The role of the parietal lobe in task-irrelevant suppression during learning

BACKGROUND

Attention optimizes the selection of visual information, while suppressing irrelevant visual input through cortical mechanisms that are still unclear. We set to investigate these processes using an attention task with an embedded to-be-ignored interfering visual input.

OBJECTIVE

We delivered electrical stimulation to attention-related brain areas to modulate these facilitatory/inhibitory attentional mechanisms. We asked whether overtly training on a task while being covertly exposed to visual features from a visually identical but different task tested at baseline might influence post-training performance on the baseline task.

METHODS

In Experiment one, at baseline subjects performed an orientation discrimination (OD) task using a pair of gratings presented at individual's psychophysical threshold. We then trained participants over three-day separate sessions on a temporal order judgment task (TOJ), using the exact same gratings but presented with different time offsets. On the last post-training session we re-tested OD. We coupled training with transcranial random noise stimulation (tRNS) over the parietal cortex, the human middle temporal area or sham, in three separate groups. In Experiment two, subjects performed the same OD task at baseline and post-training, while tRNS was delivered at rest during the same sessions and stimulation conditions as in Experiment one.

RESULTS

Results showed that tRNS over parietal cortex facilitated learning of the trained TOJ task. Moreover, we found a detrimental effect on the untrained OD task when subjects received parietal tRNS coupled with training (Experiment one), but a benefit on OD when subjects received stimulation while at rest (Experiment two).

CONCLUSIONS

These results clearly indicate that task-irrelevant information is actively suppressed during learning, and that this prioritization mechanism of selection likely resides in the parietal cortex.

Epidemiology and outcomes of hospital-acquired bloodstream infections in intensive care unit patients: the EUROBACT-2 international cohort study

PURPOSE

In the critically ill, hospital-acquired bloodstream infections (HA-BSI) are associated with significant mortality. Granular data are required for optimizing management, and developing guidelines and clinical trials.

METHODS

We carried out a prospective international cohort study of adult patients (≥ 18 years of age) with HA-BSI treated in intensive care units (ICUs) between June 2019 and February 2021.

RESULTS

2600 patients from 333 ICUs in 52 countries were included. 78% HA-BSI were ICU-acquired. Median Sequential Organ Failure Assessment (SOFA) score was 8 [IQR 5; 11] at HA-BSI diagnosis. Most frequent sources of infection included pneumonia (26.7%) and intravascular catheters (26.4%). Most frequent pathogens were Gram-negative bacteria (59.0%), predominantly Klebsiella spp. (27.9%), Acinetobacter spp. (20.3%), Escherichia coli (15.8%), and Pseudomonas spp. (14.3%). Carbapenem resistance was present in 37.8%, 84.6%, 7.4%, and 33.2%, respectively. Difficult-to-treat resistance (DTR) was present in 23.5% and pan-drug resistance in 1.5%. Antimicrobial therapy was deemed adequate within 24 h for 51.5%. Antimicrobial resistance was associated with longer delays to adequate antimicrobial therapy. Source control was needed in 52.5% but not achieved in 18.2%. Mortality was 37.1%, and only 16.1% had been discharged alive from hospital by day-28.

CONCLUSIONS

HA-BSI was frequently caused by Gram-negative, carbapenem-resistant and DTR pathogens. Antimicrobial resistance led to delays in adequate antimicrobial therapy. Mortality was high, and at day-28 only a minority of the patients were discharged alive from the hospital. Prevention of antimicrobial resistance and focusing on adequate antimicrobial therapy and source control are important to optimize patient management and outcomes.

Nipocalimab’s Selective Targeting of FcRn and IgG Clearance Preserves Key Immune Functions

Objective

To characterize the effect of nipocalimab, a fully human, effectorless IgG1 anti-neonatal Fc receptor (FcRn) monoclonal antibody on immune function.

Background

Nipocalimab binds to FcRn with high affinity which prevents IgG recycling, leading to reduced serum levels of total IgGs, including pathogenic IgG autoantibodies. Rapid, sustained lowering of IgG was observed in the phase 2 VIVACITY study in generalized myasthenia gravis (gMG) and in phase 1 healthy volunteers. In gMG patients, nipocalimab induced rapid and sustained lowering of anti-AChR autoantibodies and MG-ADL scores, but no serious adverse events including clinically significant infections.

Design/Methods

Nipocalimab was evaluated extensively in vitro and in nonhuman primate-based chronic toxicology studies to evaluate selectivity, tolerability, safety and immunopharmacology. Safety, tolerability and immune-focused assessments in clinical phase 1 and Phase 2 MG studies were also completed (NCT02828046,NCT03772587).

Results

Nipocalimab binds specifically in vitro to FcRn without activation of effector function or inhibition of antigen presentation. In nonhuman primates administered up to 300 mg/kg nipocalimab QW for up to 6 months, sustained lowering of IgG was observed without adverse effects. Immunotoxicology identified no effect on immune cell phenotypes; CD8 T cell, NK or innate cell functions; T-dependent neoantigen IgM responses. Neoantigen IgG production was observed, but with lowered peak IgG titers consistent with the anticipated increase in IgG clearance with nipocalimab. In clinical studies, nipocalimab demonstrated a reproducible selective decrease in total serum IgG, including all subclasses of IgG, with no effect on IgM, IgA, IgE, CH50, C3, C4, inflammatory cytokines or acute phase proteins including, C-reactive protein (CRP).

Conclusions

These data suggest that nipocalimab can selectively lower IgG and IgG autoantibodies while preserving cellular immunity, complete IgM response and IgG production after neoantigen challenge. Overall, nipocalimab's selective effect on IgG recycling provides a mechanistic rationale for potentially decreased infection risk despite substantial IgG lowering.

Real-world treatment patterns in patients with nontuberculous mycobacterial lung disease in general and pneumologist practices in Germany

Background

Nontuberculous mycobacterial lung disease (NTMLD) is a rare, progressive disease with an increasing incidence worldwide.

Aims

The aim of this retrospective study was to analyze the baseline characteristics and management of NTMLD in general and pneumologist practices in Germany.

Methods

This retrospective study included patients with a culture-confirmed diagnosis of NTMLD documented between October 1, 2014 and September 30, 2019 by 125 general practitioners (GP) and 31 office-based pulmonologists from the IMS Disease Analyzer Database (IQVIA).

Results

A total of 159 patients managed by German GPs (mean age 59 ± 19 years, 51% female) and 236 patients managed by pulmonologists (mean age 62 ± 14 years, 58% female) were analyzed. In total, 45% (72/159) and 40% (94/236) of patients managed by GPs and pulmonologists respectively received antibiotic therapy for NTMLD. This therapy lasted for ≥ 6 months in 42%, for ≥ 12 months in 24%, and ≥ 18 months in 8% of patients. The average therapy duration was longer in patients treated by pulmonologists (241 ± 196 days) than in patients treated by GPs (113 ± 152 days). A total of 27% of patients managed by GPs and 45% of those managed by pulmonologists respectively received guideline-based therapy (GBT), defined as combination therapy with macrolide (azi-/ clarithromycin) + ethambutol + rifabutin/rifampicin, at least once; however, almost all patients (100% in the GP group, 96% in the pulmonologist group) also received non-GBT regimens intermediately.

Conclusions

A considerable number of patients with NTMLD were not managed in accordance with the German guidelines and a substantial proportion also discontinue therapy prematurely. NTMLD management should be improved through appropriate referral pathways and collaboration between expert centers and primary or secondary care physicians.

Elucidating the interplay between IgG-Fc valency and FcγR activation for the design of immune complex inhibitors

Autoantibody immune complex (IC) activation of Fcγ receptors (FcγRs) is a common pathogenic hallmark of multiple autoimmune diseases. Given that the IC structural features that elicit FcγR activation are poorly understood and the FcγR system is highly complex, few therapeutics can directly block these processes without inadvertently activating the FcγR system. To address these issues, the structure activity relationships of an engineered panel of multivalent Fc constructs were evaluated using sensitive FcγR binding and signaling cellular assays. These studies identified an Fc valency with avid binding to FcγRs but without activation of immune cell effector functions. These observations directed the design of a potent trivalent immunoglobulin G-Fc molecule that broadly inhibited IC-driven processes in a variety of immune cells expressing FcγRs. The Fc trimer, Fc3Y, was highly efficacious in three different animal models of autoimmune diseases. This recombinant molecule may represent an effective therapeutic candidate for FcγR-mediated autoimmune diseases.

Abstract P1-11-01: The effect of close and positive surgical margins on 10-year local recurrence and survival outcomes in women treated with breast conserving surgery plus adjuvant radiotherapy

This abstract was withdrawn by the authors.

Abstract 2509: AV-203, a humanized ERBB3 inhibitory antibody inhibits ligand-dependent and ligand-independent ERBB3 signaling in vitro and in vivo

ERBB3 is a member of the EGFR receptor tyrosine kinase (RTK) family. Agents targeting the family of EGFR RTKs have become widely used for the treatment of lung, colon, breast, gastric, and head and neck cancers. Among EGFR family members, ERBB3 is of special interest because of its ability to activate the survival pathway driven by PI3K, its essential role in HER2 mediated cancers, and its involvement in tumor progression and drug resistance. The ERBB3 receptor is expressed on cells from cancers of the head and neck, lung, breast, ovaries, prostate, colon, pancreas, and gastrointestinal tract. Its expression is often linked to poor prognosis. In addition, it has been implicated in the development of resistance to current anti-cancer agents including receptor-targeted tyrosine kinase inhibitors (TKI). ERBB3 lacks detectable tyrosine kinase activity and its activation requires the heterodimerization of ERBB3 with RTK partners, i.e., HER2, EGFR or MET. ERBB3 recruitment in heterodimer complexes takes place when RTKs are overexpressed or amplified or stimulated by ligands, i.e. Neuregulin-1 (NRG1) or epidermal growth factor (EGF). Because of the lack of ERBB3 kinase activity, antibody therapies directed against the extracellular domain of ERBB3 seem to be the most effective method to disrupt the function of ERBB3. Herein, characterization of AV-203, a humanized ERBB3 inhibitory antibody, is presented. AV-203 is a humanized immunoglobulin G1/kappa antibody that targets the ERBB3 RTK. AV-203 binds to human ERBB3 with high affinity (KD = 76 pM at 37°C) characterized by fast association and slow dissociation rates. AV-203 also binds to cynomolgus monkey ERBB3 but not to mouse ERBB3, allowing toxicological assessment of the antibody in this species. AV-203 is a potent inhibitor of ERBB3 activation and its downstream signaling molecule AKT in response to both ligands, NRG1 and EGF. In ligand-independent settings, AV-203 inhibits the steady state activation of ERBB3/AKT which depends on the presence of an overexpressed RTK such as HER2. AV-203 can prevent the ERBB3/HER2 heterodimer formation and completely inhibit the proliferation in response to NRG1 ligand in human breast cancer cell line, MCF7. AV-203 down regulates ERBB3 receptor in vitro and in vivo. Finally, AV-203 inhibits tumor growth in a broad spectrum of xenograft models in which ERRB3 is activated by its ligand NRG1 or by HER2 overexpression such as the pancreatic cancer BxPC3 or the HER2 amplified breast cancer MDA-MB-453 xenograft models, respectively. In conclusion, AV-203 demonstrated high affinity binding to ERBB3, potent inhibition of NRG1 binding and of ERBB3 activation in ligand-dependent and ligand-independent manners both in vitro and in vivo. First in human trial of AV-203 in cancer patients is planned for 2012.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 2509. doi:1538-7445.AM2012-2509

Abstract 628: Functional characterization of a diverse set of ERBB3 inhibitory antibodies

One important manifestation of the plasticity of cancer is the rapid escape from the effect of anti-cancer agents following initial therapeutic response. ERBB3, a kinase inactive member of the epidermal growth factor (EGFR) receptor family, which also includes EGFR, HER-2 and ERBB-4, has been linked to the development of resistance to multiple cancer therapies. The reactivation of ERBB3 following treatments with EGFR or HER-2 inhibitors has been observed in multiple tumor types following initial responses. The reactivation of ERBB3 signaling is thought to be the consequence of the formation of kinase active heterodimers of ERBB3 with EGFR, HER-2 and c-Met. ERBB3 heterodimer formation is consequence of a conformational change in the ErbB3 ECD (extracellular domain) in response to increased presence of the ERBB3 ligand NRG (neuregulin) or increased membrane concentrations of ERBB3 partners or ERBB3 itself which is often due overexpression or increased membrane localization.

To understand the role of NRG dependent and independent ERBB3 activation mechanisms in the development of resistance to EGFR and/or HER-2 inhibitors, we set out to identify a diverse set of ERBB3 specific inhibitory monoclonal antibodies with different mechanisms of action. Immunizations with a mixture of tethered and opened ERBB3 ECD antigens allowed us to identify a large variety of potent ERBB3 inhibitors. Competition binding experiments have identified at least 5 independent binding sites for these antibodies on ERBB3. Some of these antibodies inhibited NRG binding (ligand neutralizers) while others did not interfere with ligand binding. Since a few of these antibodies bound to the dimerization domain (domain II) of ERBB3, we have inferred that they most likely inhibit the formation of ERBB3 heterodimers (dimerization inhibitors). In vivo activity of these antibodies was tested in tumor models driven by ligand independent and dependent activation of ERBB3 to identify the most promising candidate for the development of a highly potent ERBB3 therapeutic antibody with superior activity against both ligand dependent and independent ERBB3 heterodimers.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 628. doi:10.1158/1538-7445.AM2011-628

Determining the agronomic value of composts produced from garden organics from metropolitan areas of New South Wales, Australia

About 0.3 million t/year of composted garden organics (CGO) including mulches and soil conditioners are produced annually in New South Wales, Australia, although only a small proportion of this material (<4%) is used in agriculture. A lack of information on product characteristics and agronomic performance has limited the development of agricultural markets for CGO products. These CGO products are the coarse and fine fractions separated by screening after composting. This paper presents the results of a survey of CGO mulches and soil conditioners (unblended or blended with a mixture of other organic materials including biosolids, animal manures and paper), which are commercially produced in the metropolitan areas of New South Wales and assesses their agronomic and soil amendment values in terms of chemical and biological properties. It also evaluates the short-term effects of applying increasing rates (0, 25, 50 and 100 t/ha) of selected composted soil conditioners on radish growth in a pot experiment. The mulch products had low nutrient concentrations but had high carbon (C) contents (mean C = 45%) and C/Nitrogen (N) ratios (mean C/N = 72) and are most suitable for use as surface mulch. The unblended soil conditioners were low in nutrients, particularly N (average total N = 1.0%, range 0.9–12%), and had lower and variable C contents. The pot trial results indicated lack of growth response of radish at application rates up to 100 t/ha of unblended soil conditioners from garden organics. The blended soil conditioners were more variable in quality and as confirmed by pot trial results produced highly variable plant responses. The high variability in product quality and performance of the soil conditioners, particularly the blended products might be related to the source and type of blending material as well as the composting conditions used in the manufacturing process. These results highlight the need to improve compost quality and consistency and the need for further research to advance understanding of the benefits using CGO in terms of improving soil quality, crop productivity and net economic returns to growers.

NGF receptor TrkAd5: therapeutic agent and drug design target

Biochemical studies have shown that domain 5 of the TrkA (tropomyosin receptor kinase A) receptor is involved in the binding of NGF (nerve growth factor). Crystallographic studies have confirmed this, demonstrating that one homodimer of NGF binds to two TrkAd5 molecules. TrkAd5 has been made recombinantly in Escherichia coli, purified and shown to bind NGF with picomolar affinity. We have used the co-ordinates of the crystal structure of the NGF-TrkAd5 complex to screen approximately two million compounds in silico for the identification of small molecule agonists/antagonists. Selected hits were shown to be active in an in vitro ligand-binding assay; structure-activity relationships are now being investigated. In addition, TrkAd5 has been shown to be efficacious in preclinical models of inflammatory pain and asthma by the sequestration of excess levels of endogenous NGF, and therefore represents a novel therapeutic agent.

Workshop 8 (synthesis): water governance--a key driver for food and urban security

Water governance has profound impact on the livelihoods of urban and rural people and on environmental sustainability. Yet governance has not received the same attention as technical issues. Governance is about processes of choices, decisions and estimating trade-offs.

Complete nucleotide sequence of Kashmir bee virus and comparison with acute bee paralysis virus

The complete nucleotide sequence of a novel virus is presented here together with serological evidence that it belongs to Kashmir bee virus (KBV). Analysis reveals that KBV is a cricket paralysis-like virus (family Dicistroviridae: genus Cripavirus), with a non-structural polyprotein open reading frame in the 5' portion of the genome separated by an intergenic region from a structural polyprotein open reading frame in the 3' part of the genome. The genome also has a polyadenylated tail at the 3' terminus. KBV is one of several related viruses that also includes acute bee paralysis virus (ABPV). Although KBV and ABPV are about 70 % identical over the entire genome, there are considerable differences between them in significant areas of the genome, such as the 5' non-translated region (42 % nucleotide identity), between the helicase and 3C-protease domains of the non-structural polyprotein (57 % amino acid identity) and in a 90 aa stretch of the structural polyprotein (33 % amino acid identity). Phylogenetic analyses show that KBV and ABPV isolates fall into clearly separated clades with moderate evolutionary distance between them. Whether these genomic and evolutionary differences are sufficient to classify KBV and ABPV as separate species remains to be determined.

The crisis of September 11: the emergency response of Ontario hospitals and other health system partners

The horrific events of September 11, 2001, have caused all individuals and institutions to step back and evaluate their ability to respond to a crisis of previously unimaginable proportions. A media search and incident review of Ontario Ministry of Health and Long-Term Care records confirms that no event in collective memory has had the potential to yield so many hospital patients. This article describes the legislative framework and process by which the ministry either leads or supports an emergency response. Within this context, the authors analyze the early preparations of the ministry and the Ontario hospital system as they readied to accept unknown numbers of patients from the attacks on the World Trade Center in New York City and the Pentagon in Washington, DC. While the focus of the article is on hospitals, the authors also consider the readiness actions taken by the system as a whole, including emergency services, CritiCall and the Ontario Hospital Association. The role of support agencies in helping Ontario's hospitals respond to the crisis is also examined. Whether the preparations undertaken and the commitments made by Ontario's hospitals and other health system partners would have been sufficient remains untested at this time. However, a careful review of emergency response strategies in order to identify any planning gaps is only prudent. This analysis concludes with a discussion of what has been learned and some thoughts on how those lessons can assist the ministry and our hospitals to remain prepared.

Characterisation and genetic organisation of a 24-MDa plasmid from the Brazilian Purpuric Fever clone of Haemophilus influenzae biogroup aegyptius

Strains of Haemophilus influenzae biogroup aegyptius causing septicaemia were identified in Brazil in the 1980s, causing the life-threatening illness of Brazilian Purpuric Fever (BPF). The strains were found to fall into a single clonal group, the BPF clone, characterised by their possession of the approximately 24MDa "3031" plasmid. In this work we report the characterisation and genetic organisation of this plasmid. Analysis of the gene content of what appears to be a typical broad host range conjugative plasmid, its presence in non-BPF strains as revealed by Southern hybridisation, and the recent discovery of plasmid-lacking BPF strains, has led us to conclude that it is unlikely to play a critical role in bacterial virulence. Establishing its entire sequence has nonetheless been an important step on the road to delineating, by comparison of BPF and non-BPF strains, chromosomal genetic loci that are involved in the special virulence of the BPF clone.

Regulation of monocyte chemoattractant protein (MCP)-1 transcription by interferon-gamma (IFN-gamma) in human astrocytoma cells: postinduction refractory state of the gene, governed by its upstream elements

Monocyte chemoattractant protein (MCP)-1 is expressed by astrocytes in diverse inflammatory states and is a key regulator of monocyte recruitment to the central nervous system (CNS). In the current study, we addressed mechanisms by which transcription of the human MCP-1 gene (hMCP-1) was terminated, after induction by interferon (IFN)-gamma. Our results demonstrated that IFN-gamma-induced transcription of hMCP-1 was followed by a refractory state, during which hMCP-1 was resistant to restimulation by either IFN-gamma or heterologous activators such as TNF-alpha. This refractory state affected the hMCP-1 gene selectively, as other IFN-gamma-inducible genes remained responsive to restimulation. The IFN-gamma-induced hMCP-1 refractory state was governed at the transcriptional level and was sensitive to protein synthesis inhibitors, suggesting a requirement for newly expressed components. A minimal 213 base pair hMCP-1 regulatory element directed both IFN-gamma-mediated transcription and the subsequent refractory state. We previously demonstrated that IFN-gamma treatment resulted in coordinate protein occupancy in vivo of two hMCP-1 promoter elements, a gamma-activated site (GAS) and a GC-rich element. During the refractory state, IFN-gamma treatment failed to induce protection of either the hMCP-1 GAS element or the GC box. These results furnish insight into the expression of hMCP-1 during CNS inflammation and provide the first delineation of an IFN-gamma-induced transcriptional refractory state.

Musculature of the facultative parasite Urastoma cyprinae (Platyhelminthes)

In an effort to understand how the feeding motions of Urastoma cyprinae are generated, the arrangement of its musculature was studied using fluorescence microscopy of phalloidin-linked fluorescent stains and conventional light histology and transmission electron microscopy. BODIPY 558/568 phalloidin and Alexa 488 phalloidin resolved a meshwork of ribbon-shaped body-wall muscles as well as inner-body musculature associated with the pharynx and male copulatory organ. The general pattern of body-wall muscles in U. cyprinae is similar to that of other rhabdocoel turbellarians in consisting only of circular, longitudinal, and diagonal fibers; the arrangement of these muscles readily correlates with the bending motions the animal undergoes as it feeds at the surface of gills in bivalves it parasitizes. The orogenital atrium of U. cyprinae lies at the posterior apex of the body, opening at a terminal pore. As evidenced by the arrangement of its epithelium and musculature, it appears to be an invagination of the body wall and comes closest of any such duct studied in turbellarians to satisfying the hypothetical model of a "pseudopharynx," ostensibly adapted as an organ for swallowing and so supplementing the ingestive role of the animal's true pharynx.

Analysis of Legionella pneumophila serogroup 1 isolates by pulsed-field gel electrophoresis

At a hospital in Halifax, Nova Scotia, Canada, three strains of Legionella pneumophila were detectable based on plasmid content, while the isolates collected at another hospital in Halifax had no plasmids. Genomic DNA was digested with BssHII, SalI, and SpeI and subjected to pulsed-field gel electrophoresis (PFGE). We found no relationship between plasmid profile and PFGE pattern.

Coping with loss: the development and evaluation of a children's bereavement project

The 'Kingfisher Project' is a community-based programme of support groups for bereaved children. It has been developed by a multi-disciplinary group of workers from health, education, social services and the voluntary sector. Thirty-six children and young people have have been through the first five groups of the programme. Children accessing the service are predominantly those at high risk of developing longer-term problems as a result of bereavement. Evaluation indicates that the children and young people benefit in terms of increased social, behavioural, emotional and physical well-being. Two sub-groups appear to have benefited less: these are children and young people with learning difficulties, and teenage girls. Project evaluation has enabled workers to develop insights into the programme's strengths and weaknesses and has raised questions which merit further exploration.

Reduced cholinergic function in normal and Alzheimer's disease brain is associated with apolipoprotein E4 genotype

Apolipoprotein E (ApoE) is a potent risk factor for Alzheimer's disease. Since the loss of cholinergic function in Alzheimer's disease is known to occur at an early stage in the disease we have examined this function in normal subjects with an Apoepsilon4 allele to see if the deficit occurs in the absence of Alzheimer pathology or symptoms. We report that brain tissue obtained post-mortem from normal subjects and Alzheimer patients with an Apoepsilon4 allele has a lower cholinergic activity than tissue from those subjects without this allele. This has important significance for the interpretation of the cholinergic deficits found in Alzheimer's disease.

Immunoglobulin-like domains define the nerve growth factor binding site of the TrkA receptor

Nerve growth factor (NGF) is involved in the development and maintenance of the nervous system. NGF binds with high affinity to the extracellular region of the tyrosine kinase receptor TrkA. This domain comprises leucine and cysteine rich motifs, followed by two immunoglobulin like (Ig-like) domains. We describe the expression and purification of recombinant Ig-like domains. Fluorescence and circular dichroism spectroscopy show that the protein is folded into a compact globular structure and contains mainly beta-sheet secondary structure. Recombinant protein binds to NGF and can inhibit NGF bioactivity both in vitro and in vivo.

Origin of the epidermis in parasitic platyhelminths

The epidermis of members of the major parasitic taxon Neodermata is distinctive among flatworms, being a syncytial, insunk, non-ciliated epidermis that develops through a wholesale replacement of larval epidermis at metamorphosis when the larva attacks a host. How it arose in evolution from what must have been a turbellarian-like ancestor is not immediately evident. While many turbellarian flatworms have also adopted a symbiotic way of life, the literature on ultrastructure of epidermis in these symbionts shows quite a variety of morphologies, many not so different from that of their free-living relatives. Various turbellarians do have syncytial or insunk epidermises or reduction of epidermal ciliation as is characteristic of the Neodermata, but co-occurrence in a single turbellarian of all features common to neodermatans has not been reported. Urastoma cyprinae, for example, which is ectosymbiotic on bivalves, has a ciliated cellular epidermis that is little different from what is known of epidermises of its free-living relatives. The endoparasitic Anoplodium hymanae, from the coelom of sea cucumbers, also bears a ciliated cellular epidermis, as is typical of many other rhabdocoels, but it shows marked phagocytic activity as well as incorporation of endosymbiotic bacteria. The closest similarity to neodermatan epidermis is that of the turbellarian Genostoma kozloffi, an ectosymbiont of the crustacean Nebalia: covering the bulk of the body is a non-ciliated syncytium with multiple branching connections to insunk nucleated portions, much as in epidermis of adult neodermatans and, on its ventral surface, is a field of ciliated cellular insunk epidermis resembling the epidermis of some larval neodermatans. Developmental clues to the origin of the neodermatan epidermis can be seen in turbellarian embryos. Before hatching, embryos of proseriate and triclad embryos go through 3 generations of epidermis, each replacing the next; 2 generations of epidermis are reported in the literature on rhabdocoel embryos. This process of replacement parallels the epidermal replacement that larval neodermatans undergo at metamorphosis. Ultrastructural study of developing acoel, polyclad and macrostomid embryos shows that they, too, have epidermal replacement and growth through immigration of deeper-lying cells, comparable to the processes seen in higher flatworms. Succession of distinct generations of epidermis in such animals as the proseriates, triclads and rhabdocoels is probably an adaptation to development of ectolecithal eggs, providing the means for the embryo to use yolk that resides in vitellocytes, outside its blastomeres. We propose that the Neodermata has taken advantage of this developmental mechanism, producing successive generations of epidermal cells even in its larval stages, to counter the defenses of hosts.

Tumorigenicity associated with chromosome 11p15 alterations in sv40-transformed human kidney-cells

Chromosome 11p15 has been suggested to be a potential site for a second Wilms' tumour gene (a childhood nephroblastoma). Human foetal kidney cells and normal kidney cells from Wilms' tumour patients were transformed with SV40 derivative vectors. As some of the cell lines progressed to tumorigenicity, we observed that chromosome 11p13, site of the WT1 suppressor gene, did not show any allelic loss. However, RFLP analysis showed that chromosome 11p15 was affected by allelic losses on different genes in some cell lines but not necessarily prior to the appearance of tumorigenicity. We also observed that the most aggressive cell Line (SVCU/NK), derived from the normal kidney cells of a Wilms' tumour patient, showed increased expression of c-Ha-ras proto-oncogene at later passage and in the tumour tissue extracted from nude mice. Finally we report a lack of tumour suppression activity of one cell line SVT1B6/NK, when fused with the tumorigenic G401 cell line (the latter has been used in tumour suppression experiments as a Wilms' tumour cell line before being identified as a Rhabdoid tumour cell line). These experiments are consistent with the existence of a suppressor gene at chromosome 11p15.

Multidisciplinary management of dysphagia: the first 100 cases

A report of the first 100 patients treated in the multidisciplinary Dysphagia Clinic in Salisbury District Hospital is presented. It was established in January 1992 and involves the Departments of ENT Surgery, Clinical Radiology and Speech and Language Therapy. In the first 18 months, 100 patients have been assessed and treated. These included 46 males and 54 females, between the ages of four and 93 years. Neurological problems accounted for 39 cases. The management comprised the assessment clinic, videofluoroscopy in 83 patients, and finally the appropriate treatment. Forty-four patients were treated primarily by swallowing therapy. Seventy-three patients showed complete recovery, resolution of their symptoms or did not require treatment. Two patients were still under treatment at the time of writing this paper.

Potable water and nosocomial Legionnaires' disease--check water from all rooms in which patient has stayed

We studied 7 patients with nosocomial Legionnaires' disease to determine the relationship between isolates of Legionella pneumophila recovered from potable water and those recovered from patients. Potable water was cultured from all rooms in which patients had stayed prior to the diagnosis of Legionnaires' disease. The 38 isolates of L. pneumophila (31 environmental, 7 patient) were resolved into 9 distinct patterns by pulse-field gel electrophoresis (PFGE), 3 by plasmid content and 2 each with monoclonal antibodies and conventional agarose gel electrophoresis of small fragments of DNA. Using PFGE it was determined that 4 of the 7 patients were infected with L. pneumophila identical to an isolate recovered from the potable water supply in one of the rooms each had occupied prior to the diagnosis of Legionnaires' disease. Patients had resided in a mean of 3.57 rooms before a diagnosis of nosocomial Legionnaires' disease. We conclude that in the setting of contaminated potable water and nosocomial Legionnaires' disease water from all the rooms which the patient has occupied prior to this diagnosis should be cultured. PFGE of large DNA fragments discriminated best among the isolates of L. pneumophila.