A public health approach to modern slavery in the United Kingdom: a codeveloped framework

OBJECTIVES

Modern slavery is a public health challenge. The objective of this research was to build and refine a public health approach to addressing it.

STUDY DESIGN

This was a participatory qualitative study with a proof-of-concept exercise.

METHODS

Nine deliberative workshops with 65 people working across the antislavery sector. Thematic analysis of qualitative data. Of the nine workshops, two were proof of concept. These explored and tested the public health framework devised.

RESULTS

Participants contributed to the development of a public health framework to modern slavery that included multiple elements across national, local, and service levels. There were six 'C's to national components: policy that was coherent, co-ordinated, consistent, comprehensive, co-operative and compliant with international law. Local components centred on effective local multiagency partnerships and service design and delivery focussed on trauma-informed, flexible, person-centred care.

CONCLUSIONS

A public health approach to modern slavery is a promising development in the antislavery field in the United Kingdom and globally. It was well supported by workshop participants and appeared to be operable. Barriers to its implementation exist, however, including the challenge of intersectoral working and an incongruent policy environment.

Can a community empowerment intervention improve health and wellbeing in a post-industrial UK town?

Background

'Local People' programme operates in 29 UK communities experiencing disadvantage and economic stressors that impact on population wellbeing. The programme uses a community empowerment approach to increase social connections, and collective control, improve health, and reduce inequalities. This links to SDGs 3 and 11. Mechanisms include a decision-making group led by residents, a project lead, funding, and support from a national charity.

Methods

A mixed method evaluation was conducted (2017-19) to identify processes and assess outcomes and impacts. This presentation outlines the findings from five in-depth qualitative case studies (c140 interviews) with emphasis on one post-industrial UK town suffering from the effects of industrial decline. A within case and cross case qualitative analysis was undertaken using a thematic framework.

Results

Priorities set by local areas focused on increasing community involvement and connections between people. A wide range of activities took place including regular classes and community events. The five case studies found strong qualitative evidence of increased social connectedness, community spirit and a sense of purpose, along with the area becoming a better place to live. People involved in project delivery gained confidence and skills, improved their wellbeing and gained a sense of control. There is, as yet, limited evidence that increased involvement has influenced the wider determinants of health. In the post-industrial town, people's social networks expanded, enriching their lives and providing missed companionship. Participants in the programme reported improved mental and physical health, as well as increased confidence and skills. Involvement gave a voice to marginalised older people in the area.

Conclusions

Empowering communities and putting residents in control can lead to improvements in connectedness and some aspects of health and wellbeing, even in post-industrial towns facing considerable and complex challenges.

Key messages

The community empowerment programme increased social connectedness. The programme led to improved mental and physical health in participants.

An example of involving lay people to enhance complex public health intervention evaluations

Background

Despite growing interest in understanding complex systems and public health interventions, research methodologies that take account of system-wide action are relatively underdeveloped. Community-based participatory research (CBPR) is steered and conducted by people with lived experience of the issues being researched. This paper explores the value of CBPR in complex public health intervention evaluations. The 'Local People' and 'Local Conversations' programmes use a community empowerment approach in 50 communities across the UK experiencing social disadvantage to increase social connections and collective control, improve health and wellbeing, and reduce inequalities (linked to SDG 3 and 11).

Methods

Evaluation of the programmes followed a mixed-methods design, including qualitative case studies, longitudinal survey, process appraisal, and CBPR. Residents from 10 communities across the programmes each undertook 2 rounds of CBPR. These projects resulted in written reports, which were analysed thematically alongside other data sources.

Results

There was some variation in the scope and design of the 20 completed CBPR projects. Whilst projects did not generally extend beyond the scope of the overall evaluation, peer research provided information from residents that were inaccessible to other data collection streams. Gathering community (lay) knowledge improved understanding of local priorities and actions within the programmes. However, the utility of CBPR was less consistent for community-researchers and local communities, often failing to support project development. Some community-researchers felt unprepared for the activity despite support from the academic team.

Conclusions

Conducted appropriately, CBPR can elicit data that would be less accessible through externally led research. This study highlights the value of CBPR in complex programme evaluations, enabling a deeper understanding of social context in which interventions occur.

Key messages

CBPR complements more traditional research methodologies in complex public health evaluation designs. CBPR can enable a deeper understanding of social processes necessary for the success of complex public health interventions that might be beyond the scope of other methodologies.

Impact of a community empowerment programme in disadvantaged UK neighbourhoods: results of a survey

Background

A community empowerment programme in the UK aims to enable people to have greater collective control over area-based decision making, improved health and wellbeing and reduce health inequalities, by providing small grants to support residents of deprived neighbourhoods and communities of interest to come together to take action on issues of importance to them.

Methods

A survey was conducted at 4 6-month intervals as part of a mixed methods evaluation, to collect data about participant demographics, level of involvement, opinions of the project, and impacts. The survey was self-completed online or on paper, and distributed by local project leads. Outcome questions were adapted from the UK Government Community Life Survey to facilitate comparison with national statistics. Data were analysed using SPSS to produce descriptive statistics, supported by inferential statistical tests where appropriate. Regression analysis using multi-level modelling was used to estimate the conditional correlation between health outcome and Local People project participation.

Results

1053 people from 29 local areas responded to the survey over the 4 time points; only 93 responded more than once. 43% took part in project activities, 36% were local project committee members and 19% were volunteers. The analysis found positive impacts on confidence, control, friendships, skills, happiness, life satisfaction, feelings of worth (p < 0.05), and that greater length and degree of involvement in the projects were associated with greater positive impacts on all of these outcomes.

Conclusions

The survey provides tentative evidence that participation in a community empowerment initiative may result in improved wellbeing, feelings of power and control, sense of belonging and trust. People who are involved for longer or more deeply involved are more likely to see these impacts. More community-based survey research is needed to gather people's views on neighbourhood initiatives.

Key messages

An evaluation of a community empowerment programme found positive impacts on control, wellbeing, belonging and trust. Greater length or degree of involvement were associated with greater impact.

Chronic norovirus infection and common variable immunodeficiency

Chronic infection with norovirus is emerging as a significant risk for patients with immunodeficiency - either primary or secondary to therapeutic immunosuppression. Patients with primary immunodeficiency present a range of pathological responses to norovirus infection. Asymptomatic infections occur and differentiating viral carriage or prolonged viral shedding after self-limiting infection from infection causing protracted diarrhoea can be challenging, due to relatively mild pathological changes that may mimic other causes of diarrhoea in such patients (for instance pathogenic bacteria or parasites or graft-versus-host disease). However, a subset of patients with common variable immunodeficiency (CVID) experience a severe norovirus-associated enteropathy leading to intestinal villous atrophy and malabsorption. Symptomatic infection of up to 8 years has been demonstrated with clinical and histological recovery on viral clearance. Although oral immunoglobulins and nitazoxanide have been used to treat noroviral infections associated with immunosuppression, ribavirin is the only agent to date that has been linked to viral clearance in the Noroviral enteropathy associated with CVID.

Antarctic ice sheet discharge driven by atmosphere-ocean feedbacks at the Last Glacial Termination

Reconstructing the dynamic response of the Antarctic ice sheets to warming during the Last Glacial Termination (LGT; 18,000–11,650 yrs ago) allows us to disentangle ice-climate feedbacks that are key to improving future projections. Whilst the sequence of events during this period is reasonably well-known, relatively poor chronological control has precluded precise alignment of ice, atmospheric and marine records, making it difficult to assess relationships between Antarctic ice-sheet (AIS) dynamics, climate change and sea level. Here we present results from a highly-resolved ‘horizontal ice core’ from the Weddell Sea Embayment, which records millennial-scale AIS dynamics across this extensive region. Counterintuitively, we find AIS mass-loss across the full duration of the Antarctic Cold Reversal (ACR; 14,600–12,700 yrs ago), with stabilisation during the subsequent millennia of atmospheric warming. Earth-system and ice-sheet modelling suggests these contrasting trends were likely Antarctic-wide, sustained by feedbacks amplified by the delivery of Circumpolar Deep Water onto the continental shelf. Given the anti-phase relationship between inter-hemispheric climate trends across the LGT our findings demonstrate that Southern Ocean-AIS feedbacks were controlled by global atmospheric teleconnections. With increasing stratification of the Southern Ocean and intensification of mid-latitude westerly winds today, such teleconnections could amplify AIS mass loss and accelerate global sea-level rise.

Microbiology: lessons from a first attempt at Lake Ellsworth

During the attempt to directly access, measure and sample Subglacial Lake Ellsworth in 2012-2013, we conducted microbiological analyses of the drilling equipment, scientific instrumentation, field camp and natural surroundings. From these studies, a number of lessons can be learned about the cleanliness of deep Antarctic subglacial lake access leading to, in particular, knowledge of the limitations of some of the most basic relevant microbiological principles. Here, we focus on five of the core challenges faced and describe how cleanliness and sterilization were implemented in the field. In the light of our field experiences, we consider how effective these actions were, and what can be learnt for future subglacial exploration missions. The five areas covered are: (i) field camp environment and activities, (ii) the engineering processes surrounding the hot water drilling, (iii) sample handling, including recovery, stability and preservation, (iv) clean access methodologies and removal of sample material, and (v) the biodiversity and distribution of bacteria around the Antarctic. Comparisons are made between the microbiology of the Lake Ellsworth field site and other Antarctic systems, including the lakes on Signy Island, and on the Antarctic Peninsula at Lake Hodgson. Ongoing research to better define and characterize the behaviour of natural and introduced microbial populations in response to deep-ice drilling is also discussed. We recommend that future access programmes: (i) assess each specific local environment in enhanced detail due to the potential for local contamination, (ii) consider the sterility of the access in more detail, specifically focusing on single cell colonization and the introduction of new species through contamination of pre-existing microbial communities, (iii) consider experimental bias in methodological approaches, (iv) undertake in situ biodiversity detection to mitigate risk of non-sample return and post-sample contamination, and (v) address the critical question of how important these microbes are in the functioning of Antarctic ecosystems.

Gold-coated lanthanide phosphate nanoparticles for an 225Ac in vivo alpha generator

Retaining radioactive daughter products at a clinically relevant target site remains one of the major challenges in development of in vivo α generators with radionuclides such as 225Ac and 223Ra. In this work, we examine the ability of layered nanoparticle constructs to retain 225Ac and the first decay daughter, 221Fr. Actinium-225 is cocrystalized in a lanthanide phosphate nanoparticle consisting of varying amounts of La and Gd. Additional lanthanide phosphate layers improve retention capability while an outer layer of gold facilitates the attachment of targeting moieties for in vivo use. Retention of 225Ac in the nanoparticles is near quantitative while the 221Fr retention varies from 60-89% as a function of time, the number of layers, and nanoparticle composition. Decay corrected radiochemical yield in the multi-shell syntheses are high (76%) and comparable to or better than existing delivery approaches.

Continual monitoring of intraepithelial lymphocyte immunophenotype and clonality is more important than snapshot analysis in the surveillance of refractory coeliac disease

OBJECTIVE

An aberrant immunophenotype and monoclonality of intraepithelial lymphocytes (IELs) are frequently found in refractory coeliac disease (RCD). However, the utility of continual monitoring of IEL immunophenotype and clonality in the surveillance of RCD remains to be studied.

DESIGN

The diagnostic and follow-up biopsies from 33 patients with CD, 7 with suspected RCD, 41 with RCD and 20 with enteropathy-associated T cell lymphoma (EATL) (including 11 evolved from RCD) were investigated by CD3epsilon/CD8 double immunohistochemistry and PCR-based clonality analysis of the rearranged T cell receptor (TCR) genes.

RESULTS

An aberrant immunophenotype (CD3epsilon(+)CD8(-) IELs > or =40%) and monoclonality were detected occasionally in CD biopsies, either transiently in patients with CD not compliant with a gluten-free diet or in those who subsequently developed suspected RCD, RCD or EATL. In contrast, the aberrant immunophenotype and monoclonality were found in 30 of 41 (73%) and 24 of 37 (65%) biopsies, respectively, at the time of RCD diagnosis. Among the patients with RCD who did not show these abnormalities in their diagnostic biopsies, 8 of 10 (80%) and 5 of 11 (45%) cases gained an aberrant immunophenotype and monoclonality, respectively, during follow-up. Irrespective of whether detected in diagnostic or follow-up biopsies, persistence of both abnormalities was characteristic of RCD. Importantly, the presence of concurrent persistent monoclonality and aberrant immunophenotype, especially > or =80% CD3epsilon(+)CD8(-) IELs, was a strong predictor of EATL development in patients with RCD (p=0.001).

CONCLUSIONS

Continual monitoring of both immunophenotype and clonality of IELs is more important than snapshot analysis for RCD diagnosis and follow-up, and could provide a useful tool for surveillance of patients at risk of EATL.

Parenteral Administration of Glutamine Modulates Acute Phase Response in Postparturient Dairy Cows

The objective of this study was to investigate whether administration of L-Gln would affect mediators of acute phase response in postparturient dairy cows. Twenty-four multiparous Holstein cows were blocked by the expected day of calving and randomly assigned to 1 of the 3 treatment groups (n = 8/group): 1) i.v. infusion of 10 L of 0.85% NaCl (control), 2) i.v. infusion of 106, or 3) 212 g/d of L-Gln mixed with 10 L of 0.85% NaCl solution; each treatment was given 8 h/d for each of 7 consecutive days starting on d 1 after calving. Blood samples were collected 1 wk before the expected day of parturition as well as on d 0, 7, 14, and 21 after parturition; plasma concentrations of serum amyloid A (SAA), haptoglobin, and lipopolysaccharide-binding protein were measured by ELISA, and alpha(1)-acid glycoprotein was assessed by radial immunodiffusion. Concentrations of SAA, haptoglobin, and alpha(1)-acid glycoprotein increased in control cows after parturition, reaching peak values on d 0 or 7 postpartum (60, 1,093, and 963 microg/mL, respectively). Cows infused with 106 g/d of L-Gln had greater concentrations of SAA in plasma on d 14 and 21 compared with controls (62.8 vs. 30.2 and 71.1 vs. 34.5 microg/mL, respectively). Cows infused with 212 g/d of L-Gln had greater concentrations of SAA on d 7 (82.5 vs. 53.9 microg/mL) and lower concentrations of haptoglobin on d 14 and 21 postpartum compared with controls (264 vs. 621 and 175 vs. 587 microg/mL, respectively). Cows treated with 106 and 212 g/d of L-Gln had greater plasma lipopolysaccharide-binding protein concentrations on d 7 compared with control group (50.0 and 35.6 vs. 10.8 microg/mL, respectively). There were no treatment differences with respect to milk yield and DM intake during the experimental period. In conclusion, our data indicate that i.v. administration of L-Gln modulated acute phase mediators in dairy cows after parturition and warrants further research into the mechanisms behind these effects.

The genome of the social amoeba Dictyostelium discoideum

The social amoebae are exceptional in their ability to alternate between unicellular and multicellular forms. Here we describe the genome of the best-studied member of this group, Dictyostelium discoideum. The gene-dense chromosomes of this organism encode approximately 12,500 predicted proteins, a high proportion of which have long, repetitive amino acid tracts. There are many genes for polyketide synthases and ABC transporters, suggesting an extensive secondary metabolism for producing and exporting small molecules. The genome is rich in complex repeats, one class of which is clustered and may serve as centromeres. Partial copies of the extrachromosomal ribosomal DNA (rDNA) element are found at the ends of each chromosome, suggesting a novel telomere structure and the use of a common mechanism to maintain both the rDNA and chromosomal termini. A proteome-based phylogeny shows that the amoebozoa diverged from the animal-fungal lineage after the plant-animal split, but Dictyostelium seems to have retained more of the diversity of the ancestral genome than have plants, animals or fungi.

Patients' experiences and opinions of home blood pressure measurement

Regular measurement of the blood pressure (BP) is necessary to monitor the treatment of hypertension, and self-measurement is one technique of obtaining such measurements. The aim of this study was to investigate the experiences of individuals who have carried out home BP measurement. A qualitative method using semistructured interviews was used with 13 subjects. These were adults with hypertension who had previous experience of measuring their own BP, and were recruited to the study from one UK general medical practice. Interviews were recorded and transcribed, and data from the interviews have been analysed using phenomenological principles and identifying 'meaning units.' The findings suggest that participants were willing to carry out home measurements and several were pleased to have been asked to be more involved in their own management. All found the technique straightforward. Most noted marked variability in the day-to-day BP measurements. Several exhibited the 'white coat' phenomenon (spuriously raised BP in certain settings only). Some participants showed considerable know-ledge of hypertension and its consequences. They reported being aware of their own BP level and whether this was within acceptable limits. They also reported being willing to take further measurements, and to consider adjusting their treatment in the light of these measurements. Other participants showed less knowledge and enthusiasm, and considered the management of hypertension to be the doctor's job. The findings suggest that for some individuals home BP measurement is acceptable. They also help to explain why, for some individuals, it is not. Using the findings, a number of changes to current practice could be made, which might make home measurements more acceptable and easier to perform. As a result, a new proforma for use in everyday practice has been designed. The study shows that there is considerable scope for sharing BP measurement and management decisions in hypertension with patients themselves.

Differential transcriptional regulation by human immunodeficiency virus type 1 and gp120 in human astrocytes

Astrocytes may be infected with the human immunodeficiency virus type 1 (HIV-1) or exposed to the HIV protein gp120, yet their role in the pathogenesis of HIV dementia is largely unknown. To characterize the effects of HIV on astrocytic transcription, microarray analysis and ribonuclease protection assays (RPA) were performed. Infection of astrocytes by HIV or treatment with gp120 had differential and profound effects on gene transcription. Of the 1153 oligonucleotides on the immune-based array, the expression of 108 genes (53 up; 55 down) and 82 genes (32 up; 50 down) were significantly modulated by gp120 and HIV infection respectively. Of the 1153 oligonucleotides on the neuro-based array, 58 genes (25 up; 33 down) and 47 genes (17 up; 30 down) were significantly modulated by gp120 and HIV infection respectively. Chemokine and cytokine induction occurred predominantly by HIV infection, whereas gp120 had no significant effect. These results were confirmed by RPA. The authors conclude that profound alterations of astrocytic function occur in response to HIV infection or interaction with viral proteins, suggesting that astrocytes may play an important role in the pathogenesis of HIV dementia.

Sequence of Plasmodium falciparum chromosomes 1, 3-9 and 13

Since the sequencing of the first two chromosomes of the malaria parasite, Plasmodium falciparum, there has been a concerted effort to sequence and assemble the entire genome of this organism. Here we report the sequence of chromosomes 1, 3-9 and 13 of P. falciparum clone 3D7--these chromosomes account for approximately 55% of the total genome. We describe the methods used to map, sequence and annotate these chromosomes. By comparing our assemblies with the optical map, we indicate the completeness of the resulting sequence. During annotation, we assign Gene Ontology terms to the predicted gene products, and observe clustering of some malaria-specific terms to specific chromosomes. We identify a highly conserved sequence element found in the intergenic region of internal var genes that is not associated with their telomeric counterparts.

Complete genome sequence of the model actinomycete Streptomyces coelicolor A3(2)

Streptomyces coelicolor is a representative of the group of soil-dwelling, filamentous bacteria responsible for producing most natural antibiotics used in human and veterinary medicine. Here we report the 8,667,507 base pair linear chromosome of this organism, containing the largest number of genes so far discovered in a bacterium. The 7,825 predicted genes include more than 20 clusters coding for known or predicted secondary metabolites. The genome contains an unprecedented proportion of regulatory genes, predominantly those likely to be involved in responses to external stimuli and stresses, and many duplicated gene sets that may represent 'tissue-specific' isoforms operating in different phases of colonial development, a unique situation for a bacterium. An ancient synteny was revealed between the central 'core' of the chromosome and the whole chromosome of pathogens Mycobacterium tuberculosis and Corynebacterium diphtheriae. The genome sequence will greatly increase our understanding of microbial life in the soil as well as aiding the generation of new drug candidates by genetic engineering.

Calcium-dependent protection from complement lysis in Naegleria fowleri amebae

Pathogenic Naegleria fowleri amebae are resistant to the lytic effects of serum complement. The presence of surface glycoproteins or removal of the membrane attack complex (MAC) of complement from the cell surface by vesiculation serve to protect the amebae from complement lysis. The specific mediators important in stimulating complement resistance are not defined. These studies were undertaken to examine the effect of Ca(2+) ions in initiating complement resistance of N. fowleri in contrast to non-pathogenic complement-sensitive N. gruberi. Chelation of extracellular calcium with ethylene glycol tetraacetic acid (EGTA) or chelation of intracellular calcium with 1,2-bis-(O-Aminophenoxy) ethane-N,N,N,N tetraacetic acid tetra (acetoxymethyl) ester (BAPTA-AM) increased complement lysis of N. fowleri. Chelation of calcium ions did not affect complement sensitivity of N. gruberi. Increased lysis of ionomycin-treated N. fowleri was detected after exposure to serum complement, suggesting that a threshold level of Ca(2+) mediates complement resistance before survival mechanisms are overwhelmed and lysis occurs. A differential influx of Ca(2+) ions occurred in fura-2 labeled N. fowleri after deposition of complement component C9 to form the MAC complex on the cell surface in comparison to N. gruberi. These studies suggest that Ca(2+) ions influence complement resistance in N. fowleri but do not play a role in altering the sensitivity of N. gruberi to complement.

The genome sequence of Schizosaccharomyces pombe

We have sequenced and annotated the genome of fission yeast (Schizosaccharomyces pombe), which contains the smallest number of protein-coding genes yet recorded for a eukaryote: 4,824. The centromeres are between 35 and 110 kilobases (kb) and contain related repeats including a highly conserved 1.8-kb element. Regions upstream of genes are longer than in budding yeast (Saccharomyces cerevisiae), possibly reflecting more-extended control regions. Some 43% of the genes contain introns, of which there are 4,730. Fifty genes have significant similarity with human disease genes; half of these are cancer related. We identify highly conserved genes important for eukaryotic cell organization including those required for the cytoskeleton, compartmentation, cell-cycle control, proteolysis, protein phosphorylation and RNA splicing. These genes may have originated with the appearance of eukaryotic life. Few similarly conserved genes that are important for multicellular organization were identified, suggesting that the transition from prokaryotes to eukaryotes required more new genes than did the transition from unicellular to multicellular organization.

Identification and characterization of lymphoid precursors in the murine intestinal epithelium

Although in vivo evidence supports a role for the murine intestinal epithelium in the extrathymic generation of certain intraepithelial T lymphocytes (IEL), no intraepithelial cells with in vitro lymphoid progenitor potential have yet been demonstrated. Using reaggregate fetal thymic organ culture techniques, we show that a subset of CD3(-) cells isolated from the intestinal epithelium of young mice is capable of generating T cells (alpha beta and gamma delta) and NK1.1(+) cells in vitro. A novel IEL subset bearing a low level of CD45 was identified and found to comprise cells expressing highly immature lymphoid markers including CD34, c-kit, CD122, CD127 and high levels of CD16 and CD44. This subset represents 20-30% of intraepithelial CD45(+) cells from 4-week-old wild-type and nude mouse strains and contains cells with in vitro T cell differentiation capacity. The identification of such an early pluripotent precursor phenotype within the intestinal epithelium implies that the potential for T cell generation exists at this site, and suggests that extrathymic T cell generation may occur within the epithelium itself.

In vivo chondroprotection and metabolic synergy of glucosamine and chondroitin sulfate

Supplements of glucosamine hydrochloride, low molecular weight chondroitin sulfate, and manganese ascorbate were tested separately and in combination for their ability to retard progression of cartilage degeneration in a rabbit instability model of osteoarthrosis. Computerized quantitative histologic evaluation of safranin O stained sections of the medial femoral condyles measured the grade and extent of tissue involvement of lesions. Severe lesions (Mankin grade greater than 7) were absent in all animals supplemented with a dietary mixture of glucosamine, chondroitin sulfate, and manganese ascorbate. Total linear involvement (mm of lesioned surface) and total grade (mean grade x number of lesions per animal) were reduced significantly in animals given the combination compared with controls (59% and 74% respectively). Animals supplemented with glucosamine, chondroitin sulfate, or manganese ascorbate alone had less moderate and severe tissue involvement than controls but not to the extent of the combined group. In vitro, a combination of glucosamine hydrochloride and chondroitin sulfate acted synergistically in stimulating glycosaminoglycan synthesis (96.6%). Chondroitin sulfate and manganese ascorbate but not glucosamine were effective in inhibiting degradative enzyme activity. These data suggest that the disease modifying effect (the ability to retard progression of cartilage degeneration) of a mixture of glucosamine, chondroitin sulfate, and manganese ascorbate is more efficacious than either agent alone.

First-principles determination of hybrid bilayer membrane structure by phase-sensitive neutron reflectometry

The application of a new, phase-sensitive neutron reflectometry method to reveal the compositional depth profiles of biomimetic membranes is reported. Determination of the complex reflection amplitude allows the related scattering length density (SLD) profile to be obtained by a first-principles inversion without the need for fitting or adjustable parameters. The SLD profile so obtained is unique for most membranes and can therefore be directly compared with the SLD profile corresponding to the chemical compositional profile of the film, as predicted, for example, by a molecular dynamics simulation. Knowledge of the real part of the reflection amplitude, in addition to enabling the inversion, makes it possible to assign a spatial resolution to the profile for a given range of wavevector transfer over which the reflectivity data are collected. Furthermore, the imaginary part of the reflection amplitude can be used as a sensitive diagnostic tool for recognizing the existence of certain in-plane inhomogeneities in the sample. Measurements demonstrating the practical realization of this phase-sensitive technique were performed on a hybrid bilayer membrane (self-assembled monolayer of thiahexa (ethylene oxide) alkane on gold and a phospholipid layer) in intimate contact with an aqueous reservoir. Analysis of the experimental results shows that accurate compositional depth profiles can now be obtained with a spatial resolution in the subnanometer range, primarily limited by the background originating from the reservoir and the roughness of the film's supporting substrate.

Activation of mitogen-activated protein kinases is required for alpha1-adrenergic agonist-induced cell scattering in transfected HepG2 cells

Activation of alpha1B-adrenergic receptors ((alpha1B)AR) by phenylephrine (PE) induces scattering of HepG2 cells stably transfected with the (alpha1B)AR (TFG2 cells). Scattering was also observed after stimulation of TFG2 cells with phorbol myristate acetate (PMA) but not with hepatocyte growth factor/scatter factor, epidermal growth factor, or insulin. PMA but not phenylephrine rapidly activated PKCalpha in TFG2 cells, and the highly selective PKC inhibitor bisindolylmaleimide (GFX) completely abolished PMA-induced but not PE-induced scattering. PE rapidly activated p44/42 mitogen-activated protein kinase (MAPK), p38 MAPK, c-Jun N-terminal kinase (JNK), and AP1 (c-fos/c-jun). Selective blockade of p42/44 MAPK activity by PD98059 or by transfection of a MEK1 dominant negative adenovirus significantly inhibited the PE-induced scattering of TFG2 cells. Selective inhibition of p38 MAPK by SB203850 or SB202190 also blocked PE-induced scattering, whereas treatment of TFG2 cells with the PI3 kinase inhibitors LY294002 or wortmannin did not inhibit PE-induced scattering. Blocking JNK activation with a dominant negative mutant of JNK or blocking AP1 activation with a dominant negative mutant of c-jun (TAM67) significantly inhibited PE-induced cell scattering. These data indicate that PE-induced scattering of TFG2 cells is mediated by complex mechanisms, including activation of p42/44 MAPK, p38 MAPK, and JNK. Cell spreading has been reported to play important roles in wound repair, tumor invasion, and metastasis. Therefore, catecholamines acting via the (alpha1)AR may modulate these physiological and pathological processes.

Glucose and lactate metabolism after severe human head injury: influence of excitatory neurotransmitters and injury type

The survival of traumatized brain tissue depends on energy substrate delivery and consumption. Excitatory amino acids produce a disturbance of ion homeostasis and thus, increase energy demand. In head-injured patients, massive release of glutamate has been reported, especially in patients with focal contusions. Therefore, we studied the interrelationship between glutamate, glucose and lactate in relation to the type of injury. We investigated 37 severely head-injured patients in which a microdialysis probe was placed next to a focal contusion (n = 14) or together with a ventricular catheter in diffusely injured tissue (n = 23). Within-subject Spearman-rank correlation revealed an overall strong relationship between glutamate and lactate (p < 0.001) and glutamate and glucose (p < 0.01), but not between glucose and lactate (n.s.). The interrelationship was more pronounced in diffusely injured brain (normal CT appearance) compared to the contused tissue. The results demonstrate that glutamate clearly influences the release of lactate following injury, supporting the hypothesis that glutamate "drives" glycolysis in astrocytes. The strong positive correlation between glutamate and glucose might indicate an effect of glutamate upon glucose uptake by cells which differs according to the type of injury.

Evidence for time-dependent glutamate-mediated glycolysis in head-injured patients: a microdialysis study

In the brain, lactate is not only a marker of anaerobic glycolysis due to hypoxia/ischemia, but also a neuronal energy source which is provided by glutamate-induced astrocytic glycolysis. In the present study we wanted to investigate the relationship between glutamate release and lactate production during the entire time-course and during three time periods of microdialytic monitoring in 54 severely head injured patients. Within-subject Spearman rank correlations were calculated in each period for glutamate and lactate, for each patient and the mean of all correlation coefficients were analyzed for difference from zero by a one-sample t-test. The results show a strong overall positive relationship between glutamate and lactate. However, during the first 12 hours after injury, there was no significant correlation. Thereafter, good correlation was seen. The splitting of patients into groups with good (Glasgow Outcome Scale; GOS 0-2) and poor outcome (GOS 3-4) showed a similar strong correlation for patients with good outcome, but this was lost for patients with poor outcome. The results clearly indicate that glutamate "drives" astrocytic lactate production in head-injured patients. The contribution of glutamate to overall lactate release is thus time-dependent. During the first 12 hours after injury, factors such as hypoxia, ischemia or edema overshadowed glutamate-induced glycolysis in astrocytes. In addition, the effect of glutamate is more pronounced in patients with good outcome.

The mechanism of cellulase action on cotton fibers: evidence from atomic force microscopy

Two cellulases from Trichoderma reesei--an exoglucanase, CBH I, and an endoglucanase, EG II--alone and in combination were incubated with cotton fibers. The effects of the cellulases on the surfaces of the cotton fibers were examined by atomic force microscopy. At high magnification, the physical effects on the fibers caused by the two types of enzymes were considerably different. Treatment with CBH I resulted in the appearance of distinct pathways or tracks along the length of the macrofibril. Treatment with EG II appeared to cause peeling and smoothing of the fiber surface. In combination, their effect was observed to be greatest when both enzymes were present simultaneously. When fibers smoothed by treatment with EG II were treated subsequently with CBH I, further evidence of path way formation caused by the action of CBH I along the fibers was observed. Incubation with a cellulase from Thermotoga maritima that lacks a cellulose binding domain had no effect on the surface of cotton fibers. These images provide the first physical evidence of differences in the effect of cellulase components action on the surface of cotton fibers and provide evidence for the movement or tracking of CBH I along the fibers. The first AFM image of CBH I molecules are presented.

Cortical extracellular sodium transients after human head injury: an indicator of secondary brain damage?

Animal studies indicate that elevated extracellular sodium can increase glutamate-induced excitotoxicity. Therefore, we investigated the relationship between sodium and glutamate and the effect of changes in sodium concentrations on the outcome of head-injured patients. Thirty-four (34) patients were selected for this study and divided into a group of patients having episodes (> or = 30-min) of high sodium in dialysates (> or = 200 mM; HIGH, n = 11) and a group of patients having no such episodes (NORMAL, n = 23). Levels for sodium (226 +/- 5.7 mM), glutamate (12.53 +/- 2.2 microM) and ICP (32.2 +/- 4.0 mm Hg,) were relatively high during the high sodium episodes. Overall, mean values for glutamate, ICP and outcome did not differ amono both groups. The mean dialysate sodium concentration, however, was significantly higher in the HIGH (178 +/- 6 mM) compared to the NORMAL group (158 +/- 3 mM; p < 0.01). Spearman rank correlation between sodium and glutamate or ICP were not significant. The HIGH sodium group did not have significantly more patients with poor outcome than the NORMAL group. The results indicated sodium concentrations did not affect the outcome of head-injured patients. However, other sodium monitoring techniques are desirable to elucidate these apparent potentially major sodium transients, which we have observed in the human cortex, after severe head injury.

In vitro activity of RPR 106972 alone and in combination with vancomycin, ampicillin, and gentamicin against multidrug-resistant enterococci

This investigation used checkerboard and time-kill assays to evaluate the in vitro activity of RPR 106972 (45% pristinamycin IB and 55% pristinamycin IIB) alone and in combination with vancomycin or ampicillin +/- gentamicin against multidrug-resistant enterococci. The checkerboard procedure resulted in synergistic or additive effects in 91% of the isolates with the combination of RPR 106972 plus vancomycin versus 68% with RPR 106972 plus ampicillin. The addition of gentamicin to either combination resulted in synergistic or additive results in 100% of the isolates. Inhibitory activity was observed with the time-kill assay with mean change in log10 CFU/mL at 24 h of -0.31 for RPR 106972, 3.3 for vancomycin, -0.46 for RPR 106972 plus vancomycin, and -0.35 for RPR 106972 plus vancomycin and gentamicin. No antagonism was noted with any of the combinations. RPR 106972 demonstrates good inhibitory activity against Enterococcus faecium and may prove useful in the treatment of enterococcal infections.

Anaerobic degradation of polycyclic aromatic hydrocarbons and alkanes in petroleum-contaminated marine harbor sediments

Although polycyclic aromatic hydrocarbons (PAHs) have usually been found to persist under strict anaerobic conditions, in a previous study an unusual site was found in San Diego Bay in which two PAHs, naphthalene and phenanthrene, were oxidized to carbon dioxide under sulfate-reducing conditions. Further investigations with these sediments revealed that methylnaphthalene, fluorene, and fluoranthene were also anaerobically oxidized to carbon dioxide in these sediments, while pyrene and benzo[a]pyrene were not. Studies with naphthalene indicated that PAH oxidation was sulfate dependent. Incubating the sediments with additional naphthalene for 1 month resulted in a significant increase in the oxidation of [14C]naphthalene. In sediments from a less heavily contaminated site in San diego Bay where PAHs were not readily degraded, naphthalene degradation could be stimulated through inoculation with active PAH-degrading sediments from the most heavily contaminated site. Sediments from the less heavily contaminated site that had been adapted for rapid anaerobic degradation of high concentrations of benzene did not oxidize naphthalene, suggesting that the benzene- and naphthalene-degrading populations were different. When fuels containing complex mixtures of alkanes were added to sediments from the two sites, there was significant degradation in the alkanes. [14C]hexadecane was also anaerobically oxidized to 14CO2 in these sediments. Molybdate, a specific inhibitor of sulfate reduction, inhibited hexadecane oxidation. These results demonstrate that a wide variety of hydrocarbon contaminants can be degraded under sulfate-reducing conditions in hydrocarbon-contaminated sediments, and they suggest that it may be possible to use sulfate reduction rather than aerobic respiration as a treatment strategy for hydrocarbon-contaminated dredged sediments.

The significance of white-centered retinal hemorrhages in the shaken baby syndrome

Retinal hemorrhages in healthy children with or without a history of associated trauma are a strong indicator of child abuse. This report describes six cases of battered infants who presented with white-centered retinal hemorrhages. We discuss potential mechanisms for the presence of white-centered retinal hemorrhages in battered children.

Performance of anesthesia machines' devices that are not part of the Food and Drug Administration's daily checkout

OBJECTIVE

The Food and Drug Administration's (FDA) checkout recommendations are to be applied, at least daily, on anesthesia machines. Devices included in the checkout are crucial to the safe operation of the machine. Remaining devices do not need to be checked as often. However, they should be checked at some appropriate interval. We calculated the reliability of the non-FDA checkout devices, to predict failure rates of these devices.

METHODS

The study included 36 North American Drager Narkomed anesthesia machines that were in service a total of 109,410 days at a university hospital. Reliability (i.e., statistical) analyses were done using in-house data recorded by biomedical technicians during 3359 monthly machine inspections. If any one device was operating outside of the limits of the manufacturer's specifications, the machine was labeled as having failed its inspection.

RESULTS

Assumptions of the failure analysis were satisfied. The mean time between failures equaled 1351 days or 3.7 years (lower 95% confidence bound 1123 days or 3.1 years). The mean daily probability of one or more devices failing to perform within the manufacturer's specification between inspections equaled 1.1, 2.2%, and 4.4% for inspections every 1, 2, or 4 months, respectively. Probabilities that a machine would fail on demand between inspections were approximately equal to the mean daily probabilities of machine failure. The mean number of days per year that a machine would be operating with a device that is outside of the limits of its specifications equaled 4, 8, and 12, days, respectively. The mean daily probabilities of failure and the probabilities of failure on demand were both directly proportional to the inspection interval.

CONCLUSIONS

Our failure analysis provides a rational basis for choosing an appropriate inspection interval for anesthesia machines' devices that are not included in the FDA's checkout recommendations.