bluuebunny/crossref_metadata_2025 huggingface dataset:
Osmotic responses of unicellular blue‐green algae (cyanobacteria): changes in cell volume and intracellular solute levels in response to hyperosmotic treatment
Authors: REED R. H. , RICHARDSON D. L. , STEWART W. D. P.
Published: April 2006

Abstract Changes in cell volume and solute content upon hyperosmotic shock have been studied for six unicellular blue‐green algae (cyanobacteria): Synechococcus PCC 6301, PCC 6311; Synechocystis PCC 6702, PCC 6714, PCC 6803 and PCC 7008. The extent of change in volume was shown to be dependent upon the solute used to establish the osmotic gradient, with cells in NaCl showing a reduced shrinkage when compared to cells in media containing added sorbitol and sucrose. Uptake of extracellular solutes during hyperosmotic shock was observed in Synechocystis PCC 6714, with maximum accumulation of external solutes in NaCl and minimum solute uptake in sucrose solutions. Conversely, solute loss from the cells (K+ and amino acids) was greatest in sucrose‐containing media and least in NaCl. The results show that these blue‐green algae do not behave as ‘ideal osmometers’ in media of high osmotic strength. It is proposed that short‐term changes in plasmalemma permeability in these organisms may be due to transient membrane instability resulting from osmotic imbalance between the cell and its surrounding fluid at the onset of hyperosmotic shock.
Local climate, topography and plant growth in Lathkill Dale NNR. II. Growth and nutrient uptake within a single season
Authors: RORISON I. H. , GUPTA P. L. , HUNT R.
Published: April 2006

Abstract In a 30‐week field experiment, observations on growth and nutrient uptake in potted plants were made concurrently with soil and air temperatures on north‐ and south‐facing slopes. Parallel observations were also made in a controlled environment. Growth in the field was slow but steady, declines in shoot weight fraction with time being matched by increases in rate of dry weight increment per unit of shoot. Increases in root weight fraction, however, failed to match low and declining rates of nitrogen uptake per unit of root; hence, nutrient concentrations generally declined with time. Thermal time in the form of degree‐day integrals above the base 3°C was found to correlate well with growth, each degree day contributing a 0.16% increase in total dry weight, on average. Soil, locational and moisture effects caused this average to vary ca. two‐fold in either direction.
Visualization of mitochondria and nuclei in living plant cells by the use of a potential‐sensitive fluorescent dye
Authors: MATZKE M. A. , MATZKE A. J. M.
Published: April 2006

Abstract Cationic potential‐sensitive dyes have previously been used to selectively stain mitochondria in living animal cells (Johnson, Walsh & Chen, 1980; Johnson et al., 1981). The present work demonstrates that the cyanine dye 3,3′‐dihexyloxacarbocyanine iodide (DiOC6(3)) can also be used as a mitochondrial stain in living plant cells. The stained mitochondria were easily visualized by fluorescence microscopy. The accumulation of DiOC6(3) in mitochondria seemed to be potential‐dependent since it was prevented by protonophores, valinomycin and inhibitors of electron transport. It was often observed that DiOC6(3) also stained the nuclear membrane of some cells. This fluorescence, limited to the perinuclear region, was possibly due to a potential across one or both nuclear membranes, although it was not completely dissipated by any of the ionophores or inhibitors tested. Our observations demonstrate the usefulness of using DiOC6(3) for studying relative membrane potentials of plant mitochondria and, perhaps, other organelles and membrane systems in living plant cells.
Characterization of alternating‐temperature regimes that remove seed dormancy in seeds of Brachiaria humidicola (Rendle) Schweickerdt
Authors: GOEDERT C. O. , ROBERTS E. H.
Published: April 2006

Abstract Seeds of Brachiaria humidicola were subjected, on a thermogradienl plate, to a wide range of alternating‐temperature cycles (24 h) and constant temperatures with intermittent exposure to diffuse laboratory light, in the presence and absence of 10 mol m−3 KNOV The optimum regime for maximum percentage germination was alternating temperatures of 35°C for 4hd−1 and 13°C for 20 hd−1. Almost no germination occurred at any constant temperature. Thermoperiods in which the warmer temperature was applied for the longer part of the 24 h cycle were much less stimulatory; in the presence of KNO3, however, the germination under such regimes was much improved, although there was little effect on seeds experiencing near‐optimum alternating‐temperature regimes. This investigation is the first step in identifying which of 10 attributes of alternating temperatures are stimulatory, in order to predict the efficacy of different temperature regimes and to identify the stimulatory characteristics that must ultimately be explained by cellular physiology. The work shows that amplitude, thermoperiod and mean temperature must all be incorporated in a quantitative model.
Prolonged chilling under moderate light: effect on photosynthetic activity measured with the photoacoustic method
Authors: D YAKIR  , RUDICH J. , BRAVDO B. A. , MALKIN S.
Published: April 2006

Abstract Exposure of tomato plants to a mild chilling temperature and relatively low ambient photon flux density for an extended period (10°C and 400 μmol photons m−2 s−1 d and 5°C night for 6 d) resulted in a significant decrease in the variable chlorophyll fluorescence, the quantum yield of oxygen evolution and the amount of total absorbed energy stored in photochemical intermediates, but not in the chlorophyll concentration or in the activity of ribulose biphosphate carboxylase. These results indicate that photochemical processes involving PSII were affected, and might reflect photoinhibitory effects on the photosynthetic apparatus.

Chilling treatment had relatively small influence on the maximal extent of the Emerson effect. This observation, together with the sharp decrease found in the quantum yield of oxygen evolution, could be reconciled with the above results only if some dependency between the two photosystems was assumed. On the basis of this interpretation, it was concluded that the strong Emerson effect after chilling still reflects the typical imbalance between PSI and PSII centres, even though populations of such unaffected pairs are smaller than in the untreated plants.

The relatively new photoacoustic technique employed in this study is shown to be useful both as a diagnostic tool and as a means of investigating changes in photochemical activity in the study of environmental stress effects on photosynthesis. The results support the view that photoinhibition can play an important role in limiting photosynthetic activity, and therefore productivity, in chilling‐sensitive plants such as the tomato under the natural conditions that prevail during the winter in mediterranean climates.
Photoperiod and photosynthetic capacity in Lotus scoparius
Authors: COMSTOCK J. , EHLERINGER J. R.
Published: April 2006

Abstract Leaves of Lotus scoparius Nutt., a Mediterranean‐climate shrub, exhibited higher photosynthetic capacities when grown under winter (10/14 h, day/night) than summer (14/10 h) photo‐periods, even though total daily photon irradiance was higher under summer photoperiods. Photosynthetic dependence on natural variations in photo‐period, such that activity was higher under photo‐periods associated with expected precipitation, may be a more dependable environmental parameter than total irradiance in temperate habitats with winter‐spring precipitation patterns and where seasonal cloudiness may cause total daily irradiance levels to be highly variable.
Low‐molecular‐weight heparin (enoxaparin) as adjuvant therapy in the treatment of active ulcerative colitis: a randomized, controlled, comparative study
Authors: ZEZOS P. , PAPAIOANNOU G. , NIKOLAIDIS N. , PATSIAOURA K. , PAPAGEORGIOU A. , VASSILIADIS T. , GIOULEME O. , EVGENIDIS N.
Published: April 2006

Background

Heparin could be beneficial to the treatment of active ulcerative colitis because of its anticoagulant, anti‐inflammatory and immunomodulatory properties.

Aim

To evaluate the tolerability, safety and efficacy of low‐molecular‐weight heparin as adjuvant therapy in patients with active ulcerative colitis.

Methods

Thirty‐four adult patients with active ulcerative colitis were consecutively included in a prospective, randomized, comparative study, and were treated for 12 weeks. Eighteen patients in the ‘standard therapy’ group were treated with aminosalicylates and weekly tapered corticosteroids. Sixteen patients in the ‘heparin therapy’ group were treated with standard therapy plus enoxaparin 100 Anti‐Xa IU/kg/day subcutaneously.

Results

Seventeen patients in the ‘standard therapy’ group and 15 patients in the ‘heparin therapy’ group completed the study. Tolerability and compliance to therapy were excellent and no withdrawals were noted because of complications. There was a significant improvement in the disease severity in both groups (P < 0.001), without any difference between them (P = not significant). Both treatment groups showed similar proportions of disease improvement (65% and 73%, respectively; P = not significant). There were no significant differences in inflammation (fibrinogen, ESR, CRP) and coagulation (thrombin–antithrombin complex, F1 + 2, D‐dimers) parameters during and at the end of the study between treatment groups.

Conclusion

Adjuvant administration of low‐molecular heparin in patients with active ulcerative colitis is safe and well tolerated, but no additive benefit over standard therapy for ulcerative colitis was noted.
Bioavailability and therapeutic activity of alicaforsen (ISIS 2302) administered as a rectal retention enema to subjects with active ulcerative colitis
Authors: MINER P. B. , GEARY R. S. , MATSON J. , CHUANG E. , XIA S. , BAKER B. F. , WEDEL M. K.
Published: April 2006

Background

Alicaforsen is a phosphorothioate‐modified antisense oligodeoxynucleotide designed to sequence‐specifically reduce intercellular adhesion molecule 1 messenger RNA levels.

Aims

To determine the systemic and local bioavailability of alicaforsen, and its activity when administered as a once daily enema in subjects with active ulcerative colitis.

Methods

An open‐label study was conducted to assess the relative absorption (local and systemic pharmacokinetics) and pharmacologic activity of alicaforsen enema in subjects with active ulcerative colitis. Fifteen subjects received nightly enemas of alicaforsen (240 mg) for a treatment period of 6 weeks. Alicaforsen concentrations in plasma and colonic tissue biopsies were determined. Disease activity index and multiple measurements including endoscopy were used to assess alicaforsen activity in these subjects.

Results

Plasma concentrations of parent alicaforsen represented < 0.6% mean bioavailability when compared with historical intravenous area under the plasma concentration–time curves. Concentrations of the intact oligonucleotide in mucosal colonic tissue biopsies were orders of magnitude higher than those observed in plasma. A 46% reduction in mean Disease Activity Index and 33% rate of remission as defined by complete mucosal healing were observed at the end of treatment.

Conclusion

These data confirm that alicaforsen enema provides local treatment for a local disease with little meaningful systemic exposure.
The impact of low‐dose aspirin on endoscopic gastric and duodenal ulcer rates in users of a non‐selective non‐steroidal anti‐inflammatory drug or a cyclo‐oxygenase‐2‐selective inhibitor
Authors: GOLDSTEIN J. L. , LOWRY S. C. , LANZA F. L. , SCHWARTZ H. I. , DODGE W. E.
Published: April 2006

Background

The effect of low‐dose aspirin on endoscopic ulcer incidence in cyclo‐oxygenase‐2‐selective inhibitor or non‐selective non‐steroidal anti‐inflammatory drug users remains controversial.

Aim

To compare prospectively the incidence of endoscopic ulcers in healthy subjects receiving low‐dose aspirin plus celecoxib or naproxen.

Methods

In this double‐blind, placebo‐controlled, 1‐week study, subjects (50–75 years) were randomized to receive aspirin 325 mg o.d. plus either celecoxib 200 mg o.d., naproxen 500 mg b.d., or placebo. Baseline and end of study endoscopies were performed. The primary end point was incidence of one or more gastric and duodenal ulcers.

Results

A lower incidence of gastric and duodenal ulcers was seen in celecoxib/aspirin‐treated subjects (19%) vs. naproxen/aspirin (27%; RR: 0.63, 95% CI: 0.44–0.92). Both naproxen/aspirin and celecoxib/aspirin groups demonstrated a higher incidence of gastric and duodenal ulcers vs. placebo/aspirin (8%; RR: 3.7, 95% CI: 1.8–7.6 and RR: 2.6, 95% CI: 1.2–5.8, respectively).

Conclusions

Fewer endoscopic ulcers were observed in patients treated with celecoxib/aspirin vs. naproxen/aspirin. However, celecoxib/aspirin was associated with a significantly higher incidence of gastric and duodenal ulcers than aspirin alone. Further studies are required to determine the generalizability of these findings in the aspirin users and to determine the appropriate strategy to minimize risk in susceptible patients.
Review article: oesophageal spasm – diagnosis and management
Authors: TUTUIAN R. , CASTELL D. O.
Published: April 2006

Oesophageal spasm is a common empiric diagnosis clinically applied to patients with unexplained chest pain. In contrast it is an uncommon manometric abnormality found in patients presenting with chest pain and/or dysphagia and diagnosed by ≥20% simultaneous oesophageal contractions during standardized motility testing.

Using Medline we searched for diagnostic criteria and treatment options for oesophageal spasm.

While the aetiology of this condition is unclear, studies suggest the culprit being a defect in the nitric oxide pathway. Well‐known radiographic patterns have low sensitivities and specificities to identify intermittent simultaneous contractions.

Recognizing that simultaneous contractions may result from gastro‐oesophageal reflux this diagnosis should be investigated or treated first. Studies have documented improvements with proton‐pump inhibitors, nitrates, calcium‐channel blockers and tricyclic antidepressants or serotonin reuptake inhibitors. Small case series reported benefits after botulinium toxin injections, dilatations and myotomies.

Uncertainties persist regarding the optimal management of oesophageal spasm and recommendations are based on controlled studies with small numbers of patients or on case series. Acid suppression, muscle relaxants and visceral analgetics should be tried first. Botulinum toxin injections should be reserved for patients who do not respond. Pneumatic dilatations or myotomies represent rather heroic approaches for non‐responding patients.
Specific humoral immune responses in 12 cases of food sensitization to sesame seed
Authors: KOLOPP‐SARDA M. N. , MONERET‐VAUTRIN D. A. , GOBERT B. , KANNY G. , BRODSCHII M. , BENE M. C. , FAURE G. C.
Published: April 2006

Background
Hypersensitivity to sesume seeds is becoming increasingly frequent, probably owing to the larger use of this compound in international food.

Objectives
This study investigated serum responses of 12 sesame sensitized patients (seven with food allergy, five with food sensitization), to a sesame protein extract, and attempted at identifying sesame major antigens.

Methods
Sesame protein extracts were prepared from black, white and brown sesame seeds. Electrophoretic analysis showed similar protein patterns in the three extracts, and proper preservation of the proteins integrity. The brown sesame extract was used to set‐up an ELISA assay and measure serum levels of antisesame IgG, IgA, IgM and IgE in 12 samples from sesame‐sensitized individuals and six controls. It also allowed to perform western blot analyses in order to investigate the molecular weight of sesame proteins recognized by IgG, IgA and IgE.

Results
Nineteen protein bands were observed upon polyacrylamide gel electrophoresis of the sesame protein extracts. Using this whole extract in ELISA, significant antisesame IgG. IgA and IgE‐responses were observed in the serum of sensitized individuals, different from the lower signals obtained with control samples. Western blot analysis demonstrated highly polymorphic IgG and IgA responses and a more restricted IgE response pattern, suggesting that two proteins, respectively. 14kDa and 25 kDa are mostly involved in sesame IgE‐dependent hypersensitivity, the 25 kDa band presenting several characteristics of a major allergen.

Conclusions
This study reports novel information on the possible involvement of a 25 kDa sesame protein in IgE‐dependent hypersensitivity to sesame seeds.
Cloning and high level expression of Cynodon dactylon (Bermuda grass) pollen profilin (Cyn d 12) in Escherichia coli: purification and characterization of the allergen
Authors: ASTURIAS J. A. , ARILLA M. C. , GOMEZ‐BAYON N. , MARTINEZ J. , MARTINEZ A. , PALACIOS R.
Published: April 2006

Background
Profilin, an actin‐binding protein, was previously described as a panallergen which is involved in about 20% of Ihe crossreactivity found among pollen and food allergic patients. This allergen is usually under‐represented in natural extracts used for allergy diagnosis.

Objectives
To obtain an immunologically active and soluble recombinant profilin from Cynodon dactylon pollen which could be used for diagnostic and therapy.

Methods
Isolation of cDNA clones was performed by polymerase chain reaction amplification using degenerate primers. Expression in Eschehchia coli BL21 (DE3) was carried out using vector pKN172, and the expressed product was isolated by affinity chromatography on poly L‐proline‐Sepharose.

Results
Four cDNA inserts coding for Cynodon dactylon (Bermuda grass) pollen profilin (Cyn d 12) were cloned and sequenced. Full‐length C. dactylon profilin gene was expressed in Escherichia coli as non fusion protein. Induced cells could produce high amounts of recombinant Cyn d 12, and after a single purification step on poly (L‐proline)‐Sepharose, up to 45 mg of pure allergen per litre culture could be obtained. The reactivity of recombinant Cyn d 12 with IgE antibodies present in sera from Bermuda grass‐allergic patients is comparable to that of the natural Bermuda grass allergen. Recombinant Bermuda grass pollen profilin was shown to share B‐epitopes with sunflower prolilin.

Conclusions
Our results showed that this heterologous expression system and purification procedure are suitable for the production of large amounts of pure allergen which can be used for the characterization of allergenic epitopes recognized by T and B cells and finally for diagnostic and therapeutic purposes.
Immunolocalization of cytokines to mast cells in normal and allergic conjunctiva
Authors: MACLEOD J. D. A. , ANDERSON D. F , BADDELEY S. M. , HOLGATE S. T. , MCGILL J. I. , ROCHE W. R.
Published: April 2006

Background
Recently, the potential role of mast cells in allergic reactions has been extended by the discovery that these cells synthesize, store and secrete multifunctional cytokines. Seasonal allergic conjunctivitis is characterized as an immediate hypersensitivity reaction, in which allergen binds to specitic IgE on mast cells, leading to release of preformed and newly synthesized inflammatory mediators.

Objective
In this study we aimed to localize the cytokines IL‐4, IL‐5, IL‐6, IL‐8 and TNFα to conjunctival mast cells and lo examine the relationship between mast cell‐associated ctokines and allergic conjunctivitis.

Methods
Immunobistochemistry was perfonned on serial sections of conjunctival biopsies from patients with seasonal allergic conjunctivitis, in and out of tbe hay fever season, as well as from non‐allergic volunteers.

Results
IL‐4, IL‐5, IL‐6 and TNFα were localized to mast cells in normal and allergic conjunctiva. IL‐8 was localized to mast cells in two patients with seasonal allergic conjunctivitis, one during and the other outside the pollen season. Using the monoclonal antibody 3H4, which identifies the secreted form of IL‐4, biopsies frotn patients with active seasonal allergic conjunctivitis contained a significantly bigher proportion of mast cells positive for IL‐4. than those from out‐of‐season patients (P= < 0.016). There was no difference between the two groups in the number of mast cells immunostained by the antibody 4D9 which identifies the stored form of IL‐4.

Conclusions
These results suggest that conjunctival mast cells can store a range of multifunctional cytokines and release IL‐4 during active disease, which may give them an important role in upregulating allergic inflamtnation in the conjunctiva.
A new role for interleukin‐7 in the induction of LFA‐1 and VLA‐4 adhesion molecules in Phorbol 12myristate 13acetate activated CD4+CD23+ T‐cell subset
Authors: FRATAZZI C. , CARINI C.
Published: April 2006

Background
The low affinity receptor for IgE, CD23, has been described in several pathological conditions. However, the factors involved in the upregulation or downregulation of this receptor are still debated.

Methods and Results
We studied the effect of interleukin 7 (IL‐7) on the expression of CD23 in normal PBT cells stimulated with PMA + Ca2. The data indicate that activated PB‐T cultured in the presence of IL‐7 showed an increased expression of CD23. The induction of IL‐7 on CD23 production appears to be independent of IL‐2, IL‐4, IL‐9, IL‐15. Indeed, the addition of specific MoAbs anti‐IL‐2, IL‐4, IL‐9, IL‐15 oranti‐IL2R was unable to block the effect of IL‐7 on CD23. The addition of IL‐7 to a specific subset CD4+CD23+ was able to augment the adhesiveness of T cells to parenchymal cell monalayers. The use of different cytokine (IL‐2, IL‐4, IL‐9, IL‐15) resulted in no increase of adhesiveness. In contrast the addition of IL‐7 to a different T‐cell subset (i.e. CD4+CD23‐) was unable to rescue the lack of adhesiveness observed in these cells. Blocking experiments with MHM6 MoAb were able to drastically reduce the adhesiveness observed in CD4+FCD23+ subsets. The presence of LFA‐1 and VLA‐4 adhesion molecules were responsible for the augmented adhesiveness of activated CD4+CD23+ T cells cultured in the presence of IL‐7. Blocking experiments with anti‐LFA‐1, VLA‐4. anti‐LFA‐1β plus VLA‐4α MoAbs or anti‐ICAM‐1 MoAb added to the monolayers resulted in a complete inhibition of adhesion to parenchymal monolayers. In contrast, the addition of anti‐IL‐7 oranti‐IL‐7R MoAbs were able to block the augmented adhesiveness of CD4+CD23+ cells to monolayers observed in the presence of IL‐7.

Conclusions
Taken together these findings point to the likelihood that IL‐7 is responsible for the observed quantitative difference in the level of adhesion molecules and may open a new role of CD23 in the immune regulation.
Human antibody responses of patients living in endemic areas for schistosomiasis to the tegumental protein Sm29 identified through genomic studies
Authors: Cardoso F C , Pacífico R N A , Mortara R A , Oliveira S C
Published: April 2006

Surface proteins of schistosomes are exposed to host tissues and thus present as potential candidate molecules for the development of new intervention strategies. Herein, we have identified a new tegumental protein of Schistosoma mansoni, termed Sm29. In silico analysis revealed a signal peptide, three glycosylation sites and a transmembrane region on Sm29 amino acid sequence. Sm29 transcription in mammalian developmental stages cDNA libraries of S. mansoni was verified by PCR using specific primers for Sm29 nucleotide sequence and it revealed the presence of transcripts in schistosomula and adult worm stages of the parasite. Sm29 (40–169) fragment was produced in Escherichia coli and purified by affinity chromatography to be used in the immunological assays. Confocal microscopy confirmed bioinformatic studies, revealing that Sm29 is a membrane-bound protein localized on the tegument of S. mansoni adult worm. ELISA was performed using rSm29 protein to investigate the antibody isotype profile to Sm29 in sera of patients living in endemic areas for schistosomiasis. IgG1 and IgG3 subclass antibodies to rSm29 were predominant in sera of individuals naturally resistant to infection and resistant to re-infection whereas low levels of IgM, IgA or IgE were measured. Since, IgG1 and IgG3 are involved in parasite killing and in protective immunity the findings reported here suggest the use of Sm29 as a potential candidate vaccine against schistosomiasis.
Induction of CXC chemokines in A549 airway epithelial cells by trypsin and staphylococcal proteases − a possible route for neutrophilic inflammation in chronic rhinosinusitis
Authors: Sachse F , Von Eiff C , Stoll W , Becker K , Rudack C
Published: April 2006

While various microorganisms have been recovered from patients with chronic rhinosinusitis, the inflammatory impact of virulence factors, in particular proteases from Staphylococcus aureus and coagulase negative staphylococci on the nasal epithelium, has not yet been investigated. Expression of CXC chemokines was determined in the epithelium of patients with chronic rhinosinusitis by immunohistochemistry. In a cell culture system of A549 respiratory epithelial cells, chemokine levels were quantified by enzyme-linked immunosorbent assay (ELISA) after stimulation with supernatants originating from three different staphylococcal strains or with trypsin, representing a serine protease. Inhibition experiments were performed with prednisolone, with the serine protease inhibitor 4-(2-aminoethyl)-benzenesulphonylfluoride (AEBSF) and with the nuclear transcription factor (NF)-κΒ inhibitor (2E)-3-[[4-(1,1-dimethylethyl)phenyl]sulphonyl]-2-propenenitrite (BAY) 11–7085. Electromobility shift assays (EMSA) were used to demonstrate NF-κB-dependent protein synthesis. CXC chemokines interleukin (IL)-8, growth-related oncogene alpha (GRO-α) and granulocyte chemotactic protein-2 (GCP-2) were expressed in the patients’ epithelium whereas epithelial cell-derived neutrophil attractant 78 (ENA-78) was rarely detected. In A549 cells, chemokines IL-8, ENA-78 and GRO-α but not GCP-2 were induced by trypsin and almost equal levels were induced by staphylococcal supernatants. IL-8, GRO-α and ENA-78 synthesis was suppressed almost completely by AEBSF and BAY 11–7085, whereas prednisolone reduced chemokine levels differentially dependent on the supernatant added. CXC chemokines were detectable in the epithelium of patients with chronic rhinosinusitis. Staphylococcal serine proteases induced CXC chemokines in A549 cells, probably by the activation of proteases activated receptors, and thus might potentially be involved in neutrophilic inflammation in chronic sinusitis.
Assessing immune function in adult bronchiectasis
Authors: King P T , Hutchinson P , Holmes P W , Freezer N J , Bennett-Wood V , Robins-Browne R , Holdsworth S R
Published: April 2006

Bronchiectasis is characterized by chronic airway infection and damage and remains an important health problem. Recent literature has emphasized the role of host defence and immune deficiency in the pathogenesis of bronchiectasis, but there have been few studies of immune function in adult bronchiectasis. A comprehensive screen of immune function was conducted in 103 adult patients with bronchiectasis, encompassing full blood examinations, immunoglobulins and IgG isotypes, complement levels, lymphocyte subsets and neutrophil function. Full blood examinations were normal in this cohort, as were complement levels. Statistical analysis confirmed that a significant number of subjects had low levels of IgG3 (13 patients), B cell lymphocytes (six patients) and T helper cell lymphocytes (seven patients) when compared with controls (P < 0.05). The most common abnormality was found with testing of the neutrophil oxidative burst. All subjects had a normal neutrophil phagocytic function but 33 of the subjects had an oxidative burst that was below the normal range (P < 0001). Almost half the group (45 subjects) had abnormally low levels of one of these four parameters. The findings of low B cells, Th cells and oxidative burst in bronchiectasis are novel. The results emphasize the importance of immune function assessment for adult bronchiectasis.
Listeriolysin O derived fromListeria monocytogenesinhibits the effector phase of an experimental allergic rhinitis induced by ovalbumin in mice
Authors: Yamamoto K , Kawamura I , Tominaga T , Nomura T , Ito J , Mitsuyama M
Published: April 2006

Listeriolysin O (LLO) derived from Listeria monocytogenes is highly capable of inducing interleukin (IL)-12, IL-18 and interferon (IFN)-γ, and facilitates the generation of Th1 cells. We have recently shown that recombinant LLO (rLLO) inhibits generation of ovalbumin (OVA)-specific Th2 immune response by skewing maturation of antigen-specific T cells into Th1 cells. In the present study, we investigated the effect of rLLO on the effector phase of Th2-dependent allergic rhinitis in BALB/c mice sensitized with OVA. In mice sensitized intraperitoneally and challenged intranasally with OVA, nasal allergic symptoms such as sneezing and nose-scratching were observed at a high frequency. A high titre of anti-OVA IgE antibody was detected in sera and a large number of eosinophils migrated into the nasal tissue. However, rLLO treatment during the intranasal challenge inhibited the allergic symptoms, production of anti-OVA IgE antibody and eosinophil infiltration. Though rLLO did not affect antigen-specific cytokine production from splenic CD4+ T cells, rLLO significantly suppressed OVA-specific IL-4 and IL-5 production from nasal mononuclear cells. We further found that rLLO inhibited the recruitment of CD4+ T cells in nasal mucosa, and diminished the transcription and cell surface expression of CCR4 on splenic CD4+ T cells. Moreover, rLLO was able to inhibit the passive cutaneous anaphylaxis reaction mediated by anaphylactic antibodies (IgE and IgG1) and mast cells. Taken together, these data showed that rLLO suppresses the effector phase of allergic rhinitis by inhibition of Th2 cell recruitment to nasal mucosa and type I allergic reaction.
High prevalence of mannose-binding lectin (MBL) deficiency in premature neonates
Authors: Frakking F N J , Brouwer N , Zweers D , Merkus M P , Kuijpers T W , Offringa M , Dolman K M
Published: April 2006

Mannose-binding lectin (MBL) is a component of innate immunity and thus particularly important in neonates in whom adaptive immunity is not yet completely developed. Promoter polymorphisms and structural exon-1 mutations in the MBL2 gene cause reduced or deficient MBL plasma concentrations. The aim of our study was to determine the prevalence of MBL deficiency in neonates admitted to the neonatal intensive care unit (NICU). Eighty-five NICU patients (69 premature) were included in the study. We measured MBL concentrations in umbilical cord and neonatal blood within 24 h after birth by ELISA technique. MBL2 genotypes (n = 67) were determined by Taqman analysis. MBL concentrations were measured longitudinally during three weeks in 26 premature neonates. The association between pre- and intra-partum clinical data and MBL concentrations was investigated. At birth, 29 (42%) premature and six (38%) term neonates had MBL plasma concentrations ≤  0.7 µg/ml which was regarded as deficient. Twenty-one (38%) premature and four (36%) term neonates had variant MBL2 haplotypes, corresponding to exon-1 mutations and the LXPA haplotype. MBL concentrations increased over time in neonates with wild-type MBL2 haplotypes, but not in neonates with variant haplotypes. Low MBL plasma concentrations were related to lower gestational age and variant MBL2 haplotypes. Umbilical cord and neonatal MBL plasma concentrations appeared to be similar. In conclusion, almost half of our NICU patients, especially the premature ones, were MBL-deficient at birth. These infants may be at increased risk of neonatal infections. MBL concentration can reliably be measured in umbilical cord blood and it is positively correlated with gestational and postnatal age.
CD28 co-stimulation via tumour-specific chimaeric receptors induces an incomplete activation response in Epstein–Barr virus-specific effector memory T cells
Authors: Altvater B , Pscherer S , Landmeier S , Niggemeier V , Juergens H , Vormoor J , Rossig C
Published: April 2006

Expression of tumour antigen-specific chimaeric receptors in T lymphocytes can redirect their effector functions towards tumour cells. Integration of the signalling domains of the co-stimulatory molecule CD28 into chRec enhances antigen-specific proliferation of polyclonal human T cell populations. While CD28 plays an essential role in the priming of naive CD4+ T cells, its contribution to effector memory T cell responses is controversial. We compared the function of the chRec with and without the CD28 co-stimulatory domain, expressing it in peripheral blood T cells or Epstein–Barr virus (EBV)-specific T cell lines. The chimaeric T cell receptors contain an extracellular single-chain antibody domain, to give specificity against the tumour ganglioside antigen GD2. The transduced cytotoxic T lymphocytes (CTL) maintained their specificity for autologous EBV targets and their capacity to proliferate after stimulation with EBV-infected B cells. Intracellular cytokine staining demonstrated efficient and comparable antigen-specific interferon (IFN)-γ secretion by CTL following engagement of both the native and the chimaeric receptor, independent of chimaeric CD28 signalling. Furthermore, tumour targets were lysed in an antigen-specific manner by both chRec. However, while antigen engagement by CD28ζ chRec efficiently induced expansion of polyclonal peripheral blood lymphocytes in an antigen-dependent manner, CD28 signalling did not induce proliferation of EBV–CTL in response to antigen-expressing tumour cells. Thus, the co-stimulatory requirement for the efficient activation response of antigen-specific memory cells cannot be mimicked simply by combining CD28 and ζ signalling. The full potential of this highly cytolytic T cell population for adoptive immunotherapy of cancer requires further exploration of their co-stimulatory requirements.
Guided seismic waves in layered poroviscoelastic media for continuity logging applications: model studies1
Authors: Parra Jorge O.
Published: April 2006

The gas industry is continuing to concentrate its research and development efforts on new and advanced technology to improve reservoir descriptions through the producing life and development history of heterogeneous gas reservoirs. A very important aspect of this need is the ability to reduce the uncertainty of estimating probable reserves and to lower the operating costs to recover incremental reserves in producing and depleted gasfields. Established methods for reducing uncertainty in heterogeneous reservoir compartments, such as VSP and cross‐well techniques may enhance resolution, but they are currently not economically justifiable in on‐shore gasfields. Continuity logging using guided waves is an alternative approach to analysing inter‐well seismic data to confirm the continuity of heterogeneous gas reservoir compartments; in particular, the continuity of sand and shale stratigraphy in gas reservoirs.

The solution of a coupled system of differential equations based on Biot and homogenization theories is adapted to calculate guided seismic waves trapped in low‐velocity layers. The general solution is for a 3D source in a horizontally layered poroviscoelastic medium having isotropic and laterally homogeneous material properties. A unified representation of the medium that includes fluid‐solid interactions and viscoelastic losses is incorporated into the solution. The guided‐wave part of the vector wave field and fluid‐pressure of the complete wave motion in layered dissipative media is verified and used to simulate dispersion and attenuation of guided seismic waves for continuity logging applications. The results of this work suggest that the multimode wave solution is appropriate to simulate guided seismic wave signatures to indicate continuity of layered earth structures in poroviscoelastic reservoirs. In particular, the normal mode information can be used for planning continuity logging surveys and for interpreting the corresponding seismic data. Further, fluid‐pressure waveforms show that maximum amplitude normal modes can be detected at layer interfaces in fluid‐filled porous media, and the corresponding Airy phase wave groups may carry information on the formation permeability.
3D Modelling of the electromagnetic response of geophysical targets using the FDTD method1
Authors: Debroux Patrick S.
Published: April 2006

A publicly available and maintained electromagnetic finite‐difference time domain (FDTD) code has been applied to the forward modelling of the response of 1D, 2D and 3D geophysical targets to a vertical magnetic dipole excitation. The FDTD method is used to analyse target responses in the 1 MHz to 100MHz range, where either conduction or displacement currents may have the controlling role. The response of the geophysical target to the excitation is presented as changes in the magnetic field ellipticity.

The results of the FDTD code compare favourably with previously published integral equation solutions of the response of 1D targets, and FDTD models calculated with different finite‐difference cell sizes are compared to find the effect of model discretization on the solution. The discretization errors, calculated as absolute error in ellipticity, are presented for the different ground geometry models considered, and are, for the most part, below 10% of the integral equation solutions.

Finally, the FDTD code is used to calculate the magnetic ellipticity response of a 2D survey and a 3D sounding of complicated geophysical targets. The response of these 2D and 3D targets are too complicated to be verified with integral equation solutions, but show the proper low‐ and high‐frequency responses.
EM target location1
Authors: Gelius L.‐J.
Published: April 2006

We consider the problem of computing the most probable location of a target based on radar measurements of the subsurface. Our algorithm makes use of the maximum likelihood estimator (MLE), which represents a correlation between the measured data and synthetic data generated for the object of interest at different locations. Previous studies assume a plane‐wave acquisition geometry and target object(s) embedded in a uniform background. In this paper, a generalization of the MLE method is presented which is valid for discrete point sources (and receivers) and a 2D model (i.e. a 2.5D acquisition geometry). Within this formulation the treatment of a non‐uniform background model is also possible. We concentrate on geotechnical ground investigations and assume that the characteristic dimensions of the target object are in the range 1–2λ, (λ being the wavelength). The potential of the method is demonstrated employing cross‐hole radar data acquired in a controlled field experiment. The MLE result is also compared with the image obtained employing a full reconstruction method such as diffraction tomography.
Velocity sensitivity in transversely isotropic media1
Authors: Chapman C.H. , Miller D.E.
Published: April 2006

We consider the problem of determining and predicting how the wave speeds in particular directions for a transversely isotropic (TI) medium depend on particular combinations of the density‐normalized moduli Aij. The expressions for the qP and qSV velocities are known to depend on four moduli. Normally, we can only determine three independent parameters from qP data, or two from qSZ data, as the others have much lower sensitivity. The resolvable parameters are conveniently described by axial and off‐axis parameters: for qP rays, P0°= A11, P90°= A33 and P45°=(A11+ A33)/4 + (A13+2A55)/2; and for qSV rays, S0°= S90°=A55 and S 45°= (A11+ A 33)/4‐ A13/2. These parameters control the magnitude of the squared‐velocities on the axes and at approximately 45°. For an arbitrary TI medium, if the medium is perturbed in a way that preserves a particular parameter, then slowness points in the associated direction and mode witl be approximately preserved in the new medium. we refer to these parameters as ‘push‐pins’, i.e. if a parameter is fixed, the associated part of the slowness surface is pinned in place.

Because, these five push‐pins only contain four independent moduli, we can only fix at most three push‐pins. Perturbing one of the other parameters inevitably perturbs the other. Numerical results illustrating the linkage between two push‐pins, when three are fixed, are presented.

So‐called anomalous TI media occur when the roles of the qP and qSV waves are reversed: in some directions the faster ray has transverse polarization. That, in turn, requires anomalous velocities at the push‐pins, i.e. S0° > P0°, S45° > P45° and/or S90° > P90° (equivalent to the usual anomalous conditions A11 < A55, < 0 and/or A33 < A55). In the Appendix, we confirm that anomalous sensitivities of the velocities at the five push‐pins only occur in such media, although the push‐pins still apply if interpreted appropriately. Truly anomalous sensitivities, in which push‐pins play no role, only occur in media near the boundary between normal and anomalous.
On the downward continuation of electromagnetic fields1
Authors: Wait James R.
Published: April 2006

A concise derivation is given for the downward continuation of the tangential fields on the surface to yield expressions for the fields at a specified depth. A homogeneous slab region is assumed for the analysis.
Ray tracing based on Fermat's principle in irregular grids1
Authors: Vesnaver Aldo L.
Published: April 2006

A new method to trace rays in irregular grids based on Fermat's principle of minimum time is introduced. Besides the usual transmitted and reflected waves, refracted, diffracted and converted waves can also be simulated. The proposed algorithm is fast and stable, and respects the reciprocity principle between source and receiver better than procedures adopting the shooting method. It is particularly suited to form part of a traveltime inversion procedure. The use of irregular grids allows adaptation of the earth discretization to the available acquisition geometry and ray distribution, to obtain more stable and reliable tomographic images.
Application of acoustic full wavetrains for the determination of lithology, reservoir and mechanical parameters of formation1
Authors: Bała Maria , Jarzyna Jadwig A.
Published: April 2006

The significant development in acoustic full waveform logging during the last ten years has made it increasingly possible for log analysts to determine the physical properties of a rock formation in situ.

Parallel to the methods applied to a single wavetrain during seismic processing, the new techniques, used for sets of wavetrains, have been successfully tested with acoustic full waveforms. Instantaneous characteristics analysis is included in this group of methods. This approach, leading to qualitative and quantitative interpretation, reveals the influence of small changes in physical properties on acoustic full wavetrains.

Applications of complex acoustic waveform analysis for the determination of inhomogeneous zones are presented. Colour diagrams of instantaneous characteristics are used for the detection of fractured regions and slow formations with increased attenuation of acoustic waves.

Results of the interpretation of individual acoustic full waveforms, based on cross‐correlation and spectral analysis, using the IDNP and IDNS computer programs, e.g. velocities of compressional waves, shear and Stoneley waves, are presented. Since the bulk density of the rocks was known, it was possible, using the velocities of P‐ and S‐waves obtained, to calculate the dynamic elastic moduli. We used the interpretation of acoustic full wavetrains to calculate porosity. The sonic porosity is compared to the porosity obtained from other logs and to that obtained from core sample analysis.

The examples of acoustic full wavetrains were recorded in the Miocene sulphur‐bearing limestones in central Poland. Field measurements were made using the domestic prototype equipment for well log recordings in shallow boreholes.
Habitat type predicts genetic population differentiation in freshwater invertebrates
Authors: MARTEN ANDREAS , BRÄNDLE MARTIN , BRANDL ROLAND
Published: April 2006

A basic challenge in evolutionary biology is to establish links between ecology and evolution of species. One important link is the habitat template. It has been hypothesized, that the spatial and temporal settings of a habitat strongly influence the evolution of species dispersal propensity. Here, we evaluate the importance of the habitat type on genetic population differentiation of species using freshwater habitats as a model system. Freshwater habitats are either lentic (standing) or lotic (running). On average, lotic habitats are more stable and predictable over space and time than lentic habitats. Therefore, lentic habitats should favour the evolution of higher dispersal propensity which ensures population survival of lentic species. To test for such a relationship, we used extensive data on species’ genetic population differentiation of lentic and lotic freshwater invertebrates retrieved from published allozyme studies. Overall, we analysed more than 150 species from all over the world. Controlling for several experimental, biological and geographical confounding effects, we always found that lentic invertebrates exhibit, on average, lower genetic population differentiation than lotic species. This pattern was consistent across insects, crustaceans and molluscs. Our results imply fundamental differences in genetic population differentiation among species adapted to either lentic or lotic habitats. We propose that such differences should occur in a number of other habitat types that differ in spatio‐temporal stability. Furthermore, our results highlight the important role of lotic habitats as reservoirs for evolutionary processes and the potential for rapid speciation.
Far-infrared detection limits – II. Probing confusion including source confusion
Authors: Jeong Woong-Seob , Pearson Chris P. , Lee Hyung Mok , Pak Soojong , Nakagawa Takao
Published: April 2006

We present a comprehensive analysis for the determination of the confusion levels for the current and the next generation of far-infrared surveys assuming three different cosmological evolutionary scenarios. We include an extensive model for diffuse emission from infrared cirrus in order to derive absolute sensitivity levels taking into account the source confusion noise due to point sources, the sky confusion noise due to the diffuse emission, and instrumental noise. We use our derived sensitivities to suggest best survey strategies for the current and the future far-infrared space missions Spitzer, AKARI (ASTRO-F), Herschel and SPICA. We discuss whether the theoretical estimates are realistic and the competing necessities of reliability and completeness. We find the best estimator for the representation of the source confusion and produce predictions for the source confusion using far-infrared source count models. From these confusion limits considering both source and sky confusions, we obtain the optimal, confusion limited redshift distribution for each mission. Finally, we predict the cosmic far-infrared background (CFIRB), which includes information about the number and distribution of the contributing sources.