bluuebunny/crossref_metadata_2025 huggingface dataset:
Aberrant development of Plasmodium falciparum in hemoglobin CC red cells: implications for the malaria protective effect of the homozygous state
Authors: Fairhurst Rick M. , Fujioka Hisashi , Hayton Karen , Collins Kathleen F. , Wellems Thomas E.
Published: April 2003

Although selection of hemoglobin C (HbC) by malaria has been speculated for decades, only recently have epidemiologic studies provided support for HbC protection against malaria in West Africa. A reduced risk of malaria associated with the homozygous CC state has been attributed to the inability of CC cells to support parasite multiplication in vitro. However, there have been conflicting data and conclusions regarding the ability of CC red cells to support parasite replication. Reports that parasites cannot multiply in CC cells in vitro contrast with detection of substantial parasite densities in CC patients with malaria. We have therefore investigated Plasmodium falciparum growth in CC cells in vitro. Our data show that the multiplication rate of several P falciparum lines is measurable in CC cells, but lower than that in AA (HbA-normal) cells. A high proportion of ring forms and trophozoites disintegrates within a subset of CC cells, an observation that accounts for the overall lower replication rate. In addition, knobs present on the surface of infected CC cells are fewer in number and morphologically aberrant when compared with those on AA cells. Events in malaria pathogenesis that involve remodeling of the erythrocyte surface and the display of parasite antigens may be affected by these knob abnormalities. Our data suggest that only a subset of CC cells supports normal parasite replication and that components of malaria protection associated with the CC state may affect the parasite's replication capacity and involve aberrant knob formation on CC cells.
Duodenal nonheme iron content correlates with iron stores in mice, but the relationship is altered by Hfe gene knock-out
Authors: Simpson Robert J. , Debnam Edward S. , Laftah Abas H. , Solanky Nita , Beaumont Nick , Bahram Seiamak , Schümann Klaus , Srai S. Kaila S.
Published: April 2003

Hereditary hemochromatosis is a common iron-loading disorder found in populations of European descent. It has been proposed that mutations causing loss of function of HFE gene result in reduced iron incorporation into immature duodenal crypt cells. These cells then overexpress genes for iron absorption, leading to inappropriate cellular iron balance, a persistent iron deficiency of the duodenal mucosa, and increased iron absorption. The objective was to measure duodenal iron content in Hfe knock-out mice to test whether the mutation causes a persistent decrease in enterocyte iron concentration. In both normal and Hfe knock-out mice, duodenal nonheme iron content was found to correlate with liver iron stores (P < .001, r = 0.643 and 0.551, respectively), and this effect did not depend on dietary iron levels. However, duodenal iron content was reduced in Hfe knock-out mice for any given content of liver iron stores (P < .001).
A novel murine model of Cooley anemia and its rescue by lentiviral-mediated human β-globin gene transfer
Authors: Rivella Stefano , May Chad , Chadburn Amy , Rivière Isabelle , Sadelain Michel
Published: April 2003

Patients affected by β-thalassemia major require lifelong transfusions because of insufficient or absent production of the β chain of hemoglobin (Hb). A minority of patients are cured by allogeneic bone marrow transplantation. In the most severe of the hitherto available mouse models of β-thalassemia, a model for human β-thalassemia intermedia, we previously demonstrated that globin gene transfer in bone marrow cells is curative, stably raising Hb levels from 8.0-8.5 to 11.0-12.0 g/dL in long-term chimeras. To fully assess the therapeutic potential of gene therapy in the context of a lethal anemia, we now have created an adult model of β0-thalassemia major. In this novel model, mice engrafted with β-globin–null (Hbbth3/th3) fetal liver cells succumb to ineffective erythropoiesis within 60 days. These mice rapidly develop severe anemia (2-4 g/dL), massive splenomegaly, extramedullary hematopoiesis (EMH), and hepatic iron overload. Remarkably, most mice (11 of 13) treated by lentivirus-mediated globin gene transfer were rescued. Long-term chimeras with an average 1.0-2.4 copies of the TNS9 vector in their hematopoietic and blood cells stably produced up to 12 g/dL chimeric Hb consisting of muα2:huβ2tetramers. Pathologic analyses indicated that erythroid maturation was restored, while EMH and iron overload dramatically decreased. Thus, we have established an adult animal model for the most severe of the hemoglobinopathies, Cooley anemia, which should prove useful to investigate both genetic and pharmacologic treatments. Our findings demonstrate the remarkable efficacy of lentivirus-mediated globin gene transfer in treating a fulminant blood disorder and strongly support the efficacy of gene therapy in the severe hemoglobinopathies.
Mutations of the BCL6 proto-oncogene disrupt its negative autoregulation in diffuse large B-cell lymphoma
Authors: Pasqualucci Laura , Migliazza Anna , Basso Katia , Houldsworth Jane , Chaganti R. S. K. , Dalla-Favera Riccardo
Published: April 2003

The BCL6 proto-oncogene encodes a transcriptional repressor whose expression is deregulated by chromosomal translocations in approximately 40% of diffuse large B-cell lymphomas (DLBCLs). The BCL6 regulatory sequences are also targeted by somatic hypermutation in germinal center (GC) B cells and in a fraction of all GC-derived lymphomas. However, the functional consequences of these mutations are unknown. Here we report that a subset of mutations specifically associated with DLBCL causes deregulated BCL6 transcription. These mutations affect 2 adjacent BCL6 binding sites located within the first noncoding exon of the gene, and they prevent BCL6 from binding its own promoter, thereby disrupting its negative autoregulatory circuit. These alterations were found in approximately 16% of DLBCLs devoid of chromosomal translocations involving the BCL6 locus, but they were not found in normal GC B cells. This study establishes a novel mechanism for BCL6 deregulation and reveals a broader involvement of this gene in DLBCL pathogenesis.
Impaired neutrophil maturation in truncated murine G-CSF receptor–transgenic mice
Authors: Mitsui Tetsuo , Watanabe Sumiko , Taniguchi Yoshihiro , Hanada Sachiyo , Ebihara Yasuhiro , Sato Takeshi , Heike Toshio , Mitsuyama Masao , Nakahata Tatsutoshi , Tsuji Kohichiro
Published: April 2003

Severe congenital neutropenia (SCN) is a hematopoietic disorder characterized by neutropenia in peripheral blood and maturation arrest of neutrophil precursors in bone marrow. Patients with SCN may evolve to have myelodysplastic syndrome or acute myelocytic leukemia. In approximately 20% of SCN cases, a truncation mutation is found in the cytoplasmic region of the granulocyte colony-stimulating factor receptor (G-CSFR). We then generated mice carrying murine wild-type G-CSFR and its mutants equivalent to truncations at amino acids 718 and 731 in human G-CSFR, those were reported to be related to leukemic transformation of SCN. Although numbers of peripheral white blood cells, red blood cells, and platelets did not differ among mutant and wild-type G-CSFR transgenic (Tg) mice, both of the mutant receptor Tg mice had one third of peripheral neutrophil cell counts compared with wild-type receptor Tg mice. The mutant receptor Tg mice also showed impaired resistance to the infection with Staphylococcus aureus. Moreover, bone marrow of these Tg mice had an increased percentage of immature myeloid cells, a feature of SCN. This maturation arrest was also observed in in vitro cultures of bone marrow cells of truncated G-CSFR Tg mice under G-CSF stimulation. In addition, clonal culture of bone marrow cells of the truncated G-CSFR Tg mice showed the hypersensitivity to G-CSF in myeloid progenitors. Our Tg mice may be useful in the analysis of the role of truncated G-CSFR in SCN pathobiology.
Comparison of two methods of collecting induced sputum in asthmatic subjects
Authors: Gershman NH , Wong HH , Liu JT , Mahlmeister MJ , Fahy JV
Published: April 2003

The method that we have previously reported for sputum induction involves collecting the entire expectorate produced over a 20 min inhalation of 3% saline aerosol. This method presents the potential disadvantage of a considerable and variable salivary contribution to the induced sputum sample. In this study, we examined whether separate collection of saliva and sputum represents a better method for collecting induced sputum during sputum induction. In 11 stable asthmatics, we compared the volume, total and differential cell counts, and eosinophil cationic protein (ECP) levels in four induced sputum samples, two performed using our previous method (Method A) and two using another method (Method B) in which subjects spit saliva into one container before coughing sputum into another. We found that the volume of sputum obtained with Method B was lower than that obtained with Method A (6.16 +/- 0.61 vs 20.1 +/- 2.7 mL; p = 0.003), as was the percentage of squamous cells (34 +/- 4 vs 47 +/- 6; p = 0.023). In addition, the ECP levels in samples collected by Method B were higher (261 +/- 42 vs 145 +/- 26 ng.mL-1; p = 0.01). The differential counts of nonsquamous cells were similar except for the percentage of neutrophils, which was lower in Method B (37 +/- 4 vs 50 +/- 5%; p = 0.019). The repeatability of measurements of eosinophil percentages and of ECP levels was similar for the two methods. We conclude that separate collection of saliva and sputum yields induced sputum samples with reduced amounts of saliva and is, therefore, a better method for collecting induced sputum.
Increased expression of mRNA encoding RANTES and MCP-3 in the bronchial mucosa in atopic asthma
Authors: Powell N , Humbert M , Durham SR , Assoufi B , Kay AB , Corrigan CJ
Published: April 2003

The selective recruitment of eosinophils into the mucosal lining of the airways is a prominent feature of atopic asthma, and is believed to be an important component in the disease pathogenesis. The precise stimuli responsible for the influx of eosinophils remain unclear. Using a semiquantitative reverse transcriptase polymerase chain reaction (RT-PCR) technique, the numbers of copies (relative to the "housekeeping" gene beta-actin) of messenger ribonucleic acid (mRNA) encoding the eosinophil-active chemotactic cytokines, the factor regulated upon activation in normal T-cells expressed and secreted (RANTES) and monocyte chemotactic protein-3 (MCP-3), was measured in bronchial biopsies from atopic asthmatic patients (n = 9), and compared with atopic nonasthmatic (n = 8) and nonatopic nonasthmatic (n = 8) control subjects. In addition, further biopsies from each subject were prepared for immunohistochemistry and the numbers of activated (EG2+) eosinophils measured. The expression of RANTES mRNA was significantly elevated in the atopic asthmatic group as compared to the atopic nonasthmatic controls (p = 0.013) and the nonatopic nonasthmatic controls (p = 0.007). Similarly, the expression of mRNA encoding MCP-3 was significantly elevated in the atopic asthmatic group, relative to the atopic nonasthmatic controls (p = 0.014) and the nonatopic nonasthmatic control group (p = 0.011). Elevated RANTES and MCP-3 mRNA expression was associated with significantly increased numbers of bronchial mucosal eosinophils in the atopic asthmatic patients as compared to the atopic nonasthmatic (p = 0.03) and nonatopic nonasthmatic (p = 0.006) control subjects. In conclusion, we have identified elevated expression of messenger ribonucleic acid encoding RANTES and monocyte chemotactic protein-3 in the bronchial mucosa of atopic asthmatic patients relative to controls. These findings are compatible with the hypothesis that eosinophil-active beta-chemokines play a role in the mechanism of eosinophil recruitment to the asthmatic bronchial mucosa.
Effect of frusemide on Cl- channel in rat peritoneal mast cells
Authors: Meyer G , Doppierio S , Vallin P , Daffonchio L
Published: April 2003

Frusemide can be used as an antiasthma drug and appears to inhibit the release (conditioned by activation of Cl- channels) of mast cell proinflammatory mediators. We studied the cause of the effects of frusemide, checking its action on Cl- channels. The patch-clamp technique was used to study single-channel currents, and differences in electrical potential of the cellular membrane of rat peritoneal mast cells were measured. In inside-out configuration, outwardly-rectifying Cl- channels were identified whose conductance was 2.4/1.7 pS at positive and negative voltages. In cell-attached configuration, the open probability (Po) of the channel increased with depolarization or with the presence of cyclic adenosine monophosphate (cAMP) in the incubation medium. Po increased with a rise of cytoplasmic free calcium concentration [Ca2+] and was inhibited by 5-nitro-2-(3-phenylpropylamino)-benzoate (NPPB) and by 4-4'-diisothiocyanatoostilbene-2-2'-disulphonic acid (DIDS). These channels seem to be the main cause of mast cell Cl- conductance. Frusemide (10(-5) and 10(-3) M) did not affect Cl- channel activity when using excised patches. In cell-attached configuration experiments, the presence of frusemide (from 10(-5) to 10(-3) M) in the cell incubation medium, increasingly reduced Po (median inhibitory concentration (IC50) = 4.3 x 10(-7) M). In similar conditions, bumetanide also inhibited Po (IC50 = 5.7 x 10(-3) M). The results of this study suggest that frusemide can inhibit mast cell Cl- channels only via an indirect mechanisms, which probably involves an inhibition of a Na(+)-K(+)-2Cl- symport.
Modified epithelial cell distribution in chronic airways inflammation
Authors: Chapelin C , Coste A , Gilain L , Poron F , Verra F , Escudier E
Published: April 2003

Although airway epithelium is known to be modified during chronic respiratory diseases, epithelial cells have rarely been precisely quantified. We therefore intended to evaluate epithelial cell distribution in inflammatory airways, using a cytological approach. Nasal airway cells in 12 patients with nonallergic chronic rhinitis were sampled by brushing, quantified after cytocentrifugation and compared to those from eight controls. Cell populations were quantified after May-Grunwald Giemsa staining and alpha-tubulin immunolabelling to demonstrate ciliary differentiation. When compared to controls, rhinitis patients exhibited lower percentages of ciliated cells (59 +/- 4 versus 32 +/- 2%, respectively), and higher percentages of goblet (24 +/- 3 versus 37 +/- 2%) and basal cells (9 +/- 1 versus 18 +/- 2%). After tubulin immunolabelling, positive staining was specifically detected in cells with cilia (LC+), and in the cytoplasm of some small round cells without obvious cilia (LC-). Fewer immunolabelled cells were detected in rhinitis patients than in controls (with significantly lower percentages of LC+ and higher percentages of LC-). Nasal brushing is an effective technique for quantification of airway epithelial cells. Tubulin immunolabelling is useful to detect ciliated cells and distinguishes another cell population, possibly preciliated cells. These cytological findings suggest the presence of modifications of epithelial differentiation and proliferation, possibly related to local chronic inflammation.
Videomicroscopy of methacholine-induced contraction of individual airways in precision-cut lung slices
Authors: Martin C , Uhlig S , Ullrich V
Published: April 2003

Contraction of airways of different size can be studied in viable lung slices by videomicroscopy. However, at present, application of this technique is limited by the heterogeneous responses obtained. We investigated the use of precision-cut lung slices to examine contraction of individual airways. Lung slices of 250 +/- 20 microns were prepared from Wistar rats and cultured in a roller incubator in serum-free minimum essential medium (MEM). Under these conditions, the slices were viable for at least 70 h, as indicated by leakage of lactate dehydrogenase into the supernatant, thymidine incorporation and ciliary beating. The slices were placed in a newly developed incubation chamber and mounted by a nylon thread that was fixed to a platinum wire. The whole chamber was positioned on a microscope stage, and contraction of single airways was followed under a microscope that was coupled to a CCD-camera. Reduction in airway area was taken as an index of bronchoconstriction and was determined by a computer program. Addition of methacholine resulted in a concentration-dependent (concentration producing half the maximal effect (EC50) = 0.64 +/- 0.08 (mean +/- SD) microM; n = 64) contraction of single airways. In the presence of hydrocortisone, the EC50 was about six times greater, i.e. 3.7 +/- 0.9 microM (n = 7), and the effect of the steroid was largely abolished by propanolol (EC50 = 1.1 +/- 0.1 microM; n = 7). Airways with an area smaller than 35,000 microns2 were nearly nine times more sensitive to methacholine (EC50 = 0.1 +/- 0.03 microM; n = 20) than larger ones (EC50 = 87 +/- 0.27 microM; n = 22). We conclude that cultured precision-cut lung slices are a useful model for routine study of contraction of individual airways of various sizes. The measurements were precise and reproducible and showed that smaller airways are more sensitive to methacholine than larger ones.
Eosinophil cationic protein and immunoglobulin levels in bronchoalveolar lavage fluid obtained from patients with chronic eosinophilic pneumonia
Authors: Boomars KA , van Velzen-Blad H , Mulder PG , Koenderman L , Lammers JW , van den Bosch JM
Published: April 2003

In chronic eosinophilic pneumonia (CEP), histopathological evidence exists for the degranulation of eosinophils and the release of various toxic proteins. In vitro studies have demonstrated the degranulation of eosinophils in response to aggregated and complexed immunoglobulins. The aims of this study were to investigate: 1) whether the eosinophil cationic protein (ECP) and immunoglobulin (Ig) levels in bronchoalveolar lavage (BAL) fluid from patients with CEP are increased compared to those of healthy controls; 2) and whether a relationship is present between immunoglobulin levels and ECP levels in BAL fluid from patients with CEP. The BAL from 12 patients with CEP was selected, retrospectively, from all BAL analyses performed in our centre between 1986 and 1992. ECP levels were measured using a radioimmunoassay in BAL fluid of patients with CEP and 10 healthy controls. ECP levels and immunoglobulin levels in BAL fluid from patients with CEP were found to be elevated compared to controls (p < 0.001). A relationship was found between IgA levels and ECP levels in BAL fluid from patients with CEP (r = 0.72; p = 0.043). In conclusion, eosinophil cationic protein and immunoglobulin levels were found to be increased in bronchoalveolar lavage fluid from patients with chronic eosinophilic pneumonia. The relationship found between immunoglobulin A levels and eosinophil cationic protein levels may suggest that immunoglobulin A could be involved in the degranulation of eosinophils in chronic eosinophilic pneumonia.
Adhesion molecule expression on eosinophils in idiopathic eosinophilic pneumonia
Authors: Azuma M , Nakamura Y , Sano T , Okano Y , Sone S
Published: April 2003

Idiopathic eosinophilic pneumonia (IEP) is characterized by the accumulation of eosinophils in the alveolar spaces and the interstitium of the lung, frequently accompanied by peripheral eosinophilia. To clarify the roles of adhesion molecules of eosinophils in the pathogenesis of eosinophilic pneumonia, we analysed their expression by eosinophil and T-lymphocyte populations in peripheral blood and bronchoalveolar lavage fluid (BALF) obtained from 11 patients with eosinophilic pneumonia, using flow cytometric methods. Cell differentials in BALF showed increased numbers of eosinophils, the increase correlating with the number of activated T-lymphocytes in BALF. The expressions of CD11a (lymphocyte function-associated antigen-1 (LFA-1)), CD11b (Mac-1), CD18, CD49d (very late activation antigen-4 (VLA-4)), and CD62L (L-selectin) by eosinophils in BALF were all lower than those of eosinophils in peripheral blood. In contrast, CD54 (intercellular adhesion molecule-1 (ICAM-1)) was expressed by eosinophils in BALF, but not by those in peripheral blood. These results indicate that intercellular adhesion molecule-1 expression by eosinophils in bronchoalveolar lavage fluid but not in peripheral blood may be induced by locally activated T-cells or macrophages and may be important in the pathogenesis of idiopathic eosinophilic pneumonia.
Diverse cellular TGF-beta 1 and TGF-beta 3 gene expression in normal human and murine lung
Authors: Coker RK , Laurent GJ , Shahzeidi S , Hernandez-Rodriguez NA , Pantelidis P , du Bois RM , Jeffery PK , McAnulty RJ
Published: April 2003

A role for transforming growth factor-beta 1, (TGF-beta 1) has been proposed in lung development and in the pathogenesis of pulmonary disease. However, previous studies have not delineated the cells expressing TGF-beta 1 in normal adult lung, nor compared its gene expression with that of other TGF-beta isoforms. We used digoxigenin-labelled riboprobes to localize TGF-beta 1 and TGF-beta 3 gene expression in normal adult human and mouse lung. This procedure was technically simple, providing excellent resolution. TGF-beta 1 and TGF-beta 3 messenger ribonucleic acid (mRNA) transcripts were detected in a wide variety of cells. In human lung, mRNA for both isoforms was localized to bronchiolar epithelium and alveolar macrophages. TGF-beta 1, but not TGF-beta 3 mRNA was detected in mesenchymal and endothelial cells. In murine tissue, TGF-beta 1, mRNA was localized to bronchiolar epithelium, Clara cells, mesenchymal cells, pulmonary endothelium and alveolar cells, including macrophages. TGF-beta 3 mRNA was similarly distributed but not detected in endothelium. In summary, using a nonisotopic technique in lung tissue, we have detailed the cells expressing the transforming growth factor-beta 1 and beta 3 genes in human and murine lung. There was widespread expression of these cytokines in normal lung consistent with autocrine or paracrine roles in regulating cellular turnover, immune defence and matrix protein metabolism.
Proinflammatory effect of Pediococcus pentosaceus, a bacterium used as hay preservative
Authors: Duchaine C , Israel-Assayag E , Fournier M , Cormier Y
Published: April 2003

Bacterial cultures, such as Pediococcus pentosaceus, are used to treat hay with the objective of preventing hay heating and moulding, and thus, the development of the microbial growth which causes farmer's lung. The aim of this study was to investigate whether such bacterial cultures have the potential to induce a pulmonary inflammatory response. Mice were instilled 3 days week-1 for 3 weeks with either saline or nonviable preparations of P. pentosaceus, Saccharopolyspora rectivirgula, Lactococcus lactis (control bacteria) or with the combinations of S. rectivirgula and P. pentosaceus. P. pentosaceus induced a significant inflammatory response in the lung which was similar to that produced by S. rectivirgula. L. lactis produced a response of a lower intensity. The total number of cells in bronchoalveolar lavage were: S. rectivirgula: 6.4 x 10(5) cells.mL-1; P. pentosaceus: 4.3 x 10(5) cells.mL-1; S. rectivirgula + P. pentosaceus: 5.4 x 10(5) cells.mL-1, L. lactis: 6.8 x 10(5) cells.mL-1 and saline group 3.7 x 10(4) cells.mL-1. The lung index was higher in S. rectivirgula+P. pentosaceus and P. pentosaceus groups than in S. rectivirgula, L. lactis and saline groups. The quantity of specific immunoglobulin G and A (IgG and IgA) to P. pentosaceus and L. lactis levels (in the blood and/or lavage fluid) were similar to those against S. rectivirgula. In mice, P. pentosaceus has the potential to induce a similar inflammatory response in the lung as S. rectivirgula, which is the most common antigen responsible for farmer's lung disease in Quebec. Further studies are needed to verify whether farmers can develop farmer's lung or other lung responses to this new potential antigen.
The diagnostic value of bronchoalveolar lavage and transbronchial lung biopsy in cryptogenic organizing pneumonia
Authors: Poletti V , Cazzato S , Minicuci N , Zompatori M , Burzi M , Schiattone ML
Published: April 2003

In order to determine the diagnostic value of bronchoalveolar lavage (BAL) and transbronchial lung biopsy (TBLB) in cryptogenic organizing pneumonia (COP) a prospective study was carried out. Thirty seven consecutive patients (20 males and 17 females) with clinicoradiological features of COP were enrolled in the study. The statistical analyses were completed in 35 cases. Twenty eight patients were diagnosed to have COP, all of them with a confirmatory biopsy. In seven cases, a different diagnosis was made. BAL cytological and phenotypical criteria considered for the diagnosis of COP were: a lymphocytosis of more than 25% (with a CD4/CD8 ratio less than 0.9); combined with at least two of the following data (foamy macrophages of > 20%, and/or neutrophils of > 5%, and/or eosinophils of > 2% and < 25%). TBLB specimens were classified as positive for COP if they showed: buds of granulation tissue within the centrilobular air spaces; infiltration of alveolar walls with chronic inflammatory cells; and preservation of alveolar architecture. BAL was performed in 34 patients; 17 cases were consistent with the final diagnosis of COP (sensitivity 63%), and four cases were correctly classified as negative (specificity 57%). BAL had a positive predictive value (PPV) of 85% and a negative predictive value (NPV) of 29%. TBLB was performed in 32 patients; it correctly identified COP in 16 cases (sensitivity 64%), and six cases were correctly classified as negative (specificity 86%). TBLB had a PPV of 94% and a NPV of 40%. The accuracy of the examinations, that is the probability of correctly diagnosing both diseased and nondiseased patients by BAL or TBLB, was 62 and 69%, respectively. Our findings suggest that the combination of cytological bronchoalveolar lavage and histological transbronchial lung biopsy data obtained during a fibreoptic procedure appears to be an effective method for the initial investigation in cryptogenic organizing patients pneumonia presenting with patchy radiographic shadows.
Oxidant-antioxidant balance in alveolar macrophages from newborn rats
Authors: Delacourt C , d'Ortho MP , Macquin-Mavier I , Pezet S , Housset B , Lafuma C , Harf A
Published: April 2003

An oxidant-antioxidant imbalance in neonatal alveolar macrophages (AMs) may contribute to the increased susceptibility to lung injury described in the neonatal period. We therefore evaluated oxygen radical production by rat AMs at various postnatal ages, and measured in parallel cellular antioxidant enzyme activities. AMs were obtained by bronchoalveolar lavage from rats aged < 24 h, 21 days and 5 weeks, and results were compared to those obtained with adult rat AMs. Intracellular production of oxygen radical species, estimated fluorometrically using 2',5'-dichlorofluorescein diacetate as the substrate, was significantly reduced in neonates as compared with adults, both in the presence and in the absence of cell stimulation with phorbol myristate acetate (PMA) or opsonized zymosan. A similar pattern was observed for the extracellular release of oxygen radical species, evaluated by lucigenin-enhanced chemiluminescence (CL) or peroxidase-catalysed CL oxidation of luminol: peak CL values measured after cell stimulation with PMA or opsonized zymosan remained significantly lower for AMs from newborn rats than for AMs from adults. By contrast, high values for antioxidant enzyme activities (superoxide dismutase and glutathione peroxidase) in AMs were demonstrated in newborns as compared to adults. We conclude that high antioxidant activity in rat AMs after birth may be at least partly responsible for the low production of oxygen metabolites observed during the same period.
Surfactant apoprotein-A concentration in airway secretions for the detection of pulmonary oedema
Authors: Shimura S , Masuda T , Takishima T , Shirato K
Published: April 2003

Patients with cardiogenic pulmonary oedema expectorate foamy sputum containing surfactant, which might be expected to include surfactant apoprotein A (SP-A). SP-A is specific for lung surfactant. We have measured the SP-A concentration in airway secretions to determine whether it is useful in distinguishing pulmonary oedema from other disorders. Samples of sputum and of aspirated airway secretion were obtained from 11 patients with cardiogenic pulmonary oedema, seven patients with clinically stable congestive heart failure, five patients with adult respiratory distress syndrome (ARDS) and 20 control patients (10 intubated) with other respiratory diseases. The samples were used for the measurement of SP-A concentration by a two-site simultaneous immunoassay with monoclonal antibodies against SP-A. SP-A concentrations, measured in samples of sputum and aspirated secretions, depended on the diagnosis of the patients from which they had come. In descending order these samples came from patients with: cardiogenic pulmonary oedema (1324 +/- 197 micrograms.mL-1; n = 33); ARDS (311 +/- 47 micrograms.mL-1; n = 23); clinically stable congestive heart failure (78 +/- 10 micrograms.mL-1; n = 21); and control conditions (3.0 +/- 0.6 micrograms.mL-1; n = 30). Concentrations from disease samples did not overlap with controls. In samples from patients with cardiogenic pulmonary oedema, the SP-A concentration correlated with mean pulmonary capillary wedge pressure (PCWP) (p < 0.001; n = 39). These findings indicate that the measurement of the surfactant apoprotein A concentration in airway secretions may be useful for the detection of pulmonary oedema.
L-NAME aggravates pulmonary oxygen toxicity in rats
Authors: Capellier G , Maupoil V , Boillot A , Kantelip JP , Rochette L , Regnard J , Barale F
Published: April 2003

Exposure to high oxygen concentration leads to acute lung injury and death in rats after 72 h. The pathophysiology of this phenomenon relies on several mechanisms, including alteration of vascular reactivity, recruitment and activation of neutrophils and alveolar macrophages, production of cytokines and excess production of free radicals. In addition to its potent vasodilating effect, nitric oxide (NO) has also been reported to prevent free radical-mediated damage. We wanted to determine whether NG-nitro-L-arginine methyl ester (L-NAME), a NO synthase inhibitor, might modulate oxygen toxicity. In rats exposed to continuous high oxygen concentration, we studied the effect of administration of 50 mg.kg-1 of intraperitoneal L-NAME twice a day on the first day of oxygen exposure. L-NAME resulted in earlier death, since 57% of the animals exposed to oxygen and injected with L-NAME died within 60 h as compared to 22% of the animals exposed to oxygen and treated with saline (p < 0.01). Haematocrit and bronchoalveolar lavage fluid protein were also significantly increased in animals exposed to oxygen and receiving L-NAME. The lung water content was higher in the oxygen-exposed groups (p < 0.01) and slightly decreased by L-NAME (p < 0.05). Thiobarbituaric acid reactive substances (TBARS) were elevated in plasma (p < 0.01) and decreased in lung (p < 0.001) of oxygen-exposed animals, but no significant effect of L-NAME was observed. NG-nitro-L-arginine methyl ester had a deleterious effect in rats exposed to hyperoxia, which might suggest that endogenous nitric oxide has a protective role against hyperoxia-induced pulmonary lesions.
Airway nitric oxide in asthmatic children and patients with cystic fibrosis
Authors: Dotsch J , Demirakca S , Terbrack HG , Huls G , Rascher W , Kuhl PG
Published: April 2003

We evaluated the effects of asthma and cystic fibrosis on nitric oxide (NO) concentrations in the respiratory tract. NO levels in orally exhaled air and nasal gas samples were studied in 90 asthmatic patients (4-14 yrs), 67 patients with cystic fibrosis (CF) (5-32 yrs), and 68 controls (4-34 yrs). NO concentrations measured by chemiluminescene were correlated with the patient's vital capacity, forced expiratory volume in one second (FEV1) and specific airway resistance. In all groups, NO concentrations in orally-exhaled air correlated with the inhaled ambient NO (r = 0.85-0.91). At an ambient NO concentration of 0 parts per billion (ppb), asthmatic patients exhaled air with higher NO concentrations than cystic fibrosis patients and controls (8.0 +/- 6.1 ppb (n = 33); 4.9 +/- 2.6 ppb (n = 23); and 3.0 +/- 2.5 ppb (n = 37); respectively; p < 0.001). Similar results were obtained for ventilation-adjusted orally-exhaled NO. Nasal NO concentrations were lower in patients with CF (23 +/- 17 ppb) than in controls and asthmatics (96 +/- 47 and 103 +/- 64 ppb; p < 0.001). There was no relationship between nasal or oral NO and pulmonary function tests. Our results suggest that ambient NO levels influence NO concentrations in orally-exhaled air. Like adults, asthmatic children exhale more NO than their controls. Reduced nasal NO concentrations in patients with cystic fibrosis may reflect chronic epithelial cell damage or an increased mucosal barrier impeding NO diffusion into the airway.
Prevalence of respiratory symptoms, bronchial hyperresponsiveness and atopy among adults: west and east Germany
Authors: Nowak D , Heinrich J , Jorres R , Wassmer G , Berger J , Beck E , Boczor S , Claussen M , Wichmann HE , Magnussen H
Published: April 2003

The prevalence of respiratory symptoms, atopic sensitization and bronchial hyperresponsiveness was compared in a random sample of adults, 20-44 yrs of age, in two cities in West and East Germany, Hamburg and Erfurt, respectively. There were much higher levels of outdoor air pollution due to sulphur dioxide and suspended particulates in Erfurt, and major differences in living conditions during the last 40 yrs. Within the European Respiratory Health Survey, a short questionnaire was answered by 3,156 (80% response rate) subjects in Hamburg and 3,272 (74%) in Erfurt. A subset of responders to the short questionnaire completed a long questionnaire, spirometry, methacholine or bronchodilator test, skin test, and total and specific immunoglobulin E (IgE) measurements, with a total number of 1,159 participants in Hamburg and 731 in Erfurt. Six out of 8 questions on respiratory symptoms and diagnoses were answered in the affirmative more frequently in Hamburg than in Erfurt. In Hamburg, mean forced expiratory volume in one second (FEV1)% of predicted was 105 vs 107% in Erfurt (p < 0.0001), and bronchial hyperresponsiveness was more frequently observed in Hamburg than in Erfurt (25 vs 19%; p < 0.05). Atopic sensitization was more prevalent in Hamburg than in Erfurt regarding the results of skin tests against grass pollen (24 vs 19%; p < 0.05), birch pollen (19 vs 8%; p < 0.0005), cat (10 vs 2%; p < 0.0005), and Dermatophagoides pteronyssinus (14 vs 10%; p < 0.05). This was reflected by the prevalences of positive specific IgE values, which were higher in Hamburg than in Erfurt for grass (26 vs 20%; p < 0.05), birch (20 vs 10%; p < 0.0005) and cat (12 vs 8%; p < 0.05). In Hamburg, compared to Erfurt, there was: a lower mean number of siblings (p < 0.005); a higher degree of childhood and current exposure to environmental tobacco smoke (p < 0.005); and a higher frequency of fitted carpets and reported mould or mildew inside the house (p < 0.005). Therefore, these data may support the hypothesis that childhood factors and exposure to indoor allergens and irritants may have been more relevant for the development of asthma and atopy than the potential long-term exposure to high concentrations of sulphur dioxide and particulate matter.
Effect of hemithorax irradiation alone or combined with doxorubicin and cyclophosphamide in 47 pleural mesotheliomas: a nonrandomized phase II study
Authors: Linden CJ , Mercke C , Albrechtsson U , Johansson L , Ewers SB
Published: April 2003

In order to assess the value of radiotherapy in the treatment of pleural mesotheliomas, we studied tumour response and survival after hemithorax irradiation alone (RT), or radiotherapy combined with doxorubicin and cyclophosphamide chemotherapy (RTCT). Forty seven patients with pleural mesotheliomas received irradiation of the diseased hemithorax at 8 MV (megavolt) photons to a total dose of 40 Gy, administered in 20 daily fractions of 2 Gy for 5 days a week. One month after RT, patients aged < or = 70 yrs with a good performance status were offered supplementary chemotherapy (CT) with doxorubicin 30 mg.m-2 body surface on Day 1 and Day 8, combined with cyclophosphamide 600 mg.m-2 on Day 1, in cycles of 21 days. Tumour response was evaluated by computed axial tomography (CAT) before and 1 month after RT and/or CT. Only 3 of the 47 (95% confidence interval (95% CI)-0.6-13%) irradiated tumours responded with a partial response (PR). In 31 patients treated with RT alone, one PR was observed; whereas, in the combined treatment group, 2 out of 16 responded with PR to RT. CT with doxorubicin and cyclophosphamide induced only 2 out of 16 PRs (95% CI -3.4-28.4%), and the combined treatment consisting of RT followed by CT induced 2 out of 16 PRs. The median survival following the initiation of RT was 7 months in all patients (n = 47), 6 months in the RT group (n = 31), and 13 months in the combined RTCT group (n = 16). Chest pain, performance status and body weight were not favourably affected by the radiotherapy. We conclude that hemithorax irradiation of pleural mesotheliomas with a moderately high dose is not useful, since it produces no improvement in chest pain, few objective tumour responses and no prolongation of survival.
Pulmonary gas exchange in elderly subjects
Authors: Guenard H , Marthan R
Published: April 2003

Although important alterations in structure and function develop with age, the hypothesis that the lungs are capable of maintaining adequate gas exchange for the maximum human life span is generally accepted. This hypothesis was examined by measuring arterial oxygen and carbon dioxide tension (Pa,O2 and Pa,CO2) alveolo-arterial differences in oxygen and carbon dioxide tension (PA-a,O2 and Pa-A,CO2), steady state transfer capacity of the lung for carbon monoxide (TL,CO,ss) as well as the gas exchange ratio (R) in a series of 74 healthy subjects aged more than 68 yrs (69-104 yrs). In addition, Pa,O2 and Pa,CO2 were measured in a series of 55 young healthy subjects, who acted as controls. In the elderly subjects, except for TL,CO,ss, there was no significant correlation between any of the other variables and age. However, for a given Pa,CO2, Pa,O2 was always lower in the group of elderly subjects than in the group of young control subjects. TL,CO,ss, as well as TL,CO,ss/minute ventilation (V'k) ratio, was correlated with age, according to the following regression equations: TL,CO,ss (mL.min-1.kPa-1) = 126-0.90 x age (yrs), and TL,CO,ss/V'k (kPa-1 x 10(3)) = 13.5-0.085 x age, respectively. These results show that arterial oxygen tension did not decrease with age in this series of elderly subjects. However, the decrease in steady-state transfer capacity of the lungs for carbon monoxide with age indicates that oxygen transport could be diffusion-limited in elderly subjects, at least when oxygen consumption is increased.
Analysis of the double occlusion which provides four pressure gradients
Authors: Hakim TS , Sugimori K , Ferrario L
Published: April 2003

The arterial, double and venous occlusions are used to partition pulmonary vascular resistance into four segments. In this study, we tested whether the same can be accomplished from one double occlusion. In an isolated canine lung left lower lobe perfused with blood (flow rate = 500 mL.min-1), the pulmonary arterial and venous pressures (Pa and Pv, respectively) were measured directly. Arterial, double, and venous occlusions were performed and analysed as usual (Method 1) to measure pressures in small arteries and small veins (Pa' and Pv', respectively) and capillary pressure (Pc). Alternatively, one double occlusion was analysed (Method 2), not only for Pa, Pv and Pc, but also as independent arterial and venous occlusions to measure Pa' and Pv'. Method 1 yielded Pa, Pa', Pc, Pv', and Pv (Baseline) of 14.2 +/- 1.7, 10.8 +/- 1.6, 8.9 +/- 1.9, 7.3 +/- 1.5 and 1.3 +/- 0.6 mmHg, respectively (1 mmHg = 0.133 kPa). Method 2 yielded values for the same five pressures equal to 14.7 +/- 2.1, 11.0 +/- 2.2, 8.9 +/- 1.9, 7.3 +/- 1.3 and 1.3 +/- 0.6 mmHg, respectively. There was no significant difference in the pressure profile obtained using the two methods, nor were there differences during hypoxia and angiotensin infusion. These results suggest that a more thorough analysis of the double occlusion can provide the same information about distribution of vascular resistance as provided by a combination of the three occlusions. The advantage of the new approach is that fewer occlusions are needed and resistance distribution can be assessed during a transient response. Because all pressures are derived from one occlusion, the pressures would be more accurate relative to each other.
Oxygen saturation during daily activities in chronic obstructive pulmonary disease
Authors: Soguel Schenkel N , Burdet L , de Muralt B , Fitting JW
Published: April 2003

Patients with chronic obstructive pulmonary disease (COPD) frequently develop nocturnal oxygen desturation because of alveolar hypoventilation, worsening of ventilation-perfusion mismatch, and sometimes obstructive sleep apnoeas. In contrast, little is known about their oxygen status during the various activities of daily life. The aim of this study was to compare the oxygen saturation profile during day and night, and to assess the influence of different daily activities in COPD. During a rehabilitation programme, we studied 30 patients with moderate-to-severe COPD (median forced expiratory volume in one second (FEV1) 37% of predicted), without marked hypoxaemia (median arterial oxygen tension (Pa,O2) 9.1 kPa). Arterial oxygen saturation (Sa,O2) was assessed by pulse oximetry during night (8 h) and day (10.5 h). The mean and minimal Sa,O2 were calculated, and desaturations were defined as Sa,O2 falls > 4%.h-1. Daily activities were identified by the patients as resting, eating, washing, nebulization therapy and walking. Mean Sa,O2 was lower during the night (88%) than during the day (89%). In contrast, minimal Sa,O2 was lower during the day (69%) than during the night (72%), and the number of desaturations was higher during the day (8.6 desaturations.h-1) than during the night (6.8 desaturations.h-1). Mean Sa,O2 was 88% during walking, which was lower than during resting (90%), nebulization (90%), and meals (89%). The number of desaturations was higher during walking (13.1 desaturations.h-1), washing (12.6 desaturations.h-1), and eating (9.2 desaturations.h-1) than during resting (5.3 desaturations.h-1). We conclude that daily activities, such as walking, washing and eating, are associated with transient oxygen desaturation in patients with moderate-to-severe chronic obstructive pulmonary disease, even without marked resting hypoxaemia.
Diagnostic accuracy of a portable recording device (MESAM IV) in suspected obstructive sleep apnoea
Authors: Esnaola S , Duran J , Infante-Rivard C , Rubio R , Fernandez A
Published: April 2003

This study evaluated the accuracy of a portable recording device (MESAM IV) in identifying obstructive sleep apnoea (OSA). The MESAM IV system measures arterial oxygen saturation (Sa,O2), heart rate, snoring sounds and body position, and allows both automatic and manual scoring of the recordings. Nocturnal polysomnography and MESAM IV recordings were performed simultaneously in 150 patients with suspected OSA, and were analysed blindly by a different observer. Patients with an apnoea-hypopnoea index (AHI) greater than or equal to 10 were diagnosed as having OSA. In the evaluation of the discriminatory ability of MESAM IV scores, the cut-off point was set to minimize first the exclusion of truly diseased patients (i.e. false-negative interpretations), and then confirmation of nondiseased subjects (i.e. false-positives). When used as an exclusion test, the portable device reached a sensitivity of 0.98 and a specificity of 0.78; as a confirmation test, these values were 0.69 and 0.97, respectively. These results were achieved with manual scoring, which was superior to automatic scoring. Manual scoring was also better than automatic scoring when OSA was defined according to other threshold values (> or = 5, 15 and 20) for the AHI. The combination of MESAM IV manual scores could reduce the need for diagnostic polysomnography in three quarters of the patients clinically suspected of having obstructive sleep apnoea, substantially reducing costs associated with diagnostic procedures.
Risk of traffic accidents in patients with sleep-disordered breathing: reduction with nasal CPAP
Authors: Cassel W , Ploch T , Becker C , Dugnus D , Peter JH , von Wichert P
Published: April 2003

Sleepiness whilst driving constitutes a road safety risk. Sleep-related breathing disorders are the most frequent medical cause of daytime sleepiness, and untreated patients with this condition have been shown to be at a higher risk of having accidents while driving. This study addressed the question of the extent to which treatment of sleep-disordered breathing by nasal continuous positive airway pressure (nCPAP) is related to changes in patient's accident risk. Seventy eight male patients requiring treatment of sleep-related breathing disorders with nCPAP were enrolled in the study. The protocol included a questionnaire dealing with alertness-related problems while driving, an 80 min vigilance test, and the Multiple Sleep Latency Test. These baseline evaluations were repeated after 1 year of treatment with nCPAP. Fifty nine patients completed the study. The accident rate was significantly decreased from 0.8 per 100,000 km (untreated) to 0.15 per 100,000 km with nCPAP treatment. Variables that were considered to be likely to increase accident risk (sleeping spells, fatigue, vigilance test reaction time, daytime sleep latency) also improved with treatment. We conclude that treatment of sleep-disordered breathing by nasal continuous positive airway pressure is related to reduction in patient motor vehicle accident rates, probably due to the reversal of excessive daytime sleepiness.
Home dampness, moulds and their influence on respiratory infections and symptoms in adults in Finland
Authors: Pirhonen I , Nevalainen A , Husman T , Pekkanen J
Published: April 2003

The aim of this study was to analyse the prevalence of mouldy homes and their association with respiratory symptoms and diseases in a subarctic climate. A questionnaire was mailed to a random sample of 2,000 males and females, aged 25-64 yrs, living in the county of Kuopio, Finland. A total of 1,521 (76%) responded and 1,460 were selected for the final analysis. The prevalence of homes with visible mould was 4%; with the odour of mould 5%; with damp spots, visible mould or the odour of mould 15%; and with moisture/ water damage, damp spots, visible mould or the odour of mould 23%. The number of reports of bronchitis, common cold, atopy, allergic rhinitis, rhinitis, fever and chills, hoarseness, fatigue, difficulties in concentration, lumbar backache and stomach ache were strongly associated with living in a damp home. Bronchitis, hoarseness and difficulties in concentration had the strongest associations, with adjusted odds ratios (95% confidence limits) of: 2.04 (1.49-2.78), 2.23 (1.37-3.63) and 2.17 (1.35-3.50), respectively. After controlling for a possible reporting bias by excluding those subjects reporting lumbar backache and recurrent stomach pain, eye irritation and tiredness remained significant. In conclusion, living in a home with mould problems may increase the risk of respiratory infections and symptoms in adults.