Depletion of tet2 results in age-dependent changes in DNA methylation and gene expression in a zebrafish model of myelodysplastic syndrome

Introduction

Myelodysplastic syndrome (MDS) is a heterogeneous group of clonal hematopoietic disorders characterized by ineffective hematopoiesis, cytopenias, and dysplasia. The gene encoding ten-eleven translocation 2 (tet2), a dioxygenase enzyme that catalyzes the conversion of 5-methylcytosine (5mC) to 5-hydroxymethylcytosine, is a recurrently mutated tumor suppressor gene in MDS and other myeloid malignancies. Previously, we reported a stable zebrafish line with a loss-of-function mutation in the tet2 gene. The tet2m/m-mutant zebrafish developed a pre-MDS state with kidney marrow dysplasia, but normal circulating blood counts by 11 months of age and accompanying anemia, signifying the onset of MDS, by 24 months of age.

Methods

In the current study, we collected progenitor cells from the kidney marrows of the adult tet2m/m and tet2wt/wt fish at 4 and 15 months of age and conducted enhanced reduced representation of bisulfite sequencing (ERRBS) and bulk RNA-seq to measure changes in DNA methylation and gene expression of hematopoietic stem and progenitor cells (HSPCs).

Results and discussion

A global increase in DNA methylation of gene promoter regions and CpG islands was observed in tet2m/m HSPCs at 4 months of age when compared with the wild type. Furthermore, hypermethylated genes were significantly enriched for targets of SUZ12 and the metal-response-element-binding transcription factor 2 (MTF2)-involved in the polycomb repressive complex 2 (PRC2). However, between 4 and 15 months of age, we observed a paradoxical global decrease in DNA methylation in tet2m/m HSPCs. Gene expression analyses identified upregulation of genes associated with mTORC1 signaling and interferon gamma and alpha responses in tet2m/m HSPCs at 4 months of age when compared with the wild type. Downregulated genes in HSPCs of tet2-mutant fish at 4 months of age were enriched for cell cycle regulation, heme metabolism, and interleukin 2 (IL2)/signal transducer and activator of transcription 5 (STAT5) signaling, possibly related to increased self-renewal and clonal advantage in HSPCs with tet2 loss of function. Finally, there was an overall inverse correlation between overall increased promoter methylation and gene expression.

Immunotherapy targeting different immune compartments in combination with radiation therapy induces regression of resistant tumors

Radiation therapy (RT) increases tumor response to CTLA-4 inhibition (CTLA4i) in mice and in some patients, yet deep responses are rare. To identify rational combinations of immunotherapy to improve responses we use models of triple negative breast cancer highly resistant to immunotherapy in female mice. We find that CTLA4i promotes the expansion of CD4+ T helper cells, whereas RT enhances T cell clonality and enriches for CD8+ T cells with an exhausted phenotype. Combination therapy decreases regulatory CD4+ T cells and increases effector memory, early activation and precursor exhausted CD8+ T cells. A combined gene signature comprising these three CD8+ T cell clusters is associated with survival in patients. Here we show that targeting additional immune checkpoints expressed by intratumoral T cells, including PD1, is not effective, whereas CD40 agonist therapy recruits resistant tumors into responding to the combination of RT and CTLA4i, indicating the need to target different immune compartments.

Abstract 3155: Gene expression profiles reveal distinct regulatory activities of transcription factors GATA1 and TAL1 upon AML relapse

The purpose of this study is to identify key regulatory pathways that potentially drive abnormal gene expression program in relapsed Acute Myeloid Leukemia (AML) patients, by integrative computational analyses on multi-omics molecular profiles. Relapsed AML remains a clinical challenge. Epigenetic heterogeneity may contribute to transcriptional dysregulation and disease progression in AML. However, what specific transcriptional programs and potential regulatory mechanisms contribute to disease relapse are not yet well understood. To characterize the global transcriptional landscapes in relapsed AML, we integrated genomics data from two cohorts of matched diagnosis and relapse patient specimens. We identified 5,416 differentially expressed genes (DEGs) between diagnosis and relapse in Cohort I. Unsupervised clustering yielded three distinct DEG groups: group A, B and C genes that were predominantly (88%) down-regulated, divergently regulated, or predominantly (65%) up-regulated, respectively, upon relapse. The expression pattern of all DEGs separated the patients into two clusters, most robustly by Group B genes. Interestingly, the majority of DEGs did not associate with changes in gene promoter methylation. Similar patterns were observed in Cohort II. We used Binding Analysis for Regulation of Transcription (BART) to identify transcriptional regulators (TRs) that potentially regulated the DEGs not associated with DNA methylation changes, and assessed the differential expression of identified TRs during disease progression. PU.1 was identified as a potential TR for Group A genes and was down-regulated upon relapse. GATA1 and TAL1 were identified as regulating Group B genes and were up-regulated in patient cluster1 and down-regulated in cluster2, consistent with the expression pattern of Group B genes. RBBP5 was a top predicted TR for Group C genes and was up-regulated upon relapse. We next validated the potential functionality of those predicted factors. In NSG mice transplanted with a human AML specimen, TAL1 and GATA1 were downregulated in AML cells collected four weeks after chemotherapy treatment, and were inferred as TRs for the down-regulated genes, similar to the patient data. PU.1 was inferred as regulating the up-regulated genes. Furthermore, we found that the level of differential expression of TAL1, GATA1, and PU.1 in each patient specimen associated with the correlation of DEG profiles between the patient specimen and TR perturbation in human-derived hematopoietic cell lines. Our results support the possibility that in some AML patients, TRs with roles in hematopoiesis and leukemia might contribute to disease relapse. Further mechanistic studies deciphering the molecular and phenotypic events facilitated by these TRs will yield significant insight into disease biology and possible therapeutic targeting approaches in relapsed AML.

Citation Format: Zhenjia Wang, Yaseswini Neelamraju, Cem Meydan, Nicholas Dunham, Jorge Gandara, Tak Lee, Subhash Prajapati, Franck Rapaport, Caroline Sheridan, Paul Zumbo, Michael Becker, Lars Bullinger, Martin Carroll, Richard D’Andrea, Richard Dillon, Ross Levine, Christopher E. Mason, Ari Melnick, Donna Neuberg, Stefan Bekiranov, Chongzhi Zang, Francine E. Garrett-Bakelman. Gene expression profiles reveal distinct regulatory activities of transcription factors GATA1 and TAL1 upon AML relapse [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 3155.

262 THE IMPACT OF COVID-19 PUBLIC HEALTH MEASURES ON THE SOCIAL RELATIONS OF MEN AND WOMEN IN LATER LIFE

Background

Despite the burgeoning literature on the impact of Covid-19 on the lives of older populations, gaps remain in our knowledge around the lived experience of social relationship change during the pandemic, and the implications for longer-term relational well-being. Even with the clear significance of Covid-19 for older populations across Europe, research involving cross-national comparisons of these experiences is largely absent. Addressing these gaps is critical given concerns for some older people’s social connectedness, their future relational embeddedness, and our societal preparedness for pandemic and other public health crises. The aim of this paper is to chart the impact of the pandemic on older people’s subjective lived experience of social connectedness across seven countries, and to contrast the differential impact of public health measures, if any, in these jurisdictions.

Methods

The analysis draws on 210 semi-structured interviews with men and women aged sixty-five and over across Austria, Czech Republic, Ireland, Israel, Norway, Spain, Sweden (as part of a wider study into exclusion from social relations), with a focus on direct social distancing measures and people’s response to these measures.

Results

Four themes emerged from the data: reduced informal social contact, depleted social opportunities, fear and lack of social confidence, and relational life course and impacts in context. Given the largely common approach to preventing the spread of the virus, more cross-national similarities than differences, although there were clear exceptions to this in relation to approach, and cultural nuances are evident. Cross-cutting these themes, structural and self-ageism emerged as intensifying formal constraints for some participants, in some settings.

Conclusion

For most participants, public health measures had a negative impact on their subjective well-being, while others experienced disruption to their relational life course trajectories. The data points to a clear need to consider the social infrastructure of older people, particularly in times of crises.

Evaluation of prognostic risk models for postoperative pulmonary complications in adult patients undergoing major abdominal surgery: a systematic review and international external validation cohort study

BACKGROUND

Stratifying risk of postoperative pulmonary complications after major abdominal surgery allows clinicians to modify risk through targeted interventions and enhanced monitoring. In this study, we aimed to identify and validate prognostic models against a new consensus definition of postoperative pulmonary complications.

METHODS

We did a systematic review and international external validation cohort study. The systematic review was done in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. We searched MEDLINE and Embase on March 1, 2020, for articles published in English that reported on risk prediction models for postoperative pulmonary complications following abdominal surgery. External validation of existing models was done within a prospective international cohort study of adult patients (≥18 years) undergoing major abdominal surgery. Data were collected between Jan 1, 2019, and April 30, 2019, in the UK, Ireland, and Australia. Discriminative ability and prognostic accuracy summary statistics were compared between models for the 30-day postoperative pulmonary complication rate as defined by the Standardised Endpoints in Perioperative Medicine Core Outcome Measures in Perioperative and Anaesthetic Care (StEP-COMPAC). Model performance was compared using the area under the receiver operating characteristic curve (AUROCC).

FINDINGS

In total, we identified 2903 records from our literature search; of which, 2514 (86·6%) unique records were screened, 121 (4·8%) of 2514 full texts were assessed for eligibility, and 29 unique prognostic models were identified. Nine (31·0%) of 29 models had score development reported only, 19 (65·5%) had undergone internal validation, and only four (13·8%) had been externally validated. Data to validate six eligible models were collected in the international external validation cohort study. Data from 11 591 patients were available, with an overall postoperative pulmonary complication rate of 7·8% (n=903). None of the six models showed good discrimination (defined as AUROCC ≥0·70) for identifying postoperative pulmonary complications, with the Assess Respiratory Risk in Surgical Patients in Catalonia score showing the best discrimination (AUROCC 0·700 [95% CI 0·683-0·717]).

INTERPRETATION

In the pre-COVID-19 pandemic data, variability in the risk of pulmonary complications (StEP-COMPAC definition) following major abdominal surgery was poorly described by existing prognostication tools. To improve surgical safety during the COVID-19 pandemic recovery and beyond, novel risk stratification tools are required.

FUNDING

British Journal of Surgery Society.

The SEQC2 epigenomics quality control (EpiQC) study

BACKGROUND

Cytosine modifications in DNA such as 5-methylcytosine (5mC) underlie a broad range of developmental processes, maintain cellular lineage specification, and can define or stratify types of cancer and other diseases. However, the wide variety of approaches available to interrogate these modifications has created a need for harmonized materials, methods, and rigorous benchmarking to improve genome-wide methylome sequencing applications in clinical and basic research. Here, we present a multi-platform assessment and cross-validated resource for epigenetics research from the FDA's Epigenomics Quality Control Group.

RESULTS

Each sample is processed in multiple replicates by three whole-genome bisulfite sequencing (WGBS) protocols (TruSeq DNA methylation, Accel-NGS MethylSeq, and SPLAT), oxidative bisulfite sequencing (TrueMethyl), enzymatic deamination method (EMSeq), targeted methylation sequencing (Illumina Methyl Capture EPIC), single-molecule long-read nanopore sequencing from Oxford Nanopore Technologies, and 850k Illumina methylation arrays. After rigorous quality assessment and comparison to Illumina EPIC methylation microarrays and testing on a range of algorithms (Bismark, BitmapperBS, bwa-meth, and BitMapperBS), we find overall high concordance between assays, but also differences in efficiency of read mapping, CpG capture, coverage, and platform performance, and variable performance across 26 microarray normalization algorithms.

CONCLUSIONS

The data provided herein can guide the use of these DNA reference materials in epigenomics research, as well as provide best practices for experimental design in future studies. By leveraging seven human cell lines that are designated as publicly available reference materials, these data can be used as a baseline to advance epigenomics research.

84 IMPACT OF RELOCATION AND MIGRATION ON THE SOCIAL RELATIONS OF OLDER MEN AND WOMEN OVER THEIR LIFE COURSE

Background

While there is a recognition in the established literature of the need to investigate life-course factors in the construction of exclusion from social relations and gender pathways, how those pathways intersect with the relocation and migration histories of older people has not been sufficiently explored. Thus, illuminating this intersection is important in understanding major turning points in people’s social connections, and this has particular significance in Ireland given that most older people are likely to have experienced some form of migration.

Methods

Thirty in-depth semi-structured qualitative telephone interviews with older men and women in Ireland, as part of a wider GENPATH study into exclusion from social relations.

Results

There is preliminary evidence to suggest that relocation and migration has a differential impact on the social relations of men and women over their life course. The findings reflect the common phenomenon in Ireland where it was usual for women to move into new communities upon marriage. Also, women’s experience of within-country relocation was often linked to their husband’s working-life trajectories, whereas employment was the motivation behind this form of relocation for the male participants. For those who had experienced emigration, returning to Ireland was driven by a desire to return to their place of origin or to retire in Ireland to be nearer to family in later life.

Conclusion

Findings point to the intersection between relocation and migration life histories and gendered pathways to exclusion from social relations. The impact on social connectivity is experienced differently at different points across the lives of these older men and women. Consideration needs to be given to gender normative roles and structural influences to gain a greater understanding of how these intersect with migration.

Epigenetic encoding, heritability and plasticity of glioma transcriptional cell states

Single-cell RNA sequencing has revealed extensive transcriptional cell state diversity in cancer, often observed independently of genetic heterogeneity, raising the central question of how malignant cell states are encoded epigenetically. To address this, here we performed multiomics single-cell profiling-integrating DNA methylation, transcriptome and genotype within the same cells-of diffuse gliomas, tumors characterized by defined transcriptional cell state diversity. Direct comparison of the epigenetic profiles of distinct cell states revealed key switches for state transitions recapitulating neurodevelopmental trajectories and highlighted dysregulated epigenetic mechanisms underlying gliomagenesis. We further developed a quantitative framework to directly measure cell state heritability and transition dynamics based on high-resolution lineage trees in human samples. We demonstrated heritability of malignant cell states, with key differences in hierarchal and plastic cell state architectures in IDH-mutant glioma versus IDH-wild-type glioblastoma, respectively. This work provides a framework anchoring transcriptional cancer cell states in their epigenetic encoding, inheritance and transition dynamics.

Evaluation of Self-Reported Agricultural Tasks, Safety Concerns, and Health and Safety Behaviors of Young Adults in U.S. Collegiate Agricultural Programs

Young adults enrolled in collegiate agricultural programs are a critical audience for agricultural health and safety training. Understanding the farm tasks that young adults engage in is necessary for tailoring health and safety education. The project analyzed evaluation survey responses from the Gear Up for Ag Health and Safety^™ program, including reported agricultural tasks, safety concerns, frequency of discussing health and safety concerns with healthcare providers, safety behaviors, and future career plans. The most common tasks reported included operation of machinery and grain-handling. Most participants intended to work on a family-owned agricultural operation or for an agribusiness/cooperative following graduation. Reported safety behaviors (hearing protection, eye protection, and sunscreen use when performing outdoor tasks) differed by gender and education type. Male community college and university participants reported higher rates of "near-misses" and crashes when operating equipment on the roadway. One-third of participants reported discussing agricultural health and safety issues with their medical provider, while 72% were concerned about the health and safety of their family and co-workers in agriculture. These findings provide guidance for better development of agricultural health and safety programs addressing this population-future trainings should be uniquely tailored, accounting for gender and educational differences.

EPCO-14. DECIPHERING DIFFERENTIATION HIERARCHIES, HERITABILITY AND PLASTICITY IN HUMAN GLIOMAS VIA SINGLE-CELL MULTI-OMICS

Human diffuse gliomas are incurable malignancies, where cellular state diversity fuels tumor progression and resistance to therapy. Single-cell RNA-sequencing (scRNAseq) studies recently charted the cellular states of the two major categories of human gliomas, IDH-mutant gliomas (IDH-MUT) and IDH-wildtype glioblastoma (GBM), showing that malignant cells partly recapitulate neurodevelopmental trajectories. This raises the central questions of how cell states are encoded epigenetically and whether unidirectional hierarchies or more plastic state transitions govern glioma cellular architectures. To address these questions, we generated multi-omics single-cell profiling, integrating DNA methylation (DNAme), transcriptome and genotyping of 1,728 cells from 11 GBM and IDH-MUT primary patient samples. Direct comparison of the methylomes of distinct glioma cell states revealed Polycomb repressive complex 2 (PRC2) targets DNAme as a key switch in the differentiation of malignant GBM cells. In contrast, dissecting aberrant circuits of hyper-methylation and gene expression in IDH-MUT gliomas, we observed a decoupling of the promoter methylation-expression relationship, with disruption of CTCF insulation and enhancer vulnerability which increases with cellular differentiation. To define cell state transition dynamics directly in patient samples, we generated high-resolution lineage histories of glioma cells using heritable DNAme changes, and projected the scRNAseq-derived cell states onto the lineage trees. This analysis demonstrated that cell states are heritable across malignant gliomas and, while in IDH-MUT differentiation far outpaces de-differentiation, GBM harbors a higher degree of cell state plasticity allowing reversion of GBM cells from a differentiated to a stem-like state. Overall, our work provides detailed insights into gliomagenesis, dissecting the epigenetic encoding, regulatory programs, and dynamics of the cellular states that drive human gliomas. Importantly, it also carries significant translational implication, as the high degree of de-differentiation in GBM challenges the paradigm of therapeutically targeting glioma stem-like cells to deprive tumors of their ability to regenerate.

Abstract PO-019: Deciphering differentiation hierarchies, heritability and plasticity in human gliomas via single-cell multi-omics

Human diffuse gliomas are incurable brain tumors, where cellular state diversity fuels tumor progression and resistance to therapy. Single-cell RNA-sequencing (scRNAseq) studies recently charted the cellular states of the two major categories of human gliomas, IDH-mutant gliomas (IDH-MUT) and IDH-wildtype glioblastoma (GBM), showing that malignant cells partly recapitulate neurodevelopmental trajectories. This raises the central questions of how cell states are encoded epigenetically and whether unidirectional hierarchies or more plastic state transitions govern glioma cellular architectures. To address these questions, we generated multi-omics single-cell profiling, integrating DNA methylation (DNAme), transcriptome and genotyping of 1,728 cells from 11 GBM and IDH-MUT primary patient samples. The assessment of DNAme intra-tumoral heterogeneity of malignant cells revealed that single-cell DNAme profiles within tumors span multiple bulk subtypes, are associated with important biological features of malignant cells, and may be confounded by the tumor micro-environment. Such sources of intra-tumoral heterogeneity in bulk profiles are important to recognize, as DNAme profiling is increasingly being utilized for bulk clinical brain tumor classification. The direct comparison of the methylomes of distinct glioma cellular states revealed Polycomb repressive complex 2 (PRC2) targets DNAme as a key switch in the differentiation of malignant GBM cells. In contrast, dissecting aberrant circuits of hypermethylation and gene expression in IDH-MUT gliomas, we observed a decoupling of the promoter methylation-expression relationship, with disruption of CTCF insulation and enhancer vulnerability which increases with cellular differentiation. To define cell state transition dynamics directly in patient samples, we generated high-resolution lineage histories of glioma cells using heritable DNAme changes, and projected the scRNAseq-derived cell states onto the lineage trees. This analysis demonstrated that cell states are heritable across malignant gliomas and, while in IDH-MUT differentiation far outpaces de-differentiation, GBM harbors a higher degree of cellular state plasticity allowing reversion of GBM cells from a differentiated to a stem-like state. Overall, our work provides detailed insights into gliomagenesis, dissecting the epigenetic encoding, regulatory programs, and dynamics of the cellular states that drive human gliomas. Importantly, it also carries significant translational implication, as the high degree of de-differentiation in GBM challenges the paradigm of therapeutically targeting glioma stem-like cells to deprive tumors of their ability to regenerate.

Citation Format: Federico Gaiti, Ronan Chaligne, Dana Silverbush, Joshua S. Schiffman, Hannah R. Weisman, Lloyd Kluegel, Simon Gritsch, Sunil D. Deochand, Alyssa R. Richman, Johanna Klughammer, Tommaso Biancalani, Christoph Muus, Caroline Sheridan, Alicia Alonso, Franco Izzo, Orit Rozenblatt-Rosen, Aviv Regev, Mario L. Suvà, Dan A. Landau. Deciphering differentiation hierarchies, heritability and plasticity in human gliomas via single-cell multi-omics [abstract]. In: Proceedings of the AACR Virtual Special Conference on Tumor Heterogeneity: From Single Cells to Clinical Impact; 2020 Sep 17-18. Philadelphia (PA): AACR; Cancer Res 2020;80(21 Suppl):Abstract nr PO-019.

Targeted detection and quantitation of histone modifications from 1,000 cells

Histone post-translational modifications (PTMs) create a powerful regulatory mechanism for maintaining chromosomal integrity in cells. Histone acetylation and methylation, the most widely studied histone PTMs, act in concert with chromatin-associated proteins to control access to genetic information during transcription. Alterations in cellular histone PTMs have been linked to disease states and have crucial biomarker and therapeutic potential. Traditional bottom-up mass spectrometry of histones requires large numbers of cells, typically one million or more. However, for some cell subtype-specific studies, it is difficult or impossible to obtain such large numbers of cells and quantification of rare histone PTMs is often unachievable. An established targeted LC-MS/MS method was used to quantify the abundance of histone PTMs from cell lines and primary human specimens. Sample preparation was modified by omitting nuclear isolation and reducing the rounds of histone derivatization to improve detection of histone peptides down to 1,000 cells. In the current study, we developed and validated a quantitative LC-MS/MS approach tailored for a targeted histone assay of 75 histone peptides with as few as 10,000 cells. Furthermore, we were able to detect and quantify 61 histone peptides from just 1,000 primary human stem cells. Detection of 37 histone peptides was possible from 1,000 acute myeloid leukemia patient cells. We anticipate that this revised method can be used in many applications where achieving large cell numbers is challenging, including rare human cell populations.

Somatic mutations and cell identity linked by Genotyping of Transcriptomes

Defining the transcriptomic identity of malignant cells is challenging in the absence of surface markers that distinguish cancer clones from one another, or from admixed non-neoplastic cells. To address this challenge, here we developed Genotyping of Transcriptomes (GoT), a method to integrate genotyping with high-throughput droplet-based single-cell RNA sequencing. We apply GoT to profile 38,290 CD34+ cells from patients with CALR-mutated myeloproliferative neoplasms to study how somatic mutations corrupt the complex process of human haematopoiesis. High-resolution mapping of malignant versus normal haematopoietic progenitors revealed an increasing fitness advantage with myeloid differentiation of cells with mutated CALR. We identified the unfolded protein response as a predominant outcome of CALR mutations, with a considerable dependency on cell identity, as well as upregulation of the NF-κB pathway specifically in uncommitted stem cells. We further extended the GoT toolkit to genotype multiple targets and loci that are distant from transcript ends. Together, these findings reveal that the transcriptional output of somatic mutations in myeloproliferative neoplasms is dependent on the native cell identity.

Epigenetic evolution and lineage histories of chronic lymphocytic leukaemia

Genetic and epigenetic intra-tumoral heterogeneity cooperate to shape the evolutionary course of cancer¹. Chronic lymphocytic leukaemia (CLL) is a highly informative model for cancer evolution as it undergoes substantial genetic diversification and evolution after therapy^2,3. The CLL epigenome is also an important disease-defining feature^4,5, and growing populations of cells in CLL diversify by stochastic changes in DNA methylation known as epimutations⁶. However, previous studies using bulk sequencing methods to analyse the patterns of DNA methylation were unable to determine whether epimutations affect CLL populations homogeneously. Here, to measure the epimutation rate at single-cell resolution, we applied multiplexed single-cell reduced-representation bisulfite sequencing to B cells from healthy donors and patients with CLL. We observed that the common clonal origin of CLL results in a consistently increased epimutation rate, with low variability in the cell-to-cell epimutation rate. By contrast, variable epimutation rates across healthy B cells reflect diverse evolutionary ages across the trajectory of B cell differentiation, consistent with epimutations serving as a molecular clock. Heritable epimutation information allowed us to reconstruct lineages at high-resolution with single-cell data, and to apply this directly to patient samples. The CLL lineage tree shape revealed earlier branching and longer branch lengths than in normal B cells, reflecting rapid drift after the initial malignant transformation and a greater proliferative history. Integration of single-cell bisulfite sequencing analysis with single-cell transcriptomes and genotyping confirmed that genetic subclones mapped to distinct clades, as inferred solely on the basis of epimutation information. Finally, to examine potential lineage biases during therapy, we profiled serial samples during ibrutinib-associated lymphocytosis, and identified clades of cells that were preferentially expelled from the lymph node after treatment, marked by distinct transcriptional profiles. The single-cell integration of genetic, epigenetic and transcriptional information thus charts the lineage history of CLL and its evolution with therapy.

Microbial Community Dynamics and Response to Plant Growth-Promoting Microorganisms in the Rhizosphere of Four Common Food Crops Cultivated in Hydroponics

Plant growth promoting microorganisms (PGPMs) of the plant root zone microbiome have received limited attention in hydroponic cultivation systems. In the framework of a project aimed at the development of a biological life support system for manned missions in space, we investigated the effects of PGPMs on four common food crops (durum and bread wheat, potato and soybean) cultivated in recirculating hydroponic systems for a whole life cycle. Each crop was inoculated with a commercial PGPM mixture and the composition of the microbial communities associated with their root rhizosphere, rhizoplane/endosphere and with the recirculating nutrient solution was characterised through 16S- and ITS-targeted Illumina MiSeq sequencing. PGPM addition was shown to induce changes in the composition of these communities, though these changes varied both between crops and over time. Microbial communities of PGPM-treated plants were shown to be more stable over time. Though additional development is required, this study highlights the potential benefits that PGPMs may confer to plants grown in hydroponic systems, particularly when cultivated in extreme environments such as space.

Terrestrial runoff influences white syndrome prevalence in SW Madagascar

Terrestrial runoff and sedimentation have been implicated in a variety of impacts on scleractinian corals. However, despite accumulating evidence, little work has been done to investigate their influence on coral disease development. This study examined the role that river runoff and the associated sedimentation could play in affecting the prevalence of the coral disease "white syndrome" in SW Madagascar. Corals from reefs affected by river discharge and terrestrial sediments were more affected by white syndrome than reefs located far from any source of terrestrial runoff. Terrestrial runoff-affected reefs also displayed a wider diversity of coral species affected by this disease. While much evidence has been pointing in the direction of indirect effects of such runoff on coral disease development, our data corroborates earlier suggestions that pathogens are present within the sediments. As such, sediments released on reefs through river discharge could act as reservoirs of coral pathogens.

Diagnostic gene expression biomarkers of coral thermal stress

Gene expression biomarkers can enable rapid assessment of physiological conditions in situ, providing a valuable tool for reef managers interested in linking organism physiology with large-scale climatic conditions. Here, we assessed the ability of quantitative PCR (qPCR)-based gene expression biomarkers to evaluate (i) the immediate cellular stress response (CSR) of Porites astreoides to incremental thermal stress and (ii) the magnitude of CSR and cellular homeostasis response (CHR) during a natural bleaching event. Expression levels largely scaled with treatment temperature, with the strongest responses occurring in heat-shock proteins. This is the first demonstration of a 'tiered' CSR in a coral, where the magnitude of expression change is proportional to stress intensity. Analysis of a natural bleaching event revealed no signature of an acute CSR in normal or bleached corals, indicating that the bleaching stressor(s) had abated by the day of sampling. Another long-term stress CHR-based indicator assay was significantly elevated in bleached corals, although assay values overall were low, suggesting good prospects for recovery. This study represents the first step in linking variation in gene expression biomarkers to stress tolerance and bleaching thresholds in situ by quantifying the severity of ongoing thermal stress and its accumulated long-term impacts.

Culture of Iris Pigment Epithelial Cells on Expanded-Polytetrafluroethylene (ePTFE) Substrates for the Treatment of Age-Related Macular Degeneration

Introduction:

Transplantation of an intact differentiated retinal pigment epithelial (RPE) cell layer may provide a means to treat Age-Related Macular Degeneration (AMD). However, harvesting RPE cells can be a technically complicated procedure. Our current work aimed to prepare intact differentiated iris pigment epithelial (IPE) cell layers, which are easy to obtain and have the same embryonic origin and similar properties as RPE cells, on ePTFE substrates for transplantation purposes to rescue deteriorated photoreceptors in AMD.

Methods:

IPE cells isolated from rat eyes were seeded on different substrates, including fibronectin n-heptylamine (HA) ePTFE substrates, HA ePTFE substrates, ePTFE substrates and fibronectin tissue culture polystyrene (TCPS) as control. Cell number and morphology were assessed at each time interval. The formation of tight junction was examined by immunostaining of junction proteins.

Results:

An obvious increasing trend of cell number was observed in IPE cells on fibronectin n-heptylamine (HA) ePTFE substrate, exhibiting heavy pigmentation and epithelial morphology. At Day 28, tight junction formation was indicated by cell-cell junctional proteins along cell borders.

Conclusion:

Harvested IPE cells cultured on fibronectin HA-ePTFE substrates can differentiate and form a cell monolayer that may be suitable for transplantation.

Dental nursing education and the introduction of technology-assisted learning

The aim of this paper is to explore the profile of dental nursing students in the National Dental Nurse Training Programme of Ireland and their adjustment to a technology-assisted learning environment. Evaluation by students of the course and their reactions to the course were analysed. Dental nurses must possess the skills and knowledge to proficiently function in the modern day dental surgery. The implementation of a dental nurse programme that is heavily reliant on technology has started to create a group of dental nurses equipped with basic skills to access and retrieve information over a lifetime. However, the transition to a technology-assisted learning environment including online learning activities requires adaptation and expertise by educators and students alike. Careful evaluation and stakeholder feedback is imperative in the creation and maintaining of a quality programme. In conclusion, the students in this study responded well to the transition to a technology-based learning environment. Furthermore, the findings of this study suggest that the use of an online environment is an effective and stimulating learning environment for the students of a dental nurse programme; however, familiarity skills and knowledge of information technology is a prerequisite for success.

Near miss maternal morbidity

Audit of severe maternal morbidity is a potent tool in determining standards of maternity care. This study determines the incidence of severe acute maternal morbidity in our population, identifies the underlying organ dysfunction and associated obstetric risk factors, and compares them to published international reports. Over a 5 year period, 1999-2003, data were collected prospectively from patients with severe acute maternal morbidity. There were 36,802 women who delivered infants weighing more than 500 g over the 5 years with 53 cases of severe maternal morbidity. There were two indirect maternal deaths yielding an incidence of 1.4/1000 for severe maternal morbidity and 5.4/100,000 for maternal mortality. The severe maternal morbidity to mortality ratio was 26.5:1. Massive obstetric haemorrhage requiring acute blood transfusion of > or = 5 units of packed red cells occurred in 77% of cases. This study identifies the feasibility of audit of severe maternal morbidity using simple defined clinical criteria. The incidence and underlying aetiology of severe maternal morbidity in our unit is comparable to other developed countries. It is essential that data on severe maternal morbidity are reviewed and analysed continuously at local hospital and national level to assess, maintain and improve clinical standards.

Polyurethanes as potential substrates for sub-retinal retinal pigment epithelial cell transplantation

Transplantation of cultured retinal pigment epithelial (RPE) cells under the failing macular is a potential treatment for age related macular degeneration. An important step in the development of this procedure is the identification of a suitable membrane on which to grow and transplant the cells. This paper evaluates the potential of using polyurethanes in this application since they possess several of the required properties, such as, flexibility, robustness, biostability and good biocompatiblilty although their hydrophobicity can limit cell adhesion. Three commercially available polyether urethanes (Pellethane, Tecoflex and Zytar) were evaluated in terms of their wettability using dynamic contact angle analysis and their ability to support a monolayer of functioning RPE cells (ARPE-19) . Furthermore Pellethane and Tecoflex were treated with a simple air plasma treatment and analysed as above. In the "as received condition" only a few RPE cells attached to the Pellethane and Tecoflex and remained clumped. RPE cells grew to confluence on the Zytar substrate by 7 days without further surface modification. Air gas plasma treatment of both Pellethane and Tecoflex increased the wettability of the surfaces and this resulted in the growth of a monolayer of well-spread RPE cells on both materials. Morphologically these cells grew with a normal 'cobblestone' phenotype. These results demonstrate the potential of these polyurethanes for this application.

Edible mushroom (Agaricus bisporus) lectin modulates human retinal pigment epithelial cell behaviour in vitro

The retinal pigment epithelium (RPE) plays a major role in the development of proliferative vitreoretinopathy (PVR). In particular, RPE cells are implicated in generating the contraction forces seen. The present study was undertaken to investigate whether human RPE binds a lectin from the common edible mushroom, Agaricus bisporus, and to evaluate the effect of any binding on RPE-mediated matrix contraction in an in vitro model of PVR. Fluorescein isothiocyanate (FITC)-labelled Agaricus bisporus lectin (ABL) was used to study binding of lectin to normal retina, PVR scar tissue specimens and cultured human RPE. The effect of a 3-day exposure of ABL on human RPE-mediated contraction was evaluated using 2- and 3D RPE-populated collagen matrices. Effect of ABL on cell adhesion was measured using a collagen type I adhesion assay and determining the relative cellular attachment using absorbance readings. The normal RPE monolayer did not stain with FITC-ABL while PVR scar tissue stained intensely. Staining of in vitro RPE was characteristic but time-dependent. ABL caused a dose-dependent inhibition of RPE-mediated contraction of both 2D (one-way ANOVA, F = 7.94, p < 0.008) and 3D collagen matrices (one-way ANOVA, F = 164.955, p < 0.001). Pre-incubation of ABL with RPE in the 2D model caused a dramatic arrest of contraction (one-way ANOVA, F = 20.1, p < 0.001) that was due to a dose-dependent inhibition of adhesion (one-way ANOVA, F = 15.603, p < 0.001). Recovery of contraction was partially reversible on removal of ABL and was dependent on initial concentration of the lectin. ABL inhibits contraction and adhesion of human RPE cells in vitro without apparent cytotoxicity. It therefore deserves consideration as a potential therapeutic agent in the prevention and treatment of PVR and other non-ocular anomalous wound-healing processes.

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Predictive value of proton magnetic resonance spectroscopy in pediatric closed head injury

We studied 26 infants (1-18 months old) and 27 children (18 months or older) with acute nonaccidental (n = 21) or other forms (n = 32) of traumatic brain injury using clinical rating scales, a 15-point MRI scoring system, and occipital gray matter short-echo proton MRS. We compared the differences between the acutely determined variables (metabolite ratios and the presence of lactate) and 6- to 12-month outcomes. The metabolite ratios were abnormal (lower NAA/Cre or NAA/Cho; higher Cho/Cre) in patients with a poor outcome. Lactate was evident in 91% of infants and 80% of children with poor outcomes; none of the patients with a good outcome had lactate. At best, the clinical variables alone predicted the outcome in 77% of infants and 86% of children, and lactate alone predicted the outcome in 96% of infants and 96% of children. No further improvement in outcome prediction was observed when the lactate variable was combined with MRI ratios or clinical variables. The findings of spectral sampling in areas of brain not directly injured reflected the effects of global metabolic changes. Proton MRS provides objective data early after traumatic brain injury that can improve the ability to predict long-term neurologic outcome.

Influence of pigment content, intracellular calcium and cyclic AMP on the ability of human retinal pigment epithelial cells to contract collagen gels

PURPOSE

The aim of the study was to determine to what extent collagen gel contraction could be reduced by calcium and calmodulin antagonists and agents that elevate cyclic AMP in order to develop a pharmacological approach to prevent/arrest RPE contraction of epiretinal membranes in proliferative vitreoretinopathy. We also explored a possible role of pigment in collagen gel contraction.

METHOD

We measured RPE mediated contraction of 3D collagen gels in the presence and absence of the calcium and calmodulin antagonists TMB8, Verapamil and Tamoxifen and the cAMP elevating agents IBMX and Forskolin. The effect of pigment on collagen gel contraction was assessed by comparing gel contraction mediated by RPE cells re-pigmented with melanin with that mediated by unpigmented RPE. The effect of IBMX on RPE proliferation was assessed using a BrdU ELISA and the effects of IBMX on RPE cytoskeleton and cell shape were assessed using Actin and Cytokeratin immunocytochemistry.

RESULTS

We report that both cAMP elevating agents and calcium and calmodulin antagonists reduce RPE mediated collagen gel contraction. Cyclic AMP elevation was more effective than a reduction in calcium in reducing contraction. There were no significant advantages in combining both approaches. The presence of melanin had no effect on gel contraction. Calcium antagonists and particularly agents which elevate cAMP caused RPE cells in collagen gels to extend fewer and shorter processes. cAMP elevation in particular caused RPE cells to become more rounded and develop arborized cell processes. Immunostaining for actin and cytokeratin revealed changes in cytoskeletal organisation in response to IBMX in that cells contained less actin than untreated cells and concentrated cytokeratins more centrally.

CONCLUSION

We have identified two possible pharmacological approaches which may provide a new direction for preventing or slowing down the development of PVR.

A video-based performance in noise test for measuring audio-visual disability in young school children: test development, with validation by trained teachers, parents and audiometry as relative standards for disability

BACKGROUND

impaired ability to detect target sounds in noisy surroundings is a particular feature of children with a history of otitis media with effusion (OME). Children with current OME are also likely to experience difficulty in speech reception in classrooms where a high level of background noise has been recorded. No tests are currently available which are feasible in primary care and which objectively measure school-related disabilities. The effects of speech in noise and the extent to which this is offset by speech reading contribute important dimensions to disability.

METHODS

a video-based speech reception test has been developed using the same principles in 227 English and 182 Danish 4-8 year-old children. Distribution data was collected for both language versions of the test. The test has been compared with audiometry and teacher and parents assessments to establish its validity.

INTERPRETATION

there are no gold standards for audio-visual disability in current clinical use. The poor positive predictive value of audiometry for likely classroom functioning is a cause for concern, particularly in relation to inappropriate referral of children by primary care physicians.

Matrix and the retinal pigment epithelium in proliferative retinal disease

In their normal state, RPE cell are strongly adherent to Bruch's membrane. Certain pathological conditions such as retinal detachment cause an injury-type response (probably augmented or induced by the local accumulation of a variety of substances which modulate cell behaviour) in which RPE begin to dissociate from the membrane. This RPE-Bruch's membrane separation may be mediated by proteins with counter-adhesive properties and proteolytic enzymes, partly derived from the RPE themselves. Concomitant with the RPE disassociation, the cells begin to lose tertiary differentiation characteristics and gain macrophage-like features. When the "free" RPE arrive at the surface of the neuroretina, they may attach to or create a provisional matrix. Some of the cells adopt a fibroblast-like phenotype. This phenotype is similar to that of the dermal fibroblast during cutaneous wound repair and the fibroblastic RPE synthesise the types of matrix components found in healing skin wounds. Many of these molecules in turn further modulate the activities of the cells via several families of cell surface receptors, while the RPE continue to remodel the new matrix with a range of proteolytic enzymes. The resulting tissue (or membrane) has many of the features of a contractile scar and is the hallmark of the condition known as proliferative vitreoretinopathy (PVR). Thus the development of PVR, and the resulting tractional distortion of the neuroretina, appears to be dependent on RPE-matrix interactions. The interactions present a number of potential therapeutic targets for the management of the disorder.

Using the Unger system to classify 386 long bone fractures in dogs

A system already described by Unger and others was used to classify long bone fractures in dogs. The present paper reports experiences using the fracture classification system regarding its ease of use and the ability to analyse the data generated. Three hundred and eighty-six canine long bone fractures were classified from radiographs. Results were assessed by reviewing the medical records or by sending questionnaires to referring veterinarians. There were a few inconsistencies, particularly in classifying proximal ulnar fractures, but the system was easy to use and data retrieval was readily accomplished. Data from the system were used to compare the results of repairs of diaphyseal fractures of the radius/ulna, femur and tibia/fibula. A chi square analysis was used to determine significant differences between the outcome scores of the three fracture types. Fractures of the femoral diaphysis had a statistically poorer outcome than did diaphyseal fractures of the radius/ulna or tibia/fibula.

Effects of single, short-term exposures of human retinal pigment epithelial cells to thiotepa or 5-fluorouracil: implications for the treatment of proliferative vitreoretinopathy

AIM

To investigate the effects of single, short-term (5 or 30 minutes) exposures to thiotepa or 5-fluorouracil (5-FU) on collagen lattice contraction and retinal pigment epithelial (RPE) cell proliferation.

METHODS

For collagen contraction studies, RPE cells seeded into free floating type I collagen lattices were exposed to single 5 or 30 minute treatments with thiotepa (0.06-4 mg/ml), or 5-FU (0.25-25 mg/ml), or phosphate buffered saline alone as a control. For proliferation studies, RPE cell monolayers were similarly exposed to these agents. The degree of contraction, effects on cell number, and viability were determined up to 14 days after treatment.

RESULTS

Contraction of collagen lattices containing RPE cells and proliferation of RPE cells were significantly inhibited (p < 0.05) by thiotepa and 5-FU at concentrations above 0.06 mg/ml and 0.25 mg/ml respectively (for both 5 and 30 minute treatments), compared with controls. Cell death did not occur except for exposure of the RPE cells in collagen lattices to the highest concentration of thiotepa (4 mg/ml).

CONCLUSION

It was concluded that single 5 or 30 minute exposures to thiotepa or 5-FU significantly inhibited collagen contraction and the proliferation of RPE cells. These findings suggest that short, single, non-toxic exposures to thiotepa or 5-FU which can be reproduced clinically may be useful in the modulation of proliferative vitreoretinopathy.

A stage-specific enhancer of immunoglobulin J chain gene is induced by interleukin-2 in a presecretor B cell stage

Interleukin-2 (IL-2)-induced transcription of the J chain gene was used as a model for analyzing cytokine regulation during B cell development. To determine whether IL-2 signals are targeted to a J chain gene enhancer as well as to its promoter, the sequences flanking the J chain gene were first examined for DNase I hypersensitivity. Of six sites identified, two strong ones, 7.5 kb upstream of the J chain gene, were found to be associated with an enhancer that is active only during the antigen-driven stages of B cell development. Further analyses of the enhancer in the IL-2-responsive presecretor BCL1 cells showed that the enhancer is activated at this stage by an IL-2 signal that functions by opening the enhancer chromatin and stimulating STAT5 to bind to a STAT5 element critical for the enhancer induction. Moreover, after this early induction stage, the enhancer was shown to be constitutively open and active in terminally differentiated plasma cells.

'En bloc' dissection of epimacular membranes using aspiration delamination

'En bloc' dissection is a technique in which epiretinal membranes (ERM) are separated from the retina as a single lamina with a 20-gauge blunt flute needle. We used this technique to remove epimacular membranes of various aetiologies in a consecutive series of 25 eyes, with a minimum follow-up of 5 months (mean 10.4 months). Small residual epicentres of ERM away from the fovea remained in 7 (29.1%) eyes only; 3 were inside and 4 outside the temporal vascular arcades. Postoperatively 64% (16/25) of patients achieved a final visual acuity of 6/12 or better and 76% (19/25) achieved a final visual acuity of 6/18 or better. Progressive lens opacities were the most important postoperative complication in phakic eyes that significantly affected the visual results. This technique successfully removed epimacular membranes over a wide area, without the need to find a starting edge or the use of sharp instruments near the retina. Diaphanous ERMs with ill-defined borders and tenaciously adherent membranes could be removed with minimal trauma to the underlying retina. Histopathological and immunohistochemical examination of 10 ERMs demonstrated the absence of internal limiting lamina in 6 (60%).

Non-vascular vitreoretinopathy: the cells and the cellular basis of contraction

BACKGROUND

We consider epiretinal membrane in terms of the two repair processes of gliosis and fibrosis and look at the cellular basis of contraction.

METHODS

Pathological material removed at surgery was examined by a range of morphological procedures. Cultures of fibroblasts, retinal pigment epithelium cells and retinal glia were subjected to bioassays which relate to behavioural activities in scar formation.

RESULTS AND CONCLUSIONS

Our findings highlight the importance of activities such as migration and adhesion in the formation of epiretinal membranes, and also show that these activities are central to our understanding of contraction.

Comparison of two cochlear implant speech processors in better versus poorer performers

The performance and subjective preferences for two different speech-processing strategies, the Speak strategy in the Cochlear Spectra 22 speech processor and the Multipeak (Mpeak) strategy in the Mini Speech Processor (MSP), are compared within two adult patient groups. Ten experienced cochlear implant (CI) users were selected for this study. One group of 5 CI users have significant open-set speech recognition, and the second group consisted of experienced CI users who have little or no open-set speech recognition on standardized tests (< 30% on sentence tests; < 10% on monosyllabic word tests). While only 4 of the 5 users in each group were available to complete this evaluation, suitable comparisons on the Speak and Mpeak strategies on test performance were possible within each patient group. The performance tests were necessarily different to suit each patient group; however, general trends of test scores and subjective evaluations of each speech processor are compared between these two groups. While the performance scores and subjective ratings consistently favored the Speak strategy in the first group of users, with good open-set speech recognition, the results within the second group were more variable. These findings have significant implications for individual patient and processor selection.

Phase I trial of intravenous and intraperitoneal administration of granulocyte-macrophage colony-stimulating factor

To assess the toxicity, pharmacokinetics, and local and systemic effects of the intraperitoneal (i.p.) administration of granulocyte-macrophage colony-stimulating factor (GM-CSF) at various dosages, 13 patients with predominantly i.p. malignancies refractory to standard chemotherapy were studied. GM-CSF was administered intravenously (i.v.) for 5 consecutive days; 21 days later the same dosage of GM-CSF was administered i.p. for 5 consecutive days. Four dosage levels were studied: 1, 2, 4, and 8 micrograms/kg/day. GM-CSF was well tolerated after i.v. and i.p. administration at doses up to 8 micrograms/kg/day. A transient fall followed by an elevation of circulating white cells was observed over a 24-h period after both i.v. and i.p. GM-CSF administration (mean minimum +/- SE as % baseline): 38 +/- 8% at 30 min after i.v. administration, 21 +/- 5% at 60 min after i.p. administration; mean maximum: 220 +/- 41% at 6 h after i.v. administration, 202 +/- 39% at 12 h after i.p. administration). The magnitude and time course of these changes were very similar for the two routes despite an up to 400-fold difference in serum GM-CSF levels at the same time points. Changes in leukocyte count and differential and neutrophil function were also similar over the 3-week period after both i.v. and i.p. administration. In the only patient who had i.p. GM-CSF levels assayed, i.p. administration achieved high levels of GM-CSF in peritoneal fluid (Cmax 343 ng/ml) with maintenance of high concentrations over 24 h (C24h 128 ng/ml).(ABSTRACT TRUNCATED AT 250 WORDS)

The development of a test of speech reception disability for use in 5- to 8-year-old children with otitis media with effusion

The study aims to develop a test of speech reception disability under simulated classroom conditions for use in young (5-8 year old) schoolchildren, to manage children with otitis media with effusion more effectively. A new video test, TADAST (Two Alternative Auditory Disability and Speech Reception Test), has been constructed in stages by extensively modifying the FADAST (Four Alternative) currently used to assess auditory disability in adults. Minimal word pair lists which were easily identifiable in picture form were developed and refined, and then formulated as a two alternative forced choice picture test. The distribution characteristics of the new test were defined in 89 schoolchildren with and without otitis media with effusion (OME) and compared with pure-tone audiometry performed at the same time. The test correlated highly with audiometry in older children. The distribution characteristics revealed a considerable proportion of children with bilateral OME with little functional disability who might otherwise be at risk of surgery. The test appeared to be sensitive to a 'history of OME' effect. Further refinements are needed to develop a final version which could also be used to evaluate hearing disability in 4-year-old children.

In search of missing links in otology. III. Development of a new animal model for cholesteatoma

An experimental study was conducted in chinchillas regarding the pathogenesis of acquired cholesteatoma (keratoma). The placement of a chemically modified gelatin membrane from the external auditory canal to the promontory through a tympanic membrane perforation stimulated squamous epithelial cell migration. Cholesteatoma formation with the presence of keratin debris and inflammatory reactions was observed in the middle ear and anterior bulla in 53.5% of the experimental animals. These experimental findings show for the first time the presence of epithelial migration and true cholesteatoma formation in the middle ear of chinchillas in an experimental model with deliberate perforation of the tympanic membrane. Erosion of the cochlear walls was observed in areas with granulation tissue and cholesteatoma. The importance and significance of the migration of squamous epithelium and of the middle ear inflammatory reaction in the genesis of acquired cholesteatomas are discussed.

A phase I trial of recombinant human interleukin-1 beta alone and in combination with myelosuppressive doses of 5-fluorouracil in patients with gastrointestinal cancer

We studied escalating doses of recombinant human interleukin-1 beta (IL-1 beta) alone and after a myelosuppressive dose of 5-fluorouracil (5-FU) in patients with gastrointestinal cancer. Transient neutropenia, monocytopenia, and lymphocytopenia were observed followed by a 1.3- to 6.0-fold (mean, 3.46-fold) dose-dependent neutrophil leukocytosis (P less than .00001) on the days of IL-1 beta administration. Increases in platelet counts were observed at a median of 14 days (range, 6 to 23) after IL-1 beta administration. Transient hypoglycemia, rebound hyperglycemia, elevations in serum cortisol, and C-reactive protein were observed. Side effects included fever, rigors, and headache in the majority of patients. Hypotension was observed in three of five patients at the highest dose level (0.1 micrograms/kg) and was dose-limiting. Fewer days of neutropenia were noted after 5-FU plus IL-1 beta than after 5-FU alone; however, this difference did not reach statistical significance. These data show that IL-1 beta has stimulatory effects in human hematopoiesis.