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1.
Prev Sci ; 19(8): 1079-1090, 2018 11.
Artículo en Inglés | MEDLINE | ID: mdl-30022356

RESUMEN

The World Health Organisation advocates a direct focus on adolescent men in reducing adolescent pregnancy; however, no trials have been conducted. This trial (ISRCTN11632300; NCT02092480) determines whether a novel Relationship and Sexuality Educational intervention, If I Were Jack, is acceptable and feasible to implement in mixed sex UK classrooms. The intervention is a teacher-delivered intervention that emphasises male alongside female  responsibility in preventing unintended pregnancies and is designed to prevent unprotected sex. The trial was a parallel-group cluster randomised controlled feasibility trial with embedded process and cost evaluation in eight secondary schools (unit of randomisation) among 831 pupils (mean age 14) in Northern Ireland, alongside a qualitative evaluation of transferability in ten schools in Scotland, Wales and England. The sampling strategy was a maximum variation quota sample designed to capture a range of school management types. Four schools were randomised to each arm and the control arm continued with usual practice. Study duration was 12 months (from November 2014), with follow-up 9 months post-baseline. Results demonstrated that the intervention was acceptable to schools, pupils and teachers, and could be feasibly implemented, cost-effectively, with minor enhancements. The between-group difference in incidence of unprotected sex (primary outcome at pupil level) of 1.3% (95% CI 0.5-2.2) by 9 months demonstrated a potential effect size consistent with those reported to have had meaningful impact on teenage pregnancy. The study responds to global health policy for a paradigm shift towards inclusion of men in the achievement of sexual and reproductive health goals in a practical way by demonstrating that a gender-sensitive as well as a gender transformative intervention targeting males to prevent teenage pregnancy is acceptable to adolescent men and women and implementable in formal education structures. If I Were Jack now merits further effectiveness testing.


Asunto(s)
Embarazo en Adolescencia/prevención & control , Instituciones Académicas , Educación Sexual/métodos , Adolescente , Análisis por Conglomerados , Estudios de Factibilidad , Femenino , Humanos , Masculino , Embarazo , Reino Unido
2.
BMJ Open ; 8(7): e022128, 2018 07 28.
Artículo en Inglés | MEDLINE | ID: mdl-30056390

RESUMEN

INTRODUCTION: Teenage pregnancy remains a worldwide health concern which is an outcome of, and contributor to, health inequalities. The need for gender-aware interventions with a focus on males in addressing teenage pregnancy has been highlighted as a global health need by WHO and identified in systematic reviews of (relationship and sexuality education (RSE)). This study aims to test the effectiveness of an interactive film-based RSE intervention, which draws explicit attention to the role of males in preventing an unintended pregnancy by reducing unprotected heterosexual teenage sex among males and females under age 16 years. METHODS AND ANALYSIS: A phase III cluster randomised trial with embedded process and economic evaluations. If I Were Jack encompasses a culturally sensitive interactive film, classroom materials, a teacher-trainer session and parent animations and will be delivered to replace some of the usual RSE for the target age group in schools in the intervention group. Schools in the control group will not receive the intervention and will continue with usual RSE. Participants will not be blinded to allocation. Schools are the unit of randomisation stratified per country and socioeconomic status. We aim to recruit 66 UK schools (24 in Northern Ireland; 14 in each of England, Scotland and Wales), including approximately 7900 pupils. A questionnaire will be administered at baseline and at 12-14 months postintervention. The primary outcome is reported unprotected sex, a surrogate measure associated with unintended teenage pregnancy. Secondary outcomes include knowledge, attitudes, skills and intentions relating to avoiding teenage pregnancy in addition to frequency of engagement in sexual intercourse, contraception use and diagnosis of sexually transmitted infections. ETHICS AND DISSEMINATION: Ethical approval was obtained from Queen's University Belfast. Results will be published in peer-reviewed journals and disseminated to stakeholders. Funding is from the National Institute for Health Research. TRIAL REGISTRATION NUMBER: ISRCTN99459996.


Asunto(s)
Conducta del Adolescente/psicología , Ensayos Clínicos Fase III como Asunto , Estudios Multicéntricos como Asunto , Embarazo en Adolescencia/prevención & control , Ensayos Clínicos Controlados Aleatorios como Asunto , Servicios de Salud Escolar , Educación Sexual , Enfermedades de Transmisión Sexual/prevención & control , Adolescente , Análisis por Conglomerados , Anticoncepción , Femenino , Conocimientos, Actitudes y Práctica en Salud , Humanos , Masculino , Grupo Paritario , Embarazo , Embarazo en Adolescencia/psicología , Conducta Sexual , Enfermedades de Transmisión Sexual/psicología , Reino Unido/epidemiología
3.
J Control Release ; 162(3): 529-37, 2012 Sep 28.
Artículo en Inglés | MEDLINE | ID: mdl-22960496

RESUMEN

Dissolving polymeric microneedle arrays formulated to contain recombinant CN54 HIVgp140 and the TLR4 agonist adjuvant MPLA were assessed for their ability to elicit antigen-specific immunity. Using this novel microneedle system we successfully primed antigen-specific responses that were further boosted by an intranasal mucosal inoculation to elicit significant antigen-specific immunity. This prime-boost modality generated similar serum and mucosal gp140-specific IgG levels to the adjuvanted and systemic subcutaneous inoculations. While the microneedle primed groups demonstrated a balanced Th1/Th2 profile, strong Th2 polarization was observed in the subcutaneous inoculation group, likely due to the high level of IL-5 secretion from cells in this group. Significantly, the animals that received a microneedle prime and intranasal boost regimen elicited a high level IgA response in both the serum and mucosa, which was greatly enhanced over the subcutaneous group. The splenocytes from this inoculation group secreted moderate levels of IL-5 and IL-10 as well as high amounts of IL-2, cytokines known to act in synergy to induce IgA. This work opens up the possibility for microneedle-based HIV vaccination strategies that, once fully developed, will greatly reduce risk for vaccinators and patients, with those in the developing world set to benefit most.


Asunto(s)
Adyuvantes Inmunológicos/administración & dosificación , Lípido A/análogos & derivados , Microinyecciones , Productos del Gen env del Virus de la Inmunodeficiencia Humana/administración & dosificación , Vacunas contra el SIDA , Administración Cutánea , Animales , Citocinas/inmunología , Femenino , VIH-1 , Inmunoglobulina A/sangre , Inmunoglobulina A/inmunología , Inmunoglobulina G/sangre , Inmunoglobulina G/inmunología , Lípido A/administración & dosificación , Ratones , Ratones Endogámicos BALB C , Agujas , Proteínas Recombinantes/administración & dosificación , Bazo/citología , Bazo/inmunología , Receptor Toll-Like 4/agonistas , Vagina/inmunología , Productos del Gen env del Virus de la Inmunodeficiencia Humana/inmunología
4.
Int J Pharm ; 430(1-2): 89-97, 2012 Jul 01.
Artículo en Inglés | MEDLINE | ID: mdl-22486955

RESUMEN

A major goal in vaccine development is elimination of the 'cold chain', the transport and storage system for maintenance and distribution of the vaccine product. This is particularly pertinent to liquid formulation of vaccines. We have previously described the rod-insert vaginal ring (RiR) device, comprising an elastomeric body into which are inserted lyophilised, rod-shaped, solid drug dosage forms, and having potential for sustained mucosal delivery of biomacromolecules, such as HIV envelope protein-based vaccine candidates. Given the solid, lyophilised nature of these insert dosage forms, we hypothesised that antigen stability may be significantly increased compared with more conventional solubilised vaginal gel format. In this study, we prepared and tested vaginal ring devices fitted with lyophilised rod inserts containing the model antigen bovine serum albumin (BSA). Both the RiRs and the gels that were freeze-dried to prepare the inserts were evaluated for BSA stability using PAGE, turbidimetry, microbial load, MALDI-TOF and qualitative precipitate solubility measurements. When stored at 4 °C, but not when stored at 40 °C/75% RH, the RiR formulation offered protection against structural and conformational changes to BSA. The insert also retained matrix integrity and release characteristics. The results demonstrate that lypophilised gels can provide relative protection against degradation at lower temperatures compared to semi-solid gels. The major mechanism of degradation at 40 °C/75% RH was shown to be protein aggregation. Finally, in a preliminary study, we found that addition of trehalose to the formulation significantly reduces the rate of BSA degradation compared to the original formulation when stored at 40 °C/75% RH. Establishing the mechanism of degradation, and finding that degradation is decelerated in the presence of trehalose, will help inform further development of RiRs specifically and polymer based freeze-dried systems in general.


Asunto(s)
Sistemas de Liberación de Medicamentos/instrumentación , Albúmina Sérica Bovina/química , Vacunas/química , Administración Intravaginal , Química Farmacéutica , Cromatografía Líquida de Alta Presión , Dicroismo Circular , Preparaciones de Acción Retardada , Portadores de Fármacos , Composición de Medicamentos , Estabilidad de Medicamentos , Elastómeros/química , Electroforesis en Gel de Poliacrilamida , Contaminación de Equipos , Diseño de Equipo , Excipientes/química , Femenino , Liofilización , Geles , Humanos , Humedad , Derivados de la Hipromelosa , Metilcelulosa/análogos & derivados , Metilcelulosa/química , Nefelometría y Turbidimetría , Polisorbatos/química , Conformación Proteica , Estabilidad Proteica , Albúmina Sérica Bovina/administración & dosificación , Solubilidad , Espectrometría de Masa por Láser de Matriz Asistida de Ionización Desorción , Tecnología Farmacéutica/métodos , Temperatura , Termogravimetría , Factores de Tiempo , Trehalosa/química , Vacunas/administración & dosificación
5.
Eur J Pharm Sci ; 46(5): 315-22, 2012 Aug 15.
Artículo en Inglés | MEDLINE | ID: mdl-22360941

RESUMEN

Mucosally-administered vaccine strategies are widely investigated as a promising means of preventing HIV infection. This study describes the development of liposomal gel formulations, and novel lyophilised variants, comprising HIV-1 envelope glycoprotein, CN54gp140, encapsulated within neutral, positively charged or negatively charged liposomes. The CN54gp140 liposomes were evaluated for mean vesicle diameter, polydispersity, morphology, zeta potential and antigen encapsulation efficiency before being incorporated into hydroxyethyl cellulose (HEC) aqueous gel and subsequently lyophilised to produce a rod-shaped solid dosage form for practical vaginal application. The lyophilised liposome-HEC rods were evaluated for moisture content and redispersibility in simulated vaginal fluid. Since these rods are designed to revert to gel form following intravaginal application, mucoadhesive, mechanical (compressibility and hardness) and rheological properties of the reformed gels were evaluated. The liposomes exhibited good encapsulation efficiency and the gels demonstrated suitable mucoadhesive strength. The freeze-dried liposome-HEC formulations represent a novel formulation strategy that could offer potential as stable and practical dosage form.


Asunto(s)
Vacunas contra el SIDA/química , Lípidos/química , Productos del Gen env del Virus de la Inmunodeficiencia Humana/química , Vacunas contra el SIDA/administración & dosificación , Vacunas contra el SIDA/inmunología , Adhesividad , Administración Intravaginal , Animales , Celulosa/análogos & derivados , Celulosa/química , Química Farmacéutica , Fuerza Compresiva , Composición de Medicamentos , Femenino , Liofilización , Geles , Dureza , Liposomas , Ratones , Mucinas/metabolismo , Proteínas Recombinantes/química , Reología , Propiedades de Superficie , Tecnología Farmacéutica/métodos , Vacunas Sintéticas/química , Productos del Gen env del Virus de la Inmunodeficiencia Humana/administración & dosificación , Productos del Gen env del Virus de la Inmunodeficiencia Humana/inmunología
6.
Vaccine ; 30(17): 2778-85, 2012 Apr 05.
Artículo en Inglés | MEDLINE | ID: mdl-22361120

RESUMEN

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.


Asunto(s)
Vacunas contra el SIDA/administración & dosificación , Proteína gp41 de Envoltorio del VIH/inmunología , VIH-1/inmunología , Vagina/inmunología , Vacunas contra el SIDA/inmunología , Administración Intravaginal , Animales , Especificidad de Anticuerpos/inmunología , Citocinas/metabolismo , Femenino , Anticuerpos Anti-VIH/inmunología , Infecciones por VIH/inmunología , Infecciones por VIH/prevención & control , Humanos , Inmunoglobulina A/inmunología , Interleucina-2/metabolismo , Ratones , Ratones Endogámicos BALB C , Membrana Mucosa/inmunología , Bazo/inmunología , Bazo/metabolismo , Células Th2/inmunología
7.
Vaccine ; 29(27): 4512-20, 2011 Jun 15.
Artículo en Inglés | MEDLINE | ID: mdl-21514349

RESUMEN

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.


Asunto(s)
Vacunas contra el SIDA/administración & dosificación , Anticuerpos Anti-VIH/sangre , Infecciones por VIH/prevención & control , Inmunidad Mucosa , Vacunas Sintéticas/administración & dosificación , Productos del Gen env del Virus de la Inmunodeficiencia Humana/administración & dosificación , Vacunas contra el SIDA/genética , Vacunas contra el SIDA/inmunología , Resinas Acrílicas , Administración Intravaginal , Animales , Química Farmacéutica , Femenino , Liofilización , Geles/administración & dosificación , Geles/química , Anticuerpos Anti-VIH/inmunología , Infecciones por VIH/inmunología , VIH-1/inmunología , Humanos , Inmunización , Ratones , Polivinilos/química , Reología , Almidón/análogos & derivados , Almidón/química , Vacunas Sintéticas/genética , Vacunas Sintéticas/inmunología , Productos del Gen env del Virus de la Inmunodeficiencia Humana/química , Productos del Gen env del Virus de la Inmunodeficiencia Humana/genética , Productos del Gen env del Virus de la Inmunodeficiencia Humana/inmunología
10.
Vaccine ; 27(48): 6791-8, 2009 Nov 12.
Artículo en Inglés | MEDLINE | ID: mdl-19747994

RESUMEN

Rheologically structured vehicle (RSV) gels were developed as delivery systems for vaginal mucosal vaccination with an HIV-1 envelope glycoprotein (CN54gp140). RSVs comprised a mucoadhesive matrix-forming and vaginal fluid absorbing polymer. The mucoadhesive and rheological properties of the RSVs were evaluated in vitro, and the distribution, antigenicity and release of CN54gp140 were analysed by ELISA. CN54gp140 was uniformly distributed within the RSVs and continuously released in vitro in an antigenically intact form over 24h. Vaginal administration to rabbits induced specific serum IgG, and IgG and IgA in genital tract secretions. The RSVs are a viable delivery modality for vaginal immunization.


Asunto(s)
Vacunas contra el SIDA/administración & dosificación , Vacunas contra el SIDA/inmunología , Anticuerpos Anti-VIH/sangre , Productos del Gen env del Virus de la Inmunodeficiencia Humana/inmunología , Administración Intravaginal , Animales , Formación de Anticuerpos , Ensayo de Inmunoadsorción Enzimática , Femenino , Geles , Inmunidad Mucosa , Inmunoglobulina A Secretora/inmunología , Inmunoglobulina G/sangre , Conejos , Reología
11.
Biomacromolecules ; 10(9): 2427-35, 2009 Sep 14.
Artículo en Inglés | MEDLINE | ID: mdl-19642670

RESUMEN

This investigation describes the formulation and characterization of rheologically structured vehicles (RSVs) designed for improved drug delivery to the vagina. Interactive, multicomponent, polymeric platforms were manufactured containing hydroxyethylcellulose (HEC, 5% w/w) polyvinylpyrrolidone (PVP, 4% w/w), Pluronic (PL, 0 or 10% w/w), and either polycarbophil (PC, 3% w/w) or poly(methylvinylether-co-maleic anhydride) (Gantrez S97, 3% w/w) as a mucoadhesive agent. The rheological (torsional and dynamic), mechanical (compressional), and mucoadhesive properties were characterized and shown to be dependent upon the mucoadhesive agent used and the inclusion/exclusion of PL. The dynamic rheological properties of the gel platforms were also assessed following dilution with simulated vaginal fluid (to mimic in vivo dilution). RSVs containing PC were more rheologically structured than comparator formulations containing GAN. This trend was also reflected in formulation hardness, compressibility, consistency, and syringeability. Moreover, formulations containing PL (10% w/w) were more rheologically structured than formulations devoid of PL. Dilution with simulated vaginal fluids significantly decreased rheological structure, although RSVs still retained a highly elastic structure (G' > G'' and tan delta < 1). Furthermore, RSVs exhibited sustained drug release properties that were shown to be dependent upon their rheological structure. It is considered that these semisolid drug delivery systems may be useful as site-retentive platforms for the sustained delivery of therapeutic agents to the vagina.


Asunto(s)
Sistemas de Liberación de Medicamentos/métodos , Geles/química , Adhesividad , Administración Intravaginal , Preparaciones de Acción Retardada , Fenómenos Mecánicos , Reología
12.
Toxicon ; 54(4): 491-8, 2009 Sep 15.
Artículo en Inglés | MEDLINE | ID: mdl-19481560

RESUMEN

Okadaic acid (OA) and structurally related toxins dinophysistoxin-1 (DTX-1), and DTX-2, are lipophilic marine biotoxins. The current reference method for the analysis of these toxins is the mouse bioassay (MBA). This method is under increasing criticism both from an ethical point of view and because of its limited sensitivity and specificity. Alternative replacement methods must be rapid, robust, cost effective, specific and sensitive. Although published immuno-based detection techniques have good sensitivities, they are restricted in their use because of their inability to: (i) detect all of the OA toxins that contribute to contamination; and (ii) factor in the relative toxicities of each contaminant. Monoclonal antibodies (MAbs) were produced to OA and an automated biosensor screening assay developed and compared with ELISA techniques. The screening assay was designed to increase the probability of identifying a MAb capable of detecting all OA toxins. The result was the generation of a unique MAb which not only cross-reacted with both DTX-1 and DTX-2 but had a cross-reactivity profile in buffer that reflected exactly the intrinsic toxic potency of the OA group of toxins. Preliminary matrix studies reflected these results. This antibody is an excellent candidate for the development of a range of functional immunochemical-based detection assays for this group of toxins.


Asunto(s)
Anticuerpos Monoclonales/inmunología , Toxinas Marinas/inmunología , Ácido Ocadaico/inmunología , Piranos/inmunología , Animales , Técnicas Biosensibles , Bivalvos/química , Ensayo de Inmunoadsorción Enzimática , Contaminación de Alimentos/prevención & control , Toxinas Marinas/toxicidad , Ratones , Ratones Endogámicos BALB C , Ácido Ocadaico/toxicidad , Piranos/toxicidad
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