Comparison of digital scanning and polyvinyl siloxane impression techniques by dental students: instructional efficiency and attitudes towards technology.

INTRODUCTION: With increasing use of digital scanning with restorative procedures in the dental office, it becomes necessary that educational institutions adopt instructional methodology for introducing this technology together with conventional impression techniques. OBJECTIVE: To compare the time differences between instructing dental students on digital scanning (DS) (LAVA C.O.S. digital impression system) and a conventional impression technique (CI) (polyvinyl siloxane), and to compare students' attitudes and beliefs towards both techniques. MATERIALS AND METHODS: Volunteer sophomore dental students (n = 25) with no prior experience in clinical impressions were recruited and IRB consent obtained. Participants responded to a pre-and post-exposure questionnaire. Participants were instructed on the use of both DS and CI for a single tooth full coverage crown restoration using a consecutive sequence of video lecture, investigator-led demonstration and independent impression exercise. The time necessary for each step (minutes) was recorded. Statistical significance was calculated using dependent t-tests (time measurements) and 2-sample Mann-Whitney (questionnaire responses). RESULTS: The time spent teaching students was greater for DS than CI for video lecture (15.95 and 10.07 min, P = 0.0000), demonstration time (9.06 and 4.70 min, P = 0.0000) and impression time (18.17 and 8.59 min, P = 0.0000). Prior to the instruction and practice, students considered themselves more familiar with CI (3.96) than DS (1.96) (P = 0.0000). After the instruction and practice, participants reported CI technique proved significantly easier than expected (pre-instruction: 3.52 and post-instruction: 4.08, P = 0.002). However, overall participants' perception of ease of use for DS was not influenced by this instruction and practice experience (pre-instruction: 3.84 and post-instruction: 3.56, P = 0.106). Despite the results, 96% of participants expressed an expectation that DS will become their predominant impression technique during their careers. CONCLUSIONS: Dental students with no clinical experience have high expectations for digital scanning, and despite their initial difficulty, expect it to become their primary impression technique during their professional futures. The instructional time necessary for introducing DS into the curriculum is significantly greater than CI in both classroom (lecture) and clinical simulation settings (investigator-led demonstration).

[Transretinal Biopsy of Intraocular Lymphoma]. / Transretinale Biopsie beim intraokularen Lymphom.

BACKGROUND: Intraocular lymphoma is in most cases a diagnostic challenge. Gold standard is a diagnostic vitrectomy. Vitreous biopsy and transretinal biopsies are therefore employed. METHODS: A retrospective analysis was undertaken of all cases of cytological or histological proven intraocular lymphoma between 2002 and the beginning of 2015 in our clinic. RESULTS: The diagnosis of intraocular lymphoma could be established in 16 cases by cytological or histological analysis. Six patients had previously been treated with steroids in the assumption of uveitis. Five of 16 patients had a systemic or CNS lymphoma in their history. The diagnosis of intraocular lymphoma could be made on the basis of a vitreous biopsy in only in 3 cases. In 7 cases an additional vitrectomy with transretinal biopsy was needed. In 1 case a transretinal biopsy was performed initially and in 1 case a re-transretinal biopsy was needed to establish the diagnosis. Two patients underwent iris biopsy to diagnose a secondary metastatic intraocular lymphoma. One amaurotic eye was diagnosed with intraocular lymphoma after enucleation. DISCUSSION: Due to the high relevance for the diagnosis intraocular lymphoma, when a vitreous biopsy was non-informative, a transretinal biopsy should always be considered in cases of retinal or subretinal involvement.

[Uveal melanoma: current insights into clinical relevance of genetic testing]. / Aktuelles zur klinischen Bedeutung genetischer Veränderungen bei malignen Melanomen der Uvea.

Uveal melanoma is the most common primary intraocular tumour in Caucasians. There are approximately 500 new cases of uveal melanoma in Germany per year and the incidence rate peaks at the age of 70 years. Half of all uveal melanoma patients develop metastatic disease, which can be observed even many years after successful treatment of the primary tumour. In most cases the liver is the location of first manifestation. Based on the chromosome 3 status uveal melanomas can be divided into two major classes that differ in their metastatic potential. Tumours with a high risk to metastasise usually show monosomy 3, whereas tumours showing disomy 3 rarely metastasise. If a patient wishes to know about his individual risk, prognostic testing of the primary tumour tissue can be performed after obtaining tumour material via transscleral or transretinal biopsy, or by enucleation. To date results of prognostic testing do not influence therapeutic strategies. Recently, major key genes involved in uveal melanoma development, GNAQ, GNA11, BAP1, SF3B1 and EIF1AX, have been identified. Mutation profiling, in addition to chromosomal 3 analysis, will further refine the classification or subclassification of uveal melanomas and will hopefully influence diagnostic or therapeutic concepts. Hereditary mutations in tumour suppressor gene BAP1 are associated with an increased risk for different tumour entities. Detection of germ line mutations in this tumour suppressor gene should implicate further general screening examinations of the patient to be able to detect these tumour entities. Moreover relatives of these patients should be offered a screening for BAP1 mutation.

Reproducibility of non-contrast enhanced multi breath-hold ultrashort echo time functional lung MRI.

PURPOSE: To evaluate the intraindividual reproducibility of functional lung imaging using non-contrast enhanced multi breath-hold 3D-UTE MRI. METHODS: Ten healthy volunteers underwent non-contrast enhanced 3D-UTE MRI at three time points for same-day and different-day measurements employing a stack-of-spirals trajectory at 3 T. At each time point, inspiratory and expiratory breathing states were acquired for tidal and deep breathing, each within a single breath-hold. For functional image analysis, fractional ventilation (FV) was calculated pixelwise after image registration from the MR signal change. To decouple FV from breathing depth, the individual lung volume was used for volume adjustment (rFV). Reproducibility evaluation was performed in eight lung segments. Statistical analyses included two way mixed intraclass correlation (ICC), sign-test, Friedman-test and modified Bland-Altman analyses. RESULTS: FV from tidal breathing showed an ICC of 0.81, a bias of 1.3% and an interval of confidence (CI) ranging from -67.1 to 69.6%. FV from deep breathing was higher reproducible with an ICC of 0.92 (bias, -0.2%; CI, -34.2 to 33.7%). Following volume adjustment, reproducibility of rFV for tidal breathing improved (ICC, 0,86; bias, 2.0%; CI, -34.3 to 38.3%), whereas it did not bear significant benefits for deep breathing (ICC, 0.89; bias, 2.8%; CI, -24.9 to 30.5%). Reproducibility was independent from the examination day. CONCLUSION: Non-contrast-enhanced multi breath-hold 3D-UTE MRI allows for highly reproducible ventilation imaging.

Bilateral Bartonella henselae neuroretinitis with stellate maculopathy in a 6-year-old boy.

PURPOSE: Bartonella henselae, the cause of cat-scratch disease in humans, may lead to characteristic vision-threatening ocular findings, which importantly indicate diagnosis. METHODS: This is an observational case report of a 6-year-old boy who presented with bilateral stellate maculopathy and lymphadenopathy. RESULTS: After serologic verification of B. henselae infection, systemic azithromycin therapy initiated the full recovery of visual acuity and bilateral complete resolution of stellate exudates during the following months. CONCLUSION: Stellate maculopathy should always include the differential diagnosis of B. henselae infection. In this rare case of bilateral stellate maculopathy, we observed full recovery of function following systemic macrolide therapy.

Regulatory role for macrophage migration inhibitory factor in acute respiratory distress syndrome.

Migration inhibitory factor (MIF) is known to exert significant pro-inflammatory effects and has the potential to override the anti-inflammatory action of glucocorticoids. In this study we have identified significant quantities of MIF in the alveolar airspaces of patients with acute respiratory distress syndrome (ARDS). We show in alveolar cells from patients with ARDS that MIF augments pro-inflammatory cytokine secretion (TNF alpha and IL-8), anti-MIF significantly attenuates TNF alpha and IL-8 secretion and MIF overrides, in a concentration-related fashion, the anti-inflammatory effects of glucocorticoids. These findings suggest that MIF may act as a mediator sustaining the pulmonary inflammatory response in ARDS and that an anti-MIF strategy may represent a novel therapeutic approach in inflammatory diseases such as ARDS.

Protection from septic shock by neutralization of macrophage migration inhibitory factor.

Identification of new therapeutic targets for the management of septic shock remains imperative as all investigational therapies, including anti-tumor necrosis factor (TNF) and anti-interleukin (IL)-1 agents, have uniformly failed to lower the mortality of critically ill patients with severe sepsis. We report here that macrophage migration inhibitory factor (MIF) is a critical mediator of septic shock. High concentrations of MIF were detected in the peritoneal exudate fluid and in the systemic circulation of mice with bacterial peritonitis. Experiments performed in TNFalpha knockout mice allowed a direct evaluation of the part played by MIF in sepsis in the absence of this pivotal cytokine of inflammation. Anti-MIF antibody protected TNFalpha knockout from lethal peritonitis induced by cecal ligation and puncture (CLP), providing evidence of an intrinsic contribution of MIF to the pathogenesis of sepsis. Anti-MIF antibody also protected normal mice from lethal peritonitis induced by both CLP and Escherichia coli, even when treatment was started up to 8 hours after CLP. Conversely, co-injection of recombinant MIF and E. coli markedly increased the lethality of peritonitis. Finally, high concentrations of MIF were detected in the plasma of patients with severe sepsis or septic shock. These studies define a critical part for MIF in the pathogenesis of septic shock and identify a new target for therapeutic intervention.

[TTF-1 (8G7G3/1) positive colon adenocarcinoma: diagnostic implications]. / TTF-1- (Klon 8G7G3/1) positives Kolonkarzinom: Diagnostische Implikationen.

Immunohistochemical evaluation of primary and secondary (adeno-) carcinomas of the lung often includes utilisation of two different clones (8G7G3/1 or SPT24) of TTF-1 (thyroid transcription factor 1) antibodies. In a subgroup of adenocarcinomas with a primary site other than the lung a positive reaction of clone SPT24 and also of clone 8G7G3/1 is described. We report on a patient with TTF-1 (clone 8G7G3/1) positive adenocarcinoma of the colon with metastases to the eye and lung and discuss TTF-1 based diagnostic considerations.

An essential role for macrophage migration inhibitory factor in the tuberculin delayed-type hypersensitivity reaction.

30 years ago, investigations into the molecular basis of the delayed-type hypersensitivity reaction (DTH) provided evidence for the first lymphokine activity: a lymphocyte-derived mediator called macrophage migration inhibitory factor (MIF), which inhibited the random migration of peritoneal macrophages. Despite the long-standing association of MIF with the DTH reaction and the cloning of a human protein with macrophage migration inhibitory activity, the precise role of MIF in this classic cell-mediated immune response has remained undefined. This situation has been further complicated by the fact that two other cytokines, interferon gamma and IL-4, similarly inhibit macrophage migration and by the identification of mitogenic contaminants in some preparations of cloned human MIF. Using recently developed molecular probes for mouse MIF, we have examined the role of this protein in a classical model of DTH, the tuberculin reaction in mice. Both MIF messenger RNA and protein were expressed prominently in DTH lesions, as assessed by reverse transcription polymerase chain reaction, in situ hybridization, and immunostaining with anti-MIF antibody. The predominant cellular origin of MIF appeared to be the monocyte/macrophage, a cell type identified recently to be a major source of MIF release in vivo. The administration of neutralizing anti-MIF antibodies to mice inhibited significantly the development of DTH, thus affirming the central role of MIF in this classic immunological response.

The pathogenic role of macrophage migration inhibitory factor in immunologically induced kidney disease in the rat.

Macrophage migration inhibitory factor (MIF) plays a pivotal role in the inflammatory response in endotoxemia and in the delayed-type hypersensitivity response, but its potential as a regulator of immunologically induced disease is unknown. We have addressed this issue by administering a neutralizing anti-MIF antibody in a rat model of immunologically induced crescentic anti-glomerular basement membrane (GBM) glomerulonephritis. Six individual experiments using paired inbred littermates were performed. Rats were primed with rabbit immunoglobulin on day -5 and then injection with rabbit anti-rat GBM serum on day 0. Pairs of animals were treated with anti-MIF or a control monoclonal antibody from the time of anti-GBM serum administration until being killed 14 d later. Control antibody-treated animals developed severe proteinuria and renal function impairment with severe histological damage due to marked leukocytic infiltration and activation within the kidney. In contrast, anti-MIF treatment substantially reduced proteinuria, prevented the loss of renal function, significantly reduced histological damage including glomerular crescent formation, and substantially inhibited renal leukocytic infiltration and activation (all P <0.001 compared with control treatment). Inhibition of renal disease by anti-MIF treatment was attributed to preventing the marked upregulation of interleukin-1beta, leukocyte adhesion molecules including intercellular adhesion molecule-1 and vascular cell adhesion molecule-1, and inducible nitric oxide synthase expression seen in the control antibody-treated animals. This inhibition of progressive renal injury was mirrored by the complete suppression of the skin delayed-type hypersensitivity response to the challenge antigen (rabbit IgG). Interestingly, anti-MIF treatment did not effect the secondary antibody response or immune deposition within the kidney, indicating that MIF participates in cellular-based immunity in this primed macrophage-dependent anti-GBM glomerulonephritis. In conclusion, this study has demonstrated a key regulatory role for MIF in the pathogenesis of immunologically induced kidney disease. These results argue that blocking MIF activity may be of benefit in the treatment of human rapidly progressive glomerulonephritis, and suggest that MIF may be important in immune-mediated disease generally.

Quality of life in breast cancer survivors: An assessment of international breast cancer dragon boat racers.

Resistance exercise is deemed safe for women recovering from conventional breast cancer therapies but few clinicians are aware that dragon boat racing, as a form of resistive exercise, is available to the breast cancer community. The objectives of this study were to 1) increase clinician awareness of dragon boat racing (DBR) in breast cancer survivors as a community-based physical activity, and 2) evaluate quality of life (QOL) in breast cancer survivors with or without lymphedema who participate in DBR. This prospective, observational study surveyed 1,069 international breast cancer dragon boat racers from eight countries to compare function, activity, and participation in women with and without selfreported lymphedema using the Lymph-ICF questionnaire. Seventy-one percent of women (n=758) completed the questionnaires. Results revealed significantly higher Lymph-ICF scores in the lymphedema participants, signifying reduced QOL, when compared to the nonlymphedema participants (p<0.05), except for "go on vacation" for which no statistical difference was reported (p=0.20). International breast cancer survivors with lymphedema participating in DBR at an international competition had reduced function, limited activity, and restricted participation compared to participants without lymphedema. Clinicians should consider utilizing DBR as a community-based activity to support exercise and physical activity after a breast cancer diagnosis.

Transforming growth factor-beta 1 regulates axon/Schwann cell interactions.

We have investigated the potential regulatory role of TGF-beta in the interactions of neurons and Schwann cells using an in vitro myelinating system. Purified populations of neurons and Schwann cells, grown alone or in coculture, secrete readily detectable levels of the three mammalian isoforms of TGF-beta; in each case, virtually all of the TGF-beta activity detected is latent. Expression of TGF-beta 1, a major isoform produced by Schwann cells, is specifically and significantly downregulated as a result of axon/Schwann cell interactions. Treatment of Schwann cells or Schwann cell/neuron cocultures with TGF-beta 1, in turn, has dramatic effects on proliferation and differentiation. In the case of purified Schwann cells, treatment with TGF-beta 1 increases their proliferation, and it promotes a pre- or nonmyelinating Schwann cell phenotype characterized by increased NCAM expression, decreased NGF receptor expression, inhibition of the forskolin-mediated induction of the myelin protein P0, and induction of the Schwann cell transcription factor suppressed cAMP-inducible POU protein. Addition of TGF-beta 1 to the cocultures inhibits many of the effects of the axon on Schwann cells, antagonizing the proliferation induced by contact with neurons, and, strikingly, blocking myelination. Ultrastructural analysis of the treated cultures confirmed the complete inhibition of myelination and revealed only rudimentary ensheathment of axons. Associated defects of the Schwann cell basal lamina and reduced expression of laminin were also detected. These effects of TGF-beta 1 on Schwann cell differentiation are likely to be direct effects on the Schwann cells themselves which express high levels of TGF-beta 1 receptors when cocultured with neurons. The regulated expression of TGF-beta 1 and its effects on Schwann cells suggest that it may be an important autocrine and paracrine mediator of neuron/Schwann cell interactions. During development, TGF-beta 1 could serve as an inhibitor of Schwann cell proliferation and myelination, whereas after peripheral nerve injury, it may promote the transition of Schwann cells to a proliferating, nonmyelinating phenotype, and thereby enhance the regenerative response.

Latent transforming growth factor-beta binding protein domains involved in activation and transglutaminase-dependent cross-linking of latent transforming growth factor-beta.

Transforming growth factor-beta (TGF-beta) is secreted by many cell types as part of a large latent complex composed of three subunits: TGF-beta, the TGF-beta propeptide, and the latent TGF-beta binding protein (LTBP). To interact with its cell surface receptors, TGF-beta must be released from the latent complex by disrupting noncovalent interactions between mature TGF-beta and its propeptide. Previously, we identified LTBP-1 and transglutaminase, a cross-linking enzyme, as reactants involved in the formation of TGF-beta. In this study, we demonstrate that LTBP-1 and large latent complex are substrates for transglutaminase. Furthermore, we show that the covalent association between LTBP-1 and the extracellular matrix is transglutaminase dependent, as little LTBP-1 is recovered from matrix digests prepared from cultures treated with transglutaminase inhibitors. Three polyclonal antisera to glutathione S-transferase fusion proteins containing amino, middle, or carboxyl regions of LTBP-1S were used to identify domains of LTBP-1 involved in cross-linking and formation of TGF-beta by transglutaminase. Antibodies to the amino and carboxyl regions of LTBP-1S abrogate TGF-beta generation by vascular cell cocultures or macrophages. However, only antibodies to the amino-terminal region of LTBP-1 block transglutaminase-dependent cross-linking of large latent complex or LTBP-1. To further identify transglutaminase-reactive domains within the amino-terminal region of LTBP-1S, mutants of LTBP-1S with deletions of either the amino-terminal 293 (deltaN293) or 441 (deltaN441) amino acids were expressed transiently in CHO cells. Analysis of the LTBP-1S content in matrices of transfected CHO cultures revealed that deltaN293 LTBP-1S was matrix associated via a transglutaminase-dependent reaction, whereas deltaN441 LTBP-1S was not. This suggests that residues 294-441 are critical to the transglutaminase reactivity of LTBP-1S.

Coronary centerline extraction from CT coronary angiography images using a minimum cost path approach.

PURPOSE: The application and large-scale evaluation of minimum cost path approaches for coronary centerline extraction from computed tomography coronary angiography (CTCA) data and the development and evaluation of a novel method to reduce the user-interaction time. METHODS: A semiautomatic method based on a minimum cost path approach is evaluated for two different cost functions. The first cost function is based on a frequently used vesselness measure and intensity information, and the second is a recently proposed cost function based on region statistics. User interaction is minimized to one or two mouse clicks distally in the coronary artery. The starting point for the minimum cost path search is automatically determined using a newly developed method that finds a point in the center of the aorta in one of the axial slices. This step ensures that all computationally expensive parts of the algorithm can be precomputed. RESULTS: The performance of the aorta localization procedure was demonstrated by a success rate of 100% in 75 images. The success rate and accuracy of centerline extraction was quantitatively evaluated on 48 coronary arteries in 12 images by comparing extracted centerlines with a manually annotated reference standard. The method was able to extract 88% and 47% of the vessel center-lines correctly using the vesselness/intensity and region statistics cost function, respectively. For only the proximal part of the vessels these values were 97% and 86%, respectively. Accuracy of centerline extraction, defined as the average distance from correctly automatically extracted parts of the centerline to the reference standard, was 0.64 mm for the vesselness/intensity and 0.51 mm for the region statistics cost function. The interobserver variability was 99% for the success rate measure and 0.42 mm for the accuracy measure. Qualitative evaluation using the best performing cost function resulted in successful centerline extraction for 233 out of the 252 coronaries (92%) in 63 additional CTCA images. CONCLUSIONS: The presented results, in combination with minimal user interaction and low computation time, show that minimum cost path approaches can effectively be applied as a preprocessing step for subsequent analysis in clinical practice and biomedical research.

Cholinergic agonists attenuate renal ischemia-reperfusion injury in rats.

Inflammation plays a significant role in the pathophysiology of renal ischemia-reperfusion injury. Local inflammation is modulated by the brain via the vagus nerve and nicotinic acetylcholine receptors such that electrical or pharmacologic stimulation of this cholinergic anti-inflammatory pathway results in suppression of proinflammatory cytokine production. We examined the effects of cholinergic stimulation using agonists, nicotine or GTS-21, given before or after bilateral renal ischemia-reperfusion injury in rats. Pretreatment of rats with either agonist significantly attenuated renal dysfunction and tubular necrosis induced by renal ischemia. Similarly, tumor necrosis factor-alpha protein expression and leukocyte infiltration of the kidney were markedly reduced following treatment with cholinergic agonists. We found functional nicotinic acetylcholine receptors were present on rat proximal tubule epithelial cells. Cholinergic stimulation significantly decreased tubular necrosis in vagotomized rats after injury, implying an intact vagus nerve is not required for this renoprotective effect.

Epidemiological studies of leukaemia in children and young adults around nuclear facilities: a critical review.

The existence of an increased risk of childhood leukaemia near nuclear installations is a recurrent issue. A review of the related epidemiological literature is presented here. Results for 198 nuclear sites throughout 10 countries were included in the review. In addition to local studies, 25 multi-site studies have been published for eight countries. A large variability was noticed in the quality of the data as well as in the definition of the study population and in the methods of analysis. Many studies present important limits that make the results difficult to interpret. The review confirms that some clusters of childhood leukaemia cases exist locally. However, results based on multi-site studies around nuclear installations do not indicate an increased risk globally. Many studies were launched to investigate possible origins of the observed clusters around specific sites, but up to now, none of the proposed hypotheses have explained them.

Progenitor cells isolated from the human heart: a potential cell source for regenerative therapy.

BACKGROUND: In recent years, resident cardiac progenitor cells have been identified in, and isolated from the rodent heart. These cells show the potential to form cardiomyocytes, smooth muscle cells, and endothelial cells in vitro and in vivo and could potentially be used as a source for cardiac repair. However, previously described cardiac progenitor cell populations show immature development and need co-culture with neonatal rat cardiomyocytes in order to differentiate in vitro. Here we describe the localisation, isolation, characterisation, and differentiation of cardiomyocyte progenitor cells (CMPCs) isolated from the human heart. METHODS: hCMPCs were identified in human hearts based on Sca-1 expression. These cells were isolated, and FACS, RT-PCR and immunocytochemistry were used to determine their baseline characteristics. Cardiomyogenic differentiation was induced by stimulation with 5-azacytidine. RESULTS: hCMPCs were localised within the atria, atrioventricular region, and epicardial layer of the foetal and adult human heart. In vitro, hCMPCs could be induced to differentiate into cardiomyocytes and formed spontaneously beating aggregates, without the need for co-culture with neonatal cardiomyocytes. CONCLUSION: The human heart harbours a pool of resident cardiomyocyte progenitor cells, which can be expanded and differentiated in vitro. These cells may provide a suitable source for cardiac regeneration cell therapy. (Neth Heart J 2008;16:163-9.).

The proinflammatory mediator macrophage migration inhibitory factor induces glucose catabolism in muscle.

Severe infection or tissue invasion can provoke a catabolic response, leading to severe metabolic derangement, cachexia, and even death. Macrophage migration inhibitory factor (MIF) is an important regulator of the host response to infection. Released by various immune cells and by the anterior pituitary gland, MIF plays a critical role in the systemic inflammatory response by counterregulating the inhibitory effect of glucocorticoids on immune-cell activation and proinflammatory cytokine production. We describe herein an unexpected role for MIF in the regulation of glycolysis. The addition of MIF to differentiated L6 rat myotubes increased synthesis of fructose 2,6-bisphosphate (F2,6BP), a positive allosteric regulator of glycolysis. Increased expression of the enzyme 6-phosphofructo-2-kinase/fructose-2,6-bisphosphatase (PFK-2) enhanced F2,6BP production and, consequently, cellular lactate production. The catabolic effect of TNF-alpha on myotubes was mediated by MIF, which served as an autocrine stimulus for F2, 6BP production. TNF-alpha administered to mice decreased serum glucose levels and increased muscle F2,6BP levels; pretreatment with a neutralizing anti-MIF mAb completely inhibited these effects. Anti-MIF also prevented hypoglycemia and increased muscle F2,6BP levels in TNF-alpha-knockout mice that were administered LPS, supporting the intrinsic contribution of MIF to these inflammation-induced metabolic changes. Taken together with the recent finding that MIF is a positive, autocrine stimulator of insulin release, these data suggest an important role for MIF in the control of host glucose disposal and carbohydrate metabolism.

Human circulating eosinophils secrete macrophage migration inhibitory factor (MIF). Potential role in asthma.

Macrophage migration inhibitory factor (MIF) is a potent proinflammatory mediator that has been shown to potentiate lethal endotoxemia and to play a potentially important regulatory role in human acute respiratory distress syndrome (ARDS). We have investigated whether eosinophils are an important source of MIF and whether MIF may be involved in the pathophysiology of asthma. Unstimulated human circulating eosinophils were found to contain preformed MIF. Stimulation of human eosinophils with phorbol myristate acetate in vitro yielded significant release of MIF protein. For example, eosinophils stimulated with phorbol myristate acetate (100 nM, 8 h, 37 degreesC) released 1,539+/-435 pg/10(6) cells of MIF, whereas unstimulated cells released barely detectable levels (< 142 pg/10(6) cells, mean+/-SEM, n = 8). This stimulated release was shown to be (a) concentration- and time-dependent, (b) partially blocked by the protein synthesis inhibitor cycloheximide, and (c) significantly inhibited by the protein kinase C inhibitor Ro-31,8220. In addition, we show that the physiological stimuli C5a and IL-5 also cause significant MIF release. Furthermore, bronchoalveolar lavage fluid obtained from asthmatic patients contains significantly elevated levels of MIF as compared to nonatopic normal volunteers (asthmatic, 797.5+/-92 pg/ml; controls, 274+/-91 pg/ml). These results highlight the potential importance of MIF in asthma and other eosinophil-dependent inflammatory disorders.

Macrophage migration inhibitory factor induces cell death and decreases neuronal nitric oxide expression in spinal cord neurons.

Macrophage migration inhibitory factor is a potent proinflammatory cytokine; however, its role in spinal cord injury is poorly understood. Therefore, the aim of the present study was to investigate the effects of macrophage migration inhibitory factor on spinal cord neuron survival and viability. Due to the importance of nitric oxide metabolism in these events, part of our study was also focused on the influence of recombinant macrophage migration inhibitory factor on neuronal nitric oxide expression. Exposure of cultured mouse spinal cord neurons to macrophage migration inhibitory factor markedly increased cellular oxidative stress as measured by 2',7'-dichlorofluorescein fluorescence and intracellular calcium levels. In addition, an antagonist of the inositol 1,4,5-triphosphate receptor, 8-(diethylamino)octyl 3,4,5-trimethoxybenzoate, completely blocked the macrophage migration inhibitory factor-induced increase in intracellular calcium levels. Macrophage migration inhibitory factor treatment also decreased cell viability, increased cellular lactate dehydrogenase release, and induced chromatin condensation and aggregation in cultured spinal cord neurons. Finally, exposure to macrophage migration inhibitory factor markedly decreased expression and activity of neuronal nitric oxide, accompanied by a decrease in cellular guanosine 3'5'-cyclic monophosphate levels. The present results indicate that macrophage migration inhibitory factor can induce dysfunction of spinal cord neurons, leading to cell death through oxidative stress and intracellular calcium-dependent pathways.