Convolutional Neural Network-Based Automated Segmentation of the Spinal Cord and Contusion Injury: Deep Learning Biomarker Correlates of Motor Impairment in Acute Spinal Cord Injury

BACKGROUND AND PURPOSE

Our aim was to use 2D convolutional neural networks for automatic segmentation of the spinal cord and traumatic contusion injury from axial T2-weighted MR imaging in a cohort of patients with acute spinal cord injury.

MATERIALS AND METHODS

Forty-seven patients who underwent 3T MR imaging within 24 hours of spinal cord injury were included. We developed an image-analysis pipeline integrating 2D convolutional neural networks for whole spinal cord and intramedullary spinal cord lesion segmentation. Linear mixed modeling was used to compare test segmentation results between our spinal cord injury convolutional neural network (Brain and Spinal Cord Injury Center segmentation) and current state-of-the-art methods. Volumes of segmented lesions were then used in a linear regression analysis to determine associations with motor scores.

RESULTS

Compared with manual labeling, the average test set Dice coefficient for the Brain and Spinal Cord Injury Center segmentation model was 0.93 for spinal cord segmentation versus 0.80 for PropSeg and 0.90 for DeepSeg (both components of the Spinal Cord Toolbox). Linear mixed modeling showed a significant difference between Brain and Spinal Cord Injury Center segmentation compared with PropSeg (P < .001) and DeepSeg (P < .05). Brain and Spinal Cord Injury Center segmentation showed significantly better adaptability to damaged areas compared with PropSeg (P < .001) and DeepSeg (P < .02). The contusion injury volumes based on automated segmentation were significantly associated with motor scores at admission (P = .002) and discharge (P = .009).

CONCLUSIONS

Brain and Spinal Cord Injury Center segmentation of the spinal cord compares favorably with available segmentation tools in a population with acute spinal cord injury. Volumes of injury derived from automated lesion segmentation with Brain and Spinal Cord Injury Center segmentation correlate with measures of motor impairment in the acute phase. Targeted convolutional neural network training in acute spinal cord injury enhances algorithm performance for this patient population and provides clinically relevant metrics of cord injury.

Aminopiperidine based complexes for lactide polymerisation

A series of new ligands based on a 2-(aminomethyl)piperidine motif have been prepared. An interesting diversity in structure is observed, all complexes have been trialled for the polymerisation of rac-lactide.

Evaluating a systematic voiding programme for patients with urinary incontinence after stroke in secondary care using soft systems analysis and Normalisation Process Theory: findings from the ICONS case study phase

BACKGROUND

Urinary incontinence (UI) affects between 40 and 60% of people in hospital after stroke, but is often poorly managed in stroke units.

OBJECTIVES

To inform an exploratory trial by three methods: identifying the organisational context for embedding the SVP; exploring health professionals' views around embedding the SVP and measuring presence/absence of UI and frequency of UI episodes at baseline and six weeks post-stroke.

DESIGN

A mixed methods single case study included analysis of organisational context using interviews with clinical leaders analysed with soft systems methodology, a process evaluation using interviews with staff delivering the intervention and analysed with Normalisation Process Theory, and outcome evaluation using data from patients receiving the SVP and analysed using descriptive statistics.

SETTING

An 18 bed acute stroke unit in a large Foundation Trust (a 'not for profit' privately controlled entity not accountable to the UK Department of Health) serving a population of 370,000.

PARTICIPANTS

Health professionals and clinical leaders with a role in either delivering the SVP or linking with it in any capacity were recruited following informed consent. Patients were recruited meeting the following inclusion criteria: aged 18 or over with a diagnosis of stroke; urinary incontinence (UI) as defined by the International Continence Society; conscious; medically stable as judged by the clinical team and with incontinence classified as stress, urge, mixed or 'functional'. All patients admitted to the unit during the intervention period were screened for eligibility; informed consent to collect baseline and outcome data was sought from all eligible patients.

RESULTS

Organisational context: 18 health professionals took part in four group interviews. Findings suggest an environment not conducive to therapeutic continence management and a focus on containment of UI. Embedding the SVP into practice: 21 nursing staff took part in six group interviews. Initial confusion gave way to embedding of processes facilitated by new routines and procedures. Patient outcome: 43 patients were recruited; 28 of these commenced the SVP. Of these, 6/28 (21%) were continent at six weeks post-stroke or discharge.

CONCLUSION

It was possible to embed the SVP into practice despite an organisational context not conducive to therapeutic continence care. Recommendations are made for introducing the SVP in a trial context.

Synthesis and structural study of precursors of novel methylsilanediols by IR and Raman spectroscopies, single-crystal X-ray diffraction and DFT calculations

On the way towards the development of a synthetic route aimed at obtaining new methylsilanediol derivatives with an aminocarbonyl group in β to silicon (which may have a potential biological interest), we have synthesized, isolated and purified five diphenylic possible precursors, namely chloromethyl(methyl)diphenylsilane, 2-{[methyl(diphenyl)silyl]methyl}-1H-isoindole-1,3(2H)-dione, N-[(methyl(diphenyl) silanyl)-methyl]-benzamide, N-[(methyl(diphenyl)silyl)-methyl]-acetamide and N-[(methyl(diphenyl)silyl)-methyl]-formamide. The conformational landscape of the five species in this study are explored by means of DFT calculations at the B3LYP/6-311++G(∗∗) level. The theoretical molecular structures predicted are confirmed by the reproduction of their respective IR and Raman spectral profiles, that are completely assigned. Some evidence in the vibrational spectra points to the occurrence of conformational mixtures in the samples. Further, single-crystal X-ray diffraction has allowed the elucidation of the crystalline structure of 2-{[methyl(diphenyl)silyl]methyl}-1H-isoindole-1,3(2H)-dione.

Identifying multiple forms of lateral disorder in cellulose fibres

Many strong biological materials exist in the form of fibres that are partially crystalline but contain a substantial proportion of disordered domains, which contribute to the mechanical performance but result in broadening of the reflections in the diffraction patterns of such materials and make structure determination difficult. Where multiple forms of disorder are simultaneously present, many of the accepted ways of modelling the influence of disorder on a fibre diffraction pattern are inapplicable. Lateral disorder in cellulose fibrils of flax fibres was characterized by a multi-step approach. First, a scattering component derived from domains less uniformly oriented than the rest was isolated. A second scattering component giving rise to asymmetry in the radial profiles of the equatorial reflections was then quantified and subtracted. This component was associated with domains that could be related to the crystalline cellulose lattice, but with more variable and, on average, wider equatorial d spacings. A further partially oriented component with highly disordered lateral d spacings unrelated to any of the cellulose lattice dimensions was identified. This component may be derived from non-cellulosic polysaccharides. The remaining broadening was then separated into a contribution from disorder within the crystalline lattice, including known disorder in hydrogen bonding, and a Scherrer contribution from the microfibril diameter. The methods described are likely to find applications in the study of both natural and synthetic polymer fibres in which mechanical properties are influenced by disorder.

Treatment of urinary incontinence after stroke in adults

BACKGROUND

Urinary incontinence can affect 40-60% of people admitted to hospital after a stroke, with 25% still having problems on hospital discharge and 15% remaining incontinent at one year.

OBJECTIVES

To determine the optimal methods for treatment of urinary incontinence after stroke in adults.

SEARCH STRATEGY

We searched the Cochrane Incontinence and Stroke Groups specialised registers (searched 15 March 2007 and 5 March 2007 respectively), CINAHL (January 1982 to January 2007), national and international trial databases for unpublished data, and the reference lists of relevant articles.

SELECTION CRITERIA

Randomised or quasi-randomised controlled trials evaluating the effects of interventions designed to promote continence in people after stroke.

DATA COLLECTION AND ANALYSIS

Data extraction and quality assessment were undertaken by two reviewers working independently. Disagreements were resolved by a third reviewer.

MAIN RESULTS

Twelve trials with a total of 724 participants were included in the review. Participants were from a mixture of settings, age groups and phases of stroke recovery. BEHAVIOURAL INTERVENTIONS: Three trials assessed behavioural interventions, such as timed voiding and pelvic floor muscle training. All had small sample sizes and confidence intervals were wide. SPECIALISED PROFESSIONAL INPUT INTERVENTIONS: Two trials assessed variants of professional input interventions. Results tended to favour the intervention groups: in a small trial in early rehabilitation, fewer people had incontinence at discharge from hospital after structured assessment and management than in a control group (1/21 vs. 10/13; RR 0.06, 95% CI 0.01 to 0.43); in the second trial, assessment and management by Continence Nurse Advisors was associated with fewer participants having urinary symptoms (48/89 vs. 38/54; RR 0.77, 95% CI 0.59 to 0.99) and statistically significantly more being satisfied with care. COMPLEMENTARY THERAPY INTERVENTIONS: Three small trials all reported fewer participants with incontinence after acupuncture therapy (overall RR 0.44; 95% 0.23 to 0.86), but there were particular concerns about study quality. PHARMACOTHERAPY AND HORMONAL INTERVENTIONS: There were three small trials that included groups allocated meclofenoxate, oxybutinin or oestrogen. There were no apparent differences other than in the trial of meclofenoxate where fewer participants had urinary symptoms in the active group than in the control group (9/40 vs. 27/40; RR 0.33, 95% CI 0.18 to 0.62).

AUTHORS' CONCLUSIONS

Data from the available trials are insufficient to guide continence care of adults after stroke. However, there was suggestive evidence that professional input through structured assessment and management of care and specialist continence nursing may reduce urinary incontinence and related symptoms after stroke. Better quality evidence is required of the range of interventions that have been suggested for continence care after stroke.

Repetitive task training for improving functional ability after stroke

BACKGROUND

The active practice of task-specific motor activities is a component of current approaches to stroke rehabilitation.

OBJECTIVES

To determine if repetitive task training after stroke improves global, upper or lower limb function, and if treatment effects are dependent on the amount, type or timing of practice.

SEARCH STRATEGY

We searched the Cochrane Stroke Trials Register (October 2006), The Cochrane Library, MEDLINE, EMBASE, CINAHL, AMED, SportDiscus, Science Citation Index, Index to Theses, ZETOC, PEDro, and OT Seeker (to September 2006), and OT search (to March 2006). We also searched for unpublished/non-English language trials, conference proceedings, combed reference lists, requested information on bulletin boards, and contacted trial authors.

SELECTION CRITERIA

Randomised/quasi-randomised trials in adults after stroke, where the intervention was an active motor sequence performed repetitively within a single training session, aimed towards a clear functional goal, and where the amount of practice could be quantified.

DATA COLLECTION AND ANALYSIS

Two authors independently screened abstracts, extracted data and appraised trials. Assessment of methodological quality was undertaken for allocation concealment, blinding, loss to follow up and equivalence of treatment. We contacted trial authors for additional information.

MAIN RESULTS

Fourteen trials with 17 intervention-control pairs and 659 participants were included.

PRIMARY OUTCOMES

results were statistically significant for walking distance (mean difference (MD) 54.6, 95% CI 17.5 to 91.7); walking speed (standardised mean difference (SMD) 0.29, 95% CI 0.04 to 0.53); sit-to-stand (standard effect estimate 0.35, 95% CI 0.13 to 0.56); and of borderline statistical significance for functional ambulation (SMD 0.25, 95% CI 0.00 to 0.51), and global motor function (SMD 0.32, 95% CI -0.01 to 0.66). There were no statistically significant differences for hand/arm function, or sitting balance/reach.

SECONDARY OUTCOMES

results were statistically significant for activities of daily living (SMD 0.29, 95% CI 0.07 to 0.51), but not for quality of life or impairment measures. There was no evidence of adverse effects. Follow-up measures were not significant for any outcome at six or twelve months. Treatment effects were not modified by intervention amount or timing, but were modified by intervention type for lower limbs.

AUTHORS' CONCLUSIONS

Repetitive task training resulted in modest improvement in lower limb function, but not upper limb function. Training may be sufficient to impact on daily living function. However, there is no evidence that improvements are sustained once training has ended. The review potentially investigates task specificity rather more than repetition. Further research should focus on the type and amount of training, and how to maintain functional gain.

Prevention and treatment of urinary incontinence after stroke in adults

BACKGROUND

Urinary incontinence can affect 40-60% of people admitted to hospital after a stroke, with 25% still having problems on hospital discharge and around 15% remaining incontinent at one year.

OBJECTIVES

To determine the optimal methods for prevention and treatment of urinary incontinence after stroke in adults.

SEARCH STRATEGY

We searched the Cochrane Incontinence and Stroke Groups specialised registers (searched 15 December 2004 and 26 October 2004, respectively), CINAHL (January 1982 to November 2004), national and international trial databases for unpublished data, and the reference lists of relevant articles.

SELECTION CRITERIA

Randomised or quasi-randomised controlled trials evaluating the effects of interventions designed to promote continence in people after stroke.

DATA COLLECTION AND ANALYSIS

Data extraction and quality assessment were undertaken by two reviewers working independently. Disagreements were resolved by a third reviewer.

MAIN RESULTS

Seven trials with a total of 399 participants were included in the review. Participants were from a mixture of settings, age groups and phases of stroke recovery. No two trials addressed the same comparison. Four trials tested an intervention against usual care, including acupuncture, timed voiding, and two types of specialist professional intervention. One cross-over trial tested an intervention (oestrogen) against placebo. One trial tested a specific intervention (oxybutynin) against another intervention (timed voiding), and one trial tested a combined intervention (sensory-motor biofeedback plus timed voiding) against a single component intervention (timed voiding alone). Reported data were insufficient to evaluate acupuncture or timed voiding versus usual care, oxybutynin versus timed voiding, or sensory motor biofeedback plus timed voiding versus usual care. Evidence from a single small trial suggested that structured assessment and management of care in early rehabilitation may reduce the number of people with incontinence at hospital discharge (1/21 versus 10/13; RR 0.06, 95% CI 0.01 to 0.43), and have other benefits. Evidence from another trial suggested that assessment and management of care by Continence Nurse Practitioners in a community setting may reduce the number of urinary symptoms (48/89 versus 38/54; RR 0.77, 95% CI 0.59 to 0.99), and increase satisfaction with care.

AUTHORS' CONCLUSIONS

There was suggestive evidence that specialist professional input through structured assessment and management of care and specialist continence nursing may reduce urinary incontinence after stroke. Data from trials of other physical, behavioural, complementary and anticholinergic drug interventions are insufficient to guide continence care of adults after stroke.

Identification of CD4+ T cell epitopes on the fusion (F) and attachment (G) proteins of bovine respiratory syncytial virus (BRSV)

To gain insight into the antigenic structure of the F and G proteins of BRSV, we have mapped CD4+ T cell epitopes on these proteins using synthetic peptides and lymphocytes from vaccinated, naturally infected or experimentally infected calves, in proliferation assays. Bovine CD4+ T cells recognised epitopes that were distributed predominantly within the F1 subunit of the F protein, some of which were adjacent to previously identified B cell epitopes. Bovine CD4+ T cell epitopes within the G protein were mainly located within the cytoplasmic tail. Several immunodominant bovine T cell epitopes within the F protein, that were recognised by calves with different haplotypes, are also recognised by human T cells. Thus, cattle and humans appear to recognise similar T cell epitopes on the F protein. Studies using antibodies to bovine MHC class II and BoLA DR-transfected CHO cells as antigen-presenting cells indicated that immunodominant regions of the F and G proteins contained both DR- and DQ-restricted epitopes. The finding that there was little recognition of the extracellular domain of the G protein by T cells has important implications for vaccine design based on the soluble form of this protein.

Synergistic upregulation of interleukin-8 secretion from pulmonary epithelial cells by direct and monocyte-dependent effects of respiratory syncytial virus infection

Respiratory syncytial virus (RSV) infection is the major cause of severe bronchiolitis in infants. Pathology of this infection is partly due to excessive proinflammatory leukocyte influx mediated by chemokines. Although direct infection of the respiratory epithelium by RSV may induce chemokine secretion, little is known about the role of cytokine networks. We investigated the effects of conditioned medium (CM) from RSV-infected monocytes (RSV-CM) on respiratory epithelial (A549) cell chemokine release. RSV-CM, but not control CM (both at a 1:5 dilution), stimulated interleukin-8 (IL-8) secretion from A549 cells within 2 h, and secretion increased over 72 h to 11,360 +/- 1,090 pg/ml without affecting cell viability. In contrast, RSV-CM had only a small effect on RANTES secretion. RSV-CM interacted with direct RSV infection to synergistically amplify IL-8 secretion from respiratory epithelial cells (levels of secretion at 48 h were as follows: RSV-CM alone, 8,140 +/- 2,160 pg/ml; RSV alone, 12,170 +/- 300 pg/ml; RSV-CM plus RSV, 27,040 +/- 5,260 pg/ml; P < 0.05). RSV-CM induced degradation of IkappaBalpha within 5 min but did not affect IkappaBbeta. RSV-CM activated transient nuclear binding of NF-kappaB within 1 h, while activation of NF-IL6 was delayed until 8 h and was still detectable at 24 h. Promoter-reporter analysis demonstrated that NF-kappaB binding was essential and that NF-IL6 was important for IL-8 promoter activity in RSV-CM-activated cells. Blocking experiments revealed that the effects of RSV-CM depended on monocyte-derived IL-1 but that tumor necrosis factor alpha was not involved in this network. In summary, RSV infection of monocytes results in and amplifies direct RSV-mediated IL-8 secretion from respiratory epithelial cells by an NF-kappaB-dependent, NF-IL6-requiring mechanism.

Regulation of IL-10 secretion after phagocytosis of Mycobacterium tuberculosis by human monocytic cells

Downregulation of pro-inflammatory events in the immune response to Mycobacterium tuberculosis is critical to prevent host tissue injury. Interleukin (IL-)10 is an important anti-inflammatory cytokine secreted in human tuberculosis but little is known about the control of such IL-10 release. Using an established cellular model, we measured IL-10 secretion after phagocytosis of M. tuberculosis. Phagocytosis of M. tuberculosis but not of inert latex beads by human monocytic (THP-1) cells resulted in IL-10 secretion maximal at 24 h. The magnitude and kinetics of IL-10 secretion were distinct from IL-10 secretion after phagocytosis of yeast-derived zymosan and depended on transcriptional activity and protein synthesis in infected monocytes. IL-10 secretion was decreased in a dose-dependent manner by specific inhibitors of tyrosine kinases, protein kinase (PK) C and PKA. Inhibition of more than one pathway did not result in further synergistic or additive reduction in IL-10 secretion. Finally, specific neutralising antibody directed against IL-10 demonstrated that IL-10 secreted by infected monocytic cells did not block autologous IL-8 secretion.

Depletion of bovine CD8+ T cells with chCC63, a chimaeric mouse-bovine antibody

In order to investigate the role of T cells in immune responses to infectious pathogens, depletion of individual T cell subsets using monoclonal antibodies (mAbs) is commonly undertaken. Since most mAbs are of murine origin, such depletion studies in cattle are restricted by the bovine anti-mouse antibody (BAMA) response to the mouse mAbs used for the depletions. In this study, we describe the use of antibody engineering to overcome the BAMA response. The variable region cDNA from CC63, a monoclonal mouse anti-bovine CD8 antibody, has been expressed in conjunction with bovine constant region genes to produce a mouse-bovine chimaeric antibody (chCC63). Characterisation of chCC63 showed that the antibody contained a bovine constant region and specifically bound bovine CD8+ T cells. Furthermore, chCC63 blocked the binding of the original mouse antibody, CC63, and mediated complement-dependent lysis of bovine CD8+ cells in vitro. In vivo, chCC63 depleted calves of CD8+ T cells as effectively as CC63 and provoked a BAMA response that was about one-tenth of that seen with the mouse antibody.

Pulmonary epithelial cells are a source of IL-8 in the response to Mycobacterium tuberculosis: essential role of IL-1 from infected monocytes in a NF-kappa B-dependent network

Pulmonary epithelial cells, covering a 70-m2 surface area, have not previously been considered an important source of chemokines in pulmonary tuberculosis. We analyzed IL-8 secretion from A549 cells and primary normal human bronchial epithelial cells (NHBE) infected by Mycobacterium tuberculosis. Direct infection of A549 cells by M. tuberculosis caused IL-8 secretion of 7720 +/- 1610 pg/106 cells, but no IL-8 secretion from NHBE after 24 h. In contrast, conditioned media from M. tuberculosis-infected human monocytes (CoMTB) induced a much greater IL-8 secretion of 92,635 +/- 13,180 pg/106 A549 cells and 13,416 +/- 3,529 pg/106 NHBE after 24 h. CoMTB induced rapid IL-8 mRNA accumulation, which was stable over 24 h, compared with TNF-alpha-induced transcripts. CoMTB stimulated nuclear binding of p65, p50, and c-Rel subunits of NF-kappa B to IL-8 promoter sequences. Transient transfections with IL-8 promoter reporter constructs showed NF-kappa B binding-site mutations abolished IL-8 promoter activity while NF-IL-6 binding-site mutations decreased promoter activity to 50.2 +/- 6.3% of wild-type activity. IL-1R antagonist but not neutralizing anti-TNF-alpha inhibited epithelial cell IL-8 secretion, mRNA accumulation, and NF-kappa B binding. Recombinant IL-1 beta (2 ng/ml) induced similar levels of IL-8 secretion to CoMTB in both A549 cells and NHBE. Pulmonary epithelial cells are a major source of IL-8 in the initial host response to pulmonary tuberculosis. Such IL-8 secretion is NF-kappa B dependent, NF-IL-6 requiring, and activated by an IL-1-mediated pathway as a consequence of phagocytosis of M. tuberculosis by monocytes.

Clinical guidelines in nursing, midwifery and the therapies: a systematic review

BACKGROUND

While nursing, midwifery and professions allied to medicine (PAMs) are increasingly using clinical guidelines to reduce inappropriate variations in practice and ensure higher quality care, there have been no rigorous overviews of their effectiveness in relation to these professions. We identified 18 evaluations of guidelines which met established quality for evaluations of interventions aimed at changing professional practice. This paper describes characteristics of guidelines evaluated and the effectiveness of different dissemination and implementation strategies used.

METHODS

Guideline evaluations conducted since 1975 which used a randomized controlled trial, controlled before-and-after, or interrupted time-series design, were identified using a combination of database and hand searching.

FINDINGS

It is mostly impossible to tell whether the guidelines evaluated were based on evidence. The most common method of guideline dissemination was the distribution of printed educational materials. Three studies compared different dissemination and/or implementation strategies: findings suggest educational interventions may be of value in the dissemination of guidelines and confer a benefit over passive dissemination.

Effect of clinical guidelines in nursing, midwifery, and the therapies: a systematic review of evaluations

BACKGROUND

Although nursing, midwifery, and professions allied to medicine are increasingly using clinical guidelines to reduce inappropriate variations in practice and ensure higher quality care, there have been no rigorous overviews of their effectiveness, 18 evaluations of guidelines were identified that meet Cochrane criteria for scientific rigor.

METHODS

Guideline evaluations conducted since 1975 which used a randomised controlled trial, controlled before and after, or interrupted time series design were identified through a combination of database and hand searching.

RESULTS

18 studies met the inclusion criteria. Three studies evaluated guideline dissemination or implementation strategies, nine compared use of a guideline with a no guideline state; six studies examined skill substitution: performance of nurses operating according to a guideline were compared with standard care, generally provided by a physician. Significant changes in the process of care were found in six out of eight studies measuring process and in which guidelines were expected to have a positive impact on performance. In seven of the nine studies measuring outcomes of care, significant differences in favour of the intervention group were found. Skill substitution studies generally supported the hypothesis of no difference between protocol driven by nurses and care by a physician. Only one study included a formal economic evaluation, with equivocal findings.

CONCLUSIONS

Findings from the review provide some evidence that care driven by a guideline can be effective in changing the process and outcome of care. However, many studies fell short of the criteria of the Cochrane Effective Practice and Organisation of Care Group (EPOC) for methodological quality.

Activity of the mitogenic Pasteurella multocida toxin requires an essential C-terminal residue

Pasteurella multocida toxin (PMT) is a potent mitogen that also affects bone resorption. PMT acts intracellularly and is therefore postulated to have several domains involved in different aspects of its function. The toxin contains eight cysteine residues. Mutants with individual substitutions for each of these residues were constructed, and the effects of these on the biological activity of the toxin were determined by cultured-cell assays. Only the most C-terminal of the eight cysteines (C1165) was essential for full activity, although mutation of the cysteine residue at position 1159 caused a slight but reproducible loss of potency. In animal challenge experiments, mutant toxin (C1165S) was not toxic to piglets, even at doses exceeding a lethal dose of active PMT 1, 000-fold. The mutant and wild-type toxins displayed identical purification characteristics, similar susceptibility to proteolytic digestion, and circular dichroism profiles, which indicated that no gross structural changes had taken place. The function of the essential C1165 residue is not yet known, although its most likely role is an enzymatic one at or near the catalytic center of the toxin.

Prolonged nasal shedding and viraemia of cytopathogenic bovine virus diarrhoea virus in experimental late-onset mucosal disease

A calf persistently infected with bovine virus diarrhoea virus (BVDV) was super-infected with a heterologous BVDV strain, C874, which contained non-cytopathogenic and cytopathogenic viruses. High titres of cytopathogenic BVDV were recovered in the three to four weeks after the challenge. Thereafter low titres of cytopathogenic virus were recovered repeatedly from the blood and the nose, with the titres in nasal secretions increasing in the four weeks before the onset of clinical signs. Neutralising antibodies against the challenge cytopathic virus (C874cp) were first detected 21 days after the super-infection, but these antibodies failed to neutralise the persisting non-cytopathogenic and cytopathogenic viruses isolated from the animal during the course of the infection. Serum collected from 105 days after the super-infection neutralised the cytopathogenic viruses isolated on day 105 and postmortem. These data indicate that unaltered wild-type C874cp was not directly responsible for the late-onset mucosal disease.

Respiratory Syncytial Virus-Induced RANTES Production from Human Bronchial Epithelial Cells Is Dependent on Nuclear Factor-κB Nuclear Binding and Is Inhibited by Adenovirus-Mediated Expression of Inhibitor of κBα

Respiratory syncytial virus (RSV) infection is an important cause of lower respiratory tract illness, the severity of which may be partly due to cellular recruitment. RSV infection activates chemokine secretion from airway epithelial cells by largely unknown mechanisms. We investigated the regulation of RSV-induced activation of the chemokine RANTES in the bronchial epithelial cell line BEAS-2B and primary normal human tracheobronchial epithelial cultures. RANTES protein and mRNA were detected at 24 h and up until 72 h from cultures of BEAS-2B infected with replicating virus, but not with UV-inactivated RSV. RSV infection of BEAS-2B or normal human tracheobronchial epithelial cells stimulated NF-κB translocation to the nucleus and binding to the RANTES-specific κB-binding sequences within 2 h, with levels peaking at 24 h. Supershift assays indicated that binding was due to p50/p65 heterodimers. BEAS-2B cells were transfected with a replication-deficient adenoviral vector, expressing a mutated, nondegradable form of IκBα. IκBα overexpression specifically blocked NF-κB translocation and inhibited mRNA accumulation and secretion of RANTES induced by RSV or TNF-α plus IFN-γ. Adenoviral transfection did not interfere with RSV replication or significantly induce apoptosis. Further, a control adenovirus, expressing the β-galactosidase gene, did not alter cellular functions. Thus, NF-κB nuclear translocation is a critical step in RSV induction of RANTES secretion. Elucidating the mechanisms of cellular activation by RSV and targeting specific areas may lead to novel therapeutic approaches in the treatment of RSV.

Respiratory syncytial virus-induced RANTES production from human bronchial epithelial cells is dependent on nuclear factor-kappa B nuclear binding and is inhibited by adenovirus-mediated expression of inhibitor of kappa B alpha

Respiratory syncytial virus (RSV) infection is an important cause of lower respiratory tract illness, the severity of which may be partly due to cellular recruitment. RSV infection activates chemokine secretion from airway epithelial cells by largely unknown mechanisms. We investigated the regulation of RSV-induced activation of the chemokine RANTES in the bronchial epithelial cell line BEAS-2B and primary normal human tracheobronchial epithelial cultures. RANTES protein and mRNA were detected at 24 h and up until 72 h from cultures of BEAS-2B infected with replicating virus, but not with UV-inactivated RSV. RSV infection of BEAS-2B or normal human tracheobronchial epithelial cells stimulated NF-kappa B translocation to the nucleus and binding to the RANTES-specific kappa B-binding sequences within 2 h, with levels peaking at 24 h. Supershift assays indicated that binding was due to p50/p65 heterodimers. BEAS-2B cells were transfected with a replication-deficient adenoviral vector, expressing a mutated, nondegradable form of I kappa B alpha. I kappa B alpha overexpression specifically blocked NF-kappa B translocation and inhibited mRNA accumulation and secretion of RANTES induced by RSV or TNF-alpha plus IFN-gamma. Adenoviral transfection did not interfere with RSV replication or significantly induce apoptosis. Further, a control adenovirus, expressing the beta-galactosidase gene, did not alter cellular functions. Thus, NF-kappa B nuclear translocation is a critical step in RSV induction of RANTES secretion. Elucidating the mechanisms of cellular activation by RSV and targeting specific areas may lead to novel therapeutic approaches in the treatment of RSV.

Resistance to bovine respiratory syncytial virus (BRSV) induced in calves by a recombinant bovine herpesvirus-1 expressing the attachment glycoprotein of BRSV

The ability of a bovine herpesvirus-1 (BHV-1) recombinant expressing the G protein of bovine respiratory syncytial virus (BRSV) to protect against BRSV infection was examined in calves. A synthetic G gene was inserted behind the gE promoter of BHV-1 to give a gE-negative, BHV-1/G recombinant. Gnotobiotic calves, vaccinated intranasally and intratracheally with BHV-1/G were challenged 6 weeks later with the Snook strain of BRSV. As controls, calves were vaccinated with a gE-negative mutant of BHV-1 which contains a frame-shift (BHV-1/gEfs). Whereas infection with BHV-1/gEfs induced only mild clinical signs, infection with BHV-1/G resulted in more severe clinical disease and higher titres of BHV-1/G were isolated from the lungs when compared with BHV-1/gEfs. Thus, expression of the G protein of BRSV increased the virulence of BHV-1 for calves. Vaccination with BHV-1/G induced BRSV-specific antibody in serum and respiratory secretions. However, only one calf developed low levels of BRSV complement-dependent neutralizing antibody. Although BHV-1/G primed calves for BRSV-specific lymphocyte proliferative responses, there was no evidence for priming of BRSV-specific cytotoxic T cells. After challenge with BRSV, there was a significant reduction in nasopharyngeal excretion of BRSV in BHV-1/G-vaccinated calves compared with controls and BRSV was isolated from the lung of only one of five vaccinated calves compared with all four control animals. In addition, the extent of gross pneumonic lesions 7 days after BRSV challenge was significantly reduced in calves vaccinated with BHV-1/G compared with controls given BHV-1/gEfs.

Passive protection of gnotobiotic calves using monoclonal antibodies directed at different epitopes on the fusion protein of bovine respiratory syncytial virus

Two neutralizing, fusion-inhibiting bovine monoclonal antibodies (MAbs; B4 and B13) directed at different epitopes on the fusion protein of respiratory syncytial virus (RSV) protected the lungs of gnotobiotic calves from RSV infection. The MAbs were administered intratracheally 24 h before the calves were challenged with bovine RSV. A third, nonneutralizing, non-fusion-inhibiting but complement-fixing MAb, B1, provided no significant protection against infection, and the disease was not exacerbated. Pneumonic consolidation and mean virus titer in lung 7 days after challenge were significantly lower in calves given the fusion-inhibiting MAbs than in either control calves or those given MAb B1. The proliferative bronchiolitis with syncytial formation and widespread distribution of RSV antigen in the lower respiratory tract of the B1-treated and control calves were indistinguishable and typical of experimental bovine RSV infection. Syncytia were markedly absent, and little or no viral antigen was detected in either the B4- or B13-treated calves.

Recombinant vaccinia viruses expressing the F, G or N, but not the M2, protein of bovine respiratory syncytial virus (BRSV) induce resistance to BRSV challenge in the calf and protect against the development of pneumonic lesions

The immunogenicity and protective efficacy of recombinant vaccinia viruses (rVV) encoding the F, G, N or M2 (22K) proteins of bovine respiratory syncytial virus (BRSV) were evaluated in calves, the natural host for BRSV. Calves were vaccinated either by scarification or intratracheally with rVV and challenged 6 to 7 weeks later with BRSV. Although replication of rVV expressing the F protein in the respiratory tract was limited after intratracheal vaccination, the levels of serum and pulmonary antibody were similar to those induced following scarification. The serum antibody response induced by the F protein was biased in favour of IgG1 antibody, whereas the G and the N proteins induced similar levels of IgG1:IgG2, and antibody was undetectable in calves primed with the M2 protein. The F protein induced neutralizing antibodies, but only low levels of complement-dependent neutralizing antibodies were induced by the G protein, and antibody induced by the N protein was not neutralizing. The F and N proteins primed calves for BRSV-specific lymphocyte proliferative responses, whereas proliferative responses were detected in calves primed with the G protein only after BRSV challenge. The M2 protein primed lymphocytes in only one out of five calves. Although there were differences in the immune responses induced by the rVVs, the F, G and N, but not the M2, proteins induced significant protection against BRSV infection and, in contrast with the enhanced lung pathology seen in mice vaccinated with rVV expressing individual proteins of human (H)RSV, there was a reduction in lung pathology in calves.

Immunization with a peptide derived from the G glycoprotein of bovine respiratory syncytial virus (BRSV) reduces the incidence of BRSV-associated pneumonia in the natural host

Previous reports demonstrate that synthetic peptides corresponding to the amino acid region 174-187 of G glycoprotein from subgroups A and B human respiratory syncytial virus (HRSV), containing a Cys-->Ser substitution at position 186, confer complete resistance to immunized BALB/c mice against infection with the respective virus. In this report, we show that a Cys186-->Ser substituted peptide (BG/174-187) representing the corresponding region of the bovine (B) RSV G glycoprotein conferred complete protection of mice against BRSV challenge, suggesting that the 174-187 region of RSV G glycoproteins constitutes a dominant protective epitope which has been maintained throughout evolution. Furthermore, immunization of calves with peptide BG/174-187 efficiently induced the production of antibodies capable of recognizing both the parental G glycoprotein and peptide BG/174-187. Following challenge with live BRSV, although none of the animals were protected from upper respiratory tract disease, there were little or no gross pneumonic lesions in the four peptide-immunized calves. In contrast, moderate to extensive pneumonic lesions were observed in 2 out of 3 calves in the control group. Our results thus suggest that peptide BG/174-187 efficiently prevented BRSV-associated pneumonia in the natural host. The use of this system as a model is quite promising with regard to the development of a human synthetic vaccine.

The nursing record as a research tool to identify nursing interventions

This paper describes a study which was designed to test the feasibility of using retrospective case note abstraction of data from nursing records to identify the nursing interventions given to two groups of patients: those who had suffered a myocardial infarction and those who had sustained a fractured neck of femur. The aim of the study was to assess whether the data obtained from the records were an accurate reflection of the nursing care given to patients. This was done by comparing what was recorded in the notes for specific areas of care with what the nursing staff said they did. The specific areas of care for patients suffering a myocardial infarction were: pain, mobility, anxiety, patient education. The specific areas of care for patients sustaining a fractured femur were: pressure areas, pain, nutrition, mobility and rehabilitation, information and teaching. Data were collected in three ways: using a retrospective data abstraction tool to examine the case notes of a particular patient; interviewing a nurse who had looked after the same patient; interviewing a senior ward nurse to obtain information about ward policies and practices to obtain a profile of the care usually given to these groups of patients. In this paper we present some of our findings and discuss the methodological and logistical problems of using this method.

Development and characterisation of a model of bovine inflammation

Two dialysis sacs each containing 50 ml dextran sulphate solution were implanted into the peritoneal cavities of five three month-old calves. One sac was inoculated with Pasteurella haemolytica or Streptococcus uberis and the second sac served as an uninoculated control. Samples of sac fluid removed after 0, four, six, eight, 15, 24, 36 and 48 hours and then at 24 hour intervals after inoculation revealed bacterial growth up to 9.0 log10 cfu ml-1 by two to three days after inoculation. Concentrations of 25 to 48 ng ml-1 of the inflammatory mediator prostaglandin E2 (PGE2) were detected six to 96 hours after inoculation, similar amounts being generated in sacs inoculated with either bacterium, but the concentrations in control sacs remained below 10 ng ml-4 over the seven day experiment. Post mortem, a tissue cast invested each of the inoculated sacs. Histologically, the reaction was an acute inflammatory response similar to that evoked by each bacterium in the target organ.

Identification of potential CTL epitopes of bovine RSV using allele-specific peptide motifs from bovine MHC class I molecules

Respiratory syncytial virus (RSV) is a major cause of lower respiratory tract infection in young infants and housed calves. Depletion of CD8+ lymphocytes from calves inhibited their ability to clear the virus from the nasopharynx and lungs. To study these cells further, a cytotoxic T lymphocyte (CTL) assay was established. CTL could be demonstrated in the peripheral blood of gnotobiotic calves 7-10 days post infection (p.i.) with RSV and in lungs 10 days p.i. This response was both MHC-restricted and virus-specific. Following separation of the lung lymphocytes by magnetic activated cell sorting, it was shown that the cytolytic activity was mediated by cells of the CD8+ phenotype. To identify epitopes recognised by bovine CTL, the consensus motifs from MHC class I alleles found in the herd at Compton were identified. cDNA libraries were constructed and screened for full length class I sequences. The isolated cDNA clones were then transfected into mouse P815 cells and the expressed product immunoprecipitated and matched with a serological specificity. The bovine MHC class I molecules were isolated from lysed transfected cells by affinity chromatography, using a monoclonal antibody specific for bovine MHC class I, and bound peptides were separated by reverse-phase HPLC. Analysis of the protein sequences of bovine RSV for the defined motifs has identified potential CTL epitopes.