Immune and airway effects of house dust mite aeroallergen exposures during postnatal development of the infant rhesus monkey

BACKGROUND

The effect of chronic environmental aeroallergen exposure on the immune system and airways has not been experimentally defined in very young children.

OBJECTIVE

The purpose of this study was to determine the immunophenotype of peripheral blood and airway leucocytes in the newborn rhesus macaque monkey, following recurrent aerosol exposure to house dust mite (HDM) (Dermatophagoides farinae).

METHODS

A regimen of HDM aerosolization was initiated for 2 h per day, three times per week, starting when rhesus macaque monkeys were 1 week of age. All monkeys were inoculated with diptheria, tetanus, and acellular pertussis vaccine at 5 weeks of age to simulate human infant vaccination schedules.

RESULTS

Following 8 weeks of HDM aeroallergen exposure, infant monkeys exhibited a significant reduction in the total peripheral blood lymphocyte numbers and a decreased frequency of peripheral blood CD4+ T lymphocytes with a CD45RA-'memory' immunophenotype. Lavage CD4+ T lymphocytes from HDM-exposed monkeys showed elevated expression of CD25, as well as an increase in CD45RA-/CD62L-/CD11ahigh immunophenotype. Eosinophils were more abundant within airways of HDM-exposed monkeys, accumulating maximally within the trachea.

CONCLUSION

These data demonstrate the development of immunological responses following chronic inhalation of a common environmental allergen during postnatal maturation in the non-human primate.

Obliterative enteritis complicating graft versus host disease

We report a 10-year-old male with Down's syndrome, who received a bone marrow transplant for acute lymphoblastic leukaemia. Subsequent acute graft-versus-host disease (GvHD) of the gut progressed to small bowel obstruction. At laparotomy, the small bowel appeared solid and contracted with no or minimal luminal patency. Although the caecum had a lumen, it was indistensible, and it was not possible to enter the terminal ileum. Histology of the obstructed bowel showed extensive necrosis of the mucosa, muscularis mucosa and submucosa of most of the small bowel wall, causing obliteration of the lumen. The changes were presumed to be related to post inflammatory atrophy. This extreme manifestation of GvHD could thus be called obliterative enteritis. Both cytomegalovirus and adenovirus were isolated from the patient. These viruses may have contributed to the severity of the intestinal GvHD.

Cytokine profiles in patients receiving wide-field + prostate boost radiotherapy (xRT) for adenocarcinoma of the prostate

As a result of the association between ionizing irradiation and the induction of inflammatory and fibrogenic cytokines, circulating levels of IL-1alpha, macrophage colony stimulating factor (M-CSF) and TGFbeta were measured in a group of 37 patients who presented with well-defined adenocarcinoma of the prostate and were treated with wide-field pelvic (WFP) + prostate boost (PB) radiotherapy (xRT) according to RTOG protocols 94-08 and 94-13. First and foremost, patients with prostate cancer (PC) were found to have a significantly (p<0.05) elevated plasma level of the three cytokines prior to treatment. Moreover, during WFP + PB xRT, these circulating cytokine levels were further elevated, the elevation occurring in the form of cyclic waves; the concurrent waves of elevated IL-1alpha and M-CSF preceding that of TGFbeta. In addition to providing support for the existence of a humoral response to xRT in patients receiving WFP + PB xRT, the data demonstrated a significant correlation between the integral radiation dose (ID) and the temporal expression and magnitude of plasma IL-1alpha, M-CSF and TGFbeta levels in patients that had received 1-5 fractions (1.8-9Gy) of WFP + PB xRT. Thereafter, the appearance of elevated waves of cytokine expression in the patient's plasma continued independent of additional fractions of WFP + PB xRT.

Expression and regulation of the Na+-K+-2Cl- cotransporter NKCC1 in the normal and CFTR-deficient murine colon

Defective regulation and/or reduced expression of the Na+-K+-2Cl- cotransporter NKCC1 may contribute to the severe secretory defect that is observed in cystic fibrosis, but data concerning the expression and function of NKCC1 in cystic fibrosis transmembrane conductance regulator (CFTR)-deficient cells are equivocal. We therefore investigated NKCC1 mRNA expression, Na+-K+-2Cl- cotransport activity and regulation by cAMP in crypts isolated from the proximal colon of CFTR-containing (CFTR (+/+)) and CFTR-deficient (CFTR (-/-)) mice. mRNA expression levels were determined by semiquantitative PCR, transport rates were measured fluorometrically in 2',7'-bis(carboxyethyl)-5(6)-carboxyfluorescein acetomethylester (BCECF)-loaded crypts, cytoplasmic volume changes were assessed by confocal microscopy, and [Cl-]i changes were examined by N-(ethoxycarbonylmethyl)-6-methoxyquinolinium bromide (MQAE) quenching. NKCC1 mRNA expression levels were not significantly reduced in CFTR (-/-) crypts compared to controls. Azosemide-sensitive NH4+ influx (used as a measure of Na+-K+-2Cl- cotransport) was 2.23 +/- 0.72 vs. 1.56 +/- 0.16 mM min-1, and increased by 63.6 % in (+/+) and 87.3 % in (-/-) crypts upon stimulation for 5 min with forskolin. After 20 min of stimulation with forskolin, the Na+-K+-2Cl- cotransport rates in (-/-) and (+/+) crypts were identical. Crypt cross-sectional area and [Cl-]i decreased only in (+/+) crypts upon stimulation. In conclusion, normal NKCC1 expression levels, somewhat reduced Na+-K+-2Cl- cotransport rates, but preserved activation by cAMP were found in colonic crypts from CFTR (-/-) mice, ruling out a severe dysfunction of the Na+-K+-2Cl- cotransporter in the CF intestine. Furthermore, these studies establish the existence of a direct, cell-volume- and [Cl-]i-independent activation of colonic NKCC1 by an increase in intracellular cAMP.

cAMP-mediated regulation of murine intestinal/pancreatic Na+/HCO3- cotransporter subtype pNBC1

Basolateral Na(+)-HCO(3)(-) cotransport is essential for intestinal anion secretion, and indirect evidence suggests that it may be stimulated by a rise of intracellular cAMP. We therefore investigated the expression, activity, and regulation by cAMP of the Na(+)-HCO(3)(-) cotransporter isoforms NBC1 and NBCn1 in isolated murine colonic crypts. Na(+)-HCO(3)(-) transport rates were measured fluorometrically in BCECF-loaded crypts, and mRNA expression levels and localization were determined by semiquantitative PCR and in situ hybridization. Acid-activated Na(+)-HCO(3)(-) cotransport rates were 5.07 +/- 0.7 mM/min and increased by 62% after forskolin stimulation. NBC1 mRNA was more abundant in colonic crypts than in surface cells, and crypts expressed far more NBC1 than NBCn1. To investigate whether the cAMP-induced Na(+)-HCO(3)(-) cotransport activation was secondary to secretion-associated changes in HCO(3)(-) or cell volume, we measured potential forskolin-induced changes in intracellular pH and assessed Na(+)-HCO(3)(-) transport activity in CFTR -/- crypts (in which no forskolin-induced cell shrinkage occurs). We found 30% reduced Na(+)-HCO(3)(-) transport rates in CFTR -/- compared with CFTR +/+ crypts but similar Na(+)-HCO(3)(-) cotransport activation by forskolin. These studies establish the existence of an intracellular HCO(3)(-) concentration- and cell volume-independent activation of colonic NBC by an increase in intracellular cAMP.

Comparative analysis of goal achievement during rehabilitation for older and younger adults with spinal cord injury

OBJECTIVE

To evaluate rehabilitation outcome in a representative sample of older and younger SCI patients.

DESIGN

Case series, consecutive sample, survey.

SETTING

Tertiary care, spinal cord injury unit (National Spinal Injuries Centre), Stoke Mandeville Hospital.

PARTICIPANTS

One hundred and forty-seven male and 45 female newly injured in-patients (consisting of 152 younger adults, age range=16 to 54, and 40 older adults, age range=55 to 85) admitted between 1995 and 1999.

INTERVENTION

All patients were actively participating in a comprehensive, multidisciplinary Goal Planning and Needs Assessment rehabilitation programme.

MAIN OUTCOME MEASURE

The Needs Assessment Checklist. Specifically designed and developed for the spinal cord injured population, this clinical assessment tool provides a way of assessing and ensuring that rehabilitation programmes are geared toward each patient's individual needs, providing the patient with the skills appropriate to their level of lesion. As part of ongoing psychometric analyses of the Needs Assessment Checklist, internal consistency reliability coefficients are reported for this measure.

RESULTS

The type and cause of injury for the older adult group in this study was comparable with previous research. Older adults' rehabilitation gains were comparable to those of the younger age group. Younger adults were more mobile initially after their injury. However, when the two groups were matched for injury characteristics etc. the only differences in final outcome between older and younger adults were in skin management ability. Both groups showed significant improvements in all areas of need in the period between mobilisation and entering the pre-discharge ward.

CONCLUSION

These results highlight important considerations for the rehabilitation of older adults and emphasise the need for active, individually tailored rehabilitation programmes. There are specific areas of need (i.e. skin management) where older adults do not achieve comparable levels of independence. Special attention needs to be paid to the problems presented by SCI older adults and efforts should be made to better prepare rehabilitation professionals to adapt to age specific differences.

Conflict in healthcare organizations

Healthcare organizations struggle with internal and external causes of conflict. Successful organizations evaluate and retool existing conflict management systems to constructively, cost-effectively and practically control the negative impact.

Overlapping functions of lysosomal acid phosphatase (LAP) and tartrate-resistant acid phosphatase (Acp5) revealed by doubly deficient mice

To date, two lysosomal acid phosphatases are known to be expressed in cells of the monocyte/phagocyte lineage: the ubiquitously expressed lysosomal acid phosphatase (LAP) and the tartrate-resistant acid phosphatase-type 5 (Acp5). Deficiency of either acid phosphatase results in relatively mild phenotypes, suggesting that these enzymes may be capable of mutual complementation. This prompted us to generate LAP/Acp5 doubly deficient mice. LAP/Acp5 doubly deficient mice are viable and fertile but display marked alterations in soft and mineralised tissues. They are characterised by a progressive hepatosplenomegaly, gait disturbances and exaggerated foreshortening of long bones. Histologically, these animals are distinguished by an excessive lysosomal storage in macrophages of the liver, spleen, bone marrow, kidney and by altered growth plates. Microscopic analyses showed an accumulation of osteopontin adjacent to actively resorbing osteoclasts of Acp5- and LAP/Acp5-deficient mice. In osteoclasts of phosphatase-deficient mice, vacuoles were frequently found which contained fine filamentous material. The vacuoles in Acp5- and LAP/Acp5 doubly-deficient osteoclasts also contained crystallite-like features, as well as osteopontin, suggesting that Acp5 is important for processing of this protein. This is further supported by biochemical analyses that demonstrate strongly reduced dephosphorylation of osteopontin incubated with LAP/Acp5-deficient bone extracts. Fibroblasts derived from LAP/Acp5 deficient embryos were still able to dephosphorylate mannose 6-phosphate residues of endocytosed arylsulfatase A. We conclude that for several substrates LAP and Acp5 can substitute for each other and that these acid phosphatases are essential for processing of non-collagenous proteins, including osteopontin, by osteoclasts.

Reciprocal antagonism between estrogen receptor and NF-kappaB activity in vivo

The functional interaction, or "cross-talk," between estrogen receptor (ER) and the proinflammatory transcription factor nuclear factor (NF)-kappaB demonstrated in vitro has been suggested to play a role in estrogen prevention of cardiovascular disease. Here, we demonstrate that this reciprocal cross-talk occurs in vivo. Ovariectomized C57BL/6 mice fed an atherogenic diet had increased hepatic levels of active NF-kappaB and numerous inflammatory genes, including MHC invariant chain (Ii), vascular cell adhesion molecule-1, tumor necrosis factor-alpha, and RANTES. Treatment with 17alpha-ethinylestradiol (EE) strongly blocked induction of these genes but had no effect on their basal expression levels. ER was required for this activity, because the antagonist ICI 182,780 completely blocked the inhibitory activity of EE. Gene activation by EE was not required for inhibition of inflammatory gene expression, because both the phytoestrogen genistein and low doses of EE were effective in blocking inflammatory gene induction without inducing marker genes such as intestinal trefoil factor (ITF) or myo-inositol-1-phosphate synthase (IPS). The in vivo transcriptional interference was reciprocal, with EE induction of ITF and IPS greatly reduced in animals fed the atherogenic diet versus chow-fed controls. This interference was specific to the liver, because diet had no effect on uterine weight increases produced by EE. Transfection experiments confirmed that the extent of inhibition of ER-mediated transcription by inflammatory stimuli correlated with the extent of NF-kappaB activation. These results suggest that the cross-talk between ER and NF-kappaB does occur in vivo and may indeed contribute significantly to the cardioprotective effects of estrogen.

Mucus altering agents as adjuncts for nonviral gene transfer to airway epithelium

Nonviral vectors have been shown to be a safe and valid alternative to recombinant viruses for gene therapy of cystic fibrosis (CF). Nevertheless, gene transfer efficiency needs to be increased before clinical efficacy is likely in man. One barrier to increased efficacy is normal airway mucus. Using an ex vivo model of sheep tracheal epithelium, we show that this barrier can, in part, be overcome by treatment with the mucolytic agents, Nacystelyn or N-acetylcysteine using either a cationic lipid or a cationic polymer as the gene transfer agent. Further, in vivo application of either Nacystelyn or the anticholinergic glycopyrrolate, both clinically used agents, resulted in increased reporter gene expression in the mouse lung, but no significant correction of the bioelectric defect in CF null mice. These results, whilst unlikely to be sufficient in themselves to achieve clinically relevant gene therapy, may be a further useful step in the attainment of this goal.

Evaluation of post traumatic distress in the first 6 months following SCI

STUDY DESIGN

Cross-sectional questionnaire.

OBJECTIVES

To assess the degree of post traumatic stress symptomatology and its correlates amongst a group of new spinal cord injured patients.

SETTING

The National Spinal Injuries Centre, Stoke Mandeville Hospital NHS Trust.

METHOD

Eighty-five participants with an average age of 32.6 years were assessed between 6 and 24 weeks post injury. Seventeen participants were female. Seventy per cent had complete lesions. Forty per cent had paraplegia and 60% had tetraplegia. Road traffic accidents were the most common cause of injury followed by falls and then sporting accidents. The Impact of Event Scale was used to measure the experience of intrusive thoughts about the trauma and avoidance of trauma related stimuli. Anxiety (SAI), depression (BDI) and dependency (FIM) were also measured.

RESULTS

High levels of distress were evident in 14% of the sample. Trauma-related distress was significantly higher in female patients or patients with high levels of anxiety or depression.

CONCLUSION

In this sample, the rates of trauma-related distress following spinal cord injury were comparable to those found following other traumas and are of clinical significance.

Cellular and molecular characteristics of basal cells in airway epithelium

Basal cells exist as a separate layer of cells covering most of the airway basal lamina. In this central position, they can interact with columnar epithelium, neurons, basement membrane, and the underlying mesenchymal cells. In addition, they interact with inflammatory cells, lymphocytes and dendritic cells. These interactions take place in the lateral intercellular space between basal cells. In this central position basal cells become a very important part of the epithelial-mesenchymal trophic unit of larger airways. In this review it is shown that basal cells may function as progenitor cells of airway epithelium and have a role in attachment of columnar epithelium with the basement membrane. They also have the potential to function in regulation of neurogenic inflammation, the inflammatory response, transepithelial water movement, oxidant defense of the tissue and formation of the lateral intercellular space. Other characteristics of basal cells were not clearly associated with a particular function. The functions for basal cells listed attempt to explain the presence of recently identified molecules in basal cells of airway epithelium. It should be pointed out that specific studies have not been carried out which test the relationship between the molecular functions we describe in this review and the basal cell in airway epithelium.

In vitro-activated human lupus T cells express normal estrogen receptor proteins which bind to the estrogen response element

We have shown that estrogen receptor (ERalpha, ERbeta) transcripts are expressed in SLE and normal T cells. In this study, T cell nuclear extracts from female lupus patients and normal donors were tested for biologically active ER proteins capable of binding to the human estrogen response element (hERE) by electrophoretic mobility shift assays. When peripheral blood T cells were stimulated with 17beta-estradiol (E2), PMA and ionomycin, two major retarded bands in T cell nuclear extracts exhibited a migration pattern similar to slow migrating protein-ERE complexes in human breast cancer cell extracts. T cells cultured only with E2 did not have these complexes. The formation of the complexes was inhibited by competition with the hERE cold oligonucleotide and partially with anti-ERalpha antibodies. There was no notable difference in the migration pattern of ERE-binding proteins between the SLE and normal T cell extracts. Together, these results suggest that activated human T cells, whether lupus-derived or normal-derived, contain biologically active ERalpha proteins. Other factors may be responsible for differential sensitivity of lupus T cells to estrogen.

Enhanced gene delivery to human airway epithelial cells using an integrin-targeting lipoplex

BACKGROUND

Current liposome-based delivery methods for cystic fibrosis (CF) gene therapy are limited by their poor efficiencies. One way to improve this is to use a receptor/ligand interaction to increase binding of the transfection complex with the target cell.

METHODS AND RESULTS

We have tested a synthetic peptide containing an alphav integrin-binding motif (arginine-glycine-aspartic acid, RGD) and a DNA-binding domain (polylysine) for enhancement of liposome-mediated gene delivery. We have shown that integrin proteins capable of binding the RGD motif are located on the apical surface of a polarized human bronchial epithelial cell line (16HBE). Luciferase gene transfer efficiency to subconfluent 16HBE cells was 10-200 times higher than gene transfer using either liposome or peptide alone. This peptide-mediated enhancement was observed at all cellular contact times including those as short as 1 min. Although the transfection efficiency is reduced when the 16HBE cells are grown as polarized monolayers, peptide-mediated enhancement of lipofection is maintained. Transfection with a lipopolyplex containing an RGE (arginine-glucine-glutamic acid) control peptide that cannot bind to the alphav integrin molecules, or competitive inhibition with antibodies against RGD-binding integrins, reduced gene transfer. Confocal microscopy indicated that the peptide increased plasmid delivery to the cell via receptor-mediated endocytosis.

CONCLUSION

These results indicate that integrin-binding peptides represent one way to enhance liposome-mediated gene delivery to pulmonary epithelia.

Effect of anticoagulants and storage temperatures on stability of plasma and serum hormones

OBJECTIVES

To determine the effect of different anticoagulants and storage conditions on the stability of hormones in plasma and serum.

DESIGN AND METHODS

Human blood samples were collected from volunteers into EDTA, lithium heparin, sodium fluoride/potassium oxalate, or tubes without anticoagulant, plasma and serum left at -20 degrees C, 4 degrees C or 30 degrees C for 24 and 120 hours then assayed for ACTH, aldosterone, alpha-subunit, AVP, CRH, C-peptide, estradiol, FSH, glucagon, GH, IGF-1, IGFBP-3, insulin, leptin, LH, PPP, PTH, prolactin and VIP, or at room temperature for 0 to 72 hours (BNP, NT-BNP)(n = 6 per condition).

RESULTS

The anticoagulant altered the measured concentrations for 9 hormones when compared to EDTA. All hormones except ACTH were stable for > 120 hours in EDTA or fluoride at 4 degrees C, but only 13 hormones were stable in all anticoagulants. At 30 degrees C, 8 hormones were stable for > 120 hours in EDTA, and 3 hormones in all anticoagulants. BNP and NT-BNP were stable for < 24 hours when stored in EDTA or heparin at room temperature.

DISCUSSION

Storage of samples in EDTA plasma at 4 degrees C is suitable for most hormones (except ACTH) for up to 120 hours.

Prior exposure to aged and diluted sidestream cigarette smoke impairs bronchiolar injury and repair

The bronchiolar injury/repair response to naphthalene (NA) in mice includes acute distal airway epithelial injury that is followed by epithelial proliferation and redifferentiation, which result in repair of the epithelium within 14 days. To test whether prior exposure to aged and diluted sidestream cigarette smoke (TS) would alter the injury/repair response of the airway epithelium, adult mice were exposed to either filtered air (FA) or smoke for 5 days before injection with either corn oil carrier (CO) or naphthalene. Mice were killed 1 and 14 days after naphthalene injury. Lung and lobar bronchus were examined and measured using high-resolution epoxyresin sections. The control group (FACOFA) that was exposed to filtered air/corn oil/filtered air contained airway epithelium similar to untreated controls at all airway levels. The group exposed to tobacco smoke/corn oil/filtered air (TSCOFA) contained some rounded cells in the small airways and some expansion of the lateral intercellular space in the larger airways. Necrotic or vacuolated cells were not observed. As expected, the epithelium in the group exposed to filtered air/naphthalene/filtered air (FANAFA) contained many light-staining vacuolated Clara cells and squamated ciliated cells within distal bronchioles during the acute injury phase. Repair (including redifferentiation of epithelial cells and restoration of epithelial thickness) was nearly complete 14 days after injury. The extent of Clara cell injury, as assessed in lobar bronchi, was not different between the four groups. Although the FANAFA group contained greater initial injury in the distal airways at 1 day, the group exposed to tobacco smoke/naphthalene/filtered air (TSNAFA) had the least amount of epithelial repair at 14 days after naphthalene treatment; many terminal bronchioles contained abundant squamated undifferentiated epithelium. We conclude that tobacco smoke exposure prior to injury (1) does not change the target site or target cell type of naphthalene injury, since Clara cells in terminal bronchioles are still selectively injured; (2) results in slightly diminished acute injury from naphthalene in distal bronchioles; and (3) delays bronchiolar epithelial repair.

Acetylcholine induces cytosolic Ca2+ mobilization in isolated distal colonic crypts from normal and cystic fibrosis mice

In intestinal biopsies from cystic fibrosis (CF) patients acetylcholine fails to elicit a chloride secretion response, and this observation can be explained by a defect in the Ca2+ signalling pathway in CF secretory cells. We tested the hypothesis that in CF intestine, the generation of an intracellular Ca2+ signal upon cholinergic stimulation is absent. A transgenic CF mouse model was used. Electrical measurements on intact jejunum and unstripped colon were performed in Ussing chambers. Intact distal colonic crypts were isolated, and the intracellular Ca2+ concentration was monitored using the Ca2+-sensitive dye fura-2. Acetylcholine increased the short-circuit current generated by wild-type jejunum and colon, but failed to induce a response in CF tissues. Acetylcholine caused a transient elevation in the intracellular Ca2+ concentration in colonic crypts from both wild-type and CF mice; the amplitude and timing of the response in CF crypts was indistinguishable from that in wild-type crypts. The response to acetylcholine was also observed in the absence of extracellular calcium, indicating intracellular stores as the source from which the cytosolic Ca2+ concentration increased. We conclude that the absence of a cholinergically-induced secretory response in CF intestine is not due to a defect in the generation of a Ca2+ signal in intestinal cells upon cholinergic stimulation.

Lessons learned while compiling a quantitative exposure database from the published literature

The published literature was reviewed and then a quantitative hydrocarbon solvent exposure database was compiled. The data was then analyzed to determine trends in documented worker exposures to hydrocarbon solvents. It was found that an all too common limitation of the published literature was the incomplete reporting of results by the authors.

Mice lacking tartrate-resistant acid phosphatase (Acp 5) have disordered macrophage inflammatory responses and reduced clearance of the pathogen, Staphylococcus aureus

Tartrate-resistant acid phosphatase (TRAP) is a lysosomal di-iron protein of mononuclear phagocytes and osteoclasts. Hitherto, no role for the enzyme in immunity has been identified; however, knockout mice lacking TRAP have a skeletal phenotype caused by an intrinsic osteoclast defect. To investigate a putative function for TRAP in macrophages (Mphi), we investigated proinflammatory responses and systemic microbial clearance in knockout mice compared with age- and gender-matched congenic wild-type mice. Phorbol 12-myristate 13-acetate (PMA)-stimulated and interferon-gamma (IFN-gamma)-induced superoxide formation was enhanced in peritoneal Mphi lacking TRAP; nitrite production in response to stimulation with lipopolysaccharide (LPS) and IFN-gamma was also increased. In addition, secretion of the proinflammatory cytokines, tumour necrosis factor-alpha (TNF-alpha), interleukin (IL)-1beta and IL-12, was significantly greater in TRAP-deficient Mphi when stimulated with LPS, with or without addition of either TNF-alpha or IFN-gamma. The activity of tartrate-sensitive (lysosomal) acid phosphatase was increased in Mphi from the knockout mice but activities of the lysosomal hydrolases N-acetyl beta-glucosaminidase and acid beta-glucuronidase were unchanged, indicating selective activation of compensatory acid phosphatase activity. Evidence of impaired Mphi function in vivo was obtained in TRAP knockout mice, which showed delayed clearance of the microbial pathogen, Staphylococcus aureus, after sublethal intraperitoneal inoculation. After microbial challenge, peritoneal exudates obtained from TRAP knockout mice had a reduced population of Mphi. As peritoneal Mphi and neutrophils lacking TRAP were able to phagocytose and kill S. aureus normally in vitro, TRAP may directly or indirectly influence recruitment of Mphi to sites of microbial invasion. Our study shows that TRAP participates in the inflammatory response of the Mphi and influences effector signalling pathways in innate immunity.

Inflammation in cystic fibrosis airways: relationship to increased bacterial adherence

It is unclear whether inflammation in the cystic fibrosis (CF) lung relates predominantly to bacterial infection, or occurs as a direct consequence of mutant cystic fibrosis transmembrane conductance regulator (CFTR) protein. Interleukin (IL)-8 secretion from CF and non-CF cell lines, and from CF and non-CF human primary nasal epithelial cells incubated with or without Pseudomonas aeruginosa, was measured. Activation of nuclear factor-kappaB (NF-kappaB) in unstimulated CF and non-CF nasal epithelial cells, cell lines and murine tissues was measured by gel-shift assays. No significant difference in basal IL-8 production or NF-kappaB activation was observed between CF and non-CF primary nasal cells. However, CF cells exhibited a significantly (p<0.01) increased IL-8 secretion following P. aeruginosa stimulation. Equalization of the increased P. aeruginosa adherence observed in CF cells, to non-CF levels, resulted in comparable IL-8 secretion. Further, IL-8 production did not differ with mutations which result in either correctly localized CFTR, or in partial/total mislocalization of this protein. Similar levels of NF-kappaB activation were observed in a number of organs of wildtype and CF mice. Finally, IL-8 secretion and NF-kappaB activity were not consistently increased in CF cell lines. Cos-7 cell transfection with plasmids expressing deltaF508 or G551D mutant CFTR protein resulted in increased activation of a p50-containing NF-kappaB complex, but IL-8 secretion was similar to wild-type cells. The authors conclude that the stimulus produced by Pseudomonas aeruginosa is the predominant inflammatory trigger in their models.

Hydrocarbon solvent exposure data: compilation and analysis of the literature

An occupational exposure database for hydrocarbon solvent end-use applications was constructed from the published literature. The database provides exposure assessment information for such purposes as regulatory risk assessments, support of industry product stewardship initiatives, and identification of applications in which limited exposure data are available. It is quantitative, documented, and based on credible data. Approximately 350 articles containing quantitative hydrocarbon solvent exposure data were identified using a search of computer databases of published literature. Many articles did not report sufficient details of the exposure data for inclusion in the database (e.g., full-shift exposure or task-based exposure data). Others were excluded because only limited summary statistics were provided, which precluded statistical analysis of the data (e.g., arithmetic mean concentration presented, but no sample number). Following evaluation, 16,880 hydrocarbon solvent exposure measurements from 99 articles were entered into a database for analysis. Methods used to identify and evaluate published solvent exposure data are described along with more detailed analysis of worker exposure to hydrocarbon solvents in three major end-use applications: painting and coating, printing, and adhesives. Solvent exposures were evaluated against current ACGIH threshold limit values (TLVs) and trends were identified. Limited quantitative data are available prior to 1970. In general, reported hydrocarbon solvent exposures decreased fourfold from 1960 to 1998, were below the TLVs applicable to specific hydrocarbon solvents at the time, and on average have been below 40% of the TLV since 1980. The database already has proved valuable; however, the utility of published exposure data could be further improved if authors consistently reported essential data elements and supporting information.