965 resultados para Immunization Schedule
Resumo:
Vaccine-mediated prevention of primary HIV-1 infection at the heterosexual mucosal portal of entry may be facilitated by highly optimised formulations or drug delivery devices for intravaginal (i.vag) immunization. Previously we described hydroxyethylcellulose (HEC)-based rheologically structured gel vehicles (RSVs) for vaginal immunization of an HIV-1 vaccine candidate, a soluble recombinant trimeric HIV-1 clade-C envelope glycoprotein designated CN54gp140. Here we investigated the efficacy of lyophilized solid dosage formulations (LSDFs) for prolonging antigen stability and as i.vag delivery modalities. LSDFs were designed and developed that upon i.vag administration they would reconstitute with the imbibing of vaginal fluid to mucoadhesive, site-retentive semi-solids. Mice were immunized with lyophilized equivalents of (i) RSVs, (ii) modified versions of the RSVs more suited to lyophilization (sodium carboxymethyl cellulose (NaCMC)-based gels) and (iii) Carbopol® gel, all containing CN54gp140. NaCMC-based LSDFs provided significantly enhanced antigen stability compared to aqueous-based RSVs. Rheological analysis indicated the NaCMC-based LSDFs would offer enhanced vaginal retention in woman compared to more conventional vaginal gel formulations. All LSDFs were well tolerated in the mouse model. Following i.vag administration, all LSDFs boosted systemic CN54gp140-specific antibody responses in sub-cutaneously primed mice. Induction of CN54gp140-specific antibody responses in the female genital tract was evident. Of all the LSDFs the fastest releasing which was lyophilized Carbopol® gel elicited immune responses comparable to buffer instillation of antigen suggesting that rather than slower sustained release, initial high burst release from the LSDFs may suffice. The boosting of specific immune responses upon i.vag administration indicates that LSDFs are viable mucosal vaccine delivery modalities promoting antigen stability and facilitating intimate exposure of CN54gp140 to the mucosal-associated lymphoid tissue of the female genital tract.
Resumo:
A robust vaginal immune response is considered essential for an effective prophylactic vaccine that prevents transmission of HIV and other sexually acquired diseases. Considerable attention has recently focused on the potential of vaginally administered vaccines as a means to induce such local immunity. However, the potential for vaccination at this site remains in doubt as the vaginal mucosa is generally considered to have low immune inductive potential. In the current study, we explored for the first time the use of a quick release, freeze-dried, solid dosage system for practical vaginal administration of a protein antigen. These solid dosage forms overcome the common problem associated with leakage and poor retention of vaginally administered antigen solutions. Mice were immunized vaginally with H4A, an HIV gp41 envelope based recombinant protein, using quick release, freeze-dried solid rods, and the immune responses compared to a control group immunized via subcutaneous H4A injection. Vaginally immunized mice failed to elicit robust immune responses. Our detailed investigations, involving cytokine analysis, the stability of H4A in mouse cervicovaginal lavage, and elucidation of the state of H4A protein in the immediate-release dosage form, revealed that antigen instability in vaginal fluid, the state of the antigen in the dosage form, and the cytokine profile induced are all likely to have contributed to the observed lack of immunogenicity. These are important factors affecting vaginal immunization and provide a rational basis for explaining the typically poor and variable elicitation of immunity at this site, despite the presence of immune responsive cells within the vaginal mucosae. In future mucosal vaccine studies, a more explicit focus on antigen stability in the dosage form and the immune potential of available antigen-responsive cells is recommended. © 2012 Elsevier Ltd. All rights reserved.
Resumo:
Chronic lung infection by opportunistic pathogens, such as Pseudomonas aeruginosa and members of the Burkholderia cepacia complex, is a major cause of morbidity and mortality in patients with cystic fibrosis. Outer membrane proteins (OMPs) of gram-negative bacteria are promising vaccine antigen candidates. In this study, we evaluated the immunogenicity, protection, and cross-protection conferred by intranasal vaccination of mice with OMPs from B. multivorans plus the mucosal adjuvant adamantylamide dipeptide (AdDP). Robust mucosal and systemic immune responses were stimulated by vaccination of naive animals with OMPs from B. multivorans and B. cenocepacia plus AdDP. Using a mouse model of chronic pulmonary infection, we observed enhanced clearance of B. multivorans from the lungs of vaccinated animals, which correlated with OMP-specific secretory immunoglobulin A responses. Furthermore, OMP-immunized mice showed rapid resolution of the pulmonary infection with virtually no lung pathology after bacterial challenge with B. multivorans. In addition, we demonstrated that administration of B. multivorans OMP vaccine conferred protection against B. cenocepacia challenge in this mouse infection model, suggesting that OMPs provide cross-protection against the B. cepacia complex. Therefore, we concluded that mucosal immunity to B. multivorans elicited by intranasal vaccination with OMPs plus AdDP could prevent early steps of colonization and infection with B. multivorans and also ameliorate lung tissue damage, while eliciting cross-protection against B. cenocepacia. These results support the notion that therapies leading to increased mucosal immunity in the airways may help patients with cystic fibrosis.
Resumo:
A generic, parameterisable key scheduling core is presented, which can be utilised in pipelinable private-key encryption algorithms. The data encryption standard (DES) algorithm, which lends itself readily to pipelining, is utilised to exemplify this novel key scheduling method and the broader applicability of the method to other encryption algorithms is illustrated. The DES design is implemented on Xilinx Virtex FPGA technology. Utilising the novel method, a 16-stage pipelined DES design is achieved, which can run at an encryption rate of 3.87 Gbit/s. This result is among the fastest hardware implementations and is a factor 28 times faster than software implementations.
Resumo:
Pain response may be altered in infants born very preterm owing to repeated exposure to procedures in the neonatal intensive care unit. Findings have been inconsistent in studies of behavioral and cardiac responses to brief pain in preterm versus full-term infants following neonatal intensive care unit discharge. To our knowledge, cortisol reactivity to pain has not been compared in preterm and full-term infants. We examined pain reactivity to immunization in preterm and full-term infants.
Resumo:
Differential Reinforcement of Alternative behaviour (DRA) (Athens & Vollmer, 2010; Cooper, Heron, & Heward, 2007) is a procedure that consists in withholding reinforcement for the targeted inappropriate behaviour while reinforcing behaviours, i.e., that have the same function, but socially more acceptable topographies. DRA has repeatedly proven to be effective in reducing problem behaviours in individuals with autism (Campbell, 2003). On the other hand, a number of single-subject research studies have provided evidence for the use of activity schedules as a means to decrease aggressive behaviour (Dooley et al., 2001; Flannery & Hemer, 1994; Lalli, Casey, Goh, & Merlinoet al., 1994). The purpose of the present study was to evaluate the effectiveness of DRA in combination with the use of an activity schedule. We compared the impact of the visual activities schedule used in combination with a DRA procedure versus the impact of the DRA procedure used alone on problem behaviour of a boy diagnosed with an Autism Spectrum Disorder. An alternating treatments design was used to compare the rate of behaviour problems in each of the two treatment conditions. DRA was delivered as treatment A, while the combination of the activities schedule and DRA was treatment B.
Resumo:
To specifically induce a mucosal antibody response to purified human papillomavirus type 16 (HPV16) virus-like particles (VLP), we immunized female BALB/c mice orally, intranasally, and/or parenterally and evaluated cholera toxin (CT) as a mucosal adjuvant. Anti-HPV16 VLP immunoglobulin G (IgG) and IgA titers in serum, saliva, and genital secretions were measured by enzyme-linked immunosorbent assay (ELISA). Systemic immunizations alone induced HPV16 VLP-specific IgG in serum and, to a lesser extent, in genital secretions but no secretory IgA. Oral immunization, even in the presence of CT, was inefficient. However, three nasal immunizations with 5 microgram of VLP given at weekly intervals to anesthetized mice induced high (>10(4)) and long-lasting (>15 weeks) titers of anti-HPV16 VLP antibodies in all samples, including IgA and IgG in saliva and genital secretions. CT enhanced the VLP-specific antibody response 10-fold in serum and to a lesser extent in saliva and genital secretions. Nasal immunization of conscious mice compared to anesthetized mice was inefficient and correlated with the absence of uptake of a marker into the lung. However, a 1-microgram VLP systemic priming followed by two 5-microgram VLP intranasal boosts in conscious mice induced both HPV16 VLP-specific IgG and IgA in secretions, although the titers were lower than in anesthetized mice given three intranasal immunizations. Antibodies in serum, saliva, and genital secretions of immunized mice were strongly neutralizing in vitro (50% neutralization with ELISA titers of 65 to 125). The mucosal and systemic/mucosal HPV16 VLP immunization protocols that induced significant titers of neutralizing IgG and secretory IgA in mucosal secretions in mice may be relevant to genital HPV VLP-based human vaccine trials.
Resumo:
Self-controlled KR practice has revealed that providing participants the opportunity to control their KR is superior for motor learning compared to participants replicating the KR schedule of a self-control participant, without the choice (e.g., yoked). The purpose of the present experiment was two-fold. First, to examine the utility of a self-controlled KR schedule for learning a spatial motor task in younger and older adults and second, to determine whether a self-controlled KR schedule facilitates an increased ability to estimate one’s performance in retention and transfer. Twenty younger adults and 20 older adults practiced in either the self-control or yoked condition and were required to push and release a slide along a confined pathway using their non-dominant hand to a target distance. The retention data revealed that as a function of age, a self-controlled KR schedule facilitated superior retention performance and performance estimations in younger adults compared to their yoked counterparts.
Resumo:
Schedule of prices for Brown and McDonell, contractors, for sections 1, 2 and 3 of the Port Dalhousie Thorold Railway (1 page, handwritten), Sept. 24, 1856.