webster) with either EDIM or CJN VP6, i.e. EDIM VP6 immunization reduced EDIM shedding by 99% while CJN VP6 immunization produced reductions of 86-96%. Protection stimulated by oral immunization of BALB/c mice with two 8.8 microg doses of either VP6 chimera plus LT(R192G) was not significantly different from that induced by i.n. immunization. Finally, protection found after either oral or i.n. immunization with EDIM or CJN VP6 was no different when the mice were challenged with McN, another strain of murine rotavirus. These results support further evaluation of VP6 as a vaccine.
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Affiliation(s)
- Anthony H Choi
- Division of Infectious Diseases, Children's Hospital Medical Center, Cincinnati, OH 45229, USA
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Choi AH, McNeal MM, Flint JA, Basu M, Lycke NY, Clements JD, Bean JA, Davis HL, McCluskie MJ, VanCott JL, Ward RL. The level of protection against rotavirus shedding in mice following immunization with a chimeric VP6 protein is dependent on the route and the coadministered adjuvant. Vaccine 2002; 20:1733-40. [PMID: 11906760 DOI: 10.1016/s0264-410x(02)00043-9] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Intranasal (i.n.) immunization of BALB/c mice with chimeric murine rotavirus EDIM (epizootic diarrhea of infant mice) VP6 and attenuated E. coli heat-labile toxin (LT), LT(R192G), stimulated >99% protection against rotavirus shedding after EDIM challenge. Here, we evaluated other potential adjuvants with chimeric VP6 administered by two mucosal routes: i.n. and oral. Besides LT(R192G), the adjuvants examined included Adjumer, CpG oligodeoxynucleotides (CpG ODN), chimeric A1 subunit of cholera toxin (CTA1)-DD, and QS-21. All except QS-21 significantly (P<0.05) increased VP6-specific serum IgG responses after i.n. immunization, but none significantly increased these responses when administered orally. The i.n. delivery of chimeric VP6 alone induced both rotavirus IgG1 and IgG2a whose relative titers suggested a skewed Th2-like response. Inclusion of Adjumer greatly increased Th2-like responses, while CpG ODN shifted the response to a less Th2-like response. The adjuvants CTA1-DD, LT(R192G), QS-21 had no significant effect on ratios of IgG1/IgG2a titers. Following EDIM challenge of mice immunized i.n. with chimeric VP6 and either LT(R192G), CTA1-DD, Adjumer or CpG ODN, shedding was reduced >99, 95, 80, 74, respectively, relative to that found in unimmunized mice (P<0.05). QS-21 induced less protection (43%, not significant (N.S.)) while immunization with chimeric VP6 alone reduced shedding by only 16% (N.S.). Oral immunization with chimeric VP6 and all selected adjuvants except QS-21 was less effective than after i.n. immunization, with protection levels of 94 (P<0.05), 71 (P<0.05), 55, 35 and 28% for LT(R192G), QS-21, CpG ODN, CTA1-DD, and Adjumer, respectively, while immunization with chimeric VP6 alone gave no protection. Thus, different adjuvants induced different degrees of protection and oral immunization was generally less effective then the i.n. route.
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Affiliation(s)
- Anthony H Choi
- Division of Infectious Diseases, Children's Hospital Medical Center, The Children's Hospital Research Foundation, 3333 Burnet Avenue, Cincinnati, OH 45229-3039, USA.
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McNeal MM, VanCott JL, Choi AHC, Basu M, Flint JA, Stone SC, Clements JD, Ward RL. CD4 T cells are the only lymphocytes needed to protect mice against rotavirus shedding after intranasal immunization with a chimeric VP6 protein and the adjuvant LT(R192G). J Virol 2002; 76:560-8. [PMID: 11752147 PMCID: PMC136815 DOI: 10.1128/jvi.76.2.560-568.2002] [Citation(s) in RCA: 92] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
Intranasal immunization of mice with a chimeric VP6 protein and the mucosal adjuvant Escherichia coli heat labile toxin LT(R192G) induces nearly complete protection against murine rotavirus (strain EDIM [epizootic diarrhea of infant mice virus]) shedding for at least 1 year. The aim of this study was to identify the protective lymphocytes elicited by this new vaccine candidate. Immunization of mouse strains lacking one or more lymphocyte populations revealed that protection was dependent on alphabeta T cells but mice lacking gammadelta T cells and B cells remained fully protected. Furthermore, depletion of CD8 T cells in immunized B-cell-deficient mice before challenge resulted in no loss of protection, while depletion of CD4 T cells caused complete loss of protection. Therefore, alphabeta CD4 T cells appeared to be the only lymphocytes required for protection. As confirmation, purified splenic T cells from immunized mice were intraperitoneally injected into Rag-2 mice chronically infected with EDIM. Transfer of 2 x 10(6) CD8 T cells had no effect on shedding, while transfer of 2 x 10(5) CD4 T cells fully resolved shedding in 7 days. Interestingly, transfer of naive splenic CD4 T cells also resolved shedding but more time and cells were required. Together, these results establish CD4 T cells as effectors of protection against rotavirus after intranasal immunization of mice with VP6 and LT(R192G).
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MESH Headings
- Adjuvants, Immunologic/administration & dosage
- Administration, Intranasal
- Adoptive Transfer
- Animals
- Antigens, Viral
- B-Lymphocytes/immunology
- Bacterial Toxins/administration & dosage
- Bacterial Toxins/immunology
- CD4-Positive T-Lymphocytes/immunology
- CD4-Positive T-Lymphocytes/transplantation
- CD8-Positive T-Lymphocytes/immunology
- CD8-Positive T-Lymphocytes/transplantation
- Capsid/administration & dosage
- Capsid/chemistry
- Capsid/genetics
- Capsid/immunology
- Capsid Proteins
- DNA-Binding Proteins/genetics
- Enterotoxins/administration & dosage
- Enterotoxins/immunology
- Escherichia coli Proteins
- Flow Cytometry
- Gene Deletion
- Immunity, Mucosal/immunology
- Immunization
- Immunologic Deficiency Syndromes/genetics
- Immunologic Deficiency Syndromes/immunology
- Mice
- Mice, Inbred BALB C
- Mice, Inbred C57BL
- Mice, Nude
- Receptors, Antigen, T-Cell, alpha-beta/immunology
- Recombinant Fusion Proteins/administration & dosage
- Recombinant Fusion Proteins/chemistry
- Recombinant Fusion Proteins/immunology
- Rotavirus/genetics
- Rotavirus/immunology
- Rotavirus/physiology
- Rotavirus Infections/immunology
- Rotavirus Infections/prevention & control
- Rotavirus Infections/transmission
- Rotavirus Infections/virology
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Affiliation(s)
- Monica M McNeal
- Division of Infectious Diseases, Children's Hospital Medical Center, Cincinnati, Ohio 45229, USA
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Abstract
A linear filter was developed for decoding finger commands from volitional pressures distributed within the residual forelimb. Filter parameters were based on dynamic pressures recorded from the residual limb within its socket, during specific finger commands. A matrix of signal features was derived from eight-dimensional (8-D) pressure vectors, and its pseudoinverse comprised the filter parameters. Results with amputees showed that the filter could discriminate specific finger flexion commands, suggesting that pressure vector decoding (PVD) can provide them with biomimetic finger control.
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Affiliation(s)
- D J Curcie
- Orthotic and Prosthetic Laboratory, Department of Biomedical Engineering, Rutgers University, Piscatway, NJ 08854, USA
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10
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Abstract
A novel controller for a multifinger hand prosthesis was developed and tested to measure its accuracy and performance in transducing volitional signals for individual "phantom" fingers. Pneumatic sensors were fabricated from open-cell polymeric foam, and were interposed between the prosthetic socket and superficial extrinsic tendons associated with individual finger flexion. Test subjects were prompted to move individual fingers or combinations thereof to execute either taps or grasps. Sensor outputs were processed by a computer that controlled motions of individual fingers on a mechanical prosthesis. Trials on three upper-limb amputees showed that after brief training sessions, the TAP controller was effective at producing voluntary flexions of individual fingers and grasping motions. Signal energies were between 5 and 25 dB relative to noise from all sources, including adjacent sensors, indicating high degrees of both sensitivity and specificity for tendon-associated transduction. Finger flexions at up to three repetitions per second, and rhythmic tapping of sequential fingers were readily transduced. One amputee subject was able to play a short piano piece with three fingers, at approximately one-quarter normal tempo. TAP sensors responded linearly to graded forces from individual fingers, indicating proportional force control. Our results demonstrate the feasibility of restoring some degree of finger dexterity by noninvasive sensing of extrinsic tendons.
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Affiliation(s)
- R L Abboudi
- Department of Biomedical Engineering, Rutgers University, Piscataway, NJ 08854, USA
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Cooke DW, Hutson RL, Kwok RS, Maez M, Rempp H, Schillaci ME, Smith JL, Willis JO, Lichti RL, Chan KC, Boekema C, Weathersby SP, Flint JA, Oostens J. Muon depolarization and magnetic-field penetration depth in superconducting GdBa2Cu3Ox. Phys Rev B Condens Matter 1988; 37:9401-9404. [PMID: 9944328 DOI: 10.1103/physrevb.37.9401] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/11/2023]
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