Reimagine fire science for the anthropocene

Fire is an integral component of ecosystems globally and a tool that humans have harnessed for millennia. Altered fire regimes are a fundamental cause and consequence of global change, impacting people and the biophysical systems on which they depend. As part of the newly emerging Anthropocene, marked by human-caused climate change and radical changes to ecosystems, fire danger is increasing, and fires are having increasingly devastating impacts on human health, infrastructure, and ecosystem services. Increasing fire danger is a vexing problem that requires deep transdisciplinary, trans-sector, and inclusive partnerships to address. Here, we outline barriers and opportunities in the next generation of fire science and provide guidance for investment in future research. We synthesize insights needed to better address the long-standing challenges of innovation across disciplines to (i) promote coordinated research efforts; (ii) embrace different ways of knowing and knowledge generation; (iii) promote exploration of fundamental science; (iv) capitalize on the "firehose" of data for societal benefit; and (v) integrate human and natural systems into models across multiple scales. Fire science is thus at a critical transitional moment. We need to shift from observation and modeled representations of varying components of climate, people, vegetation, and fire to more integrative and predictive approaches that support pathways toward mitigating and adapting to our increasingly flammable world, including the utilization of fire for human safety and benefit. Only through overcoming institutional silos and accessing knowledge across diverse communities can we effectively undertake research that improves outcomes in our more fiery future.

AB0707 RHEUMATOLOGY PATIENT CARE IN THE COVID-19 PANDEMIC: TELEMEDICINE, DELEGATION, PATIENT SATISFACTION AND VACCINATION BEHAVIOUR

Background:

Use of telemedicine in Germany has increased due to the COVID-19 lockdown. Between March and May 2020, government restrictions led to cancellation of routine outpatient appointments to limit viral spread and optimize resources.

Objectives:

This study assesses patient satisfaction of follow-up telemedicine appointments among patients known to be in disease remission, attending either secondary or tertiary care Rheumatology clinics. Appointments were conducted either by a rheumatologist or a qualified medical assistant for rheumatology (RFA). Additional data regarding perceived concerns arising from the COVID-19 pandemic as well as attitudes to vaccination were collected.

Methods:

Methods: Patients not requiring adjustment of their DMARDs at the two previous attendances were considered stable. At cancellation of the planned attendance, patients were offered participation in the study and provided verbal informed consent. Participants were randomized to a telemedicine appointment by either a physician or RFA. Telemedicine appointments consisted of a standardized patient interview, including assessment of disease activity (modified CDAI score), attitudes to vaccination as well as current vaccine status and concerns about COVID-19. Following participation, all patients received a pseudonymized postal questionnaire to evaluate appointment satisfaction (FAPI-Score).

Results:

In total 112/116 (96%) patients that were offered appointments, participated in the study (RA 50%, axSpA 30%, PsA 20%). Of these 88/112 (79%) returned their postal questionnaires. Overall patient satisfaction was excellent (mean 4.3/5 modified FAPI score) and did not differ between care setting or clinical status of the interviewer. RFAs conducted 19/112 (17%) of appointments, 6 (32%) of which required additional physician intervention. Change of DMARDs occurred in 19/112 (17%) appointments. Patients reporting a pain score ≥7 (VAS 1-10) were most dissatisfied with the telemedicine appointment (p=0.036). Concerns about COVID-19 correlated with disease activity: high disease activity (p = 0.031), presence of tender joints (p=0.001), high pain levels (p=0.009) correlated with concern of contracting COVID-19 or experiencing severe disease course. Only 38% of the patients had been vaccinated against pneumococci in the past 5 years and 54% had been vaccinated against influenza in 2019/2020.

Conclusion:

Telemedicine can contribute to patient care in stable patients. RFAs can also contribute to patient care especially for follow-up appointment when patients are in remission. Vaccination rates and motivation needs to be improved as influenza and pneumococcal vaccination is recommended to all patients with rheumatic diseases without contraindications.

Disclosure of Interests:

None declared

Combating ecosystem collapse from the tropics to the Antarctic

Globally, collapse of ecosystems-potentially irreversible change to ecosystem structure, composition and function-imperils biodiversity, human health and well-being. We examine the current state and recent trajectories of 19 ecosystems, spanning 58° of latitude across 7.7 M km² , from Australia's coral reefs to terrestrial Antarctica. Pressures from global climate change and regional human impacts, occurring as chronic 'presses' and/or acute 'pulses', drive ecosystem collapse. Ecosystem responses to 5-17 pressures were categorised as four collapse profiles-abrupt, smooth, stepped and fluctuating. The manifestation of widespread ecosystem collapse is a stark warning of the necessity to take action. We present a three-step assessment and management framework (3As Pathway Awareness, Anticipation and Action) to aid strategic and effective mitigation to alleviate further degradation to help secure our future.

Population collapse and retreat to fire refugia of the Tasmanian endemic conifer Athrotaxis selaginoides following the transition from Aboriginal to European fire management

Untangling the nuanced relationships between landscape, fire disturbance, human agency, and climate is key to understanding rapid population declines of fire-sensitive plant species. Using multiple lines of evidence across temporal and spatial scales (vegetation survey, stand structure analysis, dendrochronology, and fire history reconstruction), we document landscape-scale population collapse of the long-lived, endemic Tasmanian conifer Athrotaxis selaginoides in remote montane catchments in southern Tasmania. We contextualized the findings of this field-based study with a Tasmanian-wide geospatial analysis of fire-killed and unburned populations of the species. Population declines followed European colonization commencing in 1802 ad that disrupted Aboriginal landscape burning. Prior to European colonization, fire events were infrequent but frequency sharply increased afterwards. Dendrochronological analysis revealed that reconstructed fire years were associated with abnormally warm/dry conditions, with below-average streamflow, and were strongly teleconnected to the Southern Annular Mode. The multiple fires that followed European colonization caused near total mortality of A. selaginoides and resulted in pronounced floristic, structural vegetation, and fuel load changes. Burned stands have very few regenerating A. selaginoides juveniles yet tree-establishment reconstruction of fire-killed adults exhibited persistent recruitment in the period prior to European colonization. Collectively, our findings indicate that this fire-sensitive Gondwanan conifer was able to persist with burning by Aboriginal Tasmanians, despite episodic widespread forest fires. By contrast, European burning led to the restriction of A. selaginoides to prime topographic fire refugia. Increasingly, frequent fires caused by regional dry and warming trends and increased ignitions by humans and lightning are breaching fire refugia; hence, the survival Tasmanian Gondwanan species demands sustained and targeted fire management.

Potential greenhouse gas reductions from Natural Climate Solutions in Oregon, USA

Increasing concentrations of greenhouse gases (GHGs) are causing global climate change and decreasing the stability of the climate system. Long-term solutions to climate change will require reduction in GHG emissions as well as the removal of large quantities of GHGs from the atmosphere. Natural climate solutions (NCS), i.e., changes in land management, ecosystem restoration, and avoided conversion of habitats, have substantial potential to meet global and national greenhouse gas (GHG) reduction targets and contribute to the global drawdown of GHGs. However, the relative role of NCS to contribute to GHG reduction at subnational scales is not well known. We examined the potential for 12 NCS activities on natural and working lands in Oregon, USA to reduce GHG emissions in the context of the state's climate mitigation goals. We evaluated three alternative scenarios wherein NCS implementation increased across the applicable private or public land base, depending on the activity, and estimated the annual GHG reduction in carbon dioxide equivalents (CO2e) attributable to NCS from 2020 to 2050. We found that NCS within Oregon could contribute annual GHG emission reductions of 2.7 to 8.3 MMT CO2e by 2035 and 2.9 to 9.8 MMT CO2e by 2050. Changes in forest-based activities including deferred timber harvest, riparian reforestation, and replanting after wildfires contributed most to potential GHG reductions (76 to 94% of the overall annual reductions), followed by changes to agricultural management through no-till, cover crops, and nitrogen management (3 to 15% of overall annual reductions). GHG reduction benefits are relatively high per unit area for avoided conversion of forests (125-400 MT CO2e ha-1). However, the existing land use policy in Oregon limits the current geographic extent of active conversion of natural lands and thus, avoided conversions results in modest overall potential GHG reduction benefits (i.e., less than 5% of the overall annual reductions). Tidal wetland restoration, which has high per unit area carbon sequestration benefits (8.8 MT CO2e ha-1 yr-1), also has limited possible geographic extent resulting in low potential (< 1%) of state-level GHG reduction contributions. However, co-benefits such as improved habitat and water quality delivered by restoration NCS pathways are substantial. Ultimately, reducing GHG emissions and increasing carbon sequestration to combat climate change will require actions across multiple sectors. We demonstrate that the adoption of alternative land management practices on working lands and avoided conversion and restoration of native habitats can achieve meaningful state-level GHG reductions.

Patterns and drivers of recent disturbances across the temperate forest biome

Increasing evidence indicates that forest disturbances are changing in response to global change, yet local variability in disturbance remains high. We quantified this considerable variability and analyzed whether recent disturbance episodes around the globe were consistently driven by climate, and if human influence modulates patterns of forest disturbance. We combined remote sensing data on recent (2001-2014) disturbances with in-depth local information for 50 protected landscapes and their surroundings across the temperate biome. Disturbance patterns are highly variable, and shaped by variation in disturbance agents and traits of prevailing tree species. However, high disturbance activity is consistently linked to warmer and drier than average conditions across the globe. Disturbances in protected areas are smaller and more complex in shape compared to their surroundings affected by human land use. This signal disappears in areas with high recent natural disturbance activity, underlining the potential of climate-mediated disturbance to transform forest landscapes.

Landscape drivers of recent fire activity (2001-2017) in south-central Chile

In recent decades large fires have affected communities throughout central and southern Chile with great social and ecological consequences. Despite this high fire activity, the controls and drivers and the spatiotemporal pattern of fires are not well understood. To identify the large-scale trends and drivers of recent fire activity across six regions in south-central Chile (~32-40° S Latitude) we evaluated MODIS satellite-derived fire detections and compared this data with Chilean Forest Service records for the period 2001-2017. MODIS burned area estimates provide a spatially and temporally comprehensive record of fire activity across an important bioclimatic transition zone between dry Mediterranean shrublands/sclerophyllous forests and wetter deciduous-broadleaf evergreen forests. Results suggest fire activity was highly variable in any given year, with no statistically significant trend in the number of fires or mean annual area burned. Evaluation of the variables associated with spatiotemporal patterns of fire for the 2001-2017 period indicate vegetation type, biophysical conditions (e.g., elevation, slope), mean annual and seasonal climatic conditions (e.g., precipitation) and mean population density have the greatest influence on the probability of fire occurrence and burned area for any given year. Both the number of fires and annual area burned were greatest in warmer, biomass-rich lowland Bío-Bío and Araucanía regions. Resource selection analyses indicate fire 'preferentially' occurs in exotic plantation forests, mixed native-exotic forests, native sclerophyll forests, pasture lands and matorral, vegetation types that all provide abundant, flammable and connected biomass for burning. Structurally and compositionally homogenous exotic plantation forests may promote fire spread greater than native deciduous-Nothofagaceae forests which were once widespread in the southern parts of the study area. In the future, the coincidence of warmer and drier conditions in landscapes dominated by flammable and fuel-rich forest plantations and mixed native-exotic and sclerophyll forests are likely to further promote large fires in south-central Chile.

Effects of high-severity fire drove the population collapse of the subalpine Tasmanian endemic conifer Athrotaxis cupressoides

Athrotaxis cupressoides is a slow-growing and long-lived conifer that occurs in the subalpine temperate forests of Tasmania, a continental island to the south of Australia. In 1960-1961, human-ignited wildfires occurred during an extremely dry summer that killed many A. cupressoides stands on the high plateau in the center of Tasmania. That fire year, coupled with subsequent regeneration failure, caused a loss of ca. 10% of the geographic extent of this endemic Tasmanian forest type. To provide historical context for these large-scale fire events, we (i) collected dendroecological, floristic, and structural data, (ii) documented the postfire survival and regeneration of A. cupressoides and co-occurring understory species, and (iii) assessed postfire understory plant community composition and flammability. We found that fire frequency did not vary following the arrival of European settlers, and that A. cupressoides populations were able to persist under a regime of low-to-mid severity fires prior to the 1960 fires. Our data indicate that the 1960 fires were (i) of greater severity than previous fires, (ii) herbivory by native marsupials may limit seedling survival in both burned and unburned A. cupressoides stands, and (iii) the loss of A. cupressoides populations is largely irreversible given the relatively high fuel loads of postfire vegetation communities that are dominated by resprouting shrubs. We suggest that the feedback between regeneration failure and increased flammability will be further exacerbated by a warmer and drier climate causing A. cupressoides to contract to the most fire-proof landscape settings.

Contribution of the Torsional Modes to the Equilibrium Distribution of Vibrational States and to the Specific Heat of a Chain Molecule

The torsional modes of a chain molecule were studied recently under the assumption that it has a well defined spatial configuration at any time. Here we show how the averages over the possible configurations, for a distribution in thermal equilibrium, should be performed in the calculation of the thermodynamical properties. Our results show that the mean density of torsional states increases in the low frequency region with increasing temperature. The specific heat behaviour shows a considerable difference from the result obtained in the previous paper, where only the lowest energetic configuration was considered. The consequences of this result with respect to the configurational properties of polymer molecules near the θ temperature are discussed.

[Cystectomy in elderly patients: analysis of complications using the Clavien-Dindo classification]

Radical cystectomy (RC) represents the gold standard in the treatment of muscle invasive urothelial cancer of the bladder. Due to improvements in operation techniques and perioperative care it has become a good and safe procedure even in elderly patients. In recent years the Clavien-Dindo classification has been frequently used for complication assessment in urological research. The Charlson comorbidity index without age correction can be used in treatment planning for RC to identify patients at risk.

Multidecadal climate variability and climate interactions affect subalpine fire occurrence, western Colorado (USA)

This study investigates the influence of climatic variability on subalpine forest fire occurrence in western Colorado during the AD 1600-2003 period. Interannual and multidecadal relationships between fire occurrence and the El Niño Southern Oscillation (ENSO), Pacific Decadal Oscillation (PDO), and Atlantic Multidecadal Oscillation (AMO) were examined, in addition to the effects of phase interactions among these oscillations. Fires occurred during short-term periods of significant drought and extreme cool (negative) phases of ENSO and PDO and during positive departures from mean AMO index. At longer time scales, fires exhibited 20-year periods of synchrony with the cool phase of the PDO, and 80-year periods of synchrony with extreme warm (positive) phases of the AMO. Years of combined positive AMO and negative ENSO and PDO phases represent "triple whammies" that significantly increased the occurrence of drought-induced fires. Fires were synchronous with this phase combination over 0-30 year periods and distinctly asynchronous with the opposite phase combination. Overall, because fires are synchronous at supra-annual to multidecadal time scales with warm AMO events, particularly when combined with cool ENSO and PDO phases, this suggests that we may be entering a qualitatively different fire regime in the next few decades due to the recent shift in 1998 to a likely long-term warm AMO phase. Although uncertainty remains regarding the effects of CO2-induced warming at regional scales, given the multidecadal persistence of the AMO there is mounting evidence that the recent shift to the positive phase of the AMO will promote higher fire frequencies in the region.

Blutreferenzwerte in Deutschland gehaltener europäischer Landschildkröten (Testudo spp.)

Gegenstand und Ziel: Erstellung von 20 Blutparametern in Deutschland gehaltener mediterraner Landschildkröten und Vergleich der erhaltenen Parameter zwischen vier unterschiedlichen Landschildkrötenspezies. Material und Methoden: Bei 61 mediterranen, in Deutschland gehaltenen Landschildkröten wurden nach Blutentnahme aus der dorsalen Kokzygealvene hämatologische und blutchemische Referenzwerte von 20 Parametern erstellt. Die Untersuchung erstreckte sich auf Nachzuchttiere oder länger als drei Jahre im Besitz befindliche Tiere aus fünf kontrollierten Beständen. Alle Probanden wurden im Frühjahr bis Spätsommer im Freiland gehalten und hielten regelmäßig Winterschlaf. Die Fütterung der Schildkröten erfolgte ausschließlich mit pflanzlicher Kost. Die 61 klinisch unauffälligen Landschildkröten gehörten den Spezies Testudo marginata (Breitrandschildkröte; n = 16), Testudo graeca (Maurische Landschildkröte; n = 15), Testudo hermanni (Griechische Landschildkröte; n = 22) und Testudo horsfieldii (Russische Steppenschildkröte; n = 8) an. Ergebnisse: Median, Minimal- und Maximalwerte, sowie p-Werte wurden für Hämatokrit, Alanin-Aminotransferase, Aspartat-Aminotransferase, Glutamat-Dehydrogenase, alkalische Phosphatase, Kreatinkinase, Harnsäure, Harnstoff, Cholesterin, Glukose, Fruktosamin, Gesamtbilirubin, Gesamteiweiß, Albumin, Cholinesterase, Natrium, Kalium, Gesamtkalzium, ionisiertes Kalzium und anorganisches Phosphat ermittelt. Schlussfolgerung und klinische Relevanz: Bei 10 der untersuchten 20 Parameter konnten statistisch signifikante speziesspezifische Unterschiede festgestellt werden. Die Ergebnisse weisen darauf hin, dass bei der Interpretation der Blutparameter so genannter „mediterraner Landschildkröten” unbedingt eine Speziesdifferenzierung stattfinden sollte.

Evidence that the hypermutated M protein of a subacute sclerosing panencephalitis measles virus actively contributes to the chronic progressive CNS disease

Subacute sclerosing panencephalitis (SSPE) is a progressive degenerative disease of the brain uniformly leading to death. Although caused by measles virus (MV), the virus recovered from patients with SSPE differs from wild-type MV; biologically SSPE virus is defective and its genome displays a variety of mutations among which biased replacements of many uridine by cytidine resides primarily in the matrix (M) gene. To address the question of whether the SSPE MVs with M mutations are passive in that they are not infectious, cannot spread within the CNS, and basically represent an end-stage result of a progressive infection or alternatively SSPE viruses are infectious, and their mutations enable them to persist and thereby cause a prolonged neurodegenerative disease, we utilized reverse genetics to generate an infectious virus in which the M gene of MV was replaced with the M gene of Biken strain SSPE MV and inoculated the recombinant virus into transgenic mice bearing the MV receptor. Our results indicate that despite biased hypermutations in the M gene, the virus is infectious in vivo and produces a protracted progressive infection with death occurring as long as 30 to 50 days after that caused by MV. In primary neuron cultures, the mutated M protein is not essential for MV replication, prevents colocalization of the viral N with membrane glycoproteins, and is associated with accumulation of nucleocapsids in cells' cytoplasm and nucleus.

rolling pebbles(rols) is required inDrosophilamuscle precursors for recruitment of myoblasts for fusion

Mutations in the rolling pebbles (rols) gene result in severe defects in myoblast fusion. Muscle precursor cells are correctly determined, but myogenesis does not progress significantly beyond this point because recognition and/or cell adhesion between muscle precursor cells and fusion-competent myoblasts is disturbed. Molecular analysis of the rols genomic region reveals two variant transcripts of rols due to different transcription initiation sites, rols6 and rols7. rols6 mRNA is detectable mainly in the endoderm during differentiation as well as in malpighian tubules and in the epidermis. By contrast, rols7 expression is restricted to the mesoderm and later to progenitor descendants during somatic and pharyngeal muscle development. Transcription starts at the extended germ band stage when progenitor/founder cells are determined and persists until stage 13. The proteins encoded by the rols gene are 1670 (Rols6) and 1900 (Rols7) amino acids in length. Both forms contain an N-terminal RING-finger motif, nine ankyrin repeats and a TPR repeat eventually overlaid by a coiled-coil domain. The longer protein, Rols7, is characterized by 309 unique N-terminal amino acids, while Rols6 is distinguishable by 79 N-terminal amino acids. Expression of rols7 in muscle founder cells indicates a function of Rols7 in these cells. Transplantation assays of rols mutant mesodermal cells into wild-type embryos show that Rols is required in muscle precursor cells and is essential to recruit fusion-competent myoblasts for myotube formation.

Constitutive beta cell expression of IL-12 does not perturb self-tolerance but intensifies established autoimmune diabetes

To analyze the function of the Th1-promoting cytokine IL-12 in vivo, we generated transgenic (tg) mice (RIP-IL12 mice) whose pancreatic beta cells constitutively express bioactive IL-12 or one of its components, p35 or p40. In contrast to non-tg littermates or single-tg RIP-p35 and RIP-p40 mice, RIP-IL12 mice developed a marked pancreatic infiltration of lymphocytes and macrophages, mainly around islets. Expression of bioactive IL-12 primarily upregulated transcript levels of IFN-inducible protein-10 (IP-10), RANTES, IFN-gamma, and TNF-alpha in the pancreas. Despite the substantial recruitment of mononuclear cells, no biochemical or clinical disease was evident in the exocrine or endocrine pancreas. Coexpression of lymphocytic choriomeningitis virus (LCMV) proteins with IL-12 in the beta cells failed to spontaneously activate or expand antigen-specific anti-self/viral T cells in uninfected tg animals. However, when RIP-IL12 x RIP-LCMV tg mice were infected with LCMV, antigen-specific anti-self/viral T cells were induced, which led to an acceleration in the kinetics and severity of insulin-dependent diabetes mellitus (IDDM). Thus, the ectopic expression of IL-12 does not spontaneously break tolerance and activate antigen-specific T cells in the periphery, but it does worsen ongoing autoimmune disease.

Neither B lymphocytes nor antibodies directed against self antigens of the islets of Langerhans are required for development of virus-induced autoimmune diabetes

We evaluated the role of the humoral arm of the immune response in causing or contributing to virus-induced diabetes. Transgenic mice expressing the nucleoprotein (NP) or glycoprotein (GP) of the lymphocytic choriomeningitis virus (LCMV) under control of the rat insulin promoter (RIP) in pancreatic beta cells (RIP-LCMV) and RIP-LCMV mice with genetic dysfunction of B cells (RIP-LCMV x microMT/microMT) were compared for development of diabetes after challenge with LCMV. After inoculation with LCMV, B and T lymphocytes and macrophages infiltrated into pancreatic islets in RIP-LCMV mice, and over 50% of these mice generated Abs against host insulin or glutamate decarboxylase. However, neither B cells nor the autoantibodies played a direct role in the initiation, kinetics, or severity of the virus-induced diabetes as judged by comparing disease in RIP-LCMV mice to littermates whose functional B cells were genetically eliminated. Furthermore, the quality and quantity of T lymphocyte and macrophage infiltration was similar in the B cell-deficient and non-B cell-deficient RIP-LCMV mice. Although the development of autoantibodies to islet Ags had no direct influence on the pathogenesis of insulin-dependent (type 1) diabetes mellitus, it served as a prediabetes marker, as such autoantibodies were often elevated before the onset of disease. Hence, the RIP-LCMV model is not only useful for understanding the pathogenetic mechanisms of how islets are destroyed and spared but also for evaluating therapeutic strategies before onset of clinical diabetes.

Immunosuppression and resultant viral persistence by specific viral targeting of dendritic cells

Among cells of the immune system, CD11c(+) and DEC-205(+) splenic dendritic cells primarily express the cellular receptor (alpha-dystroglycan [alpha-DG]) for lymphocytic choriomeningitis virus (LCMV). By selection, strains and variants of LCMV that bind alpha-DG with high affinity are associated with virus replication in the white pulp, show preferential replication in a majority of CD11c(+) and DEC-205(+) cells, cause immunosuppression, and establish a persistent infection. In contrast, viral strains and variants that bind with low affinity to alpha-DG are associated with viral replication in the red pulp, display minimal replication in CD11c(+) and DEC-205(+) cells, and generate a robust anti-LCMV cytotoxic T lymphocyte response that clears the virus infection. Differences in binding affinities can be mapped to a single amino acid change in the viral glycoprotein 1 ligand that binds to alpha-DG. These findings indicate that receptor-virus interaction on dendritic cells in vivo can be an essential step in the initiation of virus-induced immunosuppression and viral persistence.

MR imaging of infections of the cervical spine

Spine infections are serious clinical conditions that carry high morbidity and mortality rates. Cervical spine infections usually require a more aggressive medical and surgical approach than infections in the rest of the spine. Often, more than one anatomic structure or compartment becomes affected. Topics discussed in this article include incidence and predisposing factors of spine infections, types of micro-organisms involved in several disease conditions, pathophysiology and clinical manifestations, and imaging findings and MR imaging features.

Local IL-4 expression in the lung reduces pulmonary influenza-virus-specific secondary cytotoxic T cell responses

We studied the effect of lung-specific IL-4 expression on the T cell response during primary and secondary heterologous infection with influenza virus by using transgenic mice that express IL-4 under a lung-specific promoter. Subsequent to primary infection with a type A/H1N1 influenza virus these transgenic mice exhibited similar local recruitment of CD4(+) and CD8(+) T cells and only slightly decreased virus-specific CTL activity. However, during secondary challenge with a heterologous influenza virus, the local infiltration with virus-specific, MHC class I-restricted CD8(+) T cells was significantly decreased compared to that of nontransgenic littermates. The ability of IL-4 transgenic mice to clear the heterologous infection was delayed but not abrogated. This was associated with a faster virus-neutralizing antibody response in IL-4 transgenic mice and with their ability to mount significant Th1 responses even in the presence of increased local IL-4 expression. Our observations demonstrate a negative regulatory effect of IL-4 on memory Tc1/CD8(+) T cells, but are also consistent with complementary mechanisms important for virus clearance such as virus-neutralizing antibodies. The reduction of memory CTL in the presence of IL-4 might have consequences for understanding the course of influenza infection in situations where T(H)2 immunity is increased.

Myelin-associated oligodendrocytic basic protein: identification of an encephalitogenic epitope and association with multiple sclerosis

Myelin-associated oligodendrocytic basic protein (MOBP) is an abundant myelin constituent expressed exclusively by oligodendrocytes, the myelin-forming cells of the CNS. We report that MOBP causes experimental allergic encephalomyelitis and is associated with multiple sclerosis. First, we note that purified recombinant MOBP inoculated into SJL/J mice produces CNS disease. Tests of overlapping peptides spanning the murine MOBP molecule map the encephalitogenic site to amino acids 37-60. MOBP-induced experimental allergic encephalomyelitis shows a severe clinical course and is characterized by a prominent CD4+ T lymphocyte infiltration and a lesser presence of CD8+ T cells and microglia/macrophages around vessels and in the white matter of the CNS. Second, PBL obtained from patients with relapsing/remitting multiple sclerosis mount a proliferative response to human MOBP, especially at amino acids 21-39. This response equals or exceeds the response to myelin basic protein and an influenza virus hemagglutinin peptide, both serving as internal controls. Thus, a novel myelin Ag, MOBP aa 37-60, plays a role in rodent autoimmune CNS disease, and its human MOBP counterpart is associated with the human demyelinating disease multiple sclerosis.

The German monitoring and reporting system for the treatment of substance-related problems: a national system on the basis of aggregated data

The German treatment monitoring and reporting system EBIS for out-patient centres treating clients with substance-related problems and disorders was set up in 1980. A parallel system for in-patient treatment was added in 1993 under the name of SEDOS. Together they are based nation-wide on more than 600 specialised treatment centres which collect diagnosis- and treatment-related data as well as information on socio-economic and family background. As part of the data relate to the end of treatment, also evaluative elements are included. In EBIS and SEDOS, aggregated data are the basis of the national and regional statistics produced, which offers a very high level of data protection for the clients treated. The revision of the national system implementing the Treatment Demand Indicator Protocol as the European Monitoring Centre for Drugs and Drug Addiction standard has already been started.

Disruption of the STAT4 signaling pathway protects from autoimmune diabetes while retaining antiviral immune competence

The role of the STAT4 signaling pathway in autoimmune diabetes was investigated using the rat insulin promoter lymphocytic choriomeningitis virus model of virally induced autoimmune diabetes. Abrogation of STAT4 signaling significantly reduced the development of CD4+-T cell-dependent but not CD4+-T cell-independent diabetes, illustrating the fine-tuned kinetics involved in the pathogenesis of autoimmunity. However, the absence of STAT4 did not prevent the generation of autoreactive Th1/Tc1 T cell responses, as well as protective antiviral immunity. Protection from insulin-dependent diabetes mellitus was associated with decreased numbers of autoreactive CTL precursors in the pancreas and the spleen and a general as well as Ag-specific reduction of IFN-gamma secretion by T lymphocytes. A shift from Th1 to Th2 T cell immunity was not observed. Hence, our results implicate both CTL and cytokines in beta cell destruction. Selective inhibition of the STAT4 signal transduction pathway might constitute a novel and attractive approach to prevent clinical insulin-dependent diabetes mellitus in prediabetic individuals at risk.

Autoreactive CD4+ T cells protect from autoimmune diabetes via bystander suppression using the IL-4/Stat6 pathway

Targeted immune regulation can be achieved by use of tissue-specific T cells and offers the potential for organ-specific suppression of destructive autoimmune processes. Here, we report the generation and characterization of insulin B chain-specific "autoreactive" CD4+ regulatory T cells that locally suppress diabetogenic T cell responses against an unrelated self-antigen (viral transgene) in a virus-induced model for type 1 diabetes. Interleukin 4 (IL-4) is essential for prevention of diabetes since regulatory T cells cannot be induced in the absence of IL-4 or stat6 (IL-4 signaling pathway). Our observations demonstrate that autoreactive regulatory T cells can suppress autoreactive destructive T cell activity of differential antigenic specificity locally in the pancreatic draining lymph node, probably via cytokine-mediated modulation of antigen-presenting cells.

Measles virus infection in a transgenic model: virus-induced immunosuppression and central nervous system disease

Measles virus (MV) infects 40 million persons and kills one million per year primarily by suppressing the immune system and afflicting the central nervous system (CNS). The lack of a suitable small animal model has impeded progress of understanding how MV causes disease and the development of novel therapies and improved vaccines. We tested a transgenic mouse line in which expression of the MV receptor CD46 closely mimicked the location and amount of CD46 found in humans. Virus replicated in and was recovered from these animals' immune systems and was associated with suppression of humoral and cellular immune responses. Infectious virus was recovered from the CNS, replicated primarily in neurons, and spread to distal sites presumably by fast axonal transport. Thus, a small animal model is available for analysis of MV pathogenesis.

Essential genes for myoblast fusion in Drosophila embryogenesis

In Drosophila, as in vertebrates, each muscle is a syncytium and arises from mesodermal cells by successive fusion. This requires cell-cell recognition, alignment, formation of prefusion complexes, followed by electron-dense plaques and membrane breakdown. Because muscle development in Drosophila is rapid and well-documented, it has been possible to identify several genes essential for fusion. Molecular analysis of two of these genes revealed the importance of cytoplasmic components. One of these, Myoblast city, is expressed in several tissues and is homologous to the mammalian protein DOCK180. Myoblast city is presumably involved in cell recognition and cell adhesion. Blown fuse, the second cytoplasmic component, is selectively expressed in the mesoderm and essential in order to proceed from the prefusion complex to electron-dense plaques at opposed membranes between adjacent myoblasts. The rolling stone gene is transiently expressed during myoblast fusion. The Rost protein is located in the membrane and thus might be a key component for cell recognition. The molecular characterization of further genes relevant for fusion such as singles bar and sticks and stones will help to elucidate the mechanism of myoblast fusion in Drosophila.

Moyamoya disease in a patient with hereditary spherocytosis

Moyamoya disease (MMD) is a rare cerebral vasculopathy characterized by occlusion of the supraclinoid portion of the internal carotid artery and proximal portions of the anterior and middle cerebral arteries. Patients develop an extensive collateral network of parenchymal, transdural and leptomeningeal vessels to supply the compromised brain. These collateral channels, also known as "moyamoya vessels," may be seen in a number of disorders which lead to intracranial vascular occlusion. We report a case of MMD in a child with hereditary spherocytosis.

Role of viruses in type I diabetes

Viral infections frequently elicit strong cellular and humoral immune responses. This bears the inherent danger of co-activating autoreactive lymphocytes, either through bystander activation by cytokines or through direct sharing of conformational determinants between self and virus (mimicry). Autoimmune diseases could then result, even after clearance of the viral infection, if enough autoreactive cells are activated. Alternatively, viral infection of antigen presenting cells can locally enhance inflammation and drive autoreactive lymphocytes. Evidence for these mechanisms, as well as emerging therapeutic concepts, will be discussed.

Fate map and cell lineage relationships of thoracic and abdominal mesodermal anlagen in Drosophila melanogaster

We have examined the cell lineage of larval and imaginal precursors of the mesodermal anlage between 10% and 60% egg length (EL) by homotopic single-cell transplantations at the blastoderm stage. Clones in the larval somatic muscles and in the fat body were derived from transplantations everywhere between 10% and 60% EL along the ventral side of the embryo. Clones frequently overlap these tissues and can extend over a maximum of four segments in the larval somatic muscles or over two morphologically-distinct parts in the fat body. Clones in the gonadal mesoderm overlap with other mesodermal derivatives and exhibit different mitotic behaviour in the two sexes. We present a blastoderm fate map for the fat body, the larval somatic muscles and the gonadal mesoderm. Clones in the imaginal muscle precursors of the abdomen, as well as of the thorax, always show a common cell lineage with larval somatic muscles and partly with other mesodermal tissues. These clones of imaginal derivatives are always found within a single segment, while the overlapping clone parts in the larval somatic muscles can label up to three segments.

Chromosomal localization of the myelin-associated oligodendrocytic basic protein and expression in the genetically linked neurological mouse mutants ducky and tippy

The alternatively spliced cDNAs encoding the myelin-associated/oligodendrocytic basic proteins (MOBPs) have recently been identified in rat. The Mobp gene maps to the distal part of mouse chromosome 9 at a region syntenic with the human chromosome 3p22-p21.3. Two nonallelic mouse mutants, tippy and ducky, with severe neurological phenotypes map to the vicinity of the Mobp locus. We therefore tested whether MOBP malfunction could explain the tippy and ducky defects. In tippy mutant animals, MOBP expression and that of other myelin markers were indistinguishable from wild type. The ultrastructure of tippy myelin was shown to be normal. Ducky animals showed a slight reduction of the brain size, most evident in the spinal cord, but normal progress of myelination. Both MOBP and myelin basic protein expression were lowered only regionally in the CNS, but were mostly normal in the anterior parts of the brain. Ultrastructurally, ducky myelin appeared normal. MOBP transcript sizes and the molecular weights of the encoded proteins were shown to be normal in both mutants. Finally, the nucleotide sequence of the abundant MOBP-81 cDNA was determined and compared with tippy and ducky MOBP-81. Wild-type mouse MOBP-81 protein was 99% identical to the rat homologue, and tippy and ducky MOBP-81 were identical to the wild-type sequence. Our results suggest that alterations in the Mobp gene are not the cause for the severe neurological phenotypes of ducky and tippy mice.

Developmental expression of the myelin gene MOBP in the rat nervous system

The myelin-associated/oligodendrocyte basic proteins (MOBPs) are recently discovered constituents of myelin and are small, cytoplasmic, and highly basic proteins exclusively expressed postnatally by oligodendrocytes. Due to a clustering of positively charged amino acids observed in the most abundant MOBP isoform similar to myelin basic protein (MBP) and P0, it was speculated that MOBP could function in myelin sheath compaction. The present report strongly supports this view. A direct comparison of MBP and proteolipid protein (PLP) gene expression with that of MOBP by in situ hybridization revealed a very similar regional distribution. It was found that MOBP expression was abundant in the rat CNS at postnatal day 15 (P 15) but is restricted to densely myelinated regions. In contrast to MBP and PLP, expression of MOBP was undetectable in the peripheral nervous system during the entire development. Interestingly, MOBP mRNA was localized in oligodendrocyte processes even at early postnatal stages and throughout development. MOBP showed a very specific timing of expression: in spinal cord and brain, MOBP gene expression occurred significantly later (2-3 days) than that of MBP and PLP, but slightly earlier than myelin oligodendrocyte glycoprotein gene expression. MOBP proteins appeared in spinal cord and brain stem also after MBP protein, suggesting that the MOBPs functionally act after the structural myelin proteins MBP and PLP. Our findings imply a function of MOBP during the late steps of myelin formation, presumably at the initiation of sheath compaction.

Pathological changes in the islet milieu precede infiltration of islets and destruction of beta-cells by autoreactive lymphocytes in a transgenic model of virus-induced IDDM

RIP-LCMV transgenic mice that express the viral glycoprotein (GP) or nucleoprotein (NP) from lymphocytic choriomeningitis virus (LCMV) under control of the rat insulin promoter (RIP) in pancreatic beta-cells develop autoimmune diabetes (IDDM) after infection with LCMV. Previous reports have described that the viral infection activates naive, potentially autoreactive CD8+ cytotoxic T-lymphocytes (CTL) that are present in the periphery of these mice, thus leading to the breaking of immunological unresponsiveness to the viral self-antigen expressed on beta-cells. However, we find that adoptive transfer of such CTL that were active in vitro and in vivo into uninfected RIP-LCMV recipients rarely resulted in hyperglycemia nor in insulitis, despite their ability to home to the islets and induce peri-insulitis. These observations indicated that, in addition to activated autoreactive lymphocytes, other factor(s) were required for beta-cell destruction. The present study shows that upregulation of MHC class II molecules associated with the attraction/activation of antigen presenting cells (APCs) to the islets occurs as soon as 2 days after LCMV inoculation of transgenic mice, clearly before CD4+ and CD8+ lymphocytes are found entering the islets (days 6 and 7 after LCMV inoculation). In contrast, although some MHC class II upregulation is also found in islets of non-transgenic mice 2-4 days after LCMV infection, no insulitis or IDDM develops and MHC is downregulated to normal (pre-infection) levels by day 7-10 in these mice. Associated with the activation of APCs and MHC upregulation observed in transgenic mice, viral (LCMV) infection of islets was detectable 2 days post-viral inoculation in some mice. Thus, beta-cell destruction by activated autoreactive lymphocytes is a multifactorial process that is likely to require changes within the islet milieu or dysfunction of islets.

Adepithelial cells in Drosophila melanogaster: origin and cell lineage

We have analysed the cell lineage relationships between larval and imaginal mesodermal primordia at the blastoderm stage by homotopic single cell transplantations. The primordia of adepithelial cells, the precursors of adult thoracic muscles, are restricted to the region from 50 to 65% egg length within the ventrally located mesodermal anlage. Clones of adepithelial cells always show a common cell lineage with larval muscles and in some cases additionally with larval fat body. This proves that at the blastoderm stage the determination of larval vs. imaginal mesodermal primordia has not yet taken place. Larval somatic muscle clones, in contrast to clones in the ectoderm, can overlap several segments, whereas clones of adepithelial cells are always restricted to imaginal discs of one segment.

Larval and imaginal pathways in early development of Drosophila

In holometabolous development, higher insects have two different life forms, the larva and the imago. Both larval and imaginal cells are derived from cells of the blastoderm stage. After the final embryonic wave of mitosis, however, only the imaginal cells remain diploid, proliferate massively and do not differentiate until metamorphosis. The separation of these two pathways was described by many authors as a fundamental process that must take place at a very early stage of development, most probably the blastoderm stage. Mainly by using single cell transplantations at the blastoderm or early gastrula stages, respectively, we found common cell lineages between larval and imaginal structures by clones overlapping in the ectoderm (i.e. larval epidermal cells and imaginal discs within a segment, or larval and imaginal salivary gland cells), the mesoderm (i.e. larval somatic muscles and adepithelial cells), and the endoderm (i.e. larval and imaginal midgut cells). From these findings we conclude that it seems to be a principle in Drosophila embryogenesis that the separation of larval and imaginal pathways is postponed to a later developmental stage.

Molecular and developmental characterization of novel cDNAs of the myelin-associated/oligodendrocytic basic protein

Several novel myelin-associated/oligodendrocytic basic protein (MOBP) isoforms were identified in this study by cDNA cloning. They are small, highly basic polypeptides comprising 69, 81, and 99 amino acids (8.2, 9.7, and 11.7 kDa, respectively) and show no significant homology with described proteins or domain structures. All (as yet) identified MOBP isoforms are identical in amino acids 1-68 but differ in the length and polarity of the C-terminal region. One isoform, designated MOBP81, was shown to be expressed abundantly during development. Interestingly, MOBP81 has a significant clustering of positively charged residues at positions 69-81, a feature that also has been observed for myelin basic protein (MBP) and Po. As demonstrated by in situ hybridization, MOBP gene expression occurs during development of the rat optic nerve later than that of MBP and proteolipid protein and coincides exactly with the beginning of myelin compaction. The 2.6 kb MOBP81-A transcript is localized in the processes of oligodendrocytes, whereas the 3.8 kb MOBP81-B transcript is restricted to the perinuclear region. Therefore, MOBP81-A and related mRNAs seem to be transported to the periphery of the oligodendrocytes, as is known for the transcripts of the MBP gene. The late developmental expression of the MOBP gene suggests that the MOBP proteins act at the late steps of myelin formation, possibly in myelin compaction and in the maintenance of the myelin sheath.

Approach to risk reduction in manufacturing firms in Australia

A survey of the 100 largest manufacturing firms in Australia has revealed that there is a lack of emphasis on controlling the incidence of high severity injuries and diseases. In a considerable number of organizations, there appears to be a reliance on the attitude of employees and safety training to control risk. There seems to be a lack of knowledge among the respondents of information sources which can be used to assess both risk and proposed control measures. The results suggest that Robens type legislation may be of limited utility in controlling risk in the workplace and a more definitive approach to identifying hazards and instituting appropriate control measures should be provided to organizations.

Mutations in the DnaA binding sites of the replication origin of Escherichia coli

Mutations (base changes) were introduced into the four DnaA binding sites (DnaA boxes) of the Escherichia coli replication origin, oriC. Mutations in a single DnaA box did not impair the ability of these origins to replicate in vivo and in vitro. A combination of mutations in two DnaA boxes, R1 and R4, resulted in slower growth of the oriC plasmid-bearing host cells. DnaA protein interaction with mutant and wild-type DnaA boxes was analyzed by DNase I footprinting. Binding of DnaA protein to a mutated DnaA box R1 was not affected by a mutation in DnaA box R4 and vice versa. Mutations in DnaA boxes R1 and R4 did not modify the ability of the DnaA protein to bind to other DnaA boxes in oriC.

The complex of oriC DNA with the DnaA initiator protein

We describe several experimental approaches relating to the early steps in the initiation of DNA replication at oriC. 1) A matrix is given which enables calculatation of the relative affinity of DnaA boxes for DnaA protein; 2) base changes within single Dna A boxes in oriC have little effect on oriC function; 3) mutations which change the distance between DnaA boxes inactivate oriC, but changes by one helical turn (+ and -) result in near wild-type oriC activity; 4) a Fis binding site was located at oriC coordinates 206-220; 5) KMnO4 probing demonstrates Dna-A-dependent unwinding in the left part of oriC in vivo and in vitro.