RESUMO
We describe the structural characterization of the capsular polysaccharides (CPSs) of Pasteurella multocida serotypes B and E. CPS was isolated following organic solvent precipitation of the supernatant from flask grown cells. Structural analysis utilizing nuclear magnetic resonance spectroscopy enabled the determination of the CPS structures and revealed significant structural similarities between the two serotypes, but also provided an explanation for the serological distinction. This observation was extended by the development of polyclonal sera to the glycoconjugate of serotype B CPS that corroborated the structural likenesses and differences. Finally, identification of these structures enabled a more comprehensive interrogation of the genetic loci and prediction of roles for some of the encoded proteins in repeat unit biosynthesis.
Assuntos
Pasteurella multocida/química , Polissacarídeos , Configuração de Carboidratos , Pasteurella multocida/imunologia , Polissacarídeos/química , Polissacarídeos/genética , Polissacarídeos/imunologia , SorotipagemRESUMO
Fusobacterium nucleatum is becoming increasingly recognised as an emerging pathogen, gaining attention as a potential factor for exacerbating colorectal cancer and is strongly linked with pregnancy complications including pre-term and still births. Little is known about the virulence factors of this organism; thus, we have initiated studies to examine the bacterium's surface glycochemistry. In an effort to characterise the surface carbohydrates of F. nucleatum, the aims of this study were to investigate the structure of the lipopolysaccharide (LPS) O-antigen of the cancer-associated isolate F. nucleatum strain CC 7/3 JVN3 C1 (hereafter C1) and to develop monoclonal antibodies (mAbs) to the LPS O-antigen that may be beneficial to the growing field of F. nucleatum research. In this study, we combined several technologies, including nuclear magnetic resonance (NMR) spectroscopy, to elucidate the structure of the LPS O-antigen repeat unit as -[-4-ß-Gal-3-α-FucNAc4N-4-α-NeuNAc-]-. We have previously identified this structure as the LPS O-antigen repeat unit from strain 10953. In this present study, we developed a mAb to the C1 LPS O-antigen and confirmed the mAbs cross-reactivity to the 10953 strain, thus confirming the structural identity.
Assuntos
Anticorpos Antibacterianos/imunologia , Anticorpos Monoclonais/imunologia , Fusobacterium nucleatum/imunologia , Antígenos O/química , Antígenos O/imunologia , Animais , Antígenos de Bactérias/imunologia , Reações Cruzadas , Ensaio de Imunoadsorção Enzimática , Espectroscopia de Ressonância Magnética , Camundongos , Camundongos Endogâmicos BALB C , Sorotipagem , Fatores de VirulênciaRESUMO
Dental caries remains a major health issue and the Gram-positive bacterium Streptococcus mutans is considered as the major pathogen causing caries. More recently, S. mutans has been recognised as a cause of endocarditis, ulcerative colitis and fatty acid liver disease along with the likelihood of increased cerebral hemorrhage following a stroke if S. mutans is present systemically. We initiated this study to examine the vaccine candidacy of the serotype specific polysaccharides elaborated by S. mutans. We have confirmed the carbohydrate structures for the serotype specific rhamnan containing polysaccharides from serotypes c, f and k. We have prepared glycoconjugate vaccines using the rhamnan containing polymers from serotypes f and k and immunised mice and rabbits. We consistently obtained a robust immune response to the glycoconjugates with cross-reactivity consistent with the structural similarities of the polymers from the different serotypes. We developed an opsonophagocytic assay which illustrated the ability of the post-immune sera to facilitate opsonophagocytic killing of the homologous and heterologous serotypes at titers consistent with the structural homologies. We conclude that glycoconjugates of the rhamnan polymers of S. mutans are a potential vaccine candidate to target dental caries and other sequelae following the escape of S. mutans from the oral cavity.
Assuntos
Desoxiaçúcares/imunologia , Glicoconjugados/imunologia , Mananas/imunologia , Streptococcus mutans/imunologia , Animais , Linhagem Celular Tumoral , Desoxiaçúcares/química , Feminino , Glicoconjugados/química , Humanos , Mananas/química , Camundongos , Camundongos Endogâmicos BALB C , Coelhos , Sorogrupo , Streptococcus mutans/química , Streptococcus mutans/genética , Vacinas Conjugadas/imunologiaRESUMO
BACKGROUND: Rheumatoid arthritis (RA) is a highly dynamic and individualized disease in terms of its patterns of symptomatic flare-ups and periods of remission. Patient-centered care (PCC) aligns patients' lifestyle goals with their preferences for managing symptoms and side effects through the selection of therapies appropriate for disease management. Mobile health (mHealth) apps have the potential to engage and activate patients in PCC. mHealth apps can provide features that increase disease knowledge, collect patient-generated health indicators and behavioral metrics, and highlight goals for disease management. However, little evidence-based guidance exists as to which apps contain functionality essential for supporting the delivery of PCC. OBJECTIVE: The objective of this study was to evaluate the patient-centeredness of United States-based rheumatoid arthritis mobile apps in terms of patient engagement and activation. METHODS: A search of mobile apps on 2 major United States app stores (Apple App Store and Google Play) was conducted from June 2020 to July 2021 to identify apps designed for use by patients with RA by adapting the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-analyses) guidelines for mobile health app screening based on the literature. Reviewers conducted a content analysis of mobile app features to evaluate their functionality for patient engagement and activation. Engagement and activation were assessed using the Mobile Application Rating Scale (MARS) and social cognitive theory, respectively. Apps were ranked by their ability to facilitate PCC care along 2 dimensions: engagement and activation. RESULTS: A total of 202 mobile apps were initially identified, and 20 remained after screening. Two apps emerged with the greatest ability to facilitate PCC. Both apps were scored as having acceptable or good patient engagement according to the MARS. These 2 apps also had high patient activation according to social cognitive theory, with many features within those apps representing theoretical constructs such as knowledge, perceived self-efficacy, and expectations about outcomes that support behavioral management of RA. CONCLUSIONS: We found very few mobile apps available within the United States that have functionality that both engages and activates the patient to facilitate PCC. As the prevalence of mobile apps expands, the design of mobile apps needs to integrate patients to ensure that their functionality promotes engagement and activation. More research is needed to understand how mobile app use impacts patient engagement and activation, and ultimately, treatment decisions and disease trajectory.
Assuntos
Artrite Reumatoide , Aplicativos Móveis , Telemedicina , Humanos , Estados Unidos , Assistência Centrada no Paciente , Artrite Reumatoide/terapiaRESUMO
BACKGROUND: Standardized patients (SPs) are essential stakeholders in the multiple mini interviews (MMIs) that are increasingly used to assess medical school applicants' interpersonal skills. However, there is little evidence for their inclusion in the development of instruments. OBJECTIVE: This study aimed to describe the process and evaluate the impact of having SPs co-design and cocreate a global measurement question that assesses medical school applicants' readiness for medical school and acceptance status. METHODS: This study used an exploratory, sequential, and mixed methods study design. First, we evaluated the initial MMI program and determined the next quality improvement steps. Second, we held a collaborative workshop with SPs to codevelop the assessment question and response options. Third, we evaluated the created question and the additional MMI rubric items through statistical tests based on 1084 applicants' data from 3 cohorts of applicants starting in the 2018-2019 academic year. The internal reliability of the MMI was measured using a Cronbach α test, and its prediction of admission status was tested using a forward stepwise binary logistic regression. RESULTS: Program evaluation indicated the need for an additional quantitative question to assess applicant readiness for medical school. In total, 3 simulation specialists, 2 researchers, and 21 SPs participated in a workshop leading to a final global assessment question and responses. The Cronbach α's were >0.8 overall and in each cohort year. The final stepwise logistic model for all cohorts combined was statistically significant (P<.001), explained 9.2% (R2) of the variance in acceptance status, and correctly classified 65.5% (637/972) of cases. The final model consisted of 3 variables: empathy, rank of readiness, and opening the encounter. CONCLUSIONS: The collaborative nature of this project between stakeholders, including nonacademics and researchers, was vital for the success of this project. The SP-created question had a significant impact on the final model predicting acceptance to medical school. This finding indicates that SPs bring a critical perspective that can improve the process of evaluating medical school applicants.
RESUMO
Fusobacterium nucleatum is a gram-negative bacterium, part of the normal human microflora. It is associated with various health complications, including periodontitis and colorectal cancer. Its surface is covered with lipopolysaccharide, which interacts with the immune system and can be involved in various processes in health and disease conditions. Here we present the results of structural analysis of core oligosaccharides from the lipopolysaccharides of several strains of F. nucleatum. Pure compounds were isolated using mild acid hydrolysis or alkaline deacylation of the lipopolysaccharides and analyzed by NMR spectroscopy, mass-spectrometry and chemical methods. All cores analyzed had a common octasaccharide region, including five heptose residues and a non-phosphorylated 3-deoxy-d-manno-oct-2-ulosonic acid residue. The common region is substituted with different additional components specific for each strain. By structure type the F. nucleatum core is similar to that produced by Aeromonas.
Assuntos
Fusobacterium nucleatum/química , Lipopolissacarídeos/química , Oligossacarídeos/química , Configuração de Carboidratos , Espectroscopia de Ressonância Magnética , Oligossacarídeos/isolamento & purificaçãoRESUMO
Inhalation of small numbers of Francisella tularensis subspecies tularensis (Ftt) in the form of small particle aerosols causes severe morbidity and mortality in people and many animal species. For this reason, Ftt was developed into a bona fide biological weapon by the USA, by the former USSR, and their respective allies during the previous century. Although such weapons were never deployed, the 9/11 attack quickly followed by the Amerithrax attack led the U.S. government to seek novel countermeasures against a select group of pathogens, including Ftt. Between 2005-2009, we pursued a novel live vaccine against Ftt by deleting putative virulence genes from a fully virulent strain of the pathogen, SCHU S4. These mutants were screened in a mouse model, in which the vaccine candidates were first administered intradermally (ID) to determine their degree of attenuation. Subsequently, mice that survived a high dose ID inoculation were challenged by aerosol or intranasally (IN) with virulent strains of Ftt. We used the current unlicensed live vaccine strain (LVS), first discovered over 70 years ago, as a comparator in the same model. After screening 60 mutants, we found only one, SCHU S4 ΔclpB, that outperformed LVS in the mouse ID vaccination-respiratory-challenge model. Currently, SCHU S4 ΔclpB has been manufactured under current good manufacturing practice conditions, and tested for safety and efficacy in mice, rats, and macaques. The steps necessary for advancing SCHU S4 ΔclpB to this late stage of development are detailed herein. These include developing a body of data supporting the attenuation of SCHU S4 ΔclpB to a degree sufficient for removal from the U.S. Select Agent list and for human use; optimizing SCHU S4 ΔclpB vaccine production, scale up, and long-term storage; and developing appropriate quality control testing approaches.
RESUMO
BACKGROUND: Patient and Public Involvement (PPI) in research is increasingly being utilized to better connect patients and researchers. The Patient Engagement Studio (PES) supports PPI in research by working directly with researchers throughout various stages of their projects. Recently, two researchers presented to the PES for assistance with their project, Embryo+™. The purpose of Embryo+™ is to decrease miscarriage rates using RNA sequencing technology that screens for the most viable embryos. To date, no examples of PPI directly in the planning or implementation of bench research concerning in vitro fertilization and embryo transfer have been identified. MAIN BODY: Embryo+™ researchers met in-person with the PES two times (fall 2019; each meeting had 9 PES members in attendance) for initial feedback and protocol development. After these meetings, PES leadership and Embryo+™ researchers decided that the unique nature of the project merited a PPI evaluation. Subsequent evaluation of engagement efforts occurred by reviewing the PES reports for the Embryo+™ researchers, conducting two recorded web-based discussion meetings with the PES (summer 2020; meeting 1 n = 7; meeting 2 n = 6), and a brief survey (n = 13). The discussion meetings provided an opportunity for the PES members to define engagement themes through consensus via verbal agreement to the studio director's periodic summaries during the discussions. Combining survey results and PES themes allowed for a broad discussion for meaningful engagement. The Embryo+™ researchers established trust with the patients by changing some of their language in response to patient suggestions, allowing for unintended ethical conversations, and implementing the patient developed protocols. Overall, the patient experts thought this project was very meaningful and valuable, quantified by a mean loyalty score 89.43 (s.d. 10.29). CONCLUSION: Bench science researchers may need additional PPI training prior to engaging with patient groups. PPI in this project was successful in large part due to this training, where the director emphasized the importance of gaining trust with the patients. The researchers applied what they learned and several examples of how to develop trust with patients are discussed. If trust is established, PPI in an ethically charged, basic science research study can be both valuable and successful.
Patients are increasingly becoming involved in all stages of the research process. Patient and public involvement has been shown to answer questions that matter to patients, increase enrollment in studies, and improve the spread of research results to the public. However, there are limited evaluations of patient engagement in basic science research (research performed in a laboratory setting in various fields). Here, we provide an example of patients effectively involved in the planning and implementation of an ethically complex study in the field of Assistive Reproductive Technology. A Patient Engagement Studio, affiliated with an academic health center, directly connects patients and researchers through bi-monthly meetings. Recently, two researchers presented their project, Embryo+™, to the studio during the planning stage of their study. This project aims to use a new testing technology to reduce miscarriage rates. The researchers presented to the studio twice (fall 2019), and two follow-up meetings were conducted with the patients (summer 2020). Also, the patients completed a survey evaluating how engaged they felt with the project. Through the meetings, the researchers changed their language in response to patient feedback, and patients developed project protocols. Survey results showed that the patients thought this project was very meaningful and valuable. Overall, this evaluation shows that patients can add value to contentious bench science projects, particularly in the field of Assistive Reproductive Technology.
RESUMO
After the introduction of the glycoconjugate vaccine based upon the capsular polysaccharide ofHaemophilus influenzaetype b in the mid 1980s there was a remarkable decrease in the number of invasive cases reported for this organism. Since the 1990s several groups have observed the emergence ofHaemophilus influenzaetype a (Hia), especially in indigenous communities in the northern regions of Canada and Alaska, to a stage where a solution is warranted to prevent further unnecessary deaths due to this pathogen. A glycoconjugate vaccine solution based upon the type a capsular polysaccharide (CPS) was investigated pre-clinically in an effort to illustrate the proof of concept for this approach. In this study we describe the growth of Hia and the isolation, purification and conjugation of the CPS to several carrier proteins. The resulting glycoconjugates were immunised in mice and rabbits provoking sera that facilitated bactericidal killing against all type a strains that we tested. This study has illustrated the pre-clinical proof of concept of a glycoconjugate vaccine based on the CPS of Hia asa solution to this emerging disease.