Mobilisation and analyses of publicly available SARS-CoV-2 data for pandemic responses

The COVID-19 pandemic has seen large-scale pathogen genomic sequencing efforts, becoming part of the toolbox for surveillance and epidemic research. This resulted in an unprecedented level of data sharing to open repositories, which has actively supported the identification of SARS-CoV-2 structure, molecular interactions, mutations and variants, and facilitated vaccine development and drug reuse studies and design. The European COVID-19 Data Platform was launched to support this data sharing, and has resulted in the deposition of several million SARS-CoV-2 raw reads. In this paper we describe (1) open data sharing, (2) tools for submission, analysis, visualisation and data claiming (e.g. ORCiD), (3) the systematic analysis of these datasets, at scale via the SARS-CoV-2 Data Hubs as well as (4) lessons learnt. This paper describes a component of the Platform, the SARS-CoV-2 Data Hubs, which enable the extension and set up of infrastructure that we intend to use more widely in the future for pathogen surveillance and pandemic preparedness.

Abstract 3105: PDCM Finder: An open global cancer research platform for patient-derived cancer models

PDCM Finder (https://cancermodels.org) is a new portal that aggregates patient-derived models (xenografts, cell lines and organoids) from 27 academic and commercial providers, enables users to search and compare over 6000 models and associated molecular data, and connects users with model providers to facilitate collaboration among researchers.

Users can search for models of interest by either (1) exploring molecular data summaries for models of specific cancer types, or (2) using the intuitive search and faceted filtering options of the web user interface or (3) access resource database via REST API to run their own analysis. The data includes gene expression, gene mutation, copy number alteration, cytogenetics, patient treatment and drug dosing studies. We link external resources like publication platforms and cancer specific annotation tools enabling exploration and prioritization of PDCM variation data (COSMIC, CIViC, OncoMX, OpenCRAVAT).

In addition to exploring PDCM metadata and data, the portal enables users to validate their PDX models against PDX MI standard, get a FAIRness score of the model of interest, explore originating resource data processing protocols, training materials and contact the model supplier/provider.

PDCM Finder builds on the success of the PDX Finder resource (PMID:30535239). Critical PDCM attributes, such as diagnosis, drug names and genes, are harmonized and integrated into a cohesive ontological model based on the PDX Minimal information standard (PDX MI, PMID: 29092942). PDX MI has become established in the community for data exchange, adopted by the PDX providers, consortia and informatics tools integrating PDX data. We are working with the community on the PDCM Minimal Information standard in an effort to make PDCM datasets adhere to the FAIR data principles. We are driving the development of and promoting the use of descriptive standards to facilitate data interoperability and promote global sharing of models. We provide expertise and software components to support several worldwide consortia including PDXNet, PDMR and EurOPDX. PDCM Finder is freely available under an Apache 2.0 license (https://github.com/PDCMFinder). This work is supported by NCI U24 CA204781 01, U24 CA253539, and R01 CA089713. We welcome feedback on the resource and are looking for participants for usability studies - please get in touch if interested.

Citation Format: Zinaida Perova, Csaba Halmagyi, Alex Follette, Mauricio Martinez, Federico Lopez-Gomez, Jeremy Mason, Abayomi Mosaku, Nathalie Conte, Ross Thorne, Steven Neuhauser, Dale Begley, Debra Krupke, Terrence Meehan, Carol Bult, Helen Parkinson. PDCM Finder: An open global cancer research platform for patient-derived cancer models [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 3105.

The EurOPDX Data Portal: an open platform for patient-derived cancer xenograft data sharing and visualization

Background

Patient-derived xenografts (PDX) mice models play an important role in preclinical trials and personalized medicine. Sharing data on the models is highly valuable for numerous reasons – ethical, economical, research cross validation etc. The EurOPDX Consortium was established 8 years ago to share such information and avoid duplicating efforts in developing new PDX mice models and unify approaches to support preclinical research. EurOPDX Data Portal is the unified data sharing platform adopted by the Consortium.

Main body

In this paper we describe the main features of the EurOPDX Data Portal (https://dataportal.europdx.eu/), its architecture and possible utilization by researchers who look for PDX mice models for their research. The Portal offers a catalogue of European models accessible on a cooperative basis. The models are searchable by metadata, and a detailed view provides molecular profiles (gene expression, mutation, copy number alteration) and treatment studies. The Portal displays the data in multiple tools (PDX Finder, cBioPortal, and GenomeCruzer in future), which are populated from a common database displaying strictly mutually consistent views.

(Short) Conclusion

EurOPDX Data Portal is an entry point to the EurOPDX Research Infrastructure offering PDX mice models for collaborative research, (meta)data describing their features and deep molecular data analysis according to users’ interests.

The European Nucleotide Archive in 2021

The European Nucleotide Archive (ENA, https://www.ebi.ac.uk/ena), maintained at the European Molecular Biology Laboratory's European Bioinformatics Institute (EMBL-EBI) provides freely accessible services, both for deposition of, and access to, open nucleotide sequencing data. Open scientific data are of paramount importance to the scientific community and contribute daily to the acceleration of scientific advance. Here, we outline the major updates to ENA’s services and infrastructure that have been delivered over the past year.

The COVID-19 Data Portal: accelerating SARS-CoV-2 and COVID-19 research through rapid open access data sharing

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic will be remembered as one of the defining events of the 21st century. The rapid global outbreak has had significant impacts on human society and is already responsible for millions of deaths. Understanding and tackling the impact of the virus has required a worldwide mobilisation and coordination of scientific research. The COVID-19 Data Portal (https://www.covid19dataportal.org/) was first released as part of the European COVID-19 Data Platform, on April 20th 2020 to facilitate rapid and open data sharing and analysis, to accelerate global SARS-CoV-2 and COVID-19 research. The COVID-19 Data Portal has fortnightly feature releases to continue to add new data types, search options, visualisations and improvements based on user feedback and research. The open datasets and intuitive suite of search, identification and download services, represent a truly FAIR (Findable, Accessible, Interoperable and Reusable) resource that enables researchers to easily identify and quickly obtain the key datasets needed for their COVID-19 research.

A KMT2A-AFF1 gene regulatory network highlights the role of core transcription factors and reveals the regulatory logic of key downstream target genes

Regulatory interactions mediated by transcription factors (TFs) make up complex networks that control cellular behavior. Fully understanding these gene regulatory networks (GRNs) offers greater insight into the consequences of disease-causing perturbations than can be achieved by studying single TF binding events in isolation. Chromosomal translocations of the lysine methyltransferase 2A (KMT2A) gene produce KMT2A fusion proteins such as KMT2A-AFF1 (previously MLL-AF4), causing poor prognosis acute lymphoblastic leukemias (ALLs) that sometimes relapse as acute myeloid leukemias (AMLs). KMT2A-AFF1 drives leukemogenesis through direct binding and inducing the aberrant overexpression of key genes, such as the anti-apoptotic factor BCL2 and the proto-oncogene MYC However, studying direct binding alone does not incorporate possible network-generated regulatory outputs, including the indirect induction of gene repression. To better understand the KMT2A-AFF1-driven regulatory landscape, we integrated ChIP-seq, patient RNA-seq, and CRISPR essentiality screens to generate a model GRN. This GRN identified several key transcription factors such as RUNX1 that regulate target genes downstream of KMT2A-AFF1 using feed-forward loop (FFL) and cascade motifs. A core set of nodes are present in both ALL and AML, and CRISPR screening revealed several factors that help mediate response to the drug venetoclax. Using our GRN, we then identified a KMT2A-AFF1:RUNX1 cascade that represses CASP9, as well as KMT2A-AFF1-driven FFLs that regulate BCL2 and MYC through combinatorial TF activity. This illustrates how our GRN can be used to better connect KMT2A-AFF1 behavior to downstream pathways that contribute to leukemogenesis, and potentially predict shifts in gene expression that mediate drug response.

BET inhibition disrupts transcription but retains enhancer-promoter contact

Enhancers are DNA sequences that enable complex temporal and tissue-specific regulation of genes in higher eukaryotes. Although it is not entirely clear how enhancer-promoter interactions can increase gene expression, this proximity has been observed in multiple systems at multiple loci and is thought to be essential for the maintenance of gene expression. Bromodomain and Extra-Terminal domain (BET) and Mediator proteins have been shown capable of forming phase condensates and are thought to be essential for super-enhancer function. Here, we show that targeting of cells with inhibitors of BET proteins or pharmacological degradation of BET protein Bromodomain-containing protein 4 (BRD4) has a strong impact on transcription but very little impact on enhancer-promoter interactions. Dissolving phase condensates reduces BRD4 and Mediator binding at enhancers and can also strongly affect gene transcription, without disrupting enhancer-promoter interactions. These results suggest that activation of transcription and maintenance of enhancer-promoter interactions are separable events. Our findings further indicate that enhancer-promoter interactions are not dependent on high levels of BRD4 and Mediator, and are likely maintained by a complex set of factors including additional activator complexes and, at some sites, CTCF and cohesin.

Abstract 3212: PDX Finder: Largest global catalog of patient tumor derived xenograft models

Patient-derived tumor xenograft (PDX) models are a critical oncology platform for cancer research, drug development and personalized medicine. Because of the heterogeneous nature of PDX repositories, finding models of interest is a challenge. The Jackson Laboratory and EMBL-EBI are developing PDX Finder, the world's largest open PDX database containing phenomic information of over 2900 models (www.pdxfinder.org, †). In support of this initiative, we developed the PDX Minimal Information standard (PDX-MI) which defines the minimal necessary metadata required to describe models (††). Within PDX Finder, critical attributes like diagnosis, drug names or genes are harmonized into a cohesive ontological data model based on PDX-MI. An intuitive, faceted search interface allows users to select models based on clinical/PDX attributes, tumor markers, dataset availability and/or drug dosing results. We provide PDX, patient, drug and molecular data details pages where all available information can be browsed and downloaded. To further facilitate users' model selection, we link key external resources like publication platforms and cancer specific annotation tools, enabling exploration and prioritisation of PDX variation data (COSMIC, CivicDb, OpenCRAVAT). Links to originating resource protocols and contact information are provided, facilitating data understanding and further collaboration.

Alongside database development activities, PDX Finder has undertaken activities to tackle areas of standards and tool development, data integration and outreach. PDX Finder provides key expertise and software components to support several worldwide consortia including PDXNet, PDMR and EurOPDX. We are driving the development of, and promoting the use of descriptive standards to facilitate data interoperability and promote global sharing of models. Our standard has become established in the community for data exchange, adopted by PDX providers, consortia, and informatic tools integrating PDX data. It has been re-used by different initiatives in the context of data collection and data modelling allowing adherence to the FAIR data principles - Findability, Accessibility, Interoperability and Reusability. PDX Finder is increasing awareness of PDX models, facilitating data integration, and enabling international collaboration, maximising the investment in, and translational capabilities of these important models of human cancer.

PDX Finder is freely available under an Apache 2 license (github.com/pdxfinder). Work supported by NCI U24 CA204781 01, R01 CA089713 and the European Molecular Biology Laboratory.

† Conte et al, 2019. PDX Finder: A Portal for Patient-Derived tumor Xenograft Model Discovery. NAR, 2019 Jan.†† Meehan, Conte et al, 2017. PDX-MI: Minimal Information for Patient-Derived Tumor Xenograft Models. Cancer Res. 2017 Nov.PDXNet: www.pdxnetwork.org, PDMR: pdmr.cancer.gov, EUROPDX: www.europdx.eu

Citation Format: Nathalie Conte, Csaba Halmagyi, Abayomi Mosaku, Jeremy C. Mason, Alex W. Follette, Ross Thorne, Steven Neuhauser, Dale Begley, Debbie M. Krupke, Helen Parkinson, Terrence Meehan, Carol Bult. PDX Finder: Largest global catalog of patient tumor derived xenograft models [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 3212.

H3K79me2/3 controls enhancer-promoter interactions and activation of the pan-cancer stem cell marker PROM1/CD133 in MLL-AF4 leukemia cells

MLL gene rearrangements (MLLr) are a common cause of aggressive, incurable acute lymphoblastic leukemias (ALL) in infants and children, most of which originate in utero. The most common MLLr produces an MLL-AF4 fusion protein. MLL-AF4 promotes leukemogenesis by activating key target genes, mainly through recruitment of DOT1L and increased histone H3 lysine-79 methylation (H3K79me2/3). One key MLL-AF4 target gene is PROM1, which encodes CD133 (Prominin-1). CD133 is a pentaspan transmembrane glycoprotein that represents a potential pan-cancer target as it is found on multiple cancer stem cells. Here we demonstrate that aberrant PROM1/CD133 expression is essential for leukemic cell growth, mediated by direct binding of MLL-AF4. Activation is controlled by an intragenic H3K79me2/3 enhancer element (KEE) leading to increased enhancer–promoter interactions between PROM1 and the nearby gene TAPT1. This dual locus regulation is reflected in a strong correlation of expression in leukemia. We find that in PROM1/CD133 non-expressing cells, the PROM1 locus is repressed by polycomb repressive complex 2 (PRC2) binding, associated with reduced expression of TAPT1, partially due to loss of interactions with the PROM1 locus. Together, these results provide the first detailed analysis of PROM1/CD133 regulation that explains CD133 expression in MLLr ALL.

A review of permanent marking for radiotherapy in the UK

INTRODUCTION

This paper presents the results of a survey of the routine use of permanent marks for radiotherapy in the UK. This was undertaken to provide an overview of current practice. Permanent marks are a somewhat invasive procedure, and should be subject to scrutiny and judicious application.

METHOD

The authors reviewed the literature on international radiotherapy permanent marking practice. Common themes that emerged were the psychology of permanent marking and ink-type considerations, current practice and training, and safety. These were used to develop a questionnaire in order to form an overview of the use of marks nationally, and to identify any recurrent issues. The questionnaire also sought information regarding locations and numbers of permanent marks used for common treatment sites. The survey was sent to 71 departments in the UK using email.

RESULTS

70% of departments responded. 62% of departments reported patients who had refused permanent marks. The reasons for refusal varied. India or drawing ink was used in 49 of the 51 departments (96%). The most common teaching method of tattooing involved combined observation and verbal coaching. Most departments had a written procedure for tattooing, but some did not. Although sharps injuries were rare, they were documented.

CONCLUSION

Most departments in the UK had encountered patient refusal of permanent marks, with breast patients representing the largest group which declined. There is variation in practice throughout the UK, and the equipment used is not specialised for tattooing purposes. Sharps injuries, although rare, do occur, and training methods are not consistent.

IMPLICATIONS FOR PRACTICE

The requirement for national guidelines is posited. Further investigation into the need for permanent marks in an era of state-of-the-art imaging technology is also required.

DOT1L inhibition reveals a distinct subset of enhancers dependent on H3K79 methylation

Enhancer elements are a key regulatory feature of many important genes. Several general features including the presence of specific histone modifications are used to demarcate potentially active enhancers. Here we reveal that putative enhancers marked with H3 lysine 79 (H3K79) di or trimethylation (me2/3) (which we name H3K79me2/3 enhancer elements or KEEs) can be found in multiple cell types. Mixed lineage leukemia gene (MLL) rearrangements (MLL-r) such as MLL-AF4 are a major cause of incurable acute lymphoblastic leukemias (ALL). Using the DOT1L inhibitor EPZ-5676 in MLL-AF4 leukemia cells, we show that H3K79me2/3 is required for maintaining chromatin accessibility, histone acetylation and transcription factor binding specifically at KEEs but not non-KEE enhancers. We go on to show that H3K79me2/3 is essential for maintaining enhancer-promoter interactions at a subset of KEEs. Together, these data implicate H3K79me2/3 as having a functional role at a subset of active enhancers in MLL-AF4 leukemia cells.

Jupiter's interior and deep atmosphere: The initial pole-to-pole passes with the Juno spacecraft

On 27 August 2016, the Juno spacecraft acquired science observations of Jupiter, passing less than 5000 kilometers above the equatorial cloud tops. Images of Jupiter's poles show a chaotic scene, unlike Saturn's poles. Microwave sounding reveals weather features at pressures deeper than 100 bars, dominated by an ammonia-rich, narrow low-latitude plume resembling a deeper, wider version of Earth's Hadley cell. Near-infrared mapping reveals the relative humidity within prominent downwelling regions. Juno's measured gravity field differs substantially from the last available estimate and is one order of magnitude more precise. This has implications for the distribution of heavy elements in the interior, including the existence and mass of Jupiter's core. The observed magnetic field exhibits smaller spatial variations than expected, indicative of a rich harmonic content.

MLL-AF4 binds directly to a BCL-2 specific enhancer and modulates H3K27 acetylation

Survival rates for children and adults carrying mutations in the Mixed Lineage Leukemia (MLL) gene continue to have a very poor prognosis. The most common MLL mutation in acute lymphoblastic leukemia is the t(4;11)(q21;q23) chromosome translocation that fuses MLL in-frame with the AF4 gene producing MLL-AF4 and AF4-MLL fusion proteins. Previously, we found that MLL-AF4 binds to the BCL-2 gene and directly activates it through DOT1L recruitment and increased H3K79me2/3 levels. In the study described here, we performed a detailed analysis of MLL-AF4 regulation of the entire BCL-2 family. By measuring nascent RNA production in MLL-AF4 knockdowns, we found that of all the BCL-2 family genes, MLL-AF4 directly controls the active transcription of both BCL-2 and MCL-1 and also represses BIM via binding of the polycomb group repressor 1 (PRC1) complex component CBX8. We further analyzed MLL-AF4 activation of the BCL-2 gene using Capture-C and identified a BCL-2-specific enhancer, consisting of two clusters of H3K27Ac at the 3' end of the gene. Loss of MLL-AF4 activity results in a reduction of H3K79me3 levels in the gene body and H3K27Ac levels at the 3' BCL-2 enhancer, revealing a novel regulatory link between these two histone marks and MLL-AF4-mediated activation of BCL-2.

Subdivision of essential tremor patients according to physiologic characteristics

OBJECTIVE

To test the effect of different forearm postures on tremor characteristics. We hypothesized that changes in tremor characteristics in relation to posture can subclassify essential tremor (ET) patients.

METHODS

Fourteen ET patients were tested while seated and holding a full cup in three well-defined arm postures: 15 cm above the armrest, elbow at 90 degrees flexion and when the cup was near the mouth. Hand movements were recorded using a triaxial accelerometer. Concomitantly, we recorded surface electromyogram (EMG) signals from the wrist extensor muscles. Hand acceleration and the primary tremor frequency from the power spectrum were calculated for each posture in two independent trials. The coherence at the primary tremor frequency between the EMG and the accelerometry signals was calculated.

RESULTS

ET patients could be classified into two groups: ET-1 (nine patients) had position-dependent peak frequencies while ET-2 (five patients) had position-independent peak frequencies. The latter group had significantly higher coherencies between EMG and accelerometry of tremor and insignificantly higher tremor amplitudes compared with ET-1. In both groups tremor amplitude increased when the hand was near the mouth.

CONCLUSION

The results suggest that ET patients can be classified based on the position dependence of frequency and other physiologic properties.

Hand rhythmic tapping and timing in Parkinson's disease

BACKGROUND

Dysrhythmia is one of the features frequently associated with the motor disturbance in Parkinson's disease (PD). The mechanism responsible for this phenomenon is not known.

OBJECTIVES

To assess the rhythmic movements of the hand in PD patients in general and in parkinsonian subtypes.

METHODS

Fifty-one PD patients (32 males) with mean age 66.3 +/- 9.1 years (6.6 years of symptoms) and 36 healthy controls (age 64.9 +/- 13.2, range 40-85) were studied. Subjects were asked to tap with their dominant or less affected arm on a digitized switch board at their most comfortable pace (16 s), fastest tapping speed (12 s), and at different frequencies provided by a metronome. The mean rhythm and the tap-to-tap variation were compared. Performance of the PD patients and control subjects were compared, as there were different subtypes of PD patients. Patients were subclassified into: tremor predominant (TP) (14 patients), freezing predominant (FP) (11 patients), akinetic-rigid (AR) (12 patients) and an unclassified group (UC) (14 patients). Results. There was no significance difference between patients and controls in the self-chosen, most comfortable tapping rate or in the tap-to-tap variation of the self-paced task. PD patients tapped at a significantly slower rate than controls when asked to tap at their fastest rate (4.39 +/- 1.32 vs. 5.14 +/- 1.31 Hz; p < 0.01). This difference was the result of an especially slow performance of the TP and AR subgroups (3.85+/-1.20 and 3.88+/-1.46, respectively; p < 0.01 compared to the control group). TP was the only subgroup to show an increased tap-to-tap variation at their fastest tapping rate compared to the control group (0.070 +/- 0.057 vs. 0.029 +/- 0.025 s, respectively, p < 0.05). The TP subgroup also showed hastening when they followed an externally given rhythm of 2.5 Hz and they tapped at 2.73 +/- 0.36 Hz p < 0.05).

CONCLUSIONS

Externally driven and self-paced tapping are preserved in patients with PD, when examined at their best 'on' state. The tremor predominant subgroup seems to have specific pacing disturbances.

Ultra-relativistic electrons in Jupiter's radiation belts

Ground-based observations have shown that Jupiter is a two-component source of microwave radio emission: thermal atmospheric emission and synchrotron emission from energetic electrons spiralling in Jupiter's magnetic field. Later in situ measurements confirmed the existence of Jupiter's high-energy electron-radiation belts, with evidence for electrons at energies up to 20[?]MeV. Although most radiation belt models predict electrons at higher energies, adiabatic diffusion theory can account only for energies up to around 20[?]MeV. Unambiguous evidence for more energetic electrons is lacking. Here we report observations of 13.8[?]GHz synchrotron emission that confirm the presence of electrons with energies up to 50[?]MeV; the data were collected during the Cassini fly-by of Jupiter. These energetic electrons may be repeatedly accelerated through an interaction with plasma waves, which can transfer energy into the electrons. Preliminary comparison of our data with model results suggests that electrons with energies of less than 20[?]MeV are more numerous than previously believed.

Health status in 52 long-term survivors of pediatric brain tumors

The percentage of children who survive childhood brain tumors is increasing. A number have neurological and other sequelae which impact on the quality of their survival. We reviewed long-term survivors using a standardized health status instrument. The mothers of 52 survivors of brain tumors were surveyed. Eight different aspects (attributes) of health status were scored. The first 6 of these attributes were scored in a health status index (HSI) developed at McMaster University. Subgroup analysis was performed. Limitation in the quality of life was found in one of the 8 attributes in all but 2 of the subjects. The health status index (HSI) score using the first 6 attributes of this survey had a median of 0.73 (range 0.16-1.00). This score is lower than that found in previously surveyed survivors of leukemia or other childhood cancers. Examination of age at diagnosis, extent of surgery, sex and therapeutic modalities used showed no correlation with HSI score. Those with supratentorial astrocytomas had a lower HSI score (0.65) than those with infratentorial astrocytomas (0.85) (p = 0.05). Children with craniopharyngiomas had a poor score (0.64). This survey shows that the survivors of brain tumors have an appreciable burden of morbidity. Most have deficits in health status that affect many areas of their lives. Apart from site of the primary tumor, there was little correlation between subgroups studied and health status. The health status of children who survive brain tumors is lower than that of survivors of other childhood malignancies.

Health status in 52 long-term survivors of pediatric brain tumors

The percentage of children who survive childhood brain tumors is increasing. A number have neurological and other sequelae which impact on the quality of their survival. We reviewed long-term survivors using a standardized health status instrument. The mothers of 52 survivors of brain tumors were surveyed. Eight different aspects (attributes) of health status were scored. The first 6 of these attributes were scored in a health status index (HSI) developed at McMaster University. Subgroup analysis was performed. Limitation in the quality of life was found in one of the 8 attributes in all but 2 of the subjects. The health status index (HSI) score using the first 6 attributes of this survey had a median of 0.73 (range 0.16-1.00). This score is lower than that found in previously surveyed survivors of leukemia or other childhood cancers. Examination of age at diagnosis, extent of surgery, sex and therapeutic modalities used showed no correlation with HSI score. Those with supratentorial astrocytomas had a lower HSI score (0.65) than those with infratentorial astrocytomas (0.85) (p = 0.05). Children with craniopharyngiomas had a poor score (0.64). This survey shows that the survivors of brain tumors have an appreciable burden of morbidity. Most have deficits in health status that affect many areas of their lives. Apart from site of the primary tumor, there was little correlation between subgroups studied and health status. The health status of children who survive brain tumors is lower than that of survivors of other childhood malignancies.

Role of ganglionic cotransmission in sympathetic control of the isolated bullfrog aorta

1. The relation between preganglionic activity and arterial tone was studied in preparations of bullfrog lumbar sympathetic ganglia 7-10 and the dorsal aorta. 2. Two or more stimuli evoked contractions when applied to the preganglionic C, but not the B pathway. Contractions were blocked when transmission in ganglia 9 and 10 was disrupted by cutting the sympathetic chain or adding (+)-tubocurarine. Contractions were antagonized by postganglionic action of guanethidine, but not by phentolamine or suramin. 3. Aortic responses to short trains (10-100 stimuli) were half-maximal at 0.3-0.5 Hz, saturated near 1 Hz and had a minimum latency of 8.9 s. By contrast, responses to 300 stimuli were half-maximal at 1 Hz and became 2.5-fold larger at 10 Hz. 4. Exogenous luteinizing hormone releasing hormone (LHRH) potentiated preganglionically evoked contractions. Endogenous LHRH mediated contractions evoked by 10 Hz stimulation in (+)-tubocurarine. These responses had a longer latency than in normal Ringer solution and were blocked by [D-pGlu1, D-Phe2, D-Trp3.6]-LHRH. The LHRH antagonist did not alter contractions evoked by continuous stimulation in normal Ringer solution or by bursts of stimuli in hexamethonium. 5. Exogenous neuropeptide Y (NPY) potentiated neurogenic contractions and responses to adrenaline. Benextramine blocked contractions produced by nerve stimulation, adrenaline and NPY, but not ATP. 6. The results show that contractions of the isolated aorta are tuned to physiological frequencies of activity in sympathetic C neurones. Peptidergic cotransmission in the ganglia can increase arterial tension, but not during synchronous activation of primary nicotinic synapses. It is suggested that the physiological role of LHRH arises from interactions with subthreshold nicotinic EPSPs and that postganglionic release of NPY shifts frequency tuning of the circuit during prolonged activity.

Cystic angiomatosis: case report and review of the literature

The objective of this article was to offer a better characterization of the typical clinical presentation, radiologic findings, histology, treatment approaches, and differential diagnosis of cystic angiomatosis, a rare condition of which previous reports have been confusing because of unclear diagnostic criteria, different classifications, and variations in terminology. A case report using the improved imaging techniques of computed tomography scanning is presented in addition to an analysis and review of the previous literature, which relied heavily on plain film radiography, biopsy, and necropsy for diagnosis. A case report of a 26-year-old man initially symptomatic at age 12 is presented. Although a rare condition, cystic angiomatosis must be considered in pediatric and young adult patients presenting with diffuse, multifocal, cystic skeletal lesions, with or without visceral involvement.

Radon in Devon and Cornwall and paediatric malignancies

Exposure to radon in dwellings may cause cancer including paediatric malignancies. Devon and Cornwall have the highest exposure to radon of the counties of England. However, within these counties there is considerable variation in exposure. Exposure to radon in the 283 postcode sectors of the two counties has been published. The incidence of childhood malignancies between 1976 and 1985 was studied to compare postcode sectors of radon exposures > or = 100 Bq/m3 with sectors < 100 Bq/m3. No significant difference in the incidence rate of 106.7 per million child years in the high radon postcode sectors and 121.7 in the low (P = 0.29) was found. When the incidences of individual tumours were examined, a significantly increased rate of neuroblastoma (P = 0.02) and a non-significant increased rate of acute myeloid leukaemia were found in the high exposure postcode sectors. No association between radon exposure and overall rate of childhood malignancy was found.

Intracranial ependymomas: analysis of prognostic factors in a population-based series

A retrospective study of 31 children presenting in the period 1976-1993 with intracranial ependymomas in the south-west region of the UK was performed. The diagnosis was confirmed by histological review and several histological variables recorded, including pleomorphism, cellularity, numbers of mitotic figures and extent of necrosis. Histological features, presentation and treatment were correlated with outcome. Eleven patients had supratentorial primaries and 20 infratentorial primaries. Seven patients had macroscopically complete resections of which 5 had supratentorial primaries. Eight patients had no other therapy apart from surgery. Six patients received craniospinal irradiation, 11 had involved-field irradiation and 14 did not have radical radiotherapy. Twelve patients received chemotherapy. Eleven patients are relapse-free at a median of 43 months. Of the 20 relapses, 19 were local and only 1 metastatic. The grade of the tumor assigned at presentation had no correlation with outcome. On histological review, the only feature that had a significant correlation (p = 0.05) with survival was tumor cellularity. There was a survival advantage for a supratentorial primary site (p = 0.04). The event-free survival was significantly longer for patients diagnosed after 1986 than before (p = 0.006). Survival was not significantly affected by radiotherapy or chemotherapy. Children who had had a macroscopically complete excision of the tumor had a 5-year survival of 69% as opposed to 47% for those who had incomplete surgery, but this difference is not significant (p = 0.13). The data suggest that: (1) the event-free survival rate has improved significantly with time; (2) there is little correlation between a variety of pathological features and outcome, and (3) failure at the primary site is the major obstacle to improved cure rates. The role of complete resection, including second-look surgery, needs further evaluation.

An aortic projection of lumbar paravertebral sympathetic neurons in the bullfrog

A population of sympathetic neurons which projects from paravertebral ganglia to the dorsal aorta was identified in the bullfrog based on its electrophysiology and anatomy. The aorta is bilaterally supplied by about a dozen connective nerves arising from sympathetic ganglia 7-10. From compound action potentials, the majority of fibers can be identified as postganglionic axons belonging to both the B- and C-cell groups. Tracing experiments indicated that 95 +/- 21 (mean +/- SD) neurons project into each connective and that axons in connectives penetrate the wall of the aorta where they break into small bundles. Staining wholemounts of the aorta for neuropeptide Y revealed a plexus of varicose axons which presumably arise from sympathetic C neurons. These observations imply that the aorta is sympathetically innervated by paravertebral C neurons.

Childhood malignancies in the south-west region of England, 1976-1985

The incidence and pattern of childhood cancer in the South-West Region of the United Kingdom was studied in the period 1976-1985 to see if there was any unevenness in distribution. This region consists of five counties with considerable variation in radon exposure and urbanisation. Cases were identified from multiple sources and the basis of the diagnosis reviewed. Internationally accepted diagnostic categories were used. Six hundred seventy-eight cases were found, giving an age standardised incidence rate of 114.2 per million childhood years. The incidence of different cancers by sex was strikingly similar to the Manchester Children's Tumour Registry, from a noncontiguous region, with three exceptions. In the South-West, there was a higher rate of soft tissue sarcoma in boys (P = 0.01) and lower rates of sympathetic nervous system and germ-cell tumours in girls (P = 0.01 and P = 0.04, respectively). There was no significant variation in cancer incidence among the five counties or with time. The incidence rate in counties of high radon exposure was not higher than with low radon exposure. The overall incidence in counties with urban districts was not significantly increased compared to those without, although there was a nonsignificant trend towards a higher incidence of leukaemia (P = 0.08). The incidence and type of childhood cancer are similar to those in a noncontiguous region. Geographical and temporal incidence are remarkably stable. Local environmental variation may not play a major role in the causality of childhood cancer.

Ganglionic and arterial release of neuropeptide Y by bullfrog sympathetic neurons

Sympathetic C neurons in lumbar paravertebral ganglia of the bullfrog have previously been shown to be vasomotor in function and to express neuropeptide Y (NPY). In the present experiments, a sensitive radioimmunoassay was used to measure the NPY content of ganglia and the descending abdominal aorta and to measure the overflow of NPY evoked by depolarizing concentrations of K+. Paravertebral ganglia 9 and 10 contain 3.1 pg NPY/micrograms protein and the aorta contains 0.18 pg NPY/micrograms protein. During 20-min depolarizations in high K+ (58 mM) Ringer, the ganglia released approximately 5% of their NPY content and the aorta released approximately 2% of its NPY content. Pretreatment of the tissues with Ringer containing 0.18 mM Ca2+, 8 mM Mg2+, and 1 mM Co2+ blocked the NPY release elicited by high K+. These findings provide further evidence that NPY is a postganglionic co-transmitter in sympathetic C neurons of the bullfrog.

Exercise stress alters the percentage of splenic lymphocyte subsets in response to mitogen but not in response to interleukin-1

Results of previous work from this laboratory demonstrated that reduced murine splenic lymphocyte proliferation in response to Concanavalin A (Con A) is associated with acute exercise stress. The present study was conducted to determine whether the stress of physical work further affects the expression of splenic lymphocyte phenotypes following in vitro stimulation by the T-cell mitogen, Con A, and also by interleukin-1 (IL1). Mice in this study were assigned to one of five treatment conditions. Two groups of mice were exposed only to the noise and vibration of a treadmill for 8 weeks; one of these groups was given an acute exhaustive run. Three groups of mice were exposed to 8 weeks of treadmill training: one group was sacrificed immediately after training, a second group was sacrificed 72 h after training, and a third group was rested for 72 h and then given an acute exhaustive run. There was a significant effect of stimulation by Con A on the percentage of splenic lymphocytes positive for Thy1.2, Lyt-2, L3T4, and goat anti-mouse Ig, regardless of treatment condition. Acute exercise, however, affected the magnitude of the response. There was a significantly greater increase in the percentage of Thy1.2+ and, especially of, Lyt-2+ cells in stimulated splenic lymphocytes from untrained mice given an exhaustive exercise session compared with controls and with trained mice. There was no significant effect of the addition of IL1 to any culture, irrespective of treatment condition. These results suggest that reduced mitogenesis after acute exercise stress exposure may be related to the increased appearance of Lyt-2+ (T suppressor) cells.

Exercise stress alters murine lymphocyte subset distribution in spleen, lymph nodes and thymus

Our previous work indicated that exercise stress in mice was associated with reduced splenic lymphocyte proliferation to T cell mitogens. The purpose of this study was to determine the effect of acute exercise stress and exercise training on the phenotype distribution of murine lymphocytes in the spleen, lymph nodes and thymus. In mice given an exhaustive bout of treadmill exercise, the percentage of Thy 1.2 and Lyt2 antigen bearing cells decreased in the thymus, but the percentage of L3T4-positive cells did not change significantly. Acute exercise did not alter the percentage of Thy1.2, L3T4 or Lyt2-positive cells in the secondary lymphoid compartments (nodes, spleen). By contrast, in mice given a chronic exercise training programme (8 weeks duration; 30 m/min, 8 degrees slope, 30 min/session, 5 daily sessions/week) followed by a 72 h rest period, the percentage of L3T4-positive cells increased by 53% in the spleen, 19% in the lymph nodes and 29% in the thymus compared with sedentary controls; no parallel increase in the percentage of Thy1.2 antigen bearing cells was observed. These results suggest that the effect of exercise on the frequencies of lymphocyte subpopulations in murine lymphoid compartments is dependent upon the chronicity of the stress and probably on the accompanying physiological adaptations to the stress.

Chronic exercise stress in mice depresses splenic T lymphocyte mitogenesis in vitro

This study investigated changes in functional response to splenic T lymphocytes of mitogens following acute and chronic exposure to endurance exercise. Splenic T cell response in vitro to concanavalin A (Con A) and the total number of lymphocytes per spleen were compared between mice assigned to the following treatment conditions: (a) exercise training (EX) by treadmill running (28 m/min, 8 degrees slope for 30 min, 5 times per week for 4 weeks preceded by 2 weeks of endurance build-up), (b) exercise training as above followed by a single, acute bout of exercise to exhaustion (EX + AC) (35 m/min, 8 degrees slope, 30 min to 2 h duration) (c) exposure to the novel environment for 6 weeks without exercise (control), and exposure to the novel environment as in (c) followed by a single, acute bout of exercise to exhaustion. Treadmill running for 6 weeks significantly enhanced succinate dehydrogenase activity in skeletal muscle compared to the sedentary, control condition, and was broadly interpreted as indicative of a training effect. EX mice had significantly reduced splenic lymphocyte proliferative responses to optimal and supraoptimal concentrations of Con A compared with control animals. Incorporation of [3H]thymidine into splenic lymphocytes from EX + AC mice was the most markedly depressed. Total number of lymphocytes per spleen was significantly lower in EX compared with control mice. These results suggests that chronic exercise challenge in mice is associated with T lymphocyte hyporesponsiveness in the secondary lymphoid organs, such as the spleen.

Lancefield Swamp and the Extinction of the Australian Megafauna

Excavations into the Australian swamp of Lancefield show that a bone bed dated at 26,000 years ago contains perhaps 10,000 giant extinct animals. Associated artifacts suggest that humans were in the area, but the direct cause of death of the animals is, on present evidence, not explicable. Such a recent date for the classic megafauna shows that it was living together with humans for at least 7000 years in southeast Australia. This enduring association argues against a catastrophic and rapid overkill in the Australian Pleistocene.