bluuebunny/crossref_metadata_2025 huggingface dataset:
Microsporidia Infection in Immunologically Compromised Hospitalised Patients
Authors: Čisláková L. , Halánová M.
Published: July 2003

Microsporidia Encephalitozoon cuniculi, an obligate intracellular spore-forming protozoan parasite infecting a wide range of vertebrate and invertebrate hosts, has been described as an opportunistic pathogen in severely immuno-compromised human hosts.

An antibody immune response to the presence of antibodies against E. cuniculi was investigated serologically using an indirect immunofluorescence antibody test (IFAT). Of the total number of 113 sera from immunologically compromised patients examined, 16 were positive at the titre 1:32, which represented 14.1%. 11 people were positive at the titre 1:64 also, and 6 at the titre 1:256. From the 14.1% people who tested positive 12 were children and 4 adults.
Hospital Indoor Environment: Screening for Micro-Organisms and Particulate Matter
Authors: Klánová Kateřina , Hollerová Jitka
Published: July 2003

The concentrations of air-borne micro-organisms and particulate matter were measured in the air and on solid surfaces in five rooms in a hospital. For comparison the same measurements were also made outdoors. The rooms were chosen because of their different needs in terms of indoor environment quality. The highest bacterial concentrations were found in the air of a patient's room that was `unventilated' other than through its doorway. Some of the rooms were supplied with filtered air. Compared to the rest, these rooms had the lowest microbial concentrations in their air but the highest on surfaces. A correlation was found between the count of the particulate size-range ≥1.0 μm and that of bacteria ( r=0.76) and between the count of the particulate size range ≥5.0 μm and those of bacteria ( r=0.88) and staphylococci ( r=0.80) in indoor air. No correlation was found between the particulate count and the mould count in the indoor air.
Review of Isolation Ward Ventilation Design and Evaluation by Simulation
Authors: Yik Francis W. H. , Powell Greg
Published: July 2003

The recent resurgence of tuberculosis (TB) has led to calls for improvements in isolation facilities. This paper presents the findings of a literature review and an evaluation study of current design guidelines and performance expectations for isolation room mechanical ventilation systems. The inter-zone airflows in a typical isolation ward were modelled to unveil the issues that are critical to isolation performance and to determine the practicality of the recommendations in the literature. It was found that the air leakage through partitions and door gaps would be highly undesirable. With adequate supply and exhaust flow rate differences, and practicable construction quality, differential pressures of up to 7 Pa or higher should be achievable between isolation rooms and adjacent areas.
Hygiene Problems in the Building and Technical Equipping of Hospital Surgery Departments
Authors: Nosková Tana , Voleková Janka , Sobotová Ĺubica
Published: July 2003

If operations are performed in operating theatres that have been poorly rebuilt and badly technically equipped and managed there may be hygiene and technical problems that could cause considerable problems for users and their controlling authorities. These problems include the need to provide aseptic working conditions in operating theatres to prevent nosocomial infections and possible risk of damage to the health of the surgical team. It is also important to ensure good air quality, thermal and sound comfort and correct illumination within the rooms and for the various technical devices. All these factors may affect the condition and performance of operating theatres. With our long experience in this field, we would like to highlight some of the commonly repeated mistakes which building engineers and air conditioning technicians as well as surgical teams and management should avoid and which could be eliminated to improve hygienic environmental standards in surgical departments.

Common problems include not keeping to the rules of zoning in operating theatres and other rooms in surgical departments. Crossing from clean to dirty areas around the operating spaces and involvement of other staff work and materials should be avoided. Technical measures for air decontamination should be devised especially for the air evacuation zone of operating rooms. Pollution of rest room indoor air by cigarette smoke from smokers in the operating team should be prevented.
Hospital Waste Treatment and Disposal in the General University Hospital - Current Situation and Future Challenges
Authors: Bencko V. , Kapek J. , Vinš O.
Published: July 2003

The General Hospital of Prague, together with a maternity home, foundling hospital and hospice was established in 1790 under the so called “directive rules” issued by Josef II in 1781. At the time of its opening there were 300 beds and now the number varies from 1800 to 2000 beds.

The present General University Hospital (GUH) is inevitably a producer of waste and must organise the management of this in all of its premises and departments in an acceptable non-noxious manner. From an ecological point of view it is important to separate the various kinds of waste produced which must then be kept in safe containers at selected places, protected against degradation, obstruction and leakage. Since, at the present time the GUH possesses neither an incinerator nor disposal site facilities. The different hospital waste fractions are taken by specialised companies responsible for its treatment and final disposal.

Proper separation of waste has an important influence on the hospital budget. While the price of the mixed communal waste disposal is now approximately 2200 CZK (75 Euro) per tonne the specific sanitary hospital waste treatment costs 7800 CZK (260 Euro) per tonne. For this reason the GUH has its own internal directive with rules for handling all kinds of waste. According to this directive one person is nominated as responsible for waste treatment to manage the hospital waste at each work place, clinic and institute. The management of all of the hospital waste is the responsibility of the operational division of the hospital. The directive lists basic rules for safety, personal protection and emergency measures in case of accidents. This directive is part of the hospital operating instructions, based on the requirements of law No. 258/2000 on the Protection of Public Health, Waste Management Act No 185/2001 and the Methodological Instruction of the Ministry of Health of the Czech Republic issued in 2001. The expected development of present practices and future challenges in this field are discussed.
Air Quality in Operating Theatres: The Effect of Waste Anaesthetics on Personnel and Exposure Prevention Measures
Authors: Dobrovolsky Leonard
Published: July 2003

The use of gaseous anaesthetics and vapours for narcosis in operating theatres means that inevitably some fraction of these is breathed by the surgical team. The amount will depend on the anaesthetic method, the duration of the operation, and the condition of the equipment used for anaesthesia and for overall ventilation. The greatest concentrations of anaesthetics are found in the working zone of the anaesthetist, then the surgeon and the scrub nurse. Until the middle of the 1960s there was little interest in air quality in operating theatres and the occupational effect of waste anaesthetic agents on the surgical team. The situation has improved considerably since then and many studies have now been carried out. The inhalation of even low levels of these various compounds has been shown to have toxic effects. Regular occupational exposure to anaesthetics is especially dangerous for pregnant women. There is a risk of abortion and of babies born with congenital abnormalities. Prophylactic measures must be directed to monitoring (environmental, biological, medical), engineering controls and work practices. Well-designed low-leakage anaesthesia equipment and scavenging systems are needed. Air conditioning systems in operating theatres should be designed using vertical laminar flow systems of ventilation instead of horizontal ones. Proper work practices employed by the anaesthetist are very important.
Reactions of Ozone on Ventilation Filters
Authors: Hyttinen Marko , Pasanen Pertti , Salo Jutta , Björkroth Marko , Vartiainen Matti , Kalliokoski Pentti
Published: July 2003

When supply air passes through a filter, ozone and other oxidants may react with the dust and with the compounds adsorbed on it causing decomposition of ozone and producing oxidation products. These reactions have been studied on nine used supply air filters in the laboratory. Some consumption of ozone was observed in almost all the filters. The changes in the concentrations of individual organic compounds due to penetration through the filter were negligible, except for formaldehyde which was produced. Air velocity in the range of 0.1-0.2 ms−1 and ozone concentration from 20 to 60 ppb did not have an effect on reduction. In field experiments, the reduction in ozone concentrations varied from 8 to 26%; the highest reduction was obtained in a HVAC unit with a three-stage-filtration. Sensory evaluation demonstrated that the highest odour emission was caused by the pre-filter. At elevated ozone concentration, the panelists could not detect any odour differences before and after the filters. Expectedly, the reactions did not change the VOC concentrations appreciably, but the reaction products with low odour threshold concentrations may, nevertheless, have some influence on the odour perception.
Measurement of Radon and Thoron Concentrations in the Indoor Atmosphere and Drinking Water of Eastern Doon Valley, India
Authors: Choubey V. M. , Bartarya S. K. , Negi M. S. , Ramola R. C.
Published: July 2003

Radon and radium content were measured in water samples from tubewells and handpumps in the eastern Doon valley, India. Activity due to the radon concentration was found to vary from 25.4 to 72.3 Bq L-1, whereas activity due to radium in selected water samples varied from 0.10 to 0.84 Bq L-1. The values recorded for radon were generally higher than those reported by various other workers for drinking water but well below the maximum levels that have been recorded. Measurements of indoor radon, thoron and their daughter products were also made in the houses in the same area for all the four seasons of a year on a time integrated cycle using twin chamber dosimeters. Concentrations of indoor radon and thoron varied from 28.4 to 63.7 Bq m-3 and 0.01 to 15.9 Bqm-3, respectively. The total resultant radiation dose to occupants in the houses surveyed in the eastern Doon valley varied from 0.03 to 0.11 μSv h-1. A detailed analysis of the radon and thoron distribution in different houses with seasonal variation and ventilation conditions and a description of the geology of the area is presented in this paper.
Effect of Smoking on the Level of Ionising Radiation in Student Rooms
Authors: Tekbaş Ömer Faruk , Vaizoğlu Songül Acar , Güleç Mahir , Güler Çağatay
Published: July 2003

This descriptive study was designed to investigate whether there was a difference in the levels of ionising radiation in rooms where smoking was permitted and rooms where it was not permitted. The study was conducted in residential student rooms of a school of medicine. A total of 60h of measurement was conducted, measuring for 1 h in each room. Measurements were made with a “RAD-ALERT 50 Nuclear Radiation Monitor”. Although significant differences were found in the level of ambient ionising radiation between rooms where smoking was allowed and those where it was not allowed it was inconclusive whether this difference was due to cigarette smoking or was affected by other external factors. The increase in the radiation level was below that where there would be an effect on health.
Allografting with nonmyeloablative conditioning following cytoreductive autografts for the treatment of patients with multiple myeloma
Authors: Maloney David G. , Molina Arthur J. , Sahebi Firoozeh , Stockerl-Goldstein Keith E. , Sandmaier Brenda M. , Bensinger William , Storer Barry , Hegenbart Ute , Somlo George , Chauncey Thomas , Bruno Benedetto , Appelbaum Frederick R. , Blume Karl G. , Forman Stephen J. , McSweeney Peter , Storb Rainer
Published: July 2003

The full potential of a graft-versusmyeloma effect after allogeneic hematopoietic cell transplantation (HCT) for patients with multiple myeloma (MM) has not been realized because of excessive early transplantation-related mortality (TRM) with conventional HCT. Autologous HCTs have been characterized by almost universal disease recurrences. The current trial combined autologous HCT with subsequent nonmyeloablative allogeneic HCT to maintain the benefits of both approaches with acceptable toxicity. Fifty-four patients, 52 years of age (median; range, 29-71 years), with previously treated stage II or III MM (52% refractory or relapsed disease) were given melphalan 200 mg/m2 and autologous HC transplants. Regimen-related toxicities after autologous HCT were moderate with a median of 6 days of neutropenia, 7 days of hospitalization, and 1 death from infection. Forty to 229 days later (median, 62 days), 52 patients received a single fraction dose of 2 Gy total body irradiation and HC transplants from HLA-identical siblings with postgrafting immunosuppression with mycophenolate mofetil (MMF) and cyclosporine (CSP). Patients experienced medians of 0 days of hospitalization, neutropenia, and thrombocytopenia. Sustained engraftment was uniform. With a median follow-up of 552 days after allografting, overall survival is 78%. One patient (2%) died before day 100 from disease progression. Thirty-eight percent of patients developed acute graft-versus-host disease (GVHD; grade II in all but 4 cases) and 46% chronic GVHD requiring therapy. Tumor responses occurred slowly. Thus far, 57% of patients have achieved complete remissions and 26% have achieved partial remissions for an overall response of 83%. Despite being evaluated in elderly patients with MM, this 2-step approach has reduced the acute toxicities of allogeneic HCT while achieving potent antitumor activities.
STAT1 mediates differentiation of chronic lymphocytic leukemia cells in response to Bryostatin 1
Authors: Battle Traci E. , Frank David A.
Published: July 2003

Bryostatin 1 is known to exhibit in vitro and in vivo activity against chronic lymphocytic leukemia (CLL) cells by inducing their further maturation into plasmalike cells. Signal transducer and activator of transcription (STAT) proteins play a central role in B-lymphocyte growth and function and are aberrantly phosphorylated on serine residues in CLL cells. To determine whether STAT transcription factors are important in Bryostatin 1–induced differentiation of CLL cells, primary CLL cells were examined for signaling events following exposure to Bryostatin 1 in vitro. Western analysis and electrophoretic mobility shift assays revealed that Bryostatin 1 induced tyrosine phosphorylation and DNA binding of STAT1, yet there was no effect on constitutive serine phosphorylation of STAT1. Bryostatin 1–induced STAT1 activation occurred in a manner that was dependent on protein kinase C (PKC), mitogen-activated protein kinase (MAPK), and Janus tyrosine kinase (JAK) activation. Evidence indicates that Bryostatin 1 induces STAT1 activation through an interferon γ (IFNγ) autocrine loop. However, STAT1 activation by IFNγ stimulation alone was not sufficient to induce differentiation. This insufficiency is due to the broader effect on gene expression caused by Bryostatin 1 compared with IFNγ, as demonstrated by microarray analysis. Both up-regulation of CD22 expression and immunoglobulin M (IgM) production, markers of CLL differentiation, were inhibited by a decoy oligonucleotide for STAT1, indicating that STAT1 is necessary for Bryostatin 1–induced differentiation of CLL cells. This study implicates STAT transcription factors as important mediators of Bryostatin 1–induced differentiation of CLL cells and could possibly lead to improved therapeutic approaches for the treatment of CLL.
Defects in T-cell–mediated immunity to influenza virus in murine Wiskott-Aldrich syndrome are corrected by oncoretroviral vector–mediated gene transfer into repopulating hematopoietic cells
Authors: Strom Ted S. , Turner Stephen J. , Andreansky Samita , Liu Haiyan , Doherty Peter C. , Srivastava Deo Kumar , Cunningham John M. , Nienhuis Arthur W.
Published: July 2003

The Wiskott-Aldrich syndrome (WAS) is an X-linked disorder characterized by immune dysfunction, thrombocytopenia, and eczema. We used a murine model created by knockout of the WAS protein gene (WASP) to evaluate the potential of gene therapy for WAS. Lethally irradiated, male WASP— animals that received transplants of mixtures of wild type (WT) and WASP— bone marrow cells demonstrated enrichment of WT cells in the lymphoid and myeloid lineages with a progressive increase in the proportion of WT T-lymphoid and B-lymphoid cells. WASP— mice had a defective secondary T-cell response to influenza virus which was normalized in animals that received transplants of 35% or more WT cells. The WASP gene was inserted into WASP— bone marrow cells with a bicistronic oncoretroviral vector also encoding green fluorescent protein (GFP), followed by transplantation into irradiated male WASP— recipients. There was a selective advantage for gene-corrected cells in multiple lineages. Animals with higher proportions of GFP+ T cells showed normalization of their lymphocyte counts. Gene-corrected, blood T cells exhibited full and partial correction, respectively, of their defective proliferative and cytokine secretory responses to in vitro T-cell–receptor stimulation. The defective secondary T-cell response to influenza virus was also improved in gene-corrected animals.
Regulation of 25-hydroxyvitamin D3-1α-hydroxylase and production of 1α,25-dihydroxyvitamin D3 by human dendritic cells
Authors: Fritsche Jana , Mondal Krishna , Ehrnsperger Achim , Andreesen Reinhard , Kreutz Marina
Published: July 2003

25-Hydroxyvitamin D3-1α-hydroxylase (25(OH)D3-1α-hydroxylase), the key enzyme of 1α,25-dihydroxyvitamin D3 (1,25(OH)2D3) production, is expressed in monocyte-derived macrophages (MACs). Here we show for the first time constitutive expression of 25(OH)D3-1α-hydroxylase in monocyte-derived dendritic cells (DCs), which was increased after stimulation with lipopolysaccharide (LPS). Accordingly, DCs showed low constitutive production of 1,25(OH)2D3, but activation by LPS increased 1,25(OH)2D3 synthesis. In addition, 25(OH)D3-1α-hydroxylase expression was found in blood DCs but not in CD34+-derived DCs. Next we analyzed the functional consequences of these results. Addition of 1,25(OH)2D3 at concentrations comparable with those produced by DCs inhibited the allostimulatory potential of DCs during the early phase of DC differentiation. However, terminal differentiation decreased the responsiveness of DCs to 1,25(OH)2D3. In conclusion, DCs are able to produce 1,25(OH)2D3 especially following stimulation with LPS. Terminal maturation renders DCs unresponsive to the effects of 1,25(OH)2D3, but those cells are able to suppress the differentiation of their own precursor cells in a paracrine way through the production of 1,25(OH)2D3.
Amoeboid shape change and contact guidance: T-lymphocyte crawling through fibrillar collagen is independent of matrix remodeling by MMPs and other proteases
Authors: Wolf Katarina , Müller Regina , Borgmann Stefan , Bröcker Eva.-B. , Friedl Peter
Published: July 2003

The passage of leukocytes through basement membranes involves proteolytic degradation of extracellular matrix (ECM) components executed by focalized proteolysis. We have investigated whether the migration of leukocytes through 3-dimensional collagenous tissue scaffolds requires similar ECM breakdown. Human T blasts and SupT1 lymphoma cells expressed mRNA of MMP-9, MT1-MMP, MT4-MMP, cathepsin L, uPA, and uPAR as well as ADAM-9, -10, -11, -15, and -17. Upon long-term migration within 3-dimensional collagen matrices, however, no in situ collagenolysis was obtained by sensitive fluorescein isothiocyanate–collagen fragmentation analysis and confocal fluorescence/backscatter microscopy. Consistent with nonproteolytic migration, T-cell crawling and path generation were not impaired by protease inhibitor cocktail targeting MMPs, serine proteases, cysteine proteases, and cathepsins. Dynamic imaging of cell-ECM interactions showed T-cell migration as an amoeba-like process driven by adaptive morphology, crawling along collagen fibrils (contact guidance) and squeezing through pre-existing matrix gaps by vigorous shape change. The concept of nonproteolytic amoeboid migration was confirmed for multicomponent collagen lattices containing hyaluronan and chondroitin sulfate and for other migrating leukocytes including CD8+ T blasts, monocyte-derived dendritic cells, and U937 monocytic cells. Together, amoeboid shape change and contact guidance provide constitutive protease-independent mechanisms for leukocyte trafficking through interstitial tissues that are insensitive toward pharmacologic protease inhibitors.
PIAS proteins promote SUMO-1 conjugation to STAT1
Authors: Ungureanu Daniela , Vanhatupa Sari , Kotaja Noora , Yang Jie , Aittomäki Saara , Jänne Olli A. , Palvimo Jorma J. , Silvennoinen Olli
Published: July 2003

Signal transducer and activator of transcription 1 (STAT1) is a critical mediator of interferon-γ (IFN-γ)–induced transcription that is regulated through posttranslational modifications and through transacting proteins such as protein inhibitor of activated STAT1 (PIAS1). PIAS proteins have been shown to function as E3-type small ubiquitin-like modifier (SUMO) ligases, and sumoylation has been identified as a modulatory mechanism for several transcription factors. Here we show that STAT1 is subject to SUMO-1 modification, and sumoylation occurs in vivo and in vitro at a single, evolutionary conserved amino acid residue Lys703. Members of the PIAS family of proteins were found to strongly stimulate sumoylation of STAT1. Furthermore, activation of STAT1 by IFN-γ or pervanadate induced SUMO-1 conjugation. Mutation of Lys703 in STAT1 resulted in increased IFN-γ–mediated transactivation, suggesting a negative regulatory function for sumoylation. These results indicate that STAT1 is covalently modified by SUMO-1 in cytokine signaling and that PIAS proteins promote SUMO-1 conjugation to STAT1.
Identification of specific gene expression profiles in human mast cells mediated by Toll-like receptor 4 and FcϵRI
Authors: Okumura Shigeru , Kashiwakura Jun-ichi , Tomita Hisashi , Matsumoto Kenji , Nakajima Toshiharu , Saito Hirohisa , Okayama Yoshimichi
Published: July 2003

Rodent mast cells (MCs) are reported to play a pivotal role in both innate and adaptive immunity. However, there is so far no evidence that human MCs are involved in innate immunity. We found that a functional Toll-like receptor 4 (TLR4) was expressed on human MCs when it was up-regulated by interferon γ (IFN-γ). To systematically explore how human MCs modulate the immune system following TLR4-mediated activation and FcϵRI aggregation, we used high-density oligonucleotide probe arrays (GeneChip) to compare the lipopolysaccharide (LPS)-induced gene expression profile with the IgE/anti-IgE-mediated profile in MCs. Both a shared core response, and LPS- or anti-IgE-specific programs of gene expression were observed in MCs. Furthermore, MCs exhibited an antiviral response gene program in response to IFN-γ, and LPS sustained that expression. Compared with the LPS-stimulated gene expression profile of human peripheral blood mononuclear cells, LPS-stimulated MCs specifically induced a subset of genes that included a Th2 cytokine and chemokines that recruit Th2 cells and eosinophils. These results reveal that human MCs express tailored pathogen- and antigen-specific immune responses and that human MCs may play important roles in innate and adaptive immunity.(Blood. 2003;102:2547-2554)
CD3/CD28-costimulated T1 and T2 subsets: differential in vivo allosensitization generates distinct GVT and GVHD effects
Authors: Jung Unsu , Foley Jason E. , Erdmann Andreas A. , Eckhaus Michael A. , Fowler Daniel H.
Published: July 2003

Adoptive T-cell therapy using CD3/CD28 co-stimulation likely requires in vivo generation of antigen specificity. Because CD28 promotes TH1/TC1 (T1) or TH2/TC2 (T2) differentiation, costimulation may generate donor T1 or T2 cells capable of differentially mediating allogeneic graft-versus-tumor (GVT) effects and graft-versus-host disease (GVHD). Costimulation under T1 or T2 conditions indeed generated murine TH1/TC1 cells secreting interleukin-2/interferon-γ (IL-2/IFN-γ) or TH2/TC2 cells secreting IL-4/IL-5/IL-10. In vivo, allogeneic T1 cells expanded, maintained T1 secretion, and acquired allospecificity involving IFN-γ and IL-5. In contrast, allogeneic T2 cells expanded less and maintained T2 secretion but did not develop significant allospecificity.Allogeneic, but not syngeneic, T1 cells mediated a GVT effect against host-type breast cancer cells, as median survival time (MST) increased from 25.6 ± 2.6 (tumor controls) to 69.2 ± 5.9 days (P < 1.2 × 10-9). This T1-associated GVT effect operated independently of fasL because T1 cells from gld mice mediated tumor-free survival. In contrast, allogeneic T2 cells mediated a modest, noncurative GVT effect (MST, 29 ± 1.3 days; P < .0019). T1 recipients had moderate GVHD (histologic score, 4 of 12) that contributed to lethality after bone marrow transplantation; in contrast, T2 recipients had minimal GVHD (histologic score, 1 of 12). CD3/CD28 co-stimulation, therefore, generates T1 or T2 populations with differential in vivo capacity for expansion to alloantigen, resulting in differential GVT effects and GVHD.
Homeostasis and regeneration of the hematopoietic stem cell pool are altered in SHIP-deficient mice
Authors: Helgason Cheryl D. , Antonchuk Jennifer , Bodner Caroline , Humphries R. Keith
Published: July 2003

SH2-containing inositol 5-phosphatase (SHIP) is an important negative regulator of cytokine and immune receptor signaling. SHIP-deficient mice have a number of hematopoietic perturbations, including enhanced cytokine responsiveness. Because cytokines play an important role in the maintenance/expansion of the primitive hematopoietic cell pool, we investigated the possibility that SHIP also regulates the properties of cells in these compartments. Primitive hematopoietic cells were evaluated in SHIP-deficient mice and wild-type littermate controls using the colony-forming unit-spleen (CFU-S) and competitive repopulating unit (CRU) assays for multipotent progenitors and long-term lympho-myeloid repopulating cells, respectively. Absence of SHIP was found to affect homeostasis of CFU-S and CRU compartments. Numbers of primitive cells were increased in extramedullary sites such as the spleen of SHIP-deficient mice, although total body numbers were not significantly changed. In vivo cell cycle status of the CRU compartment was further evaluated using 5-fluorouracil (5-FU). SHIP-deficient CRUs were more sensitive to 5-FU killing, indicating a higher proliferative cell fraction. More strikingly, SHIP was found to regulate the ability of primitive cells to regenerate in vivo, as CRU recovery was approximately 30-fold lower in mice that received transplants of SHIP-deficient cells compared with controls. These results support a major role for SHIP in modulating pathways important in homeostasis and regeneration of hematopoietic stem cells, and emphasize the importance of negative cytokine regulation at the earliest stages of hematopoiesis. (Blood. 2003;102:3541-3547)
Eosinophil-derived neurotoxin (EDN), an antimicrobial protein with chemotactic activities for dendritic cells
Authors: Yang De , Rosenberg Helene F. , Chen Qian , Dyer Kimberly D. , Kurosaka Kahori , Oppenheim Joost J.
Published: July 2003

Recent publications have highlighted the chemotactic activities of antimicrobial proteins derived from the granules of neutrophils and basophils. Eosinophil granules also contain antimicrobial proteins. One of them is eosinophil-derived neurotoxin (EDN), a protein belonging to the ribonuclease A (RNase A) superfamily, which has recently been found to have antiviral activity in vitro. We found that EDN was selectively chemotactic for dendritic cells (DCs). The DC chemotactic activity of EDN was inhibited by either pretreatment of DCs with pertussis toxin or by simultaneous addition of placental RNase inhibitor to inhibit the activity of EDN. EDN was not chemotactic for leukocytes other than DCs. Mouse eosinophilassociated RNase 2 (mEAR2), one of a cluster of divergent orthologs of human EDN, was also chemotactic for human as well as mouse DCs. Sequence and mutational analysis demonstrated the importance of the N-terminal region of mEAR2 in mediating its chemotactic effect on DCs. EDN also induced the activation of p42/44 mitogen-activated protein kinase (MAPK) in DCs. Furthermore, injection of mEAR2 into the air pouches of mice resulted in the recruitment of DCs into the air pouches. Thus, EDN and its mouse ortholog, mEAR2, are eosinophil granule–derived antimicrobial RNases that function as chemoattractants for DCs in vitro and in vivo.
Infliximab use in patients with severe graft-versus-host disease and other emerging risk factors of non-Candida invasive fungal infections in allogeneic hematopoietic stem cell transplant recipients: a cohort study
Authors: Marty Francisco M. , Lee Stephanie J. , Fahey Michelle M. , Alyea Edwin P. , Soiffer Robert J. , Antin Joseph H. , Baden Lindsey R.
Published: July 2003

Acute graft-versus-host disease (GVHD) is a common complication of allogeneic hematopoietic stem cell transplantation (HSCT). It has been proposed that tumor necrosis factor α (TNF-α) blockade with infliximab may be an effective treatment for severe (grades III-IV) GVHD. We determined if infliximab use in this high-risk population was associated with an additional increased risk of non-Candida invasive fungal infections (IFIs). Records of the 2000-2001 HSCT cohort at our institution were reviewed. Fifty-three (20%) of 264 evaluable patients developed severe GVHD and 11 of these 53 (21%) received infliximab for treatment. Proven or probable IFI was documented in 10 (19%) of 53 patients with severe GVHD (incidence rate of 0.99 cases/1000 GVHD patient-days). When stratified by infliximab use, 5 of 11 infliximab recipients developed an IFI (6.78 cases/1000 GVHD patient-days), compared with 5 of 42 IFI cases among nonrecipients (0.53 cases/1000 GVHD patient-days). In a time-dependent Cox regression model among patients with severe GVHD, the adjusted IFI hazard ratio of infliximab exposure was 13.6 (P = .004; 95% CI, 2.29-80.2). We conclude that infliximab administration is associated with a significantly increased risk of non-Candida IFI in HSCT recipients with severe GVHD disease. Pre-emptive systemic antifungal therapy against molds should be considered in patients who develop severe GVHD after HSCT if infliximab is used.
Targeted disruption of oncostatin M receptor results in altered hematopoiesis
Authors: Tanaka Minoru , Hirabayashi Yoko , Sekiguchi Takashi , Inoue Tohru , Katsuki Motoya , Miyajima Atsushi
Published: July 2003

Oncostatin M (OSM) is a multifunctional cytokine that belongs to the interleukin 6 (IL-6) family. As OSM is expressed in adult as well as embryonic hematopoietic tissues, OSM has been considered to play a role in hematopoiesis. To uncover roles of OSM, we have generated mutant mice deficient in the OSM-specific receptor β subunit (OSMR). While OSMR–/– mice were healthy and fertile, hematologic analysis of OSMR–/– mice demonstrated that the numbers of peripheral erythrocytes and platelets were reduced compared with wild-type mice. Consistent with this, progenitors of erythroid and megakaryocyte lineages were reduced in OSMR–/– bone marrow (BM), suggesting that OSM is required for the maintenance of erythroid and megakaryocyte progenitor pools in BM. To investigate whether OSM acts on the hematopoietic progenitors directly or indirectly, we performed BM transplantation experiments. The OSMR–/– mice, engrafted with wild-type BM cells, failed to produce erythrocytic and megakaryocytic progenitors to the levels in wild-type mice, indicating that OSM affects hematopoietic microenvironments. On the other hand, erythrocytic and megakaryocytic progenitors were reduced in the wild-type mice reconstituted with OSMR–/– BM cells. Thus, OSM regulates hematopoiesis in vivo by stimulating stromal cells as well as hematopoietic progenitors, in particular megakaryocytic and erythrocytic progenitors.
Generation and role of angiostatin in human platelets
Authors: Jurasz Paul , Alonso David , Castro-Blanco Susana , Murad Ferid , Radomski Marek W.
Published: July 2003

Platelets regulate new blood vessel growth, because they contain a number of angiogenesis promoters and inhibitors. Additionally, platelets contain matrix metalloproteinases (MMPs), which when released mediate platelet adhesion and aggregation, and plasminogen, a fibrinolytic system enzyme that serves to limit blood clot formation. Enzymatic cleavage of plasminogen by MMPs generates angiostatin, an angiogenesis inhibitor. Therefore, we examined whether platelets generate angiostatin during aggregation in vitro. Platelets were isolated from healthy human donors and then aggregated with collagen, thrombin, or HT-1080 fibrosarcoma cells. Angiostatin was detected by Western blot analysis in the platelet releasates of all blood donors irrespective of the aggregating agent used. Platelet pellet homogenates showed the presence of angiostatin in all donors, which was released upon aggregation. Furthermore, platelet-derived angiostatin was isolated and purified by lysine-Sepharose affinity chromatography from collagen-aggregated platelet releasates. Bioassay of platelet-derived angiostatin showed that it inhibited the formation of capillary structures by human umbilical vein endothelial cells (HUV-EC-Cs) in an in vitro angiogenesis model. Inhibition of angiostatin in platelet releasates promoted the formation of capillary structures by HUV-EC-Cs. We conclude that healthy human platelets contain angiostatin, which is released in active form during platelet aggregation, and platelet-derived angiostatin has the capacity to inhibit angiogenesis.
Spirochete-platelet attachment and thrombocytopenia in murine relapsing fever borreliosis
Authors: Alugupalli Kishore R. , Michelson Alan D. , Joris Isabelle , Schwan Tom G. , Hodivala-Dilke Kairbaan , Hynes Richard O. , Leong John M.
Published: July 2003

Thrombocytopenia is common in persons infected with relapsing fever Borreliae. We previously showed that the relapsing fever spirochete Borrelia hermsii binds to and activates human platelets in vitro and that, after platelet activation, high-level spirochete-platelet attachment is mediated by integrin αIIbβ3, a receptor that requires platelet activation for full function. Here we established that B hermsii infection of the mouse results in severe thrombocytopenia and a functional defect in hemostasis caused by accelerated platelet loss. Disseminated intravascular coagulation, immune thrombocytopenic purpura, or splenic sequestration did not play a discernible role in this model. Instead, spirochete-platelet complexes were detected in the blood of infected mice, suggesting that platelet attachment by bacteria might result in platelet clearance. Consistent with this, splenomegaly and thrombocytopenia temporally correlated with spirochetemia, and the severity of thrombocytopenia directly correlated with the degree of spirochetemia. Activation of platelets and integrin αIIbβ3 were apparently not required for bacterium-platelet binding or platelet clearance because the bacterium-bound platelets in the circulation were not activated, and platelet binding and thrombocytopenia during infection of β3-deficient and wild-type mice were indistinguishable. These findings suggest that thrombocytopenia of relapsing fever is the result of platelet clearance after β3-independent bacterial attachment to circulating platelets.
Effects of iron regulatory protein regulation on iron homeostasis during hypoxia
Authors: Schneider Brian D. , Leibold Elizabeth A.
Published: July 2003

Iron regulatory proteins (IRP1 and IRP2) are RNA-binding proteins that affect the translation and stabilization of specific mRNAs by binding to stem-loop structures known as iron responsive elements (IREs). IREs are found in the 5′-untranslated region (UTR) of ferritin (Ft) and mitochondrial aconitase (m-Aco) mRNAs, and in the 3′-UTR of transferrin receptor (TfR) and divalent metal transporter-1 (DMT1) mRNAs. Our previous studies show that besides iron, IRPs are regulated by hypoxia. Here we describe the consequences of IRP regulation and show that iron homeostasis is regulated in 2 phases during hypoxia: an early phase where IRP1 RNA-binding activity decreases and iron uptake and Ft synthesis increase, and a late phase where IRP2 RNA-binding activity increases and iron uptake and Ft synthesis decrease. The increase in iron uptake is independent of DMT1 and TfR, suggesting an unknown transporter. Unlike Ft, m-Aco is not regulated during hypoxia. During the late phase of hypoxia, IRP2 RNA-binding activity increases, becoming the dominant regulator responsible for decreasing Ft synthesis. During reoxygenation (ReO2), Ft protein increases concomitant with a decrease in IRP2 RNA-binding activity. The data suggest that the differential regulation of IRPs during hypoxia may be important for cellular adaptation to low oxygen tension.
Granulocyte-macrophage colony-stimulating factor and interleukin-3 induce cell cycle progression through the synthesis of c-Myc protein by internal ribosome entry site–mediated translation via phosphatidylinositol 3-kinase pathway in human factor–dependent leukemic cells
Authors: Kobayashi Norihiko , Saeki Kumiko , Yuo Akira
Published: July 2003

To investigate the roles of c-myc during hematopoietic proliferation induced by growth factors, we used factor-dependent human leukemic cell lines (MO7e and F36P) in which proliferation, cell cycle progression, and c-Myc expression were strictly regulated by granulocyte-macrophage colony-stimulating factor (GM-CSF) and interleukin-3 (IL-3). In these cell lines, both c-myc mRNA and c-Myc protein stability were not affected by GM-CSF and IL-3, suggesting a regulation of c-Myc protein at the translational level. However, rapamycin, an inhibitor of cap-dependent translation, did not block c-myc induction by GM-CSF and IL-3. Thus, we studied the cap-independent translation, the internal ribosome entry site (IRES), during c-Myc protein synthesis using dicistronic reporter gene plasmids and found that GM-CSF and IL-3 activated c-myc IRES to initiate translation. c-myc IRES activation, c-Myc protein expression, and cell cycle progression were all blocked by a phosphatidylinositol 3-kinase (PI3K) inhibitor, LY294002. In another factor-dependent cell line, UT7, we observed the cell cycle progression and up-regulation of c-Myc protein, c-myc mRNA, and c-myc IRES simultaneously, which were all inhibited by LY294002. Results indicate that hematopoietic growth factors induce cell cycle progression via IRES-mediated translation of c-myc though the PI3K pathway in human factor–dependent leukemic cells.
Novel antimalarial antibodies highlight the importance of the antibody Fc region in mediating protection
Authors: Pleass Richard J. , Ogun Solabomi A. , McGuinness David H. , van de Winkel Jan G. J. , Holder Anthony A. , Woof Jenny M.
Published: July 2003

Parasite drug resistance and difficulties in developing effective vaccines have precipitated the search for alternative therapies for malaria. The success of passive immunization suggests that immunoglobulin (Ig)-based therapies are effective. To further explore the mechanism(s) by which antibody mediates its protective effect, we generated human chimeric IgG1 and IgA1 and a single-chain diabody specific for the C-terminal 19-kDa region of Plasmodium yoelii merozoite surface protein 1 (MSP119), a major target of protective immune responses. These novel human reagents triggered in vitro phagocytosis of merozoites but, unlike their parental mouse IgG2b, failed to protect against parasite challenge in vivo. Therefore, the Fc region appears critical for mediating protection in vivo, at least for this MSP119 epitope. Such antibodies may serve as prototype therapeutic agents, and as useful tools in the development of in vitro neutralization assays with Plasmodium parasites. (Blood. 2003;102:4424-4430)
RUNX/AML and C/EBP factors regulate CD11a integrin expression in myeloid cells through overlapping regulatory elements
Authors: Puig-Kröger Amaya , Sánchez-Elsner Tilman , Ruiz Natividad , Andreu Enrique J. , Prosper Felipe , Jensen Uffe B. , Gil Juana , Erickson Paul , Drabkin Harry , Groner Yoram , Corbí Angel L.
Published: July 2003

The CD11a/CD18 (leukocyte function-associated antigen 1 [LFA-1]) integrin mediates critical leukocyte adhesive interactions during immune and inflammatory responses. The CD11a promoter directs CD11a/CD18 integrin expression, and its activity in lymphoid cells depends on a functional RUNX1/AML-1–binding site (AML-110) within the MS7 sequence. We now report that MS7 contains a C/EBP-binding site (C/EBP-100), which overlaps with AML-110 and is bound by C/EBP factors in myeloid cells. C/EBP and RUNX/AML factors compete for binding to their respective cognate elements and bind to the CD11a promoter MS7 sequence in a cell lineage- and differentiation-dependent manner. In myeloid cells MS7 is primarily recognized by C/EBP factors in proliferating cells whereas RUNX/AML factors (especially RUNX3/AML-2) bind to MS7 in differentiated cells. RUNX3/AML-2 binding to the CD11a promoter correlates with increased RUNX3/AML-2 protein levels and enhanced CD11a/CD18 cell surface expression. The relevance of the AML-110 element is underscored by the ability of AML-1/ETO to inhibit CD11a promoter activity, thus explaining the low CD11a/CD18 expression in t(8;21)–containing myeloid leukemia cells. Therefore, the expression of the CD11a/CD18 integrin in myeloid cells is determined through the differential occupancy of the CD11a proximal promoter by transcription factors implicated in the pathogenesis of myeloid leukemia.
Mobilization of hematopoietic progenitor cells in healthy volunteers by AMD3100, a CXCR4 antagonist
Authors: Liles W. Conrad , Broxmeyer Hal E. , Rodger Elin , Wood Brent , Hübel Kai , Cooper Scott , Hangoc Giao , Bridger Gary J. , Henson Geoffrey W. , Calandra Gary , Dale David C.
Published: July 2003

Stromal cell-derived factor 1 (SDF1/CXCL12) and its cognate receptor, CXCR4, play key regulatory roles in CD34+ cell trafficking. We investigated whether AMD3100, a selective CXCR4 antagonist, could mobilize hematopoietic progenitor cells from marrow to peripheral blood in healthy human volunteers. Initially, 10 persons each received a single dose of AMD3100 (80 μg/kg subcutaneously), which induced rapid, generalized leukocytosis associated with an increase in peripheral blood CD34+ cells, representing pluripotent hematopoietic progenitors by in vitro colony-forming unit assays, from 3.8 ± 0.5/μL to 20.7 ± 3.5/μL at 6 hours. Subsequent dose-response studies showed a maximum increase in circulating CD34+ cells from 2.6 ± 0.3/μL to 40.4 ± 3.4/μL at 9 hours after 240 μg/kg AMD3100. Serial administration of AMD3100 (80 μg/kg/d for 3 days) resulted in consistent, reversible increases in peripheral blood CD34+ cells. AMD3100 was well tolerated and caused only mild, transient toxicity. These findings suggest potential clinical application of AMD3100 for CD34+ cell mobilization and collection for hematopoietic stem cell transplantation.
Gadd45β mediates the protective effects of CD40 costimulation against Fas-induced apoptosis
Authors: Zazzeroni Francesca , Papa Salvatore , Algeciras-Schimnich Alicia , Alvarez Kellean , Melis Tiziana , Bubici Concetta , Majewski Nathan , Hay Nissim , De Smaele Enrico , Peter Marcus E. , Franzoso Guido
Published: July 2003

In B lymphocytes, induction of apoptosis or programmed cell death (PCD) by Fas (CD95/APO-1) is suppressed by the triggering of CD40. This suppression controls various aspects of the humoral immune response, including antibody affinity maturation. The opposing effects of these receptors are also crucial to B-cell homeostasis, autoimmune disease, and cancer. Cytoprotection by CD40 involves activation of protective genes mediated by NF-κB transcription factors; however, its basis remains poorly understood. Here, we report that, in B cells, Gadd45β is induced by CD40 through a mechanism that requires NF-κB and that this induction suppresses Fas-mediated killing. Importantly, up-regulation of Gadd45β by CD40 precedes Fas-induced caspase activation, as well as up-regulation of other NF-κB–controlled inhibitors of apoptosis such as Bcl-xL and c-FLIPL. In the presence of Gadd45β, the Fas-induced apoptotic cascade is halted at mitochondria. However, in contrast to Bcl-xL, Gadd45β is unable to hamper the “intrinsic” pathway for apoptosis and in fact appears to block Fas cytotoxicity herein by suppressing a mitochondria-targeting mechanism activated by this receptor. These findings identify Gadd45β as a critical mediator of the prosurvival response to CD40 stimulation and provide important new insights into the apoptotic mechanism that is triggered by Fas in B cells.
Innate CD4+CD25+ regulatory T cells are required for oral tolerance and inhibition of CD8+ T cells mediating skin inflammation
Authors: Dubois Bertrand , Chapat Ludivine , Goubier Anne , Papiernik Martine , Nicolas Jean-François , Kaiserlian Dominique
Published: July 2003

To elucidate the role of CD4+CD25+ regulatory T cells in oral tolerance, we used the model of contact hypersensitivity (CHS) to 2,4-dinitrofluorobenzene (DNFB), which is mediated by CD8+ Tc1 effector cells independently of CD4+ T-cell help. Conversely to normal mice, invariant chain knock-out (KO) (Ii°/°) mice, which are deficient in CD4+ T cells, cannot be orally tolerized and develop a chronic hapten-specific CHS response. Transfer of naive CD4+ T cells before hapten gavage into Ii°/° mice restores oral tolerance by a mechanism independent of interleukin-10 (IL-10) production by CD4+ T cells. That naturally occurring CD4+CD25+ T cells are critical for oral tolerance induction is demonstrated by the finding that (1) transfer of CD4+CD25+ but not CD4+CD25– T cells into Ii°/° recipients completely prevents the CHS response and skin infiltration by CD8+ T cells, by blocking development of hapten-specific CD8+ T cells; (2) in vivo depletion of CD4+CD25+ cells by antibody treatment in normal mice impairs oral tolerance; and (3) CD4+CD25+ T cells inhibit hapten-specific CD8+ T-cell proliferation and interferon γ (IFNγ) production, in vitro. These data show that naturally occurring CD4+CD25+ T cells are instrumental for orally induced tolerance and are key actors for the control of antigen-specific CD8+ T-cell effectors mediating skin inflammation.