Evaluating the safety, tolerability, and immunogenicity of a 24-valent pneumococcal conjugate vaccine (VAX-24) in healthy adults aged 18 to 64 years: a phase 1/2, double-masked, dose-finding, active-controlled, randomised clinical trial

BACKGROUND

Despite substantial reductions in pneumococcal disease with the availability of pneumococcal conjugate vaccines, a significant burden of pneumococcal disease remains due to the diversity of serotypes combined with serotype replacement. We developed a new vaccine candidate, VAX-24 (24-valent pneumococcal conjugate vaccine), using cell-free protein synthesis to produce a variant of cross-reactive material 197 (eCRM) as the carrier protein, increasing serotype coverage while minimising carrier suppression. The aim of this clinical trial was to assess the safety, tolerability, and immunogenicity of three different doses of VAX-24 compared to pneumococcal 20-valent conjugate vaccine (PCV20).

METHODS

This was a phase 1/2, randomised, double-masked study of VAX-24 versus PCV20 conducted in the USA. Key inclusion criteria included being a male or female aged 18 to 64 years in good health; key exclusion criteria included previous history of pneumococcal disease, receipt of a licensed or investigational pneumococcal vaccine, or immunosuppressive therapy. Participants were randomly allocated in a 1:1:1:1 ratio by permuted block to receive one dose of VAX-24 (1·1 μg of each antigen, 2·2 μg of each antigen, or 2·2 μg of 17 antigens mixed with 4·4 μg of seven antigens), or PCV20. The safety population included all participants with safety data. The immunogenicity population was as per-treatment in phase 2. Primary outcome measures included solicited and unsolicited adverse events. Secondary outcomes included serotype-specific opsonophagocytic activity (OPA) geometric mean titres (GMT), and IgG geometric mean concentrations (GMC) were measured 1 month postvaccination. Traditional non-inferiority criteria included OPA geometric mean ratio (GMR), with a lower bound of the two sided 95% CI of greater than 0·5 for shared serotypes. This completed trial is registered at ClinicalTrials.gov, NCT05266456.

FINDINGS

Safety profiles were comparable among the treatment groups, with 170 of 209 participants (81%, 95% CI 75·2-86·2) to 178 of 207 participants (86%, 80·5-90·4) reporting at least one solicited adverse event among the three VAX-24 groups. 24 of 207 participants (12%, 7·6-16·8) to 32 of 209 of participants (15%, 10·7-20·9) experiened an unsolicited treatment emergent adverse event within 1 month postvaccination. VAX-24 2·2 μg met traditional OPA GMR non-inferiority criteria for all 20 shared serotypes; 16 serotypes elicited GMR point estimates greater than 1·0, and four reached the lower bound of the two-sided 95% CI greater than 1·0.

INTERPRETATION

VAX-24 had a safety profile similar to PCV20 at all doses, with the 2·2 μg dose showing increased serotype coverage with decreased carrier suppression.

FUNDING

Vaxcyte.

Shigella virulence protein VirG is a broadly protective antigen and vaccine candidate

Diarrhea caused by Shigella has been associated with high morbidity and mortality in young children worldwide. There are no licensed vaccines, and those clinically advanced have restricted coverage as they elicit serotype-specific immunity while disease is caused by multiple circulating serotypes. Our group had previously reported a close association between serum antibodies to the Shigella virulence factor VirG (or IcsA) and clinical protection in infected individuals. VirG is highly conserved among Shigella strains and appealing as a broad-spectrum vaccine candidate. In this study, we investigated the immunogenicity and protective capacity of VirG as a subunit vaccine in mice. The surface-exposed alpha (α) domain of VirG (VirGα) was produced as a recombinant protein. This region has almost identical immune reactivity to full-length VirG. Administered intramuscularly with alum, VirGα elicited robust immune responses and high protective efficacy against S. flexneri 2a and S. sonnei. Almost complete protection was afforded by VirGα given intranasally with the E. coli double mutant heat-labile toxin (dmLT). VirGα-specific antibodies recognized VirG expressed on live Shigella, and blocked Shigella adhesion and invasion to human colonic cells. These results show for the first time that VirGα is a promising cross-protective vaccine candidate to prevent Shigella infection.

The Group A Streptococcal Vaccine Candidate VAX-A1 Protects against Group B Streptococcus Infection via Cross-Reactive IgG Targeting Virulence Factor C5a Peptidase

Group B Streptococcus (Streptococcus agalactiae or GBS) is the leading infectious cause of neonatal mortality, causing roughly 150,000 infant deaths and stillbirths annually across the globe. Approximately 20% of pregnant women are asymptomatically colonized by GBS, which is a major risk factor for severe fetal and neonatal infections as well as preterm birth, low birth weight, and neurodevelopmental abnormalities. Current clinical interventions for GBS infection are limited to antibiotics, and no vaccine is available. We previously described VAX-A1 as a highly effective conjugate vaccine against group A Streptococcus that is formulated with three antigens, SpyAD, streptolysin O, and C5a peptidase (ScpA). ScpA is a surface-expressed, well-characterized GAS virulence factor that shares nearly identical sequences with the lesser studied GBS homolog ScpB. Here, we show that GBS C5a peptidase ScpB cleaves human complement factor C5a and contributes to disease severity in the murine models of pneumonia and sepsis. Furthermore, antibodies elicited by GAS C5a peptidase bind to GBS in an ScpB-dependent manner, and VAX-A1 immunization protects mice against lethal GBS heterologous challenge. These findings support the contribution of ScpB to GBS virulence and underscore the importance of choosing vaccine antigens; a universal GAS vaccine such as VAX-A1 whose formulation includes GAS C5a peptidase may have additional benefits through some measure of cross-protection against GBS infections.

A Novel Shigella O-Polysaccharide-IpaB Conjugate Vaccine Elicits Robust Antibody Responses and Confers Protection against Multiple Shigella Serotypes

Shigella is responsible for high burdens of diarrhea and dysentery globally. Children living in areas of endemicity are the most affected, and currently, there are no licensed vaccines to prevent shigellosis. Vaccine approaches have traditionally targeted the bacterial lipopolysaccharide as a protective antigen. Shigella O-polysaccharide (OPS) conjugated to recombinant Pseudomonas aeruginosa exotoxin A (rEPA) or tetanus toxoid (TT) is advanced in clinical evaluation. Adequate efficacy of these vaccines, particularly in the infant target group, remains to be demonstrated. A major limitation of the OPS-glycoconjugate concept is its limited coverage, since immunity to the O antigen is serotype specific, and there are multiple disease-causing serotypes. Another concern is the use of protein carriers already included in multiple other childhood vaccines. This study reports a novel Shigella OPS conjugate vaccine that uses the Shigella invasion plasmid antigen B (IpaB) as the carrier protein. IpaB is a virulence factor component of the Shigella type III secretion system and highly conserved among Shigella serotypes. It is robustly immunogenic and a protective antigen. IpaB and IpaB containing nonnative amino acids (nnAA) were produced at large scale using cell-free protein synthesis. Incorporation of nnAA enabled site-specific conjugation of IpaB to Shigella flexneri 2a OPS using click chemistry, yielding OPS-IpaB glycoconjugate. Parenteral immunization of mice with the OPS-IpaB vaccine resulted in high levels of OPS- and IpaB-specific serum IgG and robust protection against lethal S. flexneri 2a or Shigella sonnei challenge. The OPS-IpaB vaccine is a promising new vaccine candidate with the capacity to confer broad protection against clinically relevant Shigella serotypes. IMPORTANCE Diarrhea caused by Shigella species results in long-term disability and mortality globally, disproportionally affecting younger children living in poor countries. Although it is treatable by antibiotics, the rapid and widespread emergence of resistant strains and the highly contagious nature of the disease compel the development of preventive tools. Currently, several Shigella OPS conjugate vaccines are being evaluated in clinical studies, but these rely exclusively on immunity against the bacterial O antigen, which limits their coverage to only the immunizing serotype; multivalent vaccines are needed to protect against the most prevalent serotypes. This is the first report of a novel Shigella OPS-conjugate vaccine that uses Shigella IpaB as a carrier and protective antigen. This vaccine, administered parenterally, elicited robust immunity and protected mice against lethal infection by S. flexneri 2a or S. sonnei. The OPS-IpaB vaccine is a promising candidate for evaluation in vulnerable populations.

Addition of Lauryldimethylamine N-Oxide (LDAO) to a Copper-Free Click Chemistry Reaction Improves the Conjugation Efficiency of a Cell-Free Generated CRM197 Variant to Clinically Important Streptococcus pneumoniae Serotypes

Strain-promoted azide-alkyne cycloaddition (SPAAC) reactions like click chemistry have the potential to be highly scalable, robust, and cost-effective methods for generating small- and large-molecule conjugates for a variety of applications. However, despite method improvements, the rates of copper-based click chemistry reactions continue to be much faster than the rates of copper-free click chemistry reactions, which makes broader deployment of click chemistry challenging from a safety and compatibility standpoint. In this study, we used a zwitterionic detergent, namely, lauryldimethylamine N-oxide (LDAO), in a copper-free click chemistry reaction to investigate its impact on the generation of conjugate vaccines (CVs). For this, we utilized an Xpress cell-free protein synthesis (CFPS) platform to generate a proprietary variant of CRM197 (eCRM) containing non-native amino acids (nnAA) with azide-containing side chains as a carrier protein for conjugation to several clinically relevant dibenzocyclooctyne (DBCO)-derivatized S. pneumoniae serotypes (types 3, 5, 18C, and 19A). For conjugation, we performed copper-free click chemistry in the presence and absence of LDAO. Our results show that the addition of LDAO significantly enhanced the reaction kinetics to generate larger conjugates, which were similarly immunogenic and equally stable to conjugates generated without LDAO. Most importantly, the addition of LDAO substantially improved the efficiency of the conjugation process. Thus, our results for the first time show that the addition of a zwitterionic surfactant to a copper-free click chemistry reaction can significantly accelerate the reaction kinetics along with improving the efficiency of the conjugation process.

Non-Native Amino Acid Click Chemistry-Based Technology for Site-Specific Polysaccharide Conjugation to a Bacterial Protein Serving as Both Carrier and Vaccine Antigen

Surface-expressed bacterial polysaccharides are important vaccine antigens but must be conjugated to a carrier protein for efficient antigen presentation and development of strong memory B cell and antibody responses, especially in young children. The commonly used protein carriers include tetanus toxoid (TT), diphtheria toxoid (DT), and its derivative CRM197, but carrier-induced epitopic suppression and bystander interference may limit the expanded use of the same carriers in the pediatric immunization schedule. Recent efforts to develop a vaccine against the major human pathogen group A Streptococcus (GAS) have sought to combine two promising vaccine antigens-the universally conserved group A cell wall carbohydrate (GAC) with the secreted toxin antigen streptolysin O (SLO) as a protein carrier; however, standard reductive amination procedures appeared to destroy function epitopes of the protein, markedly diminishing functional antibody responses. Here, we couple a cell-free protein synthesis (CFPS) platform, allowing the incorporation of non-natural amino acids into a C-terminally truncated SLO toxoid for the precise conjugation to the polyrhamnose backbone of GAC. The combined immunogen generated functional antibodies against both conserved GAS virulence factors and provided protection against systemic GAS challenges. CFPS may represent a scalable method for generating pathogen-specific carrier proteins for multivalent subunit vaccine development.

1047. Development of a Next Generation 30+ Valent Pneumococcal Conjugate Vaccine (VAX-XP) Using Site-Specific Carrier Protein Conjugation

Background

Due to the diversity of serotypes, exacerbated by the phenomenon of serotype replacement, there remains an unmet medical need for a pneumococcal conjugate vaccine (PCV) containing additional serotypes. Using a cell-free protein synthesis (CFPS) platform to produce an enhanced carrier protein (eCRM®) based on the CRM197 sequence, Vaxcyte is developing a PCV encompassing over 30 serotypes. The eCRM carrier protein contains multiple insertions of the non-native amino acid para-azidomethyl-L-phenylalanine (pAMF) that facilitates site-specific conjugation of the pneumococcal polysaccharides (PS) to eCRM. Unlike conventional methodologies, site-selective conjugation enhances process consistency and increases capacity for inclusion of additional serotypes in a PCV without promoting carrier suppression. Using this platform, the aim of the current study was to employ CFPS technology to construct a 31-valent PCV and evaluate its immunogenicity in New Zealand White (NZW) rabbits.

Methods

The eCRM carrier protein was individually conjugated to each of 31 selected pneumococcal PSs using copper-free click chemistry to produce 31 Conjugate Drug Substances (DS), which were then mixed with aluminum phosphate to produce the VAX-XP Drug Product. 24 of the DS conjugates in VAX-XP were generated at manufacturing scale. Two doses of VAX-XP were administered to NZW rabbits at 0 and 21 days to assess its ability to elicit anti-capsular IgG antibodies. Additionally, rabbits were also administered either Prevnar13 or a mixture of Pneumovax 23 and 8 incremental PS in isotonic saline, as comparators.

Results

VAX-XP showed conjugate-like immune responses for all 31 serotypes, as demonstrated by superior responses to PS-based vaccines and comparable responses to Prevnar13. IgG responses for VAX-XP compared with Prevnar13 and Pneumovax 23 at 14 days post dose 2

Conclusion

These results demonstrate that increasing the number of pneumococcal serotypes does not result in immunological attenuation in any of the serotypes contained in VAX-XP relative to the current standard of care. Furthermore, the data confirm the scalability and reproducibility of the CFPS platform in the production of VAX-XP conjugates, creating the foundation for a next generation broad-valency PCV.

Disclosures

Chris Behrens, PhD, Vaxcyte, Inc. (Employee) Jeff Fairman, PhD, Vaxcyte, Inc. (Employee) Paresh Agarwal, PhD, Vaxcyte, Inc. (Employee) Shylaja Arulkumar, MS, Vaxcyte, Inc. (Employee) Sandrine Barbanel, MS, Vaxcyte, Inc. (Employee) Leslie Bautista, n/a, Vaxcyte, Inc. (Employee) Aym Berges, PhD, Vaxcyte, Inc. (Employee) John Burky, BS, Vaxcyte, Inc. (Employee) Peter Davey, MS, Vaxcyte, Inc. (Employee) Chris Grainger, PhD, Vaxcyte, Inc. (Employee) Sherry Guo, PhD, Vaxcyte, Inc. (Employee) Sam Iki, MS, Vaxcyte, Inc. (Employee) Mark Iverson, BS, Vaxcyte, Inc. (Employee) Neeraj Kapoor, PhD, Vaxcyte, Inc. (Employee) Olivier Marcq, PhD, Vaxcyte, Inc. (Employee) Thi-Sau Migone, PhD, Vaxcyte, Inc. (Employee) Lucy Pill, MS, Vaxcyte, Inc. (Employee) Mohammed Sardar, n/a, Vaxcyte, Inc. (Employee) Paul Sauer, MBA, Vaxcyte, Inc. (Employee) James Wassil, MS MBA, Vaxcyte, Inc. (Employee)

Repertoire of Naturally Acquired Maternal Antibodies Transferred to Infants for Protection Against Shigellosis

Shigella is the second leading cause of diarrheal diseases, accounting for >200,000 infections and >50,000 deaths in children under 5 years of age annually worldwide. The incidence of Shigella-induced diarrhea is relatively low during the first year of life and increases substantially, reaching its peak between 11 to 24 months of age. This epidemiological trend hints at an early protective immunity of maternal origin and an increase in disease incidence when maternally acquired immunity wanes. The magnitude, type, antigenic diversity, and antimicrobial activity of maternal antibodies transferred via placenta that can prevent shigellosis during early infancy are not known. To address this knowledge gap, Shigella-specific antibodies directed against the lipopolysaccharide (LPS) and virulence factors (IpaB, IpaC, IpaD, IpaH, and VirG), and antibody-mediated serum bactericidal (SBA) and opsonophagocytic killing antibody (OPKA) activity were measured in maternal and cord blood sera from a longitudinal cohort of mother-infant pairs living in rural Malawi. Protein-specific (very high levels) and Shigella LPS IgG were detected in maternal and cord blood sera; efficiency of placental transfer was 100% and 60%, respectively, and had preferential IgG subclass distribution (protein-specific IgG1 > LPS-specific IgG2). In contrast, SBA and OPKA activity in cord blood was substantially lower as compared to maternal serum and varied among Shigella serotypes. LPS was identified as the primary target of SBA and OPKA activity. Maternal sera had remarkably elevated Shigella flexneri 2a LPS IgM, indicative of recent exposure. Our study revealed a broad repertoire of maternally acquired antibodies in infants living in a Shigella-endemic region and highlights the abundance of protein-specific antibodies and their likely contribution to disease prevention during the first months of life. These results contribute new knowledge on maternal infant immunity and target antigens that can inform the development of vaccines or therapeutics that can extend protection after maternally transferred immunity wanes.

A Porphyromonas gingivalis Capsule-Conjugate Vaccine Protects From Experimental Oral Bone Loss

Periodontal diseases are chronic inflammatory diseases of the periodontium that result in progressive destruction of the soft and hard tissues supporting the teeth, and it is the most common cause of tooth loss among adults. In the US alone, over 100 million individuals are estimated to have periodontal disease. Subgingival bacteria initiate and sustain inflammation, and, although several bacteria have been associated with periodontitis, Porphyromonas gingivalis has emerged as the key etiological organism significantly contributing to the disease. Currently, intensive clinical maintenance strategies are deployed to mitigate the further progression of disease in afflicted individuals; however, these treatments often fail to stop disease progression, and, as such, the development of an effective vaccine for periodontal disease is highly desirable. We generated a conjugate vaccine, comprising of the purified capsular polysaccharide of P. gingivalis conjugated to eCRM®, a proprietary and enhanced version of the CRM197 carrier protein with predetermined conjugation sites (Pg-CV). Mice immunized with alum adjuvanted Pg-CV developed robust serum levels of whole organism-specific IgG in comparison to animals immunized with unconjugated capsular polysaccharide alone. Using the murine oral bone loss model, we observed that mice immunized with the capsule-conjugate vaccine were significantly protected from the effects of P. gingivalis-elicited oral bone loss. Employing a preclinical model of infection-elicited oral bone loss, our data support that a conjugate vaccine incorporating capsular polysaccharide antigen is effective in reducing the main clinical endpoint of periodontal disease-oral bone destruction. Further development of a P. gingivalis capsule-based conjugate vaccine for preventing periodontal diseases is supported.

Non-clinical immunological comparison of a Next-Generation 24-valent pneumococcal conjugate vaccine (VAX-24) using site-specific carrier protein conjugation to the current standard of care (PCV13 and PPV23)

Despite widespread utilization of pneumococcal conjugate vaccines (PCVs) and the resultant disease reduction, the development of PCVs containing additional serotypes remains a public health priority due to serotype replacement and the resultant shift to non-vaccine containing serotypes. However, incorporating additional serotypes to existing PCVs using conventional technologies has proven problematic. Immune responses to individual serotypes have consistently decreased as more polysaccharide-conjugates are added due to carrier suppression. Using our proprietary cell-free protein synthesis (CFPS) platform, we have successfully produced eCRM® based on the CRM₁₉₇ sequence for use as an enhanced carrier protein to develop a 24-valent PCV. The eCRM carrier protein contains multiple non-native amino acids (nnAAs) located outside of the primary T-cell epitope regions, thereby enabling site-specific covalent conjugation of the pneumococcal polysaccharides to the nnAAs to consistently expose the critical T-cell epitopes. eCRM also serves to reduce structural heterogeneity associated with classic reductive-amination conjugation while promoting formation of the conjugate matrix structures, the hallmark of PCVs. This process serves to increase the overall polysaccharide:protein ratio, enabling the inclusion of more serotypes while minimizing carrier-mediated immunological interference. The aim of this non-clinical study was to construct a 24-valent PCV and evaluate its immunogenicity. Using the XPressCF® CFPS platform, the eCRM carrier protein was separately conjugated through nnAAs to each of the 24 pneumococcal polysaccharides through click chemistry and mixed with aluminum phosphate to produce VAX-24, Vaxcyte's proprietary PCV preclinical candidate. VAX-24, Prevnar13® and Pneumovax®23 were administered to New Zealand White rabbits to compare the resulting opsonophagocytic activity (OPA) and anti-capsular IgG antibodies. VAX-24 showed conjugate-like immune responses to all 24 serotypes based on comparable OPA and IgG responses to Prevnar13 and higher responses than Pneumovax 23. This study demonstrates the utility of site-specific conjugation technology in a preclinical setting and the potential for a PCV with improved serotype coverage.

Protection against a chlamydial respiratory challenge by a chimeric vaccine formulated with the Chlamydia muridarum major outer membrane protein variable domains using the Neisseria lactamica porin B as a scaffold

Chlamydia trachomatis is the most frequently detected sexually transmitted bacterial pathogen in the world. Attempts to control these infections with screening programs and antibiotics have failed and, therefore, a vaccine is the best approach to control this epidemic. The Chlamydia major outer membrane protein (MOMP) is the most protective subunit vaccine so far tested. Protection induced by MOMP is, in part, dependent on its tertiary structure. We have previously described new recombinant antigens composed of the Neisseria lactamica PorB engineered to express the variable domains (VD) from Chlamydia muridarum MOMP. Here we tested antigens containing each individual MOMP VD and different VD combinations. Following immunization, mice were challenged intranasally with C. muridarum. Our results show that three constructs, PorB/VD1-3, PorB/VD1-4, and PorB/VD1-2-4, elicited high serum IgG titers in vivo, significant IFN-γ levels upon T cells re-stimulation in vitro, and evidence of protective immunity in vivo. PorB/VD1-3, PorB/VD1-4, and PorB/VD1-2-4 immunized mice lost less body weight, had lighter lungs, and decreased numbers of inclusion forming units (IFUs) in lungs than other PorB/VD construct tested and mock PBS-immunized mice. These results suggest that this approach may be a promising alternative to the use of MOMP in a Chlamydia vaccine.

Shaping nursing profession regulation through history - a systematic review

AIM

The aim of this systematic review was to provide a critical synthesis of the factors that historically shaped the advancements of nursing regulators worldwide.

BACKGROUND

An in-depth examination of the different factors that moulded regulatory changes over time is pivotal to comprehend current issues in nursing.

INTRODUCTION

In the light of global health scenarios, the researchers explored the factors that historically influenced the socio-contextual circumstances upon which governments made regulatory changes.

METHODS

A systematic search was performed on the following databases: PubMed, CINAHL, Scopus, OpenGrey and ScienceDirect. The review included papers from January 2000 to October 2016 published in English. The authors used the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) and an inductive thematic approach for synthesis.

RESULTS

Two main themes were identified: factors underpinning current challenges and historical and contextual triggers of regulation. The first theme was composed of three aspects: education, migration and internationalization, and policy and regulation; the second theme consisted of four attributes: demographics, economics, history of registration and wars, and historical changes in nursing practice.

DISCUSSION

Factors that shaped nursing regulation were linked to changing demographics and economics, education, history of nursing registration, shifting patterns of migration and internationalization, nursing practice, policy and regulation and significant societal turns often prompted by wars.

CONCLUSION

A deeper understanding of the developments of the nursing regulatory institutions provides the foundation for portable standards that can be applied across an array of jurisdictions to guarantee a better public safety.

IMPLICATION FOR NURSING AND HEALTH POLICY

Understanding factors that socially, legislatively and politically have influenced the development of regulatory bodies over time helps to mould local, national and international policies that have a stronger impact on health worldwide. To achieve this, there must be effective cooperation among systems of nursing regulations globally.

Malaria Derived Glycosylphosphatidylinositol Anchor Enhances Anti-Pfs25 Functional Antibodies That Block Malaria Transmission

Malaria, one of the most common vector borne human diseases, is a major world health issue. In 2015 alone, more than 200 million people were infected with malaria, out of which, 429 000 died. Even though artemisinin-based combination therapies (ACT) are highly effective at treating malaria infections, novel efforts toward development of vaccines to prevent transmission are still needed. Pfs25, a postfertilization stage parasite surface antigen, is a leading transmission-blocking vaccine (TBV) candidate. It is postulated that Pfs25 anchors to the cell membrane using a glycosylphosphatidylinositol (GPI) linker, which itself possesses pro-inflammatory properties. In this study, Escherichia coli derived extract (XtractCF^+TM) was used in cell free protein synthesis [CFPS] to successfully express >200 mg/L of recombinant Pfs25 with a C-terminal non-natural amino acid (nnAA), namely, p-azidomethyl phenylalanine (pAMF), which possesses a reactive azide group. Thereafter, a unique conjugate vaccine (CV), namely, Pfs25-GPI was generated with dibenzocyclooctyne (DBCO) derivatized glycan core of malaria GPI using a simple but highly efficient copper free click chemistry reaction. In mice immunized with Pfs25 or Pfs25-GPI, the Pfs25-GPI group showed significantly higher titers compared to the Pfs25 group. Moreover, only purified IgGs from Pfs25-GPI group were able to significantly block transmission of parasites to mosquitoes, as judged by a standard membrane feeding assay [SMFA]. To our knowledge, this is the first report of the generation of a CV using Pfs25 and malaria specific GPI where the GPI is shown to enhance the ability of Pfs25 to elicit transmission blocking antibodies.

Structural and Immunological Characterization of Novel Recombinant MOMP-Based Chlamydial Antigens

Chlamydia is the most common cause of bacterial sexually transmitted infections worldwide. While infections resolve with antibiotic treatment, this is often neglected in women due to frequent asymptomatic infections, leading to disease progression and severe sequelae (pelvic inflammatory disease, ectopic pregnancy, infertility). Development of a vaccine against Chlamydia is crucial. Whole organism-based vaccines have short-lived activity, serovar/subgroup-specific immunity and can cause adverse reactions in vaccinated subjects. The Chlamydia major outer membrane protein (MOMP) is a prime candidate for a subunit vaccine. MOMP contains four regions of sequence variability (variable domains, VDs) with B-cell and T-cell epitopes that elicit protective immunity. However, barriers for developing a MOMP-based vaccine include solubility, yield and refolding. We have engineered novel recombinant antigens in which the VDs are expressed into a carrier protein structurally similar to MOMP and suitable for recombinant expression at a high yield in a correctly folded and detergent-free form. Using a carrier such as the PorB porin from the human commensal organism N. lactamica, we show that PorB/VD chimeric proteins are immunogenic, antigenic and cross-reactive with MOMP. VDs are unique for each serovar but if combined in a single vaccine, a broad coverage against the major Chlamydia serovars can be ensured.

A cationic lipid-DNA complex adjuvant (JVRS-100) enhances the immunogenicity and cross-protective efficacy of influenza pre-pandemic H5N1 vaccine in ferrets (VAC2P.931)

Highly pathogenic avian influenza A H5N1 viruses continue to pose a public health threat. Adjuvants are needed to improve the immunogenicity of H5N1 vaccine in humans. JVRS-100 is a cationic lipid-DNA complex adjuvant. We investigated the immunogenicity and cross-protective efficacy of JVRS-100-adjuvanted H5N1 (clade 2.2) vaccine in ferrets. Four weeks after the first vaccination, significantly higher levels of serum hemagglutination-inhibition (HI), neutralizing and H5 IgG antibody were detected in ferrets immunized with adjuvanted vaccine compared to the unadjuvanted vaccine group. Following a second dose of JVRS-100 adjuvanted vaccine, cross-reactive HI antibody titers of ≥40 were detected against viruses from multiple H5N1 clades. Ferrets were challenged with a high lethal dose of heterologous H5N1 virus (clade 2.1.3.2) 2 months after the second vaccination. Ferrets that received JVRS-100 adjuvanted vaccine had significantly reduced virus titers in the nasal washes and were completely protected from severe disease and death. In contrast, ferrets that received unadjuvanted vaccine had high viral titers through day 6 and 3 of 6 animals succumbed to the lethal infection. Our results indicate that the addition of JVRS-100 to H5N1 vaccine enhanced immunogenicity and cross-protection against lethal H5N1 virus disease in ferrets. JVRS-100 warrants further investigation as a potential adjuvant for use in human vaccination against avian influenza viruses with pandemic potential.

Skin-based soluble microneedle array mediated anti-malarial CSP vaccination (65.28)

A safe, effective, easily administered, and storage-stable anti-malarial vaccine delivery platform would improve vaccination efforts in populations at risk for malaria. Painless, self-blunting soluble microneedle arrays seem ideal for skin-based inoculation. To test the ability of adjuvanted microneedle arrays to induce an immune response, anti-malarial circumsporozoite surface protein (CSP) antigen was delivered directly to skin by water-soluble polyvinyl alcohol microneedles, inducing a robust and specific immune response in BALB/c mouse cohorts. Inclusion of JVRS-100 cationic lipid DNA complex adjuvant boosted immune response and dried arrays induced strong response even after exposure to accelerated thermal storage conditions. To assess storage stability of the needle array dosage form, loaded microneedle arrays and parallel antigen solutions were subjected to one-week storage at 20°, 37°, and 50°C, and subsequently used to inoculate mouse cohorts. Serum anti-CSP IgG titers indicated that while antigen solutions showed profound (10-fold) loss of activity with increasing storage temperature, the dry arrays exhibited no such degradation.

Enhanced in vivo immunity and protection provided by cationic lipid-DNA complex adjuvanted influenza vaccination is independent of Toll-like receptor 9 (106.16)

As current licensed influenza vaccines provide little or no cross-protective immunity, we have pursued using cationic lipid-DNA complex (CLDC) adjuvant to boost adaptive immunity to inactivated influenza vaccines. CLDC consists of a non-coding plasmid DNA, rich in immunostimulatory CpG motifs, which is encapsulated in cationic lipids. Previous murine and non-human primate studies showed that CLDC adjuvanted influenza vaccination induced more robust immunity and cross-protection. We hypothesized that the CLDC plasmid mediates these effects, at least in part, in a TLR9-dependent manner. Bone-marrow derived dendritic cells (BMDCs) incubated in vitro with CLDC secreted high levels of interferon-alpha (IFN-α), and this induction required CLDC’s DNA component. CLDC-induced IFN-α expression was significantly reduced using TLR9-/- BMDCs. We next vaccinated wildtype and TLR9-/- mice with CLDC-adjuvanted inactivated influenza vaccines. Surprisingly, CLDC’s immunostimulatory responses in vivo were TLR9-independent in that there was no significant difference between wildtype and knockouts for either vaccine immunogenicity (influenza-specific antibody and T-cell responses) or for cross-protection after viral challenge. These studies suggest that the DNA moiety of CLDC enhances immune responses in vivo by a novel, TLR9-independent mechanism. Determining this mechanism will likely be important in the optimal application of CLDC as an adjuvant to human vaccination.

Adjuvanted Flu Vaccination Using a Novel High-Efficiency Hollow Microprotrusion Skin Patch (130.37)

Influenza spreads around the world in seasonal epidemics, resulting in the deaths of hundreds of thousands worldwide annually, and millions in pandemic years. Hypodermic needle-based administration of current vaccines to large underserved populations is hampered by refrigeration requirements, painful injections, and infectious sharps waste disposal issues. We have developed a prototype micro-protrusion array device (PAD), comprising water-soluble polymer microneedles loaded with a dry-stable adjuvanted flu antigen vaccine for topical application as a patch. Three groups of mice were tested to evaluate the efficacy of PAD vaccination: Non-treatment, Fluzone (Flz) and Flz adjuvanted with JVRS-100. PADs were applied to anesthetized mice with a primary dose, followed by a second boost dose applied two weeks later. Four weeks after the primary dose, the animals were challenged with 1x LD50 of HKx31 (H3N2) Flu virus. Serum antibody levels were assessed before the challenge. Total IgG of Anti-Flz was 6 fold higher in the Flz/JVRS-100 than Flz. Control and Flz mice had 60% mortality while the Flz/JVRS100 group had a 100% survival rate. We conclude that the dry PAD adjuvanted vaccine format may provide a powerful new approach to transdermal vaccine delivery. Immunization potency is significantly increased through adjuvanted antigen which generating a robust immune response that was protective against lethal influenza virus challenge.

Highly Immunogenic JVRS-100 Adjuvanted Universal Influenza A Vaccine (52.4)

A vaccine based on a conserved external ectodomain of M2 (M2e) offers the potential for inducing broad-immunity against divergent influenza A strains including pandemic viruses. Cohorts of mice were vaccinated 3x (IM) with M2e in the form of a multiple antigenic peptide with 4 copies of M2e (MAP4), with or without cationic lipid DNA complex adjuvant (JVRS-100). Lethal challenge using different strains of virus (H1N1, H3N2) were done to establish efficacy based on survival. The addition of JVRS-100 to M2e-MAP4 resulted in a significant decrease in morbidity and mortality following lethal challenge with H1N1 (survival 100% vs. 30% without adjuvant) or H3N2 (80% vs. 20%). Adjuvanted vaccine resulted in higher levels of IgG (p=0.0159), IgG1 (p<0.02) and IgG2a (p<0.005) vs. M2e-MAP4 alone. A dose titration of M2e-MAP4 inoculated with a constant amount of JVRS-100 resulted in 100% survival after challenge even at a vaccine dose of 25ng. Addition of M2e-MAP4/JVRS-100 to trivalent inactivated influenza vaccine (TIV) confers full protection with a single vaccination prior to lethal challenge. Competitive binding ELISA confirmed that the sera from vaccinated mice contained M2e conformational epitopes. Vaccination with MAP2 and MAP4 indicated the protective epitopes were dependent on dimeric and not tetrameric configuration of the MAP construct. The experiments demonstrate the potency of MAP configured M2e peptide with the JVRS-100 adjuvant in the development of universal flu vaccine.

Skin Delivery of the JVRS-100 Immunostimulant with and without Fluzone using a Protrusion Array Device (PAD) Results in Potent Adaptive Immune Responses (78.34)

Background: A protrusion array device (PAD) configured with hollow dissolvable microneedles was loaded with the JVRS-100 adjuvant or JVRS-100 combined with commercial Fluzone. The studies were designed to establish if adjuvant or adjuvant/vaccine could be administered via PAD patches. Methods: JVRS-100, Fluzone, or JVRS-100/Fluzone were loaded onto PAD patches and administered at day 0 and 14. At day 28 responses were assessed by HAI and ELISA (IgG, IgG1, and IgG2). Separate cohorts of mice were vaccinated intramuscularly (IM) with Fluzone and JVRS-100-containing patches were placed over the site of vaccination to see if intradermal administration of JVRS-100 would adjuvant IM vaccination. Results: The administration of JVRS-100 in addition to Fluzone stimulated a response greater than Fluzone alone patches as measured by geometric mean titer (EC50) for IgG (4.8x104 vs. 1.6x104) and IgG2 (4.5x103 vs 6.0x102). IgG1 titers were elevated in the Fluzone only group compared with JVRS-100/Fluzone (8.3x103 vs. 1.9x103). Administration of JVRS-100-containing patches over IM Fluzone vaccination increased IgG (3.7x105 vs. 2.2x105) and IgG2a (1.5x105 vs. 9.0x104). IgG1 titers were elevated in the Fluzone-only group compared with JVRS-100/Fluzone (1.5x105 vs. 2.9x105). HAI levels correlated with antibody titer levels for all groups. Conclusion: The antibody response from both studies indicate that the TH1 bias for JVRS-100 is retained as a dry PAD patch and intradermal administration over IM vaccination or combined for ID vaccination.

Cationic Liposome-DNA Complex Adjuvant (JVRS-100) Combined with Heat-Inactivated Whole Virion Influenza Vaccine Confers Protection against Homotypic and Heterosubtypic Lethal Challenge (132.1)

Background: Current vaccine strategies for influenza are highly dependent on matching of hemagglutinin, which is susceptible to periodic antigenic drift. A vaccine that elicits a robust antibody and T-cell response would be less susceptible to primary vaccine failure. Methods: Balb/c mice were vaccinated with heat-inactivated PR/8/34 (H1N1) or HKx31 (H3N2) with or without the JVRS-100 adjuvant. Mice were assessed for antibody and T-cell responses as well as challenged with a lethal dose of PR/8/34. Mice were monitored for clinical signs of infection, changes in body weight, and mortality. Results: Mice vaccinated with heat-inactivated virus combined with JVRS-100 adjuvant, showed increased HAI (450 vs. 30, P=0.007) and T-cell responses based on splenocyte restimulation (7700 vs. 30 pg/ml, P<0.001) when compared with unadjuvanted virus. Mice vaccinated with homologous virus with adjuvant exhibited no weight loss at six days post infection (+5.4% vs. -15.3%) compared with unadjuvanted virus following 6xLD50 challenge with PR/8/34. Mice vaccinated with JVRS-100-adjuvanted heterologous virus also showed less weight loss (-7% vs. -26.7%, P=0.004) compared with unadjuvanted virus following 6xLD50 challenge with PR/8/34. Conclusion: Heat-inactivated whole influenza virus adjuvanted with JVRS-100 showed increased immunogenicity and greater protection from homotypic and heterosubtypic lethal challenge. Adoptive transfer studies suggest that the cross-protection is due at least in part to a cross-reactive antibody response.

Enhanced in vivo immunogenicity of SIV vaccine candidates with cationic liposome-DNA complexes in a rhesus macaque pilot study

This pilot study tested the immunogenicity of a novel cationic liposome-DNA complex (CLDC) immunomodulatory vaccine adjuvant. Combined with a specific antigen, CLDC enhanced anti-SIV immune responses induced by various SIV vaccine candidates. Rhesus macaques immunized in the presence of CLDC developed stronger SIV-specific T and B cell responses compared to animals immunized without CLDC. These differences persisted and resulted in better memory responses after an in vivo boost of the animals several months later with whole AT-2 inactivated SIVmac239. Thus, CLDC should be explored further as a potential immunomodulatory adjuvant in HIV vaccine design.

A novel vaccine adjuvant for recombinant flu antigens

Many new vaccines under development consist of rationally designed recombinant proteins that are relatively poor immunogens unless combined with potent adjuvants. There is only one adjuvant in common use in the U.S., aluminum phosphate or hydroxide (e.g. alum). This adjuvant, however, has significant limitations, particularly regarding the generation of strong cell-mediated (T-cell) immune responses. A novel adjuvant, JVRS-100, composed of cationic liposome-DNA complexes (CLDC) has been evaluated for immune enhancing activity. The JVRS-100 adjuvant has been shown to elicit robust immune responses compared to CpG oligonucleotides, alum, and MPL adjuvants, and efficiently enhances both humoral and cellular immune responses. Safety has been evaluated in preclinical studies, and the adjuvant is now in early-stage clinical development. One application of this novel adjuvant is to augment the immune responses to recombinant subunit antigens, which are often poorly immunogenic. The JVRS-100 adjuvant, when combined with a recombinant influenza hemagglutinin (H1), elicited increased specific antibody and T-cell responses in mice. Single-dose vaccination and prime/boost vaccinations with JVRS-100-H1 were both shown to be protective (i.e., survival, reduced weight loss) following H1N1 (PR/8/34) virus challenge. Enhanced immunological responses could be critically important for improved efficacy and dose-sparing of a recombinant influenza vaccine.

Prophylaxis with cationic liposome-DNA complexes protects hamsters from phleboviral disease: importance of liposomal delivery and CpG motifs

Cationic liposome-DNA complexes (CLDC) are cationic/neutral lipid carriers complexed with plasmid DNA that when administered systemically results in a robust T(H)1 cytokine response. CLDC have been shown to be effective in prophylaxis and therapeutic treatment of animal models of viral disease. To determine the contribution of liposomal delivery and CpG content of the plasmid DNA to the efficacy of CLDC; plasmid, CpG-free plasmid DNA, or CpG-containing oligodeoxynucleotides (ODN) with and without liposomes, as well as poly(I:C(12)U), were evaluated for their ability to elicit protection against lethal Punta Toro virus (PTV, Bunyaviridae, phlebovirus) challenge in hamsters. CLDC-containing plasmid significantly improved survival, decreased systemic and liver viral loads, and reduced liver damage due to progression of viral infection. Mouse-reactive ODNs complexed with liposomes failed to protect hamsters, whereas ODNs known to cross-react with human and mouse (CpG 2006) or non-liposomal poly(I:C(12)U) showed survival benefit but did not limit liver injury. Liposomes complexed with a non-CpG motif-containing plasmid reduced liver viral load and tissue damage, but did not protect hamsters from death. To evaluate the mechanisms of the enhanced activity of CLDC, microarray experiments examined differences in the gene expression profile. The results suggest a broad T(H)1 response elicited by liposomal delivery of a diverse sequence containing CpG and non-CpG elements may be a more effective antiviral treatment than other nucleic acid based immunotherapeutics.

Liposome-DNA complexes infused intravenously inhibit tumor angiogenesis and elicit antitumor activity in dogs with soft tissue sarcoma

Intravenous gene delivery using liposome-DNA complexes (LDC) has previously been shown to elicit antitumor activity, but only in rodent tumor models. Therefore, we conducted a study to determine in a large animal spontaneous tumor model whether intravenous infusions of LDC could target gene expression to cutaneous tumor tissues and whether repeated treatments had an effect on tumor growth or angiogenesis. A total of 13 dogs with cutaneous soft tissue sarcomas were enrolled in the study and were randomized to receive a series of 6 weekly infusions of LDC containing either canine endostatin DNA or DNA encoding an irrelevant gene (luciferase). Serial tumor biopsies were obtained to assess transgene expression, tumor microvessel density (MVD), and intratumoral leukocyte inflammatory responses. We found that intravenous infusion of LDC did not result in detectable gene expression in cutaneous tumor tissues. However, two of 13 treated dogs had objective tumor responses and eight dogs had stable disease during the treatment period. In addition, a significant decrease in tumor MVD was noted in six of 12 treated dogs at the completion of six treatments. These results suggest that intravenous infusions of LDC may elicit nonspecific antitumor activity and inhibit tumor angiogenesis.

Protective immunity against acute phleboviral infection elicited through immunostimulatory cationic liposome-DNA complexes

Cationic liposome-DNA complexes (CLDC) have been demonstrated to induce potent antitumor activities. The ability of these complexes to elicit protective immunity against viral infections has not been fully explored. Here we report findings on the use of CLDC as an antiviral agent in a mouse model of acute phleboviral (Punta Toro virus) disease. CLDC treatment of mice challenged with Punta Toro virus (PTV) resulted in dramatic increases in survival and reduced viral burden and other parameters indicative of protection against disease. CLDC were effective when administered by intraperitoneal and intravenous routes and elicited protective immunity when given within 1 day of virus challenge. Treatments administered 36 h or longer after challenge, however, were not effective in preventing mortality or disease. CLDC treatment induced release of a number of potential antiviral cytokines including IFN-gamma, IL-12, and IFN-alpha. Taken together, our findings indicate that non-specific immunotherapy with CLDC appears to be an effective treatment for blocking PTV-induced disease and suggests that further exploration in other viral disease models may be warranted.

Sensitivity and specificity of the ViroSeq human immunodeficiency virus type 1 (HIV-1) genotyping system for detection of HIV-1 drug resistance mutations by use of an ABI PRISM 3100 genetic analyzer

The ViroSeq human immunodeficiency virus type 1 (HIV-1) genotyping system is an integrated system for identification of drug resistance mutations in HIV-1 protease and reverse transcriptase (RT). Reagents are included for sample preparation, reverse transcription, PCR amplification, and sequencing. Software is provided to assemble and edit sequence data and to generate a drug resistance report. We determined the sensitivity and specificity of the ViroSeq system for mutation detection using an ABI PRISM 3100 genetic analyzer with a set of clinical samples and recombinant viruses. Twenty clinical plasma samples (viral loads, 1,800 to 10,500 copies/ml) were characterized by cloning and sequencing individual viral variants. Twelve recombinant-virus samples (viral loads, approximately 2,000 to 5,000 copies/ml) were also prepared. Eleven recombinant-virus samples contained drug resistance mutations as 40% mixtures. One recombinant-virus sample contained an insertion at codon 69 in RT (100% mutant). Plasma and recombinant-virus samples were analyzed using the ViroSeq system. Each sample was analyzed on three consecutive days at each of three testing laboratories. The sensitivity of mutation detection was 99.65% for the clinical plasma samples and 99.7% for the recombinant-virus preparations. The specificity of mutation detection was 99.95% for the clinical samples and 100% for the recombinant-virus mixtures. The base calling accuracy of the 3100 instrument was 99.91%. Mutations in clinical plasma samples and recombinant-virus samples were detected with high sensitivity and specificity, including mutations present as mixtures. This report supports the use of the ViroSeq system for identification of drug resistance mutations in HIV-1 protease and RT genes.

Oral history of Florence Downs; the early years

BACKGROUND

Florence Downs is a well-recognized nursing leader, educator, editor, and scholar who helped shape nursing as an intellectual discipline, and wrote extensively about the importance of links between research and practice.

OBJECTIVES

Through the use of oral history data garnered over 15 hours of interviews, we constructed a narrative that describes some of Downs' formative experiences.

METHODS

Oral history is used to place the "stories" of an individual into a social and cultural context, in this case, the development of the profession of nursing.

RESULTS

From the interviews, several strands emerged that defined Downs' extended career, including the importance of developing a community of scholars both in and outside of nursing, the dangers of parochialism, and the necessity of a perspective on life that melded a keen sense of humor. Factors that affected Downs' style and choice, especially her mother, and her educational experiences, were revealed.

DISCUSSION

From the interviews we gained a sense of how Downs constructed her conceptual universe of nursing, as well as the language and political effectiveness to overcome barriers confronting the intellectual growth of nursing mounted by other nursing leaders as well as traditional academic disciplines.

Social and professional influences of the technology of electronic fetal monitoring on obstetrical nursing

Electronic fetal monitoring (EFM) is one example of a biomedical technology that rapidly diffused from an experimental innovation into a standard medical practice. First developed in the 1950s, EFM became commercially available in the early 1970s and quickly transformed intrapartum obstetrical practice. Assessments and interventions, which practitioners had previously based primarily on laboring women's subjective reports of bodily sensations, were now being based on quantifiable objective data from uterine activity and fetal heart rate transducers. Despite concerns of over-medicalization of the natural event of birth, iatrogenesis related to the increased incidence of operative deliveries, and escalating costs, EFM became widely accepted as routine and necessary by both practitioners and patients. By presenting the confident expectations and cautious reservations of various practitioners and patients to EFM, this article explores the rapid diffusion of EFM within the social context of the 1970s. A special focus is given to the perspective of intrapartum obstetrical nurses, because they have been the primary users of this perinatal technology since its introduction.

Inhibition of tumor growth correlates with the expression level of a human angiostatin transgene in transfected B16F10 melanoma cells

Although the therapeutic value of angiostatin, a proteolytic fragment of plasminogen, has been recognized for the treatment of cancer, the production of bioactive angiostatin remains a difficult task. Here we report that expression of a cDNA encoding a secreted, four-kringle human angiostatin inhibited tumor growth of B16F10 melanoma cells in mice but did not suppress tumor cell growth in culture. After transfection and selection, stable expression of the angiostatin cDNA was demonstrated in several B16F10 clones by quantitative mRNA analysis using the Taqman method. Cells that expressed angiostatin at either a low, medium, or high level were injected into C57BL/6 mice. s.c. Growth of B16F10 tumors was diminished by the angiostatin transgene, and the inhibition was directly proportional to the expression level of angiostatin in the transfected cells. However, suppression of s.c. tumor growth was transient, and eventually, tumors emerged with a strongly decreased expression of the transgene. Angiostatin expression also reduced lung metastasis from i.v.-injected B16F10 cells. Our data indicate that a cDNA encoding bioactive human angiostatin is potentially useful for gene therapy of human cancers, but the delivery of the transgene may require repeated dosing to achieve sustained dormancy of primary tumors and cancer metastases.

Creating critical care: the case of the Hospital of the University of Pennsylvania, 1950-1965

This article examines the development of critical care nursing from 1950 to 1965 through the lens of a local story--the development of the critical care unit at the Hospital of the University of Pennsylvania (HUP) in Philadelphia, Pennsylvania. The methodology used is social history. The data for the analysis were derived from oral history interviews, archival material, and secondary sources. The study concludes that powerful social contextual factors, such as work force and economic issues, architectural changes, and an increasingly complex hospital population--rather than new technology--supported the development of critical care. The study also provides parallels to contemporary nurse work force issues.

Quantitative RT-PCR to evaluate in vivo expression of multiple transgenes using a common intron

An assay measuring RNA expression levels of a gene-encoded therapeutic must distinguish between endogenous mRNA and mRNA transcribed from the transgene. Specificity for the delivered transgene is especially critical when the treatment involves genes that are expressed in the target tissue. To facilitate uniform detection of transgene RNA without interference from endogenous mRNA, we have engineered expression vectors that include a 5' untranslated region (5' UTR) containing a synthetic intron (PGL3). The synthetic intron splice junction was the target sequence for a quantitative reverse transcription (RT)-PCR assay utilizing Taq-Man technology. In this study, we demonstrate that a quantitative RT-PCR assay designed to recognize an engineered intron splice site in the 5'UTR of expression constructs effectively measures the expression level of in vivo-delivered gene therapeutics.

Virtual power: gendering the nurse-technology relationship

To date, studies of the relationship between technology and its consumers have used the constructs of traditional paradigms of production and consumption as the foundation for analysis. These studies have served to reinforce traditional concepts of gender and hierarchy in the nursing-technology dichotomy. To propose a new and more relevant framework for analysing the technology-nursing relationship, the analysis of gender within the methodology of the social history of technology will be used. Healthcare will be viewed as a technologic network, and within that network multiple knowledge domains reside and interact. These domains, in turn, are socially constructed and historically contingent. This paper operationalizes this argument by examining the domain of the early nurse practitioner movement of the 1960s as part of a gendered technologic system. The findings of this study illuminate the agency of nurses in the shaping of traditionally male knowledge domains and as a crucial factor for understanding the evolution of not only the particularities of the nurse-technology relationship, but also the generalities of the gendered ways of knowing within the healthcare-technology relationship. Perhaps most importantly, different sets of questions can be formulated to analyse the history of the nurse practitioner movement from a technologic perspective that will provide new standpoints for the nursing-technology dichotomy in the millennium.

5q- in a child with refractory anemia with excess blasts: similarities to 5q- syndrome in adults

A 19-month-old boy was referred to our institution because of chronic macrocytic anemia and severe thrombocytopenia. At age 17 months, he had developed petechiae. He had a leukocyte count of 4.4 x 10(9)/L, hemoglobin concentration of 7.9 g/dL, packed cell volume of 21%, mean corpuscular volume of 101 fL, and platelet count of 19 x 10(9)/L. At the time of referral, a bone marrow aspirate and biopsy revealed myelodysplastic changes that included megakaryocytic hyperplasia with hypolobated megakaryocytes, megaloblastoid erythropoiesis, 12% blast cells, and bone marrow fibrosis; the diagnosis was refractory anemia with excess blasts (RAEB). Cytogenetic analysis showed the following abnormalities: 47, XY, inv(3)(p21q25), del(5)(q22q31), +21/46, XY. By dinucleotide polymorphism analysis, the 5q22-q31 loci were normal in peripheral blood granulocytes. Because of severe thrombocytopenia that became refractory to platelet transfusions and because of possible progression to leukemia, the patient received an unrelated-donor bone marrow transplant. Recovery was complicated by a visceral fungal infection, but the patient now has normal, fully reconstituted bone marrow function. This patient is the youngest to be reported with RAEB and a 5q- anomaly accompanied by thrombocytopenia, megakaryocytic hyperplasia with hypolobated megakaryocytes, and macrocytic anemia with megaloblastoid erythropoiesis, similar to "5q- syndrome" in adults.

The unexplored 5q13 locus: a role in hematopoietic malignancies

Deletions and translocations at 5q13 point out a locus involved in the development of acute myeloblastic leukemia (AML) and myelodysplastic syndromes (MDS) as well as other neoplasms. The chromosomal rearrangements of 5q13 are well documented, but have not been a primary focus of research. In this report, we provide evidence for a novel critical locus at 5q13.3, encoding gene(s) which may be disrupted by chromosomal translocations or deletions. Rare cases of myeloid neoplasms with t(5q13) as the sole chromosomal anomaly argue for a gene which gives rise to fusion proteins. Our preliminary studies have localized one of the critical genes to a <3 Mb. interval between the polymorphic markers AFMB347yf9 and GATAP18104 at the band 5q13.3. Other results also suggest that the 5q 13.3 locus may span a fragile site which undergoes unbalanced translocations and interstitial deletions accompanied by loss of significant segments of chromosome 5. Molecular reagents generated by the human genome mapping and sequencing initiative will allow us to characterize the critical genes at 5q13.3 and facilitate genotypic analysis of AML and MDS.

Molecular anatomy of chromosome 7q deletions in myeloid neoplasms: evidence for multiple critical loci

Complete or partial deletions of the long arm of chromosome 7 (7q- and -7) are nonrandom abnormalities seen in primary and therapy-induced myelodysplasia (MDS) and acute myelogenous leukemia (AML). Monosomy 7, occurring as the sole cytogenetic anomaly in a small but significant number of cases, may denote a dominant mechanism involving critical tumor suppressor gene(s). We have determined the extent of allele loss in cytogenetically prescreened MDS and AML patients for microsatellite markers from chromosome 7q22 and 7q31. Whereas >80% of these cases revealed allele loss for the entire region, a rare case of the 7q- chromosome showed allele loss for only the proximal 7q31.1 loci flanked by the markers D7S486 and D7S2456, and a case of monosomy 7 revealed allele loss for loci at both 7q31 and 7q22 with retention of sequences between these sets of loci. Furthermore, a case of AML with no cytogenetic anomaly of chromosome 7 revealed a submicroscopic allelic imbalance for a third distal locus, D7S677. These findings suggest the presence of three distinct critical loci that may contribute alone or in combination to the evolution of MDS and AML. The data also provide molecular evidence for unbalanced translocation with noncontiguous deletions, as an alternate mechanism underlying monosomy 7.

Localization of SMAD5 and its evaluation as a candidate myeloid tumor suppressor

Acquired interstitial or complete losses of chromosome 5 are recurring anomalies associated with preleukemic myelodysplasia and acute myelogenous leukemia with a poor prognosis. Previous studies have delineated a potential myeloid tumor suppressor locus to a <2.4-Mb interval between the genes for IL9 and EGR1 on 5q31. In this report, we have localized the SMAD5 gene, a homologue of the tumor suppressor genes SMAD4/DPC-4 and SMAD2/JV18.1, to the minimal myeloid tumor suppressor locus and characterized its open reading frame and genomic organization. SMAD5 transcripts are readily detectable in hematolymphoid tissues and leukemic blasts. Absence of intragenic mutations in the remaining SMAD5 allele of leukemic patients and multiple solid tumor cell lines prescreened for loss of heterozygosity suggests that SMAD5 may not be a common target of somatic inactivation in malignancy.

Translocations and deletions of 5q13.1 in myelodysplasia and acute myelogenous leukemia: evidence for a novel critical locus

Acquired partial and complete deletions of chromosome 5 (5q-, -5) are common cytogenetic anomalies associated with myelodysplasia (MDS) and acute myeloid leukemia (AML). A critical region of consistent loss at 5q31.1 (in > 90% of cases) has led us and others to postulate the presence of a key negative regulator(s) of leukemogenesis. Although the interstitial deletion limits vary among patients, del(5) (q13q33) and del(5)(q13q35) constitute major subsets. Furthermore, it is not rare to encounter deletions, translocations, or paracentric inversions involving 5q11 to 5q13, which indicates inactivation or disruption of important gene(s) at that locus. In this report, we have localized a novel locus at 5q13.1 to a 2.0-Mb interval between the anonymous markers D5S672 and GATA-P1804. This locus resided within the region of loss in 12 of 27 patients with anomalies of chromosome 5; one of these cases had apparent retention of both alleles of all the telomeric loci. Fluorescence in situ hybridization (FISH) studies demonstrate that the AML cell line ML3 is disrupted at 5q13.1 by a translocation involving chromosome 3, with apparent retention of the entire chromosome 5 sequence. Our results suggest that this novel proximal locus encodes a critical gene that may be deleted or disrupted in a subset of MDS/AML patients with chromosome 5 anomalies.

Physical mapping of the minimal region of loss in 5q- chromosome

Acquired interstitial loss of all or part of the long arm of human chromosome 5 (5q-) is an anomaly that is seen frequently in patients with preleukemic myelodysplasia and acute myelogenous leukemia. Loss of a critical region of overlap at band 5q31.1 in all of these cases, with various cytogenetic breaks, signifies the existence of a key negative regulator of leukemogenesis. Previous studies have defined the proximal and distal ends of the critical region to reside between the genes for IL9 and EGR1, respectively. In this report, we describe a yeast artificial chromosome contig spanning this myeloid tumor suppressor locus. The combined order of the polymorphic loci is centromere-IL9-(D5S525-D5S558-D5S89-D5S526 -D5S393)-D5S399-D5S396-D5S414-EGR1 and telomere. The physical distance between the IL9 and EGR1 genes is estimated to be < 2.4 Mb. Here we report the utility of these polymorphic loci by detecting a submicroscopic deletion of 5q31; an acute myelogenous leukemia patient with a three-way translocation, t(5;18;17)(q31;p11;q11), as the sole anomaly revealed allele loss of the D5S399 and D5S396 loci.

Development of a sensitive PCR to detect allele loss in a model hematopoietic neoplasm

Loss or gain of an entire chromosome and interstitial deletions or amplifications are hallmarks of several hematopoietic neoplasms. These chromosomal anomalies can be identified by conventional cytogenetic analysis of bone marrow aspirates. We have developed a PCR-based assay to detect loss of chromosome 5q31 loci, in the model system of myeloid disorders with the 5q- chromosome (interstitial deletion of 5q), by taking advantage of a highly polymorphic dinucleotide repeat within the interleukin-9 (IL9) gene on 5q31. In a given sample, quantitation of amplification of individual alleles in a Phosphorimager allowed the representation of alleles to be expressed as a ratio of the larger to the smaller allele. Comparison of these ratios in paired DNA samples from Ficoll buoyant and pelletted fractions provides evidence for allele loss. Results presented here demonstrate that this technique of comparison of ratios of isotope incorporation could be expanded to Investigate any deletion or numerical abnormality in hematopoietic tumors.