Emergence of the CD226 Axis in Cancer Immunotherapy

In recent years, a set of immune receptors that interact with members of the nectin/nectin-like (necl) family has garnered significant attention as possible points of manipulation in cancer. Central to this axis, CD226, TIGIT, and CD96 represent ligand (CD155)-competitive co-stimulatory/inhibitory receptors, analogous to the CTLA-4/B7/CD28 tripartite. The identification of PVRIG (CD112R) and CD112 has introduced complexity and enabled additional nodes of therapeutic intervention. By virtue of the clinical progression of TIGIT antagonists and emergence of novel CD96- and PVRIG-based approaches, our overall understanding of the ‘CD226 axis’ in cancer immunotherapy is starting to take shape. However, several questions remain regarding the unique characteristics of, and mechanistic interplay between, each receptor-ligand pair. This review provides an overview of the CD226 axis in the context of cancer, with a focus on the status of immunotherapeutic strategies (TIGIT, CD96, and PVRIG) and their underlying biology (i.e., cis/trans interactions). We also integrate our emerging knowledge of the immune populations involved, key considerations for Fc gamma (γ) receptor biology in therapeutic activity, and a snapshot of the rapidly evolving clinical landscape.

Abstract 6268: Discovery and characterization of the CD96 antibody GSK6097608, a high-affinity, antagonistic anti-CD96 antibody for cancer immunotherapy

The overall therapeutic benefit of blocking the first generation of immune checkpoint pathways (PD-1 and CTLA-4) has been demonstrated across multiple tumor types, yielding long term protection in some patients. However, most patients do not respond to these single-agent approaches. Thus, collaborative strategies that seek to engage novel pathways and cell types may provide therapeutic options for patients wherein pre-existing host and tumor microenvironment factors do not favor current immunotherapeutic agents or in tumors where adaptive resistance has occurred.

In recent years, the CD226 (DNAX Accessory Molecule-1 [DNAM-1]) axis has emerged as a relevant regulatory node in for natural killer (NK) and T cells - particularly in the context of tumor immunology. Similar to the competitive interplay between CTLA-4/CD28 and B7 (CD80/86), inhibitory receptors within the axis (e.g., CD96 [TACTILE]) effectively compete with the co-stimulatory receptor CD226 for binding to shared ligands (e.g., CD155), thereby impairing the initiation and/or promotion of ongoing antitumor immune responses. Indeed, genetic or monoclonal antibody (mAb)-based co-inhibition of CD96 with other immune checkpoints has proven efficacious in several nonclinical tumor models.

CD96 has been shown to impact both T cell and NK cell function, offering a level of versatility as a target for cancer immunotherapy. For example, in the setting of anti-PD-1 neoadjuvant treatment, significantly improved survival of pancreatic ductal adenocarcinoma (PDAC) tumor-bearing mice was observed following enhancement of NK cell activity by CD96 antibody treatment. Equally, pronounced effects on primary tumor growth following anti-PD-1, -TIGIT, and -CD96 mAb treatment in a colorectal carcinoma tumor model (CT26) was found to be dependent on CD8+ T cells.

GSK6097608 is a clinical-stage fully-human immunoglobulin G1 (IgG1)κ mAb that targets the inhibitory immune receptor CD96. GSK6097608 was identified, in part, for its ability prevent and disrupt CD96:CD155 interactions, thereby promoting T and NK cell function. GSK6097608 demonstrated concentration-dependent rescue of human immune cell activity following exposure to plate-bound recombinant CD155 (cognate receptor/ligand); an effect that was improved with concomitant TIGIT blockade. Notably, functional activity was found to be dependent on intact Fc-FcγR co-engagement, as potentiation of primary human T and NK cell function was lost when GSK6097608 was grafted on an Fc-attenuated backbone. Here, we describe some of the biophysical and functional characteristics that support the rationale for clinical evaluation of GSK6097608.

Citation Format: Yan Degenhardt, Jun Guan, Peter Morley, David Jones, Michael Conner, Stephen Eastman, Wei Wang, Andrew Sanderson, Anand Ravindran, Julie Krueger, Iris Roth, James Smothers, Jeremy D. Waight. Discovery and characterization of the CD96 antibody GSK6097608, a high-affinity, antagonistic anti-CD96 antibody for cancer immunotherapy [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 6268.

662 Dissecting the CD226 immune axis in the tumor microenvironment using CyTOF-based high-dimensional immunophenotyping

Background

In recent years, a regulatory network involving nectin/nectin-like immune receptors has emerged as a potential point of manipulation for cancer immunotherapy. Central to this axis, CD226 (DNAM-1) is a T and NK cell co-stimulatory receptor that competes for ligand (CD155 and CD112) binding with multiple inhibitory receptors (TIGIT, CD96, and PVRIG [CD112R]). Despite a large body of literature for TIGIT, detailed cellular characterization of the entire axis is still lacking. Therefore, we used mass cytometry (CyTOF) to systematically evaluate expression of the CD226 axis in tumors from a range of indications.

Methods

To thoroughly characterize the CD226 axis in the tumor microenvironment, we immunophenotyped approximately 100 tumor samples derived from a variety of cancer types using a bespoke 46-parameter CyTOF panel. Human biological samples were sourced ethically and their research use was in accord with the terms of the informed consents under an IRB/EC approved protocol. Using a suite of high-dimensional analytical tools, including FlowSOM, UMAP, and tSNE, we revealed distinct expression profiles for each receptor; a finding that was previously obscured due to a lack of sufficient resolution.

Results

We observed a notable divergence in expression profiles between the CD226 axis members across tumor indications. For example, TIGIT expression was found to be highest on activated CD4+ regulatory T (Treg) cells, where its expression correlated strongly with ICOS, FoxP3, CD25, and CCR8. By contrast, CD96 and PVRIG exhibited broad expression across intratumoral T and NK cell populations. Other receptors (e.g., CD226) demonstrated variegated expression profiles across T and NK cell subsets. Finally, despite relatively consistent expression profiles of certain CD226 axis (i.e., TIGIT on Treg cells) across tumors, we also found several cell subsets/clusters unique to specific indications.

Conclusions

Using high-parameter CyTOF analysis, we were able to thoroughly characterize the CD226 axis (CD226, TIGIT, CD96, PVRIG) and related immune receptors across a range of tumor indications. These analyses revealed divergent expression profiles for each CD226 axis member, suggesting distinct/contextual biological role(s) for each receptor. However, future studies will need to dissect the importance of the distinct cellular representation for each CD226 axis member.

Ethics Approval

All samples were purchased from Discovery Life Sciences (DLS). DLS represents and warrants that it has ownership of all Products available for sale and has properly obtained, where required under HHS/OHRP 45 CFR 46.102 (d) (f), IRB approval (or appropriate research approval for institutions outside the U.S.) for study protocols and informed consent documents for all human subject derived biological materials.

Feasibility of Utilizing PREMM Score for Lynch Syndrome Identification in an Urban, Minority Patient Population

The PREMM₅ model is a web-based clinical prediction algorithm that estimates the gene-specific risk of an individual carrying a Lynch syndrome germline mutation based on targeted family history questions. The objectives of our study were to determine the feasibility of screening for LS in an urban, minority patient population in a primary care setting using the PREMM₅ model and characterize patient barriers associated with difficulty completing the questions. Participants were recruited from Tulane Internal Medicine primary care clinics on 9 random collection dates. Our data illustrates the difficulty patients have in recalling important details necessary to answer the PREMM questionnaire.

Screening for Colorectal Cancer

Colorectal cancer screening is essential to detect and remove premalignant lesions to prevent the development of colorectal cancer. Multiple screening modalities are available, including colonoscopy and stool-based testing. Colonoscopy remains the gold standard for detection and removal of premalignant colorectal lesions. Screening guidelines by the American Cancer Society now recommend initiating screening for all average-risk adults at 45 years old. Family history of colorectal cancer, other cancers, and advanced colon polyps are strong risk factors that must be considered in order to implement earlier testing. Epidemiologic studies continue to show disparities in colorectal cancer incidence and mortality and wide variability in screening rates.

Mission Accomplished: The ACVP/STP Coalition for Veterinary Pathology Fellows Completes Its Objectives, but Its Legacy and Spirit Live On

After 15 years of existence, the ACVP/STP Coalition for Veterinary Pathology Fellows will dissolve, primarily due to lack of renewed financial sponsorship. While in operation, the Coalition organized 32 new training position for veterinary pathologists, supported by $7.4 M from sponsors, including pharmaceutical and biotechnology companies, contract research organizations, private individuals and allied veterinary pathology support groups. All residual funds will be donated to ACVP and STP with the understanding that the two organizations will use these funds to enhance training by collaborating on outreach efforts, thus maintaining the legacy and spirit of the Coalition.

Mission Accomplished: The ACVP/STP Coalition for Veterinary Pathology Fellows Completes Its Objectives, but Its Legacy and Spirit Live On

After 15 years of existence, the ACVP/STP Coalition for Veterinary Pathology Fellows will dissolve, primarily due to lack of renewed financial sponsorship. While in operation, the Coalition organized 32 new training position for veterinary pathologists, supported by $7.4 M from sponsors, including pharmaceutical and biotechnology companies, contract research organizations, private individuals and allied veterinary pathology support groups. All residual funds will be donated to ACVP and STP with the understanding that the two organizations will use these funds to enhance training by collaborating on outreach efforts, thus maintaining the legacy and spirit of the Coalition.

Tumor-immune profiling of murine syngeneic tumor models as a framework to guide mechanistic studies and predict therapy response in distinct tumor microenvironments

Mouse syngeneic tumor models are widely used tools to demonstrate activity of novel anti-cancer immunotherapies. Despite their widespread use, a comprehensive view of their tumor-immune compositions and their relevance to human tumors has only begun to emerge. We propose each model possesses a unique tumor-immune infiltrate profile that can be probed with immunotherapies to inform on anti-tumor mechanisms and treatment strategies in human tumors with similar profiles. In support of this endeavor, we characterized the tumor microenvironment of four commonly used models and demonstrate they encompass a range of immunogenicities, from highly immune infiltrated RENCA tumors to poorly infiltrated B16F10 tumors. Tumor cell lines for each model exhibit different intrinsic factors in vitro that likely influence immune infiltration upon subcutaneous implantation. Similarly, solid tumors in vivo for each model are unique, each enriched in distinct features ranging from pathogen response elements to antigen presentation machinery. As RENCA tumors progress in size, all major T cell populations diminish while myeloid-derived suppressor cells become more enriched, possibly driving immune suppression and tumor progression. In CT26 tumors, CD8 T cells paradoxically increase in density yet are restrained as tumor volume increases. Finally, immunotherapy treatment across these different tumor-immune landscapes segregate into responders and non-responders based on features partially dependent on pre-existing immune infiltrates. Overall, these studies provide an important resource to enhance our translation of syngeneic models to human tumors. Future mechanistic studies paired with this resource will help identify responsive patient populations and improve strategies where immunotherapies are predicted to be ineffective.

A Fully Automated High-Throughput Flow Cytometry Screening System Enabling Phenotypic Drug Discovery

The goal of high-throughput screening is to enable screening of compound libraries in an automated manner to identify quality starting points for optimization. This often involves screening a large diversity of compounds in an assay that preserves a connection to the disease pathology. Phenotypic screening is a powerful tool for drug identification, in that assays can be run without prior understanding of the target and with primary cells that closely mimic the therapeutic setting. Advanced automation and high-content imaging have enabled many complex assays, but these are still relatively slow and low throughput. To address this limitation, we have developed an automated workflow that is dedicated to processing complex phenotypic assays for flow cytometry. The system can achieve a throughput of 50,000 wells per day, resulting in a fully automated platform that enables robust phenotypic drug discovery. Over the past 5 years, this screening system has been used for a variety of drug discovery programs, across many disease areas, with many molecules advancing quickly into preclinical development and into the clinic. This report will highlight a diversity of approaches that automated flow cytometry has enabled for phenotypic drug discovery.

Quantitative determination of binding of ISWI to nucleosomes and DNA shows allosteric regulation of DNA binding by nucleotides

The regulation of chromatin structure is controlled by a family of molecular motors called chromatin remodelers. The ability of these enzymes to remodel chromatin structure is dependent on their ability to couple ATP binding and hydrolysis into the mechanical work that drives nucleosome repositioning. The necessary first step in determining how these essential enzymes perform this function is to characterize both how they bind nucleosomes and how this interaction is regulated by ATP binding and hydrolysis. With this goal in mind, we monitored the interaction of the chromatin remodeler ISWI with fluorophore-labeled nucleosomes and DNA through associated changes in fluorescence anisotropy of the fluorophore upon binding of ISWI to these substrates. We determined that one ISWI molecule binds to a 20 bp double-stranded DNA substrate with an affinity of 18 ± 2 nM. In contrast, two ISWI molecules can bind to the core nucleosome with short linker DNA with stoichiometric macroscopic equilibrium constants: 1/β₁ = 1.3 ± 0.6 nM, and 1/β₂ = 13 ± 7 nM². Furthermore, to improve our understanding of the mechanism of DNA translocation by ISWI, and hence nucleosome repositioning, we determined the effect of nucleotide analogues on substrate binding by ISWI. While the affinity of ISWI for the nucleosome substrate with short lengths of flanking DNA was not affected by the presence of nucleotides, the affinity of ISWI for the DNA substrate is weakened in the presence of nonhydrolyzable ATP analogues but not by ADP.

Inhibition of Wnt/β-catenin pathway by niclosamide: a therapeutic target for ovarian cancer

Objective. The Wnt/β-catenin pathway is known to regulate cellular proliferation and plays a role in chemoresistance. Niclosamide, an FDA approved salicyclamide derivative used for the treatment of tapeworm infections, targets the Wnt/β-catenin pathway. Therefore, the objective of this study was to investigate niclosamide as a potential therapeutic agent for ovarian cancer. Methods. Tumor cells isolated from 34 patients' ascites with primary ovarian cancer were treated with niclosamide (0.1 to 5 μM) ± carboplatin (5 to 150 μM). Cell viability was assessed using the ATP-lite assay. LRP6, Axin 2, Cyclin D1, survivin and cytosolic free β-catenin levels were determined using Western blot analysis. Tumorspheres were treated, and Wnt transcriptional activity was measured by the TOPflash reporter assay. ALDH and CD133 were analyzed by Flow cytometry and IHC. ALDH1A1 and LRP6 were analyzed by IHC in solid tumor and in ascites before and after treatment with niclosamide. Results. Combination treatment produced increased cytotoxicity compared to single agent treatment in 32/34 patient samples. Western blot analysis showed a decrease in Wnt/β-catenin pathway proteins and the expression of target genes. A significant reduction of Wnt/β-catenin signaling was confirmed by TOPflash assay. There was increased staining of ALDH1A1 and LRP6 in ascites compared to solid tumor which decreased after treatment. Conclusion. This study demonstrates that niclosamide is a potent Wnt/β-catenin inhibitor. Targeting the Wnt/β-catenin pathway led to decreased cellular proliferation and increased cell death. These findings warrant further research of this drug and other niclosamide analogs as a treatment option for ovarian cancer.

Effect of niclosamide on basal-like breast cancers

Basal-like breast cancers (BLBC) are poorly differentiated and display aggressive clinical behavior. These tumors become resistant to cytotoxic agents, and tumor relapse has been attributed to the presence of cancer stem cells (CSC). One of the pathways involved in CSC regulation is the Wnt/β-catenin signaling pathway. LRP6, a Wnt ligand receptor, is one of the critical elements of this pathway and could potentially be an excellent therapeutic target. Niclosamide has been shown to inhibit the Wnt/β-catenin signaling pathway by causing degradation of LRP6. TRA-8, a monoclonal antibody specific to TRAIL death receptor 5, is cytotoxic to BLBC cell lines and their CSC-enriched populations. The goal of this study was to examine whether niclosamide is cytotoxic to BLBCs, specifically the CSC population, and if in combination with TRA-8 could produce increased cytotoxicity. Aldehyde dehydrogenase (ALDH) is a known marker of CSCs. By testing BLBC cells for ALDH expression by flow cytometry, we were able to isolate a nonadherent population of cells that have high ALDH expression. Niclosamide showed cytotoxicity against these nonadherent ALDH-expressing cells in addition to adherent cells from four BLBC cell lines: 2LMP, SUM159, HCC1187, and HCC1143. Niclosamide treatment produced reduced levels of LRP6 and β-catenin, which is a downstream Wnt/β-catenin signaling protein. The combination of TRA-8 and niclosamide produced additive cytotoxicity and a reduction in Wnt/β-catenin activity. Niclosamide in combination with TRA-8 suppressed growth of 2LMP orthotopic tumor xenografts. These results suggest that niclosamide or congeners of this agent may be useful for the treatment of BLBC.

Endoglin (CD105) contributes to platinum resistance and is a target for tumor-specific therapy in epithelial ovarian cancer

PURPOSE

Endoglin (CD105) is a membranous protein overexpressed in tumor-associated endothelial cells, chemoresistant populations of ovarian cancer cells, and potentially stem cells. Our objective was to evaluate the effects and mechanisms of targeting endoglin in ovarian cancer.

EXPERIMENTAL DESIGN

Global and membranous endoglin expression was evaluated in multiple ovarian cancer lines. In vitro, the effects of siRNA-mediated endoglin knockdown with and without chemotherapy were evaluated by MTT assay, cell-cycle analysis, alkaline comet assay, γ-H2AX foci formation, and quantitative PCR. In an orthotopic mouse model, endoglin was targeted with chitosan-encapsulated siRNA with and without carboplatin.

RESULTS

Endoglin expression was surprisingly predominantly cytoplasmic, with a small population of surface-positive cells. Endoglin inhibition decreased cell viability, increased apoptosis, induced double-stranded DNA damage, and increased cisplatin sensitivity. Targeting endoglin downregulates expression of numerous DNA repair genes, including BARD1, H2AFX, NBN, NTHL1, and SIRT1. BARD1 was also associated with platinum resistance, and was induced by platinum exposure. In vivo, antiendoglin treatment decreased tumor weight in both ES2 and HeyA8MDR models when compared with control (35%-41% reduction, P < 0.05). Endoglin inhibition with carboplatin was associated with even greater inhibitory effect when compared with control (58%-62% reduction, P < 0.001).

CONCLUSIONS

Endoglin downregulation promotes apoptosis, induces significant DNA damage through modulation of numerous DNA repair genes, and improves platinum sensitivity both in vivo and in vitro. Antiendoglin therapy would allow dual treatment of both tumor angiogenesis and a subset of aggressive tumor cells expressing endoglin and is being actively pursued as therapy in ovarian cancer.

The Structure of the Hantavirus Zinc Finger Domain is Conserved and Represents the Only Natively Folded Region of the Gn Cytoplasmic Tail

Hantaviruses, of the family Bunyaviridae, are present throughout the world and cause a variety of infections ranging from the asymptomatic to mild and severe hemorrhagic fevers. Hantaviruses are enveloped anti-sense RNA viruses that contain three genomic segments that encode for a nucleocapsid protein, two membrane glycoproteins (Gn and Gc), and an RNA polymerase. Recently, the pathogenicity of hantaviruses has been mapped to the carboxyl end of the 150 residue Gn cytoplasmic tail. The Gn tail has also been shown to play a role in binding the ribonucleoprotein (RNP), a step critical for virus assembly. In this study, we use NMR spectroscopy to compare the structure of a Gn tail zinc finger domain of both a pathogenic (Andes) and a non-pathogenic (Prospect Hill) hantavirus. We demonstrate that despite a stark difference in the virulence of both of these viruses, the structure of the Gn core zinc finger domain is largely conserved in both strains. We also use NMR backbone relaxation studies to demonstrate that the regions of the Andes virus Gn tail immediately outside the zinc finger domain, sites known to bind the RNP, are disordered and flexible, thus intimating that the zinc finger domain is the only structured region of the Gn tail. These structural observations provide further insight into the role of the Gn tail during viral assembly as well as its role in pathogenesis.

Stem cell pathways contribute to clinical chemoresistance in ovarian cancer

PURPOSE

Within heterogeneous tumors, subpopulations often labeled cancer stem cells (CSC) have been identified that have enhanced tumorigenicity and chemoresistance in ex vivo models. However, whether these populations are more capable of surviving chemotherapy in de novo tumors is unknown.

EXPERIMENTAL DESIGN

We examined 45 matched primary/recurrent tumor pairs of high-grade ovarian adenocarcinomas for expression of CSC markers ALDH1A1, CD44, and CD133 using immunohistochemistry. Tumors collected immediately after completion of primary therapy were then laser capture microdissected and subjected to a quantitative PCR array examining stem cell biology pathways (Hedgehog, Notch, TGF-β, and Wnt). Select genes of interest were validated as important targets using siRNA-mediated downregulation.

RESULTS

Primary samples were composed of low densities of ALDH1A1, CD44, and CD133. Tumors collected immediately after primary therapy were more densely composed of each marker, whereas samples collected at first recurrence, before initiating secondary therapy, were composed of similar percentages of each marker as their primary tumor. In tumors collected from recurrent platinum-resistant patients, only CD133 was significantly increased. Of stem cell pathway members examined, 14% were significantly overexpressed in recurrent compared with matched primary tumors. Knockdown of genes of interest, including endoglin/CD105 and the hedgehog mediators Gli1 and Gli2, led to decreased ovarian cancer cell viability, with Gli2 showing a novel contribution to cisplatin resistance.

CONCLUSIONS

These data indicate that ovarian tumors are enriched with CSCs and stem cell pathway mediators, especially at the completion of primary therapy. This suggests that stem cell subpopulations contribute to tumor chemoresistance and ultimately recurrent disease.

Distinguishing among perceived control, perceived difficulty, and self-efficacy as determinants of intentions and behaviours

Perceptions of control hold a dominant position in social cognitive theories yet there is a lack of conceptual and empirical clarity regarding what kind of control is most associated with particular behaviours. Three prominent types of control are perceived control (PC), perceived difficulty (PD), and perceived confidence or self-efficacy (SE) for performing the desired behaviour. Three studies are presented with a primary goal of distinguishing PC, PD, and SE from each other, and a secondary goal of determining which of the three is the superior predictor of health-related intentions and behaviours. The first study replicates earlier work by Trafimow et al. (2002) distinguishing the three constructs for reading 1, 30, and 100 pages, and extends it to exercising one, two, four, and six times per week and also to predicting intentions to exercise 4 days per week and behaviour 1 week later. The second study examines the predictive capability of the three constructs for intentions to floss one's teeth everyday and to eat 5-10 servings of fruits and vegetables everyday and subsequently on behaviour assessed 7 days later. The third study reports a meta-analysis of the relative influence of PC, PD, and SE on behaviours when defined in conceptually consistent ways. The results of all three studies support the conceptual and empirical distinction of PC, PD, and SE and the superiority of SE as a predictor of health behaviours and intentions.

Extracellular loops and ligand binding to a subfamily of Family A G-protein-coupled receptors

GPCRs (G-protein-coupled receptors) are a large family of structurally related proteins which mediate their effects by coupling to G-proteins. The V(1a)R (V(1a) vasopressin receptor) is a member of a family of related GPCRs that are activated by vasopressin {AVP ([Arg(8)]vasopressin)}, OT (oxytocin) and related peptides. These receptors are members of a subfamily of Family A GPCRs called the neurohypophysial peptide hormone receptor family. GPCRs exhibit a conserved tertiary structure comprising a bundle of seven TM (transmembrane) helices linked by alternating ECLs (extracellular loops) and ICLs (intracellular loops). The cluster of TM helices is functionally important for ligand binding, and, furthermore, activation of GPCRs involves movement of these TM helices. Consequently, it might be assumed that the extracellular face of GPCRs is composed of peptide linkers that merely connect important TM helices. However, using a systematic mutagenesis approach and focusing on the N-terminus and the second ECL of the V(1a)R, we have established that these extracellular domains fulfil a range of important roles with respect to GPCR signalling, including agonist binding, ligand selectivity and receptor activation.

Clinical trial of interconceptional antibiotics to prevent preterm birth: subgroup analyses and possible adverse antibiotic-microbial interaction

OBJECTIVE

The purpose of this study was to explore whether endometrial microbial colonization and plasma cell endometritis are risk factors for adverse pregnancy outcomes, and whether these outcomes are influenced by interactions between interconceptional antibiotics and the micro-flora.

STUDY DESIGN

Subgroup analyses of data from a double-blind, randomized, placebo-controlled trial of a course of metronidazole plus azithromycin given every 4 months to women with a prior preterm delivery to prevent recurrent preterm delivery. Endometrial cultures and histology were obtained at randomization and repeated 2 weeks after the first treatment. Fifty-nine on antibiotics versus 65 on placebo had pregnancy outcomes. Prevalence of adverse pregnancy outcomes (pregnancy loss or preterm birth < 37 weeks) was stratified by treatment group and endometrial characteristics. Subgroups were assessed and screened for potential interaction (P values for significance set a priori at < .01), prior to formal statistical testing for interaction (P values < .05).

RESULTS

The prevalence of adverse pregnancy outcome was 62.7% in the presence of endometrial microbial colonization at baseline (any microbe) and 50% in the absence of colonization (RR = 1.25; 99% CI 0.42-3.7). Prevalence of adverse pregnancy outcomes was 61.9% with plasma cell endometritis, and 70.8% without; RR = 0.87 (0.50-1.5). There was a nonsignificant reduction in adverse pregnancy outcome in the absence of Gardnerella vaginalis or gram-negative rods with RR (95% CI) = 0.60 (0.3-1.2) and 0.66 (0.4-1.2), respectively. In the presence of these microbes, antibiotics appeared to increase adverse outcomes: RR = 1.5 (1.1-2.0) and 1.5 (1.1-2.1), respectively. This reversal of impact represents a crossover interaction.

CONCLUSION

Neither baseline endometrial microbial colonization nor plasma cell endometritis were risk factors for adverse pregnancy outcome. However, colonization with specific microbes interacted with antibiotics to increase adverse outcomes.

Can the theory of planned behaviour predict maintenance of a frequently repeated behaviour?

The present study used the theory of planned behaviour to predict self-monitoring of blood glucose in patients with type 1 diabetes. Sixty-four adult patients with type 1 diabetes completed a questionnaire assessing the variables of the TPB in addition to demographic variables and a measure of conscientiousness. Self-report measures of daily self-monitoring behaviour were obtained for a two-week period. The extended model predicted 46% of the variance in behavioural intention and 57% of variance in self-monitoring behaviour, suggesting that the TPB is able to predict useful levels of variance, comparable to initiation, even in familiar and frequently repeated maintenance behaviours. Implications of these results are discussed.

Impact of interconception antibiotics on the endometrial microbial flora

OBJECTIVE

The purpose of this study was to evaluate the impact of an interconception antibiotic regimen on endometrial microbial flora and histologic type.

STUDY DESIGN

This was a secondary analysis of a double-blind randomized placebo-controlled trial of prophylactic metronidazole plus azithromycin that was given to 241 women (antibiotics, 118 women; placebo, 123 women) with a previous preterm delivery to prevent recurrent preterm delivery. Endometrial cultures and histologic types were obtained at randomization and 2 weeks after treatment. The prevalence of either the new acquisition or the resolution of individual microbes, categories of microbes, and plasma cell endometritis were compared by chi-square or Fishers' exact tests.

RESULTS

Overall, antibiotics were associated with lower acquisition and higher resolution of microbes. Of women without Gardnerella at baseline, 14% of the women who received antibiotics vs 34% of the women who received placebo had positive endometrial culture for the organism after treatment (P < .05); of those women with G. vaginalis at baseline, 57% of the women who received antibiotics vs 33% of the women who received placebo (P < .05) had a negative follow-up culture. Other gram-negative rods, especially aerobes in general, manifested similar patterns. The impact on anaerobes and plasma cell endometritis was not definitive, but there was a trend toward the increased resolution of the former (77% vs 55%) and reduced acquisition of the latter (28% vs 50%).

CONCLUSION

The antibiotic regimen prevented the acquisition and promoted the resolution, but not the eradication, of gram-negative rods such as G. vaginalis and the aerobic subcategory.

A Prospective Blinded Evaluation of the Accuracy of Frozen Section for the Surgical Management of Endometrial Cancer

OBJECTIVE

To prospectively evaluate in a blinded fashion the accuracy of frozen section in endometrial cancer.

METHODS

Sixty patients with endometrial cancer or complex atypical hyperplasia were consecutively enrolled. Intraoperatively, a frozen section was obtained, processed, and stored for interpretation by blinded pathologists. Final pathologic diagnosis was conducted in the usual fashion with the pathologists blinded to frozen results. Histologic grade and myometrial invasion on frozen section was correlated with final pathology.

RESULTS

Median age was 61 years (range, 39-82 years). Fifty-seven percent of patients were white, and mean body mass index was 40 mg/kg2. Depth of invasion on frozen correlated with final pathology in 67% (95% confidence interval [CI] 55-79%). Twenty-eight percent (95% CI 17-39%) of patients were upstaged from frozen to final. Patients with no invasion on frozen were upstaged in 46% (95% CI 28-64%). Histologic grade on frozen correlated with final pathology in 58% (95% CI 46-70%); 38% (95% CI 26-50%) of patients were upgraded by final grade. Patients with frozen grade 1 histology or less were upgraded in 61% (95% CI 45-77%). Clinically relevant upstaging occurred in 11 patients (18%) (95% CI 8-28%).

CONCLUSION

Frozen section for histologic grade and depth of myometrial invasion in endometrial cancer correlates poorly with final pathology. Because a large number of patients are potentially understaged with the use of frozen section with a subsequent risk of over and under treatment, we recommend consideration of comprehensive surgical staging for all patients with endometrial cancer.

LEVEL OF EVIDENCE

II-2.

Spontaneously Occurring Fibroid Tumors of the Laying Hen Oviduct

Spontaneously occurring benign uterine leiomyomas (fibroids) are the most common tumors of reproductive-age women. It is estimated that more than 70% of all women will develop uterine fibroids, and the presence of these tumors is a primary cause of hysterectomies. Research into the causes and treatment of uterine fibroids is hampered by a lack of reliable animal models for the disease. Leiomyomas that appear to be outwardly similar to human uterine fibroid tumors are known to occur on the oviducts of laying hens over 2 yr of age. The objective of this study was to characterize these tumors and compare them to human uterine fibroids to determine the suitability of the aging hen as a model system for the study of the disease. In this study, hens at 5 yr of age were examined for the presence of oviduct-associated fibroid tumors. Tumors were found attached to the internal surface of the oviduct, embedded in the oviduct wall, or attached to the exterior of the magnum and isthmus. Tumor and normal oviduct samples were frozen or fixed in formalin for histological analyses or immunohistochemistry for estrogen and progesterone receptors, proliferating cell nuclear antigen and Bcl-2 protein expression. Human uterine fibroid samples were acquired and evaluated compared with hen oviduct fibroids. The results indicate that laying hen fibroid tumors are similar to human fibroid tumors with respect to estrogen and progesterone receptors, localized cellular proliferation, and expression of the Bcl-2 protein.

Interconceptional antibiotics to prevent spontaneous preterm birth: a randomized clinical trial

OBJECTIVE

We hypothesized that upper genital tract microbial infection associated with spontaneous preterm birth may precede conception. Our objective was to estimate if antibiotic administration during the interpregnancy interval in nonpregnant women with a previous preterm birth before 34 weeks' gestational age would reduce the rate of spontaneous preterm birth in the subsequent pregnancy.

STUDY DESIGN

Women with a spontaneous preterm birth < 34 weeks' gestational age were randomized at 4 months' postpartum to receive oral azithromycin 1 g twice (4 days apart) plus sustained-release metronidazole 750 mg daily for 7 days, or identical-appearing placebos. This regimen was repeated every 4 months until the subsequent pregnancy.

RESULTS

A total of 241 women were randomized; 124 conceived a subsequent pregnancy and were available for study, including 59 in the antibiotic group and 65 in the placebo group. In the antibiotic versus placebo group, neither subsequent spontaneous preterm birth (< 37 weeks: 52% vs 46%, P = .568; < 35 weeks: 40% vs 30%, P = .276; < 32 weeks: 31% vs 23%, P = .376) nor miscarriage (< 15 weeks: 12% vs 14%, P = .742) was significantly different. Although not statistically significant, mean delivery gestational age in the subsequent pregnancy was 2.4 weeks earlier in the antibiotic versus placebo group (32.0 +/- 7.9 vs 34.4 +/- 6.3 weeks, P = .082), and mean birth weight was lower in the antibiotic group (2046 +/- 1209 vs 2464 +/- 1067 g, P =.060).

CONCLUSION

Intermittent treatment with metronidazole plus azithromycin of nonpregnant women with a recent early spontaneous preterm birth does not significantly reduce subsequent preterm birth, and may be associated with a lower delivery gestational age and lower birth weight.

Efficacy of telavancin (TD-6424), a rapidly bactericidal lipoglycopeptide with multiple mechanisms of action, in a murine model of pneumonia induced by methicillin-resistant Staphylococcus aureus

The efficacy of telavancin, a bactericidal lipoglycopeptide, was compared to that of vancomycin and linezolid against methicillin-resistant Staphylococcus aureus (MRSA) in a murine pneumonia model. Telavancin produced greater reductions in lung bacterial titer and mortality than did vancomycin and linezolid at human doses equivalent to those described by the area under the concentration-time curve. These results suggest the potential utility of telavancin for treatment of MRSA pneumonia.

Factors explaining the intention to give blood among the general population

BACKGROUND AND OBJECTIVES

The aim of this study was to identify factors explaining the intention to donate blood.

MATERIALS AND METHODS

A random sample of 4000 respondents drawn from the general population received a questionnaire by mail. This questionnaire assessed variables as defined by the most prominent social cognitive theories.

RESULTS

Overall, the respondents expressed a neutral mean level of intention to give blood in the next 6 months (2.84 on a five-point scale); 56.2% had never given blood in the past. The variables explaining 74% of the variance of intention were: perceived behavioural control (beta = 0.39; P < 0.001); factors facilitating taking action (beta = 0.25; P < 0.001); anticipated regret (beta = 0.16; P < 0.001); moral norm (beta = 0.11; P < 0.001); attitude (beta = 0.08; P < 0.01); level of education (beta = -0.03; P < 0.05); and past experience in giving blood (beta = 0.09; P < 0.001). Nonetheless, the predictive power of perceived behavioural control and moral norm was higher among the ever donors (both at P < 0.01) compared to the never donors, whereas the reverse was observed for attitude (P < 0.05).

CONCLUSIONS

People's intentions are mainly determined by perceived barriers and obstacles regarding blood donations. This suggests that promotional strategies should focus on the elimination of barriers to action as well as the development of a higher perception of control. Also, messages should be adapted to the targeted population, based on their previous blood donation behaviour (i.e. never donors vs. ever donors).

Endometrial microbial colonization and plasma cell endometritis after spontaneous or indicated preterm versus term delivery

OBJECTIVE

This study was undertaken to determine whether endometrial microbial colonization or plasma cell endometritis is increased after spontaneous versus indicated preterm delivery or a spontaneous term delivery.

STUDY DESIGN

Postpartum, endometrial specimens were obtained after a spontaneous (mean 83, +/- 17.6 days) or indicated (mean 83, +/- 16.7 days) preterm delivery before 34 weeks' gestation and after a spontaneous term delivery (mean 82, +/- 15.7 days; P=.980). Cultures for aerobic and anaerobic bacteria, Trichomonas vaginalis, and genital mycoplasmas were performed. Histologic endometritis was defined as the presence of plasma cells.

RESULTS

The study population (n=820) was 71% black, 29% white, 69% unmarried, and 31% had less than 12 years of education. Endometrial cultures were positive for at least 1 microorganism in 82% of the women. No significant difference in positive endometrial cultures were observed among women after a spontaneous versus an indicated preterm delivery (85% vs 79%, P=.102), or a spontaneous preterm versus a spontaneous term delivery (85% vs 81%, P=.123). Plasma cell endometritis was present in 39% of 506 specimens sufficient for histologic examination and was also similar in the three groups (P=.160).

CONCLUSION

Microbial colonization of the endometrium and plasma cell endometritis are similar 3 months after spontaneous or indicated preterm or term births. Therefore, chronic infection and inflammation of the endometrium (documented at 3 months postpartum) do not appear to be risk factors for subsequent delivery in women with a prior spontaneous delivery less than 34 weeks' gestation.

Effects of aging on cytochrome b5 expression in the human adrenal gland

CONTEXT

Aging in humans is characterized by a selective decline in circulating levels of adrenal androgens. The results of in vivo studies are suggestive of reduced adrenal 17,20-lyase activity in aging men and women.

OBJECTIVE

We sought to determine whether there are changes in the distribution and/or expression of cytochrome B5 (CytB5), an accessory protein important in the regulation of 17,20-lyase activity, in the adrenals of aging humans.

DESIGN

Comparison between younger and older adrenal glands.

SETTING

The study was conducted in a University Center.

PATIENTS OR OTHER PARTICIPANTS

Adrenal glands obtained at autopsy after sudden death as a result of trauma from 46 young (age 20-40 yr) and 26 older (age 50-91 yr) humans were obtained and fixed within 24 h postmortem.

INTERVENTIONS

Paraffin sections were stained with hematoxylin and eosin and also were subjected to immunohistochemical staining for CytB5. All sections were quantitatively evaluated using an image capture and analysis program and qualitatively evaluated with respect to staining intensity.

MAIN OUTCOME MEASURES

To determine whether there are any changes in CytB5 distribution in the adult human adrenal cortex during the aging process using qualitative and quantitative analysis with respect to age, gender, race, and postmortem interval.

RESULTS

CytB5 immunoreactivity was found in cells that corresponded to those of the zona reticularis. The percentage of the adrenal cortex immunoreactive for CytB5 decreased with aging (38.6 +/- 7.6% for young and 30.1 +/- 5.9% for older, mean +/- sd; P < 0.0001) as did the percentage of adrenocortical tissue comprising the zona reticularis (36.8 +/- 10.8% for young and 27.2 +/- 5.9% for older; P < 0.001). However, there was no apparent change in the staining intensity of CytB5 among those cells that were immunopositive for this factor with aging.

CONCLUSIONS

There appears to be a reduction in the proportion of the adrenal cortex that expresses CytB5 with aging, and this likely corresponds to a shrinkage of the zona reticularis. The mechanism and cause for this cortical regression are unknown.

Increasing daily fruit and vegetable consumption: what changes do cardiac patients make?

BACKGROUND

Interventions targeting fruit and vegetable consumption report significant increases in consumption but do not detail how increases are achieved. This prospective study explored (i) the changes in daily fruit and daily vegetable consumption of cardiac patients participating in an intervention study and (ii) how participants made these changes.

METHODS

A total of 120 cardiac patients were asked to increase their daily fruit and vegetable consumption by two portions and to maintain this over 3 months. They were telephoned at 7-, 28- and 90-day follow-up to record daily consumption using a dietary questionnaire; 94 participants completed all parts of the study.

RESULTS

Mean reported daily fruit and daily vegetable consumption increased by 1.07 (SD = 1.26) and 0.34 (SD = 0.96) portions, respectively, over 3 months. These increases were statistically significant (P < 0.001) and greatest for participants who reported eating low levels of fruit and vegetables at recruitment. Eating fresh fruit as a snack and at mealtimes were preferred choices for participants.

CONCLUSIONS

Providing information and telephone follow-up could be used by busy healthcare professionals instead of face-to-face contact. Interventions to increase total fruit and vegetable consumption could usefully focus on eating fruit. Interventions to increase vegetable consumption need further investigation.

Colocalization of P450c17 and cytochrome b5 in androgen-synthesizing tissues of the human

Androgens are an integral part of human physiology. The de novo production of androgens is generally limited to the adrenal cortex and the gonads. Androgen synthesis by these steroidogenic tissues requires the bifunctional enzyme cytochrome P450c17, which catalyzes both 17 hydroxylase and 17,20 lyase activities. 17,20-lyase activity is relevant to the regulation of androgen production, and is allosterically modulated through the action of an accessory protein, cytochrome b5 (CytB5). Our objective was to determine the cellular localization of P450c17 and CytB5 in androgen-synthesizing tissues of the human. Immunohistochemical analyses of P450c17 and CytB5 were performed on fetal and adult human adrenals, ovaries, and testes. In the fetal adrenal, CytB5 and P450c17 were both found in the cells of the fetal zone, but not in the neocortex. In the adult adrenal, the zona fasciculata was immunoreactive for P450c17 only, whereas the zona reticularis was immunopositive for both P450c17 and CytB5. In the adult gonads, P450c17 and CytB5 were colocalized in the Leydig cells of the testis, theca interna cells of the follicle, theca lutein cells, and isolated cell clusters in the ovarian stroma. Whereas P450c17 and CytB5 were colocalized in the Leydig cells of the fetal testes, there was no immunostaining for either in the midgestational fetal ovary. Our findings of colocalization of CytB5 and P450c17 are strongly supportive of the view that CytB5 plays an important role in the regulation of the androgen biosynthetic pathway in the fetal and adult human.

Ambivalence about health-related behaviours: an exploration in the domain of food choice

OBJECTIVES

Interest in attitudes and ambivalence has highlighted problems with the adequacy of conceptualizing attitudes as unitary, unidimensional, evaluations. In this paper, we report an application of the Theory of Planned Behaviour (Ajzen, 1991) in the domain of dietary choice which investigates the hypothesis that ambivalence will attenuate observed attitude-intention relationships (since the evaluations influencing the expression of attitudes are more likely to differ from the evaluations influencing the expression of intentions for people who are more ambivalent.

DESIGN

Participants completed a postal questionnaire which contained, inter alia, measures assessing the components of the Theory of Planned Behaviour and a measure of ambivalence.

METHODS

Participants (N = 296) were recruited via advertisements placed in local newspapers, asking for volunteers to assist in a research project. Participants were randomly assigned to complete a questionnaire about either their chocolate consumption or their meat consumption. Participants were paid 4.

RESULTS

The findings show considerable support for the hypothesis: there was a tendency for attitude-intention relationships to be attenuated among participants with higher levels of ambivalence, compared to participants with lower levels of ambivalence.

CONCLUSIONS

The research supports the widespread view that ambivalence is an important issue, both for those involved in basic attitude research and for those who seek to use attitude theories in applied research. In particular, the findings indicate that ambivalence may often have implications for the predictive ability of attitude-intention-behaviour models, especially when applied to health-related behaviours that are characterized by motivational conflicts.

Primary extrarenal rhabdoid tumor of the ovary. A case report

BACKGROUND

Malignant rhabdoid tumors are rare, aggressive neoplasms that consist of both renal and extrarenal subtypes. Although extrarenal rhabdoid tumors have been documented at multiple extrarenal sites, to our knowledge no primary ovarian cases have been reported.

CASE

An 18-year-old, Caucasian woman was diagnosed with a pure primary extrarenal rhabdoid tumor of the ovary following diagnostic laparoscopy for pelvic pain. The tumor exhibited rapid growth, failed to respond to chemotherapy and led rapidly to death.

CONCLUSION

Although no other reports on primary ovarian extrarenal rhabdoid tumor have been published, the aggressive behavior of the tumor in this patient was similar to that seen in patients with metastatic disease.

Developing network-based services in the NHS

Networks, based upon informal relationships, have ensured that care was delivered to patients for many years. This informal organisation of care, based upon personal relationships, ensures that where the bureaucratic organisation fails the patient, health professionals' work together to network the resources the patient needs. Networks are not new. Formalising networks and recognising their potential to deliver seamless care is new. The NHS must ensure that networks are developed, allowing them freedom from bureaucracy to reach their potential. The Northern and Yorkshire Learning Alliance (NYLA) was established as part of the Northern and Yorkshire health community's efforts to radically improve care. The NYLA operates as a network with a small team of change experts working to develop change management and service improvement capacity across 10,000 square miles. As a network based organisation the team has learned many lessons, which may inform the development of clinical networks in England.

Disseminated peritoneal tuberculosis mimicking metastatic ovarian cancer

A 41-year-old woman had a 2-week history of low-grade fever, associated with gradually increasing abdominal pain and girth. Ultrasonography showed a complex cystic right adnexal mass. Diffuse nodules (0.1 to 0.5 cm) were found at exploratory laparotomy involving the serosal surfaces of the uterus, fallopian tubes, and ovaries. She had a total abdominal hysterectomy, with bilateral salpingo-oophorectomy and omentectomy for presumed stage IIIC ovarian carcinoma. Histopathologic examination showed chronic granulomatous inflammation with no evidence of neoplasm. Special stains on tissue sections and ascitic fluid were negative for fungi and mycobacteria. Additional history indicated a recently positive PPD skin test (within 6 months), followed by isoniazid therapy for 4 months. Polymerase chain reaction (PCR) done on paraffin-embedded tissues produced evidence of Mycobacterium tuberculosis. Ascitic fluid cultures became positive for M. tuberculosis at 6 weeks. The patient was placed on four-drug antituberculous therapy and had a complete recovery.