Erratum to: 36th International Symposium on Intensive Care and Emergency Medicine: Brussels, Belgium. 15-18 March 2016

[This corrects the article DOI: 10.1186/s13054-016-1208-6.].

Retrospective assessment of the validity and use of the community balance and mobility scale among individuals with subacute spinal cord injury

STUDY DESIGN

This is a retrospective chart review.

OBJECTIVES

The objective of this study was to evaluate the convergent validity, internal consistency and use of the Community Balance & Mobility Scale (CB&M) in individuals with incomplete spinal cord injury (iSCI) during inpatient rehabilitation.

SETTING

This study was conducted in an SCI rehabilitation center in Canada.

METHODS

Inpatient charts from January 2009 to October 2015 were screened. A chart was excluded if the inpatient was aged >65 years, did not complete a CB&M and/or had a comorbid condition. Demographics, CB&M score and injury-related characteristics were extracted. Berg Balance Scale (BBS), Six-Minute Walk Test (6 MWT) and Ten-Meter Walk Test (10 mWT) scores were obtained if completed within 1 week of the CB&M. χ²-Tests were used to identify CB&M items that were uniformly distributed, implying good discrimination between individuals. Convergent validity was assessed by correlating (Pearson's r) CB&M scores with BBS, 6 MWT and 10 mWT scores. Internal consistency (Cronbach's α) was evaluated.

RESULTS

Thirty inpatients were included (23 male, 38.3±15.3 years old, three AIS C, 26 AIS D, C1-L4, 16 traumatic). BBS scores were ⩾51/56; however, CB&M scores showed a wider range (27-82/96). Unilateral Stance, Tandem Walking, Lateral Foot Scooting, Forward to Backward Walking and Descending Stairs showed uniform distributions. Scores on the CB&M correlated strongly with scores on the 6 MWT (r=0.72, P<0.001) and moderately strongly with 10 mWT and BBS scores (r=0.47-0.59, P=0.004-0.013). Cronbach's α=0.87.

CONCLUSIONS

The CB&M is a valid measure in high-functioning individuals with iSCI. Prospective studies are required to further evaluate the psychometric properties of the CB&M as a measure of high-level balance for SCI.

An ordered sequence of expression of human MHC class-II antigens during B-cell maturation?

Studies with monoclonal antibodies confirm that human MHC class-II antigens are encoded by at least three pairs of loci. Here Keith Guy and Veronica van Heyningen suggest that as B cells mature theproducts of these loci are expressed in the sequence SB → DR → DC antigens - a sequence which parallels the order of the genes on chromosome 6.

Biobased plastics in a bioeconomy

Bioeconomy plans include a biobased industries sector in which some oil-derived plastics and chemicals are replaced by new or equivalent products derived, at least partially, from biomass. Some of these biobased products are here today, but to fulfil their societal potential, greater attention is required to promote awareness, and to improve their market share while making valuable contributions to climate change mitigation.

Bioplastics science from a policy vantage point

Society is fundamentally ambivalent to the use of plastics. On the one hand, plastics are uniquely flexible materials that have seen them occupy a huge range of functions, from simple packing materials to complex engineering components. On the other hand, their durability has raised concerns about their end-of-life disposal. When that disposal route is landfill, their invulnerability to microbial decomposition, combined with relatively low density and high bulk, means that plastics will occupy increasing amounts of landfill space in a world where available suitable landfill sites is shrinking. The search for biodegradable plastics and their introduction to the marketplace would appear to be a suitable amelioration strategy for such a problem. And yet the uptake of biodegradable plastics has been slow. The term biodegradable itself has entered public controversy, with accidental and intended misuse of the term; the intended misuse has led to accusations and instances of 'greenwashing'. For this and other reasons standards for biodegradability and compostability testing of plastics have been sought. An environmental dilemma with more far-reaching implications is climate change. The need for rapid and deep greenhouse gas (GHG) emissions cuts is one of the drivers for the resurgence of industrial biotechnology generally, and the search for bio-based plastics more specifically. Bio-based has come to mean plastics based on renewable resources, but this need not necessarily imply biodegradability. If the primary purpose is GHG emissions savings, then once again plastics durability can be a virtue, if the end-of-life solution can be energy recovery during incineration or recycling. The pattern of production is shifting from the true biodegradable plastics to the bio-based plastics, and that trend is likely to persist into the future. This paper looks at aspects of the science of biodegradable and bio-based plastics from the perspective of policy advisers and makers. It is often said that the bioplastics suffer from a lack of a favourable policy regime when compared to the wide-ranging set of policy instruments that are available on both the supply and demand side of biofuels production. Some possible policy measures are discussed.

Impact of benchmarking and clinical decision making tools on rehabilitation length of stay following spinal cord injury

STUDY DESIGN

Performance improvement initiative.

OBJECTIVES

To improve efficiency of spinal cord rehabilitation by reducing length of stay (LOS) while maintaining or improving patient outcomes.

SETTING

Academic hospital in Canada.

METHODS

LOS benchmarking was completed using national comparator data from the Canadian Institute for Health Information (CIHI). Clinical decision-making tools were developed to support implementation and sustainability. A standardized 'tentative discharge date' calculator was created to establish objective LOS targets. Defined discharge criteria and an accompanying clinical decision tree were developed to support team decision making and improve transparency. A revised patient census tool was also implemented to improve team communication and facilitate data collection. The initiative was implemented in March 2010 and the following metrics were evaluated: LOS, Functional Independence Measure (FIM) change and FIM efficiency.

RESULTS

Outcomes are reported for the 2010/11 fiscal year, and compared with the two prior fiscal years. Mean LOS for individuals undergoing initial inpatient rehabilitation was 71.5 days for 2010/11, a 14 and 17% reduction compared with the 2008/09 and 2009/10 fiscal years, respectively. While LOS decreased, FIM change increased 9 and 16% compared with 2008/09 and 2009/10, respectively. Similarly, FIM efficiency increased 54 and 32% compared with 2008/09 and 2009/10.

CONCLUSION

The use of benchmarking and decision support tools improved rehabilitation efficiency while increasing standardization in practice and transparency in LOS determination.

Toll-like receptor expression on classic and pro-inflammatory blood monocytes after acute exercise in humans

Monocytes are a heterogeneous group of cells, the relative distribution of which change in peripheral blood following a strenuous bout of aerobic exercise. Monocyte subtypes can be identified in blood based on the cell surface expression of CD14 and CD16: classic (CD14(++bright)/CD16(-negative)) and the CD16(+dim) (CD14(++bright)/CD16(+dim)) and CD16(++bright) (CD14(+dim)/CD16(++bright)) pro-inflammatory subtypes. Whole monocyte population changes in TLR2, TLR4 and HLA.DR expression have previously been documented after acute exercise without accounting for relative changes in monocyte subpopulations, therefore, this study examined their expression on classic and pro-inflammatory monocyte subsets following 45min of treadmill running at 75% VO(2max). Mononuclear cells isolated from the peripheral blood of moderately trained male subjects (n=15) before (PRE), immediately after (POST) and 1h after (1H) exercise were assessed for TLR2, TLR4 and HLA.DR expression on blood monocytes and their subpopulations using three-colour flow cytometry. Compared to PRE, the proportion of CD14+/CD16+ monocytes was 27% greater POST and 49% less at 1H and was associated with changes in the CD16(++bright) pro-inflammatory subtype (p<0.05). TLR2 expression was 12% lower on CD16(+dim) monocytes POST (p<0.05), whereas TLR4 and HLA.DR expression on total monocytes was 12% and 22% lower at 1H, respectively, and was attributed to changes in the classic (p<0.05) and not the pro-inflammatory subsets (p>0.05). We conclude that acute exercise causes localised changes in TLR2, TLR4 and HLA.DR expression within specific blood monocyte subpopulations, and could therefore be occurring at the cellular level. Such alterations might have significant implications for modulation of post-exercise immune surveillance.

The impact of different nanoparticle surface chemistry and size on uptake and toxicity in a murine macrophage cell line

This study investigated the uptake, kinetics and cellular distribution of different surface coated quantum dots (QDs) before relating this to their toxicity. J774.A1 cells were treated with organic, COOH and NH2 (PEG) surface coated QDs (40 nM). Model 20 nm and 200 nm COOH-modified coated polystyrene beads (PBs) were also examined (50 microg ml(-1)). The potential for uptake of QDs was examined by both fixed and live cell confocal microscopy as well as by flow cytometry over 2 h. Both the COOH 20 nm and 200 nm PBs were clearly and rapidly taken up by the J774.A1 cells, with uptake of 20 nm PBs being relatively quicker and more extensive. Similarly, COOH QDs were clearly taken up by the macrophages. Uptake of NH2 (PEG) QDs was not detectable by live cell imaging however, was observed following 3D reconstruction of fixed cells, as well as by flow cytometry. Cells treated with organic QDs, monitored by live cell imaging, showed only a small amount of uptake in a relatively small number of cells. This uptake was insufficient to be detected by flow cytometry. Imaging of fixed cells was not possible due to a loss in cell integrity related to cytotoxicity. A significant reduction (p<0.05) in the fluorescent intensity in a cell-free environment was found with organic QDs, NH2 (PEG) QDs, 20 nm and 200 nm PBs at pH 4.0 (indicative of an endosome) after 2 h, suggesting reduced stability. No evidence of exocytosis was found over 2 h. These findings confirm that surface coating has a significant influence on the mode of NP interaction with cells, as well as the subsequent consequences of that interaction.

Senescent T-lymphocytes are mobilised into the peripheral blood compartment in young and older humans after exhaustive exercise

Senescent T-lymphocytes are antigen-experienced cells that express the killer-cell lectin-like receptor G1 (KLRG1) and/or CD57; fail to clonally expand following further antigenic stimulation and prevail in the resting blood of older adults compared to the young. Physical exercise mobilises T-lymphocytes into the bloodstream and is therefore a model with which to compare age-related phenotypes of blood-resident T-cells with those T-cells entering the blood from peripheral lymphoid compartments. Eight young (Y; Age: 21+/-3 years) and 8 older (O; Age: 56+/-3 years) healthy males completed a maximal treadmill exercise protocol. Blood lymphocytes isolated before, immediately after and 1h after exercise were assessed for cell surface expression of KLRG1, CD57, CD28, CD45RA, CD45RO, CD62L and lymphocyte subset markers using three-colour flow cytometry. Lymphocyte subset numbers (CD3+, CD3+/CD4+, CD3+/CD8 and CD3-/CD56+) increased with exercise (p<0.05) but were not different between Y and O. At rest and immediately after exercise, the percentage of CD3+/CD8+ T-lymphocytes expressing KLRG1 and CD45RO was greater in O than Y, whereas Y had a greater expression of CD45RA and CD62L than O. The percentage of all CD3+/CD8+ and CD3+/CD4+ T-lymphocytes expressing KLRG1 and CD57 increased after exercise, but the magnitude of change was not age-dependent. In conclusion, there is a greater proportion of senescent CD3+/CD8+ T-lymphocytes in the blood of older adults compared to young at rest and immediately after exhaustive exercise, indicating that the greater frequency of KLRG1+/CD8+ T-lymphocytes in older humans is ubiquitous and not localised to the peripheral blood.

Total lymphocyte CD8 expression is not a reliable marker of cytotoxic T-cell populations in human peripheral blood following an acute bout of high-intensity exercise

Cytotoxic T-lymphocytes co-express the T-cell receptor, CD3 and the MHC I restricted antigen CD8. Although total CD8 expression is often used to identify CD8(+) T-cells in blood, errors are associated with this method as some CD3 negative natural killer (NK)-cells are known to express CD8. As greater relative proportions of NK-cells are found in the blood compartment after exercise, these errors are likely to be amplified in post exercise blood samples. To test this, isolated blood lymphocytes obtained from aerobically trained male subjects before, immediately after and 1h after an exhaustive treadmill-running protocol were surface stained for CD3, CD4, CD8, CD16, and CD56 and analysed by multi-colour flow cytometry. It was found that 25.4+/-16.9% of all CD8(+) cells at rest were CD3 negative, CD8(dim+) and expressed the NK-cell markers CD16 and CD56. The magnitude of this error increased to 40.8+/-20.7% immediately after exercise due to an influx of CD8(dim+) NK-cells. Although all CD8(bright+) cells expressed CD3, gating around the CD8(bright+) cells only identified 79.2+/-8.7% of the total CD3(+)/CD8(+) T-cell population; however, the magnitude of this error did not change after exercise despite the altered proportions of CD8(bright+) and CD8(dim+) cells. In conclusion, total lymphocyte expression of CD8 should not be used as a single antigenic marker to identify CD8(+) T-cells after an acute bout of exercise. Although there are errors associated with using CD8(bright+) as a single antigenic marker to identify CD3(+) T-cells, these are not amplified in response to exercise.

Apoptosis does not contribute to the blood lymphocytopenia observed after intensive and downhill treadmill running in humans

The lymphocytopenia that occurs during the recovery stage of exercise may be a result of apoptosis through an increased expression of CD95, a loss of the complement regulatory proteins CD55 and CD59, or both. Trained subjects completed intensive, moderate, and downhill treadmill-running protocols. Blood lymphocytes isolated before, immediately after, 1h after, and 24h after each exercise test were assessed for markers of apoptosis (Annexin-V(+), HSP60(+)), and CD55, CD59, and CD95 expression by flow cytometry. Lymphocytopenia occurred 1h after intensive and downhill running exercise, but no changes in the percentage of Annexin-V + or HSP60 + lymphocytes were found. Numbers of CD95(+), CD55(dim), and CD59(dim) lymphocytes increased immediately after intensive and downhill exercise, which were attributed to the selective mobilization and subsequent efflux of CD8(+) and CD56(+) lymphocyte subsets. No differences were found between the intensive and downhill protocols. In conclusion, apoptosis of circulating lymphocytes does not appear to contribute to exercise-induced lymphocytopenia.

High-intensity exercise elicits the mobilization of senescent T lymphocytes into the peripheral blood compartment in human subjects

Clonal expansion of T lymphocytes in response to antigenic stimulation is a fundamental process of adaptive immunity. As a consequence of clonal expansion, some T lymphocytes acquire a senescent phenotype, fail to replicate in response to further antigenic stimulation, and express the killer cell lectin-like receptor G1 (KLRG1) and/or CD57. Physical exercise elicits a mobilization of large numbers of T lymphocytes into the bloodstream from peripheral lymphoid compartments, but the frequency of senescent cells in the mobilized population is not known. Eight male runners (age: 29 ± 9 yr; maximal O2 uptake 62 ± 6 ml·kg−1·min−1) performed an intensive treadmill-running protocol at 80% maximal O2 uptake to volitional exhaustion. Blood lymphocytes isolated before, immediately after, and 1 h after exercise were assessed for cell surface expression of KLRG1, CD57, CD28, CD45RA, CD45RO, CD62L, and lymphocyte subset markers (CD3, CD4, CD8, CD56) by flow cytometry. The percentage of all CD3+ T lymphocytes expressing KLRG1 and CD57 increased with exercise ( P < 0.01). The change in T-lymphocyte KLRG1 expression was attributed to both CD4+ and CD8 bright T cells, with the relative change being greater for the CD8 bright population ( P < 0.01). Mobilized T-lymphocyte populations expressing KLRG1 and CD57 appeared to extravasate the peripheral blood compartment after 1 h of recovery. In conclusion, T lymphocytes with a senescent phenotype are mobilized and subsequently removed from the bloodstream in response to acute high-intensity exercise. This suggests that T lymphocytes contained within the peripheral lymphoid compartments that are mobilized by exercise are likely to be at a more advanced stage of biological aging and have a reduced capacity for clonal expansion than blood-resident T cells.

The effects of marathon running on expression of the complement regulatory proteins CD55 (DAF) and CD59 (MACIF) on red blood cells

Exercise is known to result in the haemolysis of red blood cells (RBCs). Although mechanical stressors such as footstrike and an increased velocity of blood flow may be involved, the biological mechanisms that underpin RBC haemolysis remain elusive. RBCs are potentially susceptible to lysis by autologous complement activation. RBCs are protected from the lytic effects of complement by regulatory proteins (CRPs) bound to the cell membrane via glycosylphosphatidylinositol (GPI) anchors. This study aimed to determine if marathon running would result in RBC haemolysis through a loss of membrane expression of the CRPs CD55 (decay accelerating factor) and CD59 (membrane attack complex inhibitory factor). Blood samples were obtained from 14 male runners before, within 30 min after, and 24 h after completion of the 2004 London Marathon. RBCs were assessed for cell surface CD55 and CD59 expression using indirect immunofluorescence assays and flow cytometry. No significant changes in the total RBC count, haematocrit or haemoglobin concentrations were found in response to running the marathon (P > 0.05). Blood bilirubin concentrations after the marathon were significantly greater than the pre-race values (P < 0.01). The relative fluorescent intensity (arbitrary units) of CD55 and CD59 expression on RBC membranes did not change in response to the marathon race (P > 0.05). In conclusion, marathon running did not alter the expression of CD55 or CD59 on RBCs, despite concomitant elevations in blood bilirubin concentrations. Consequently, any haemolysis of RBCs that occurred in response to the marathon was not likely due to a loss of membrane bound CRPs and subsequent cell lysis by autologous complement.

The effects of intensive, moderate and downhill treadmill running on human blood lymphocytes expressing the adhesion/activation molecules CD54 (ICAM-1), CD18 (β2 integrin) and CD53

This study examined the effects of intensive, moderate and downhill treadmill running on blood lymphocyte expression of adhesion/activation (AA) molecules. Trained subjects completed three treadmill-running protocols of identical duration: (1) an intensive protocol at 80% VO2max to volitional exhaustion, (2) a moderate protocol at 60% VO2max and (3) a -10% downhill (eccentric) protocol at 80% VO2max. Blood samples were taken before, immediately after, 1 and 24 h after exercise. Isolated lymphocytes were assessed for expression of the AA molecules CD54, CD18 and CD53 by flow cytometry. Lymphocyte counts increased immediately after all running protocols. Lymphocytopenia was observed 1 h after the intensive and eccentric protocols only. Plasma creatine kinase increased 24 h after the downhill protocol only. Increases in the number and percentage of CD54+, CD18bright and CD53bright lymphocytes were observed immediately after the intensive and eccentric protocols, with the numbers falling below pre-exercise values at 1 h post-exercise for all protocols. No differences were found between the intensive protocol and the eccentric protocol at the same relative intensity. Analysis of lymphocyte subsets showed that the total number of CD3+, CD4+, CD8+ and CD56+ lymphocytes increased after the intensive protocol before falling below pre-exercise values at 1 h post-exercise. A relatively greater mobilisation of CD56+ and CD8+ cells accounts for the changes in CD54+, CD18bright and CD53bright cell populations. Lymphocytes that enter and exit the circulation following exercise express high levels of AA molecules, which may mediate extravasation and post-exercise lymphocytopenia. This effect appears to be influenced by exercise intensity and not muscle damage.

Expression of C-reactive protein in human lung epithelial cells and upregulation by cytokines and carbon particles

C-reactive protein (CRP) is the prototypic human acute-phase protein and is found at increased levels in the blood during episodes of inflammation. CRP was generally thought to be produced only by hepatocytes; however, several studies have shown extrahepatic synthesis of CRP. A previous study showed that PM10 and ultrafine carbon black (ufCB) were able to induce CRP expression in A549 cells. This study aims to examine the factors that lead to the production of CRP in A549 cells. A549 human lung epithelial cells were treated with cytokines (interleukin 6, tumor necrosis factor alpha, interferon gamma, or interleukin 1beta) or carbon particles (CB and ufCB) for 18 h. It was found that CRP could be expressed within the cells and that CRP was secreted from the cells particularly with tumor necrosis factor alpha, CB and ufCB treatments. It was also found that this expression of CRP with CB and ufCB treatments was dependent on nuclear factor kappa B (NFkappaB). The expression of CRP in A549 cells may indicate an important role for CRP expression and secretion from lung epithelial cells in response to inflammatory stimuli.

Immune Alterations, Lipid Peroxidation, and Muscle Damage Following a Hill Race

Hill races usually include large downhill running sections, which can induce significant degrees of muscle damage in a field setting. This study examined the link between muscle damage, oxidative stress, and immune perturbations following a 7-km mountainous hill race with 457 m of ascent and 457 m of descent. Venous blood samples were taken from 7 club level runners before, immediately after, and 48 hrs postrace. Samples were analysed for total and differential leukocyte counts, markers of muscle damage (CK), lipid peroxidation (MDA), and acute phase proteins (CRP; fibrinogen; α-1-ACT). The total antioxidant status (TEAC) and plasma levels of the proinflammatory cytokines IL-6, IL-8, and TNF-α were also determined. Subjective pain reports, and plasma activities of CK, MDA, and circulatory monocytes reached peak values at 48 hrs postrace (p <  0.05). TEAC and the cytokine IL-8 increased immediately after the race (p <  0.05). Plasma TNF-α remained unchanged (p > 0.05). Despite the reports of muscle damage and soreness, no evidence of an acute phase response was observed (p > 0.05), which may be explained by the failure of the race to induce a plasma TNF-α response. Future studies should examine the link between muscle damage, oxidative stress, and the acute phase response following hill races of longer duration with larger eccentric components. Key words: acute phase response, cytokines, antioxidant capacity, creatine kinase, field study

Expression of C-reactive protein and heat-shock protein-70 in the lung epithelial cell line A549, in response to PM10 exposure

Increased levels of C-reactive protein (CRP) and heat-shock protein-70 (Hsp70) in plasma are known to be associated with an increased risk of cardiovascular disease. In this study we have investigated the effects of environmental air pollution particles (PM10) and ultrafine carbon black (ufCB) on the expression of CRP and Hsp70 in the lung epithelial cell line, A549. After treatment with PM10 or ufCB the cells were found to have increased expression of CRP and Hsp70 localized in both the cell cytoplasm and nucleus. Analysis of the cell supernatants revealed that CRP and Hsp70 were present, suggesting secretion of both proteins in response to the particulate treatment. To investigate if the expression of CRP and Hsp70 was the result of free radical production, cells were treated with ufCB in the presence of antioxidants (NAL and Trolox). This revealed that antioxidants reduced the amount of CRP and Hsp70 secreted from the cells. These findings suggest that CRP and Hsp70 may be secreted from the lung epithelium as a result of oxidative stress and have important effects on the inflammatory response associated with inhalation of particulate matter.

Aluminium lactate treatment of DQ12 quartz inhibits its ability to cause inflammation, chemokine expression, and nuclear factor-kappaB activation

In 1997, an IARC Working Group classified quartz (crystalline silica) as a Group 1 lung carcinogen, but only in some industries, i.e., the quartz hazard is a variable entity. The reactivity of the quartz surface may underlie its ability to cause inflammation, and treatments that ameliorate this reactivity will reduce the quartz hazard. In this study we treated quartz (Q) with aluminium lactate (AL), a procedure that is reported to decrease the quartz hazard, and explored the effect this had on the highly reactive quartz surface and on proinflammatory events in rat lungs. Aluminium lactate-treated quartz showed a reduced surface reactivity as measured by electron spin resonance and the hemolysis assay. Eighteen hours after instillation of Q into the rat lung, there was massive inflammation as indicated by the number of neutrophils in the bronchoalveolar lavage (BAL). In addition, Q induced an increase in BAL macrophage inflammatory protein-2 (MIP-2) while ALQ had no significant effect compared to control. Epithelial damage, as indicated by BAL protein and gamma glutamyl transpeptidase, also increased with Q but not with ALQ. Furthermore, Q induced an increase in MIP-2 mRNA by BAL cells while ALQ had no effect compared to controls. There was an increase in nuclear binding of the transcription nuclear factor kappaB (NF-kappaB) in the Q-exposed BAL cells and again no effect on nuclear NF-kappaB binding in BAL cells from ALQ-exposed rats. In conclusion, treatment of the quartz surface with aluminium lactate reduced the reactivity of the particles both in terms of hydroxyl radical generation and in terms of the induction of molecular signaling events leading to inflammation.

Persistent depletion of I kappa B alpha and interleukin-8 expression in human pulmonary epithelial cells exposed to quartz particles

Chronic inflammation and fibrosis following quartz inhalation has been associated with persistent up-regulation of several "pro-inflammatory" genes, which are commonly regulated by nuclear factor kappa-B (NF-kappaB). Transcription of the NF-kappaB-inhibitor IkappaBalpha is also under NF-kappaB control, and its de novo synthesis is considered to comprise a negative feedback loop in transient inflammation. To investigate this mechanism in particle inflammation, we have studied IkappaBalpha degradation in A549 cells exposed to DQ12-quartz or TiO(2), in relation to the expression of IL-8. Although both quartz and TiO(2) were found to cause IkappaBalpha degradation, only quartz elicited a mild IkappaBalpha depletion, first appearing at 4 h. TiO(2) was found to cause a higher short-term increase in IkappaBalpha mRNA-expression compared to quartz, whereas the early enhancement of IL-8 expression and release was similar for both particles. Up-regulation of IL-8 expression was found to persist with quartz only. Cotreatment with PDTC and curcumin reduced particle-elicited IL-8 response, whereas cycloheximide caused enhancement of IL-8 mRNA expression in both the quartz- and TiO(2)-treated cells. Our results demonstrate that mineral dusts cause IkappaBalpha degradation, a transient increase in de novo synthesis of IkappaBalpha, and enhanced IL-8 expression in human pulmonary epithelial cells. While IkappaBalpha degradation and early IL-8 expression seem to be general particle phenomena, particle-specific characteristics impact on activation of IkappaBalpha gene transcription, apparently accounting for the different proinflammatory IL-8 responses seen with quartz and TiO(2) in the longer term. These observations may provide an explanation for the transient versus the persistent pulmonary inflammatory status and subsequent differences in pathogenic potency of TiO(2) and quartz.

Rapid naming deficits in children and adolescents with reading disabilities and attention deficit hyperactivity disorder

Seventy-one children in three groups (reading disabilities, ADHD without reading disabilities, and normal controls) were compared on their ability to rapidly name colors, letters, numbers, and objects (RAN Tasks) and alternating letters/numbers and letters/numbers/colors (RAS tasks). Children with reading disabilities were found to be slower on letter- and number-naming tasks and made more errors on all tasks than controls or children with ADHD. There was an age effect for the RAN/RAS tasks, with younger children with reading disabilities performing more poorly on all tasks, while the older children with reading disabilities showed poorer performance only on the letter- and number-naming tasks.

Prostaglandin and fatty acid modulation of Escherichia coli O157 phagocytosis by human monocytic cells

Phagocytosis by human monocytes is an important primary survival mechanism particularly during bacterial infection. However, the processes that control the events and mediators involved in the activation of monocytes and their impact on the phagocytosis of bacteria are poorly understood. The effect of bacterial endotoxin, interleukin-1 beta (IL-1 beta), fatty acids and prostaglandin E2 (PGE2) on the phagocytosis of fluoroscein isothiocyanate (FITC)-labelled Escherichia coli (O157) by human blood monocytes and U937 cells was studied by flow cytometry. Endotoxin increased the phagocytosis of labelled bacteria by both monocytes and U937 cells. IL-1 beta and the polyunsaturated fatty acids; dihomo-gamma-linolenic and arachidonic acids also increased the phagocytic activity of both monocytes and U937 cells. In contrast, PGE2 suppressed phagocytosis in a concentration-dependent manner. The cyclo-oxygenase inhibitor, ketoprofen, further enhanced the increased phagocytic activity in the presence of endotoxin and interleukin-1 (IL-1) indicating suppression by endogenous prostaglandins. This was confirmed by the data which showed that lipopolysaccharide (LPS) and IL-1 increased PGE2 release and ketoprofen inhibited release. Endotoxin and fatty acids increased IL-1 beta release also, whereas PGE2 inhibited release. The data suggest that phagocytic activity may be linked to changes in IL-1 levels. The data presented in this study also suggest that monocyte phagocytosis in the course of bacterial infection would be altered during pathophysiological events which result in elevation of extracellular fatty acids.

Insertion of SMRV-H viral DNA at the c-myc gene locus of a BL cell line and presence in established cell lines

Mutation of the c-myc gene locus has occurred during in vitro culture of the Burkitt lymphoma cell line Namalwa. Gene cloning and sequencing of this c-myc gene locus has revealed the insertion of incomplete copies of the Squirrel Monkey Retrovirus-Human (SMRV-H) proviral genome. Insertions of the SMRV-H genome were seen in all Namalwa cell lines tested, with multiple insertions being seen in some sublines. Viral particles with the morphology of type-D retrovirus, budding from these cells, were seen by transmission EM. New insertions of the genome were produced spontaneously in these cells. The origins of the type-D retrovirus and its implications for workers in the field are discussed.

The influence of the In(Lu) gene on expression of CDw75 antigens on human red blood cells

The influence of the In(Lu) gene on human red blood cell (RBC) expression of CDw75 antigens was examined. CDw75 antigens were increased in expression on Lu(a-b-) cells of the dominant inhibitor type in comparison with red cells from donors of other Lutheran (Lu) phenotypes. In contrast, CD44 epitopes detected with F10-44-2, A3D8 and BU52 monoclonal antibodies (mAb) were decreased in expression on Lu(a-b-) red cells. Among normal blood donors of the common phenotype Lu(a-b+) there was a wide range of expression of CDw75 antigens on red cells. The results show that CDw75 is a quantitative polymorphism of human red cells and, among antigens influenced by the In(Lu) gene, is unique in being up-regulated in expression.

Expression of the CDw75 (beta-galactoside alpha 2,6-sialyltransferase) antigen on normal blood cells and in B-cell chronic lymphocytic leukaemia

Using monoclonal antibodies (mAb) characterized at the last International Workshop on Human Leucocyte Antigens, we examined the expression of CDw75 antigens (beta-galactoside alpha 2,6-sialyltransferase) on normal peripheral blood cells and on cells from patients with B-cell chronic lymphocytic leukaemia (CLL). The mAb used (HH2, EBU.65, EBU.141 and OKB4) detect different epitopes of CDw75. Normal peripheral blood B cells expressed high levels of CDw75 detectable with HH2, EBU.65 and EBU.141 but did not react with OKB4. Cells from patients with B-cell CLL closely resembled normal B cells. All CDw75 epitopes, including OKB4, were strongly expressed on some Namalwa variant Burkitt lymphoma cell lines. The OKB4 epitope was also present on red cells from all normal donors. The other CDw75 mAb were unreactive with red cells from some normal donors. The CDw75 epitope detected with EBU.65 was present on most CD4+ T cells and on a minority of CD8+ cells. HH2 and EBU.141 stained only small numbers of T lymphocytes. OKB4 did not react with T cells. EBU.65+, CD4+ T cells had low levels of expression of CD45R0, CD29, CD54 and CD58, and had high levels of CD45RA antigen. Phytohaemagglutinin (PHA) activation of cells led to the loss of EBU.65 binding. These results suggest that the CDw75 epitope recognized by the EBU.65 mAb is a marker of native T lymphocytes. On B CLL cells the epitopes detected with HH2, EBU.65 and EBU.141 were destroyed by treatment with neuraminidase. Treatment of B-CLL cells and red cells with neuraminidase increased the binding of OKB4, suggesting that this epitope is masked by sialic acid. The results suggest that CDw75 is a sialylated cell-surface antigen expressed in a number of tissue-specific isoforms.

Burkitt lymphoma cell lines are prone to recombination in the switch region of the Ig mu heavy chain locus

Different recombinations have been found at the Ig heavy chain gene loci in a number of sublines of the Burkitt lymphoma (BL) cell line Namalwa, following prolonged in vitro culture. The Namalwa sublines examined are DNA fingerprint-identical and derived from a monoclonal source. Recombinant DNA clones were used to map the Ig heavy chain gene mutations to a region between the VDJ and C mu segment of the locus. This region is associated with Ig heavy chain class switching in normal B cells. Of 24 clones established from one subline, three were found to have additional VDJ-C mu region mutations, indicating a high frequency of mutation at this locus.

Recurrent mutation of immunoglobulin and c-myc genes and differential expression of cell surface antigens occur in variant cell lines derived from a Burkitt lymphoma

The phenotypic and molecular genetic characteristics of 4 variant sublines of the Burkitt lymphoma cell line Namalwa have been examined. The sublines are DNA-fingerprint-identical and derived from a monoclonal tumour, as shown by a rearrangement of the T-cell-receptor beta-chain gene common to the 4 sublines. There is non-co-ordinate expression of MHC class-I MHC class-II, surface immunoglobulin and a number of antigens recognized by CD MAbs on the different sublines. These different phenotypes of the cells are reminiscent of B cells arrested in varying states of cellular maturity. On Southern blots there are different patterns of restriction fragments hybridizing with Ig heavy- and light-chain gene probes among the sublines, indicating that multiple rearrangements or mutations of Ig genes have occurred in the cells. Different patterns of hybridizing fragments among the sublines were also found by using c-myc probes, implying the existence of different mutations of the c-myc locus. The c-myc mutation found in one of the sublines mapped to the 5' flanking sequence and in another 3' to the c-myc locus. Using the J17BS8 probe, which detects a restriction fragment length polymorphism in the 3' flanking region of the c-myc gene, a 4-fold variation in the gene copy number among the subline was found and one of the sublines was shown to be hemizygous for c-myc. Examination of DNA from early cultures of Namalwa cells showed that the alternations in Ig and c-myc structure had occurred on prolonged culture of the cells.

Establishment of a karyotypically normal B-chronic lymphocytic leukemia cell line; evidence of leukemic origin by immunoglobulin gene rearrangement

A new Epstein-Barr virus (EBV) transformed cell line was established from a patient with B-chronic lymphocytic leukemia (B-CLL). The karyotype of the cell line has remained normal for over 12 months in culture; however, identical heavy and light chain immunoglobulin (Ig) gene rearrangements in the patient's blood and the cell line provided evidence that the EBV transformed cells were derived from the neoplastic clone.

Indirect immunofluorescence labelling with complexes of phycoerythrin and monoclonal anti-phycoerythrin antibodies (PEAPE complexes)

We describe a method of immunofluorescence which is a lateral application of the principles of the APAAP immunohistochemical technique. Immune complexes of R-phycoerythrin and monoclonal anti-R-phycoerythrin (PEAPE complexes) were used in an indirect immunofluorescence technique to detect the binding to cells of monoclonal antibodies directed to IgM, HLA-DR and B cell activation and differentiation antigens. PEAPE complexes were linked to cell surface bound mAbs by unlabelled anti-mouse Ig antibodies to produce high levels of fluorescent staining. The sensitivity of this method of indirect immunofluorescence was enhanced by the sequential application of several cycles of anti-mouse Ig and PEAPE complexes.

A 0.5 kb insert polymorphism 3' to the c-myc gene

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Variant sublines of the human B-lymphoma cells Namalwa are at different stages of differentiation

Variant sublines of the Burkitt's lymphoma cell line Namalwa, previously shown to differ in MHC class II antigen and immunoglobulin expression, have been tested with monoclonal antibodies defining B-cell specific clusters of differentiation (CD). The Namalwa sublines express antigens recognized by the CD antibodies in patterns that indicate that the cells are arrested at different stages of differentiation.

T-24.B-cell differentiation factor induces immunoglobulin secretion in human B cells without prior cell replication

Stimulation of B lymphocytes from B-cell chronic lymphocytic leukaemia (B-CLL) with 12-0-tetradecanoylphorbol-13-acetate (TPA) has shown that these cells are capable of differentiation (Totterman, Nilsson & Sundstrom, 1980). Increases in the expression of different class II MHC antigens (Guy et al., 1983, 1986) and responsiveness to growth factors (Kabelitz et al., 1985; Suzuki, Butler & Cooper, 1985) have been studied. Supernatant from the human bladder carcinoma line T-24 contains a B-cell differentiation factor (BCDF) able to induce immunoglobulin secretion from CESS cells. We investigated the induction of proliferation and immunoglobulin secretion in human B cells by studying the effects of this factor on B-CLL cells, in both the presence and absence of TPA. We report here that this material (termed T-24.BCDF) causes immunoglobulin secretion to be initiated in these cells, and that this is not accompanied by detectable DNA synthesis. These observations were extended to normal human B cells and demonstrate that human B cells can secrete immunoglobulin in the absence of clonal expansion.

Immunology in diabetic pregnancy: activated T cells in diabetic mothers and neonates

Lymphocytes bearing surface antigens indicating early and full activation have been evaluated, in addition to T cell subsets, in blood samples from diabetic pregnant patients, neonates from diabetic mothers and control groups. The type of diabetes and the trimester of pregnancy were taken into account. Monoclonal antibodies were used to enumerate total T cells, helper/inducer, cytotoxic/suppressor Tlymphocytes and activated mononuclear cells using antibodies binding lymphocyte surface antigens as markers of early lymphocyte activation, and MHC Class II surface antigens as markers of late activation. A decrease in T-helper cells during the third trimester of pregnancy in Type 1 (insulin-dependent) and gestational diabetic patients (p less than 0.02) and a decrease in T-suppressor cells in Type 2 (non-insulin-dependent) diabetic pregnant patients during the third trimester (p less than 0.01) were observed in relation to normal values. As in normal pregnancy, 4F2-positive cells were increased in 48% of diabetic pregnant patients during the second and third trimesters of gestation. Class II-positive cells were increased in almost 60% of Type 1 and gestational diabetic patients during the last trimester of pregnancy in comparison with normal pregnant women and control subjects. A decrease in T-helper cells (p less than 0.02) and a clear increase in 4F2-positive cells (p less than 0.001) and Class II-positive lymphocytes (p less than 0.005) were observed in the infants of diabetic mothers in comparison with control subjects. The maternal cellular immune system, actively altered in pregnancy, is fully activated in a number of Type 1 and gestational diabetic pregnant patients. Activated lymphocytes are even found in the neonates of diabetic mothers, but these do not trigger the events leading to the onset of diabetes in the short term.