[The respiratory mucociliary system and its exploration in primary ciliary dyskinesia]

BACKGROUND

We analyzed the main characteristic features of the respiratory epithelium mucociliary system and the different tests of ciliary beat and mucociliary transport (mucociliary clearance). This knowledge is necessary for an often interdisciplinary diagnosis and treatment of primary ciliary dyskinesia.

METHODS

Review of the literature and personal experience of the different tests of ciliary structure and function.

RESULTS

This disease is characterized by abnormalities in ciliary structure/function. The genetic mechanisms and the ultrastructural abnormalities that are involved are heterogenous compared to the relative homogeneity of the clinical presentation.

CONCLUSION

The diagnostic criteria are compatible clinical features (chronic upper airway and bronchopulmonary infections, situs inversus...) coupled with tests of ciliary structure and function.

La dyskinésie ciliaire primitive

Primary ciliary dyskinesia (PCD) is a genetic disease characterized by abnormalities in ciliary structure/function.

OBJECTIVE

We analyzed the main clinical features and test results of PCD in order to evaluate their usefulness for diagnosis.

PATIENTS AND METHODS

Retrospective study of 35 cases of PCD evaluated by the same team, with nasal brushings in all cases (special light microscopy) and electron microscopy and/or by isotopic mucociliary clearance study in some.

RESULTS

In a cohort of 145 patients with suspected PCD, the diagnosis of PCD was established in 35 cases using a combination of compatible clinical features coupled with the study of nasal brushings: 13 females and 22 males, average age at time of diagnosis 25 years, situs inversus in 12 patients (34%).

CONCLUSION

In the absence of consensus in the literature for diagnosis of PCD, we propose the association of the following diagnostic criteria: upper airway and bronchopulmonary infections beginning often early in the life, more inconstantly situs inversus, familial cases of PCD, consanguinity, infertility and permanent and ubiquitous abnormalities of ciliary structure/function. Nasal brushing with ciliary study (special light microscopy) seems to be an easy and reliable diagnostic criterion. Electron microscopy is necessary for proving ultrastructural abnormalities.

Spatial variability of trends in hydrological extremes induced by orographically enhanced rainfall events due to westerly atmospheric circulations

Since the mid 1970s, the number of days with westerly atmospheric circulations has strongly increased during winter months. As a consequence, rainfall totals, rainfall event duration and intensity have been subject to significant positive trends throughout the Mosel river basin. However, the trends identified through the non-parametrical test named Kendall's tau have shown to be spatially varying. The intensity of the trends appears to be directly linked to orographic obstacles that are well known to have a strong influence on average rainfall totals. A direct consequence of the changes having affected winter rainfall under westerly atmospheric circulations on the one hand and the spatial variability of these changes on the other hand, is a spatially varying positive trend in maximum winter streamflow. Thus, even though a clear large-scale change has affected winter rainfall over the past decades, its intensity is either strongly moderated or enhanced by orographic obstacles. The related changes in streamflow are directly dependent on the spatial variability of the changed rainfall characteristics.

Polyamine, carbohydrate, and proline content changes during salt stress exposure of aspen (Populus tremula L.): involvement of oxidation and osmoregulation metabolism

Excess salt in the soil solution affects the plant either through osmotic or ionic effects. Poplar trees, as fast growing pioneer tree species, are thought to be potential suitable candidates for afforestation on saline soils. Osmotic and oxidative stress induced by salinity could be reduced by the production and accumulation of compatible solutes and osmoprotectants in the plant. In this respect, metabolites of this type could be interesting markers for the improvement of salt stress tolerance in breeding programmes. Results have shown that Populus tremula was able to cope with up to 150 mM NaCl without any effect on plant survival. During stress application, the endogenous level of malondialdehyde did not vary significantly between the treatments, indicating that the level of lipid peroxidation was similar in the control and in the stressed plants. However, proline, spermine, sucrose, mannitol, and raffinose levels increased temporarily or throughout the salt treatment. All these molecules are more or less closely related to antioxidant or osmoprotectant mechanisms during stress, suggesting a key role for these compatible solutes, osmoprotectants, and their metabolism for salt stress resistance. The accumulation of free proline, sucrose and mannitol, and the transitory increase in spermine level observable during low and high NaCl application must be considered as general salt stress reaction markers.

Responses of poplar to chilling temperatures: proteomic and physiological aspects

The effects of cold acclimation on primary metabolism in actively growing poplar ( Populus tremula L. x P. tremuloides Michaux) were studied. Three-month-old poplar plants were exposed to chilling stress (4 degrees C) and compared to plant material kept at a control temperature (23 degrees C). This treatment did not affect the survival of the plants but growth was almost stopped. The freezing tolerance of the adult leaves increased from -5.7 degrees C for the control plants to -9.8 degrees C after 14 days of exposure to 4 degrees C. During acclimation, the evolution of soluble carbohydrate contents was followed in the leaves. Sucrose, glucose, fructose and trehalose accumulated rapidly under chilling conditions, while raffinose content increased after one week at 4 degrees C. Proteomic analyses, by bidimensional electrophoresis, performed during this stage revealed that a large number of proteins had higher expression, while much less proteins disappeared or had a lower abundance. MALDI-TOF-MS analyses enabled ca. 30 spots to be proposed for candidate proteins. Among the accumulating or appearing proteins proposed, about a third presented similarities with chaperone-like proteins (heat shock proteins, chaperonins). In addition, dehydrins and other late embryogenesis abundant proteins, i.e., stress-responsive proteins, detoxifying enzymes, proteins involved in stress signalling and transduction pathways were also activated or newly synthesised. Finally, cold exposure induced a decrease in the candidate proteins involved in cell wall or energy production.

Efficacy and safety of inhaled recombinant interleukin-2 in high-risk renal cell cancer patients compared with systemic interleukin-2: an outcome study

Systemic IL-2 is an effective treatment for low to intermediate risk mRCC patients, its efficacy is marginal in high-risk cases. Therefore, other treatment approaches are required for this population. Ninety-four high-risk patients with RCC and pulmonary metastases were treated with inhaled plus concomitant low-dose subcutaneous rhIL-2. Clinical response, survival and safety were compared with those from IL-2 given systemically at the registered dose and schedule in 103 comparable historical controls. In the rhIL-2 INH group, treatment consisted of 6.5 MIU rhIL-2 nebulized 5x/day and 3.3 MIU rhIL-2 SC once daily. The rhIL-2 SYS group received treatment which consisted of intravenous infusion of 18.0 MIU/m2/day rhIL-2 or SC injection of 3.6-18.0 MIU rhIL-2. Some patients in both groups also received IFNalpha. Mean treatment durations were 43 weeks rhIL-2 INH and 15 weeks rhIL-2 SYS. Significantly longer overall survival and progression-free survival durations were observed in the rhIL-2 INH group. The probability of survival at 5 years was 21% for the rhIL-2 INH group. No patients survived 5 years in the rhIL-2 SYS group. A multivariate analysis of overall survival adjusting for differences in baseline characteristics between the two treatment groups resulted in a risk ratio of 0.43 (95% CI 0.30-0.63; P < 0.0001). The data suggested an association between the response (SD or better) and survival, especially in the rhIL-2 INH group. The inhalation regimen was well tolerated. This outcome study suggests that administration of rhIL-2 by inhalation is efficacious and safe in high-risk mRCC patients with pulmonary metastases, who have no other treatment option available.

Energy metabolism of cocks and broiler chickens fed on diets with different carbohydrate sources

Energy balances of cocks and chickens were measured using the nitrogen-carbon-balance method. In Experiment 1 twelve adult White Leghorn cocks were fed alternately on a basal ration or on a supplemental ration composed of 75% basal diet and 25% carbohydrate source as a supplement. In Experiment 2 six groups of 12 male broiler chickens were fed successively on two diets each with different carbohydrate sources (40% of DM) and on two energy levels. The investigated carbohydrate sources were glucose, fructose, sucrose, maize starch, raw and steamed potato starch, dried sugar beet pulp, tapioca, wheat, maize, rye and barley. In both experiments the energy digestibility of the diets with raw potato starch, beet pulp and barley was significantly lower compared to the other diets. Digestibility of those ranged from 88 to 81%. By simple linear regression no significant differences in efficiency of utilisation of ME of the diets between the carbohydrate sources sugars, starches and cereal grains could be proved. The corresponding MEm values agreed very close among the diets (411 to 429 kJ.kg BW-0.75.d-1).

Identification and molecular characterisation of hordoindolines from barley grain

Grain texture in barley is an important quality character as soft-textured cultivars have better malting quality. In wheat, texture is considered to be determined by the puroindolines, a group of basic hydrophobic proteins present on the surface of the starch granule. Hard wheats have been proposed to lack puroindoline a or to have mutant forms of puroindoline b which do not bind to the granule surface. Analysis of six barley cultivars (three soft-textured and three hard) showed that all contained proteins homologous to wheat puroindoline b, but PCR analysis failed to show any differences in amino acid sequences similar to those which have been proposed to determine textural differences in wheat. Southern blot analysis showed two hordoindoline b genes which were isolated and shown to encode proteins with 94% sequence identity. Expression of hordoindoline b mRNA occurred in the starchy endosperm and aleurone layer of the developing seed, but not in the embryo. Analysis of seven soft- and six hard-textured barley varieties showed that all contained hordoindoline a except two hard varieties (Sundance, Hart) which were subsequently shown to both lack hordoindoline a mRNA. It was therefore concluded that there is not a clear relationship between the presence of hordoindoline a and grain texture in barley.

Identification of the enzymatic active site of tobacco caffeoyl-coenzyme A O-methyltransferase by site-directed mutagenesis

Animal catechol O-methyltransferases and plant caffeoyl-coenzyme A O-methyltransferases share about 20% sequence identity and display common structural features. The crystallographic structure of rat liver catechol O-methyltransferase was used as a template to construct a homology model for tobacco caffeoyl-coenzyme A O-methyltransferase. Integrating substrate specificity data, the three-dimensional model identified several amino acid residues putatively involved in substrate binding. These residues were mutated by a polymerase chain reaction method and wild-type and mutant enzymes were each expressed in Escherichia coli and purified. Substitution of Arg-220 with Thr resulted in the total loss of enzyme activity, thus indicating that Arg-220 is involved in the electrostatic interaction with the coenzyme A moiety of the substrate. Changes of Asp-58 to Ala and Gln-61 to Ser were shown to increase K(m) values for caffeoyl coenzyme A and to decrease catalytic activity. Deletions of two amino acid sequences specific for plant enzymes abolished activity. The secondary structures of the mutants, as measured by circular dichroism, were essentially unperturbed as compared with the wild type. Similar changes in circular dichroism spectra were observed after addition of caffeoyl coenzyme A to the wild-type enzyme and the substitution mutants but not in the case of deletion mutants, thus revealing the importance of these sequences in substrate-enzyme interactions.

Repression of O-methyltransferase genes in transgenic tobacco affects lignin synthesis and plant growth

Among the different enzymatic steps leading to lignin biosynthesis, two methylation reactions introduce the methyl groups borne by guaiacyl (G) and syringyl (S) units. Tobacco possesses a complex system of methylation comprising three classes of CCoAOMTs (caffeoyl-CoA-O-methyltransferases) and two classes of COMTs (caffeic acid OMTs). Antisense plants transformed with the CCoAOMT sequence alone or fused to COMT I sequence have been produced and compared to ASCOMT I plants in order to study the specific role of each OMT isoform in lignin biosynthesis, plant development and resistance to pathogens. Tobacco plants strongly inhibited in OMT activities have been selected and analyzed. Whereas antisense COMT I plants exhibited no visual phenotype, CCoAOMT repression was shown to strongly affect the development of both single and double transformants: a reduction of plant growth and the alteration of flower development were observed in the most inhibited plants. Lignin analysis performed by Klason and thioacidolysis methods, showed a decrease in the lignin quantity and changes in the lignin structure of ASCCoAOMT and ASCCoAOMT/ASCOMT I transgenics but not in ASCOMT I plants. Inhibition of COMT I in single as well as in double transformed tobacco was demonstrated to decrease S unit synthesis and to provoke the accumulation of 5-hydroxyguaiacyl lignin units. ASCCoAOMT/ASCOMT I tobacco was affected in lignin amount and composition, thus demonstrating additive effects of inhibition of both enzymes. The changes of lignin profiles and the phenotypical and molecular alterations observed in the different transgenic lines were particularly prominent at the later stages of plant development.

Animal and human multidrug-resistant, cephalosporin-resistant salmonella isolates expressing a plasmid-mediated CMY-2 AmpC beta-lactamase

Salmonella spp. are important food-borne pathogens that are demonstrating increasing antimicrobial resistance rates in isolates obtained from food animals and humans. In this study, 10 multidrug-resistant, cephalosporin-resistant Salmonella isolates from bovine, porcine, and human sources from a single geographic region were identified. All isolates demonstrated resistance to cephamycins and extended-spectrum cephalosporins as well as tetracycline, chloramphenicol, streptomycin, and sulfisoxazole. Molecular epidemiological analyses revealed eight distinct chromosomal DNA patterns, suggesting that clonal spread could not entirely explain the distribution of this antimicrobial resistance phenotype. However, all isolates encoded an AmpC-like beta-lactamase, CMY-2. Eight isolates contained a large nonconjugative plasmid that could transform Escherichia coli. Transformants coexpressed cephalosporin, tetracycline, chloramphenicol, streptomycin, and sulfisoxazole resistances. Plasmid DNA revealed highly related restriction fragments though plasmids appeared to have undergone some evolution over time. Multidrug-resistant, cephalosporin-resistant Salmonella spp. present significant therapeutic problems in animal and human health care and raise further questions about the association between antimicrobial resistance, antibiotic use in animals, and transfer of multidrug-resistant Salmonella spp. between animals and man.

The pYC plasmids, a series of cassette-based yeast plasmid vectors providing means of counter-selection

A series of 24 general-purpose yeast plasmid vectors has been constructed. The plasmid series is composed of inter-replaceable cassettes, allowing for easy interconversion of plasmid types. In addition to the usual replication origins, selectable markers and multiple cloning sites (MCS), cassettes dedicated to counter-selection have been constructed. A pair of unique 8 bp restriction enzyme recognition sites flank each type of cassette, FseI in the case of yeast replication origins, AscI in the case of selectable markers, PacI in the case of counter-selectable markers and NotI in the case of the MCS. Thus, any given cassette can be replaced by another cassette of the same type, facilitating interconversion of any given plasmid from one type to another, even after the insertion of DNA into the MCS. Hence, the plasmids have been named pYC for 'yeast cassettes'. The cassettes consist of either NONE, CEN4/ARS or 2micro as replication origin, either URA3, MET2-CA (Lg-MET2) or the G418 resistance gene (the apt1 gene from bacterial transposon Tn903, encoding aminoglycoside phosphotransferase) as selectable markers, either NONE, PMET25-PKA3 or PCHA1-PKA3 as counter-selectable marker, and the MCS, containing recognition sites for AflII, AvrII, BspEI, PmeI, SacII, SalI, SunI, BamHI, EcoRI, HindIII, KpnI, MluI, NarI and SacI (of which the seven first are unique in all plasmids). The counter-selectable markers consist of the PKA3 gene under control of the conditional MET25 or CHA1 promoters. At activating conditions these promoters express the PKA3 gene at toxic levels, facilitating easy selection for loss of plasmid or 'loop-out' of plasmid DNA sequence after genomic integration.

Inhibition of croton oil-induced oedema in mice ear skin by capsular polysaccharides from cyanobacteria

The anti-inflammatory properties of hydrophilic extracts of the capsular polymers of twelve cyanobacterial strains belonging to the genera Phormidium and Nostoc from marine and terrestrial habitats were tested topically on croton oil-induced oedema in mice ear skin. The screening program identified several strains as producers of anti-inflammatory products (up to 56% inhibition of the oedema). The inhibition response was dose-dependent. The application of trichloroacetic acid-treated extracts reduced the oedema by about 60%. On the other hand, one of the strains enhanced the inflammatory response. Analysis of five of the extracts showed the presence of neutral sugars (from 34.3% to 47.1%, w/w), uronic acids (from 7.1% to 26.7%, w/w) and proteins (from 30.1% to 57.0%, w/w) in the crude polymer. Rhamnose, fucose, arabinose, xylose, mannose, glucose, galactose, galacturonic acid and glucuronic acid were detected as well as sulphate groups (from 9.6% to 21.5%, w/w of sugars). The main components found were glucose and mannose.

Capsular polysaccharide produced by the thermophilic cyanobacterium Mastigocladus laminosus. Structural study of an undecasaccharide obtained by lithium degradation

The capsular polysaccharide produced by the thermophilic cyanobacterium Mastigocladus laminosus has been subjected to a specific degradation with lithium in ethylenediamine. The released undecasaccharide attached to one unit of tetrahydroxycyclopentanecarboxylic acid has been characterized by a combination of 2D nuclear magnetic resonance spectroscopy, mass spectrometry, monosaccharidic composition and linkage analyses. From the overlap of the structure of this oligosaccharide with previously identified di-, tri- and pentasaccharides released by mild acid hydrolysis, the capsular polysaccharide was deduced to have a pentadecasaccharide repeating unit with the following structure:

Madangolide and laingolide A, two novel macrolides from lyngbya bouillonii (Cyanobacteria)

Two new macrolide derivatives, madangolide (2) and laingolide A (3), have been isolated from the cyanobacterium Lyngbya bouillonii, collected in Papua New Guinea. Their structures (without stereochemistry) have been established by detailed high-field 1D and 2D NMR studies and, in the case of 3, by comparison with the spectroscopic data of laingolide (1), previously isolated from the same organism.

Influence of brain death and cardiac preservation on systolic and diastolic function and coronary circulation in the cross-circulated canine heart

Previous studies have demonstrated hemodynamic instability and cardiac dysfunction in the brain-dead organ donor. It remains unclear if primary cardiac dysfunction is responsible for hemodynamic deterioration or decreased cardiac function is secondary to brain death-associated altered loading conditions. Therefore in the present study the effects of brain death on hemodynamics and cardiac function were analyzed in vivo in an open chest model and ex vivo in a cross-circulated heart preparation. In a second protocol, the impact of brain death-associated hemodynamic changes on postischemic graft function was investigated. Brain death was induced injecting saline in a subdural Foley catheter. Induction of brain death led to a hyperdynamic reaction followed by hemodynamic deterioration with a decrease of systemic vascular resistance and myocardial contractility. If the hearts were explanted and assessed ex vivo, no differences were found between control and brain-dead hearts. Furthermore, both control and brain-dead hearts showed full functional recovery after 4 hours of hypothermic ischemic storage. Despite hemodynamic deterioration in situ after brain death, there were no differences between the postischemic function of control and brain-dead hearts. These results indicate that myocardial dysfunction is not irreversible and may be secondary to altered loading conditions, and that the recovery of cardiac function after long-term hypothermic storage is not impaired by the hemodynamic changes observed in situ after brain death induction. These data may also indicate that potential donor hearts might not be excluded from transplantation on the basis of impaired hemodynamic characteristics, especially if they are evaluated by load-dependent parameters.

[Energy metabolism in laying hens of different body weight genotypes]

Energy metabolism and some performance parameters were investigated in laying hens of 3 different body weight-genotypes: 6 x 7 (normal-sized, crossbred from normal-sized male and female lines, group 1), 47 x 38 (dwarf-sized, breeding from a dwarf-sized male line and a normal-sized female line, group 2) and 44 x 47 (dwarf-sized, breeding from dwarf-sized male and female lines, group 3). Energy balance was measured by indirect calorimetry through C- and N-balances in 12 animals of each group during 10 consecutive days at production peak, within the period between the 27th and the 37th week of age. Hens were caged individually at 23 degrees C environmental temperature and fed ad libitum on a laying mash. The mean body weight in the dwarf-sized groups 2 and 3 was 32% lower than in the normal-sized group 1 during the energy balance period. The daily gross energy intake in group 2 and 3 was decreased by 33 and 34%, respectively. There were no significant differences in digestibility and metabolizability of gross energy between the groups. The energy requirements for maintenance [kJ ME/kg0.75.d] derived from the energy balances were lower by 4% (P > 0.05) and 14% (P < 0.05) in the dwarf-sized groups 2 and 3 as compared with the normal-sized group 1, when equal coefficients of partial efficiency of metabolizable energy utilization for energy retention in body and eggs are assumed for the 3 body-mass genotypes. There were no relevant differences in body composition at the end of the energy balance periods as well as in egg composition between the 3 experimental groups.

The role of coronary perfusion changes in cardiac dysfunction associated with brain death

BACKGROUND

Previous studies described a hemodynamic instability in the potential organ donor which has clinical relevance for cardiac transplantation. The possible pathophysiological link between altered loading conditions, coronary perfusion, and cardiac function after brain death has not been investigated yet. Therefore this study was undertaken to investigate the role of coronary perfusion changes during brain death in cardiac dysfunction.

METHODS

Dogs on cardiopulmonary bypass provided iso-volumetric left-ventricular (LV) contractions. By protocol, coronary perfusion pressure was kept at the level of mean aortic pressure. LV pressure, LV dP/dt, the slope of end-systolic pressure-volume relationship (Emax), coronary blood flow (CBF), and myocardial oxygen consumption (MVO2) were measured. Brain death was induced by a subdurally placed balloon-catheter.

RESULTS

Induction of brain death led to a transient hyperdynamic response with a significant increase of aortic and LV pressure, dP/dt, Emax, CBF, and MVO2. Thereafter, aortic pressure and, parallelly, LV pressure, dP/dt, Emax, CBF, and MVO2 decreased significantly. However, if coronary perfusion pressure was decoupled from aortic pressure and elevated to pre-brain death level, CBF and myocardial contractility were restored to baseline level.

CONCLUSION

The impairment of coronary blood flow may contribute to decreased contractility after brain death.

The metabolisable energy as a basis for standardisation of energetic feed evaluation

The advantages and disadvantages of metabolisable and net energy as parameters of energetic feed evaluation are discussed. For a global comprehensive standardisation of the energetic feed evaluation, the metabolisable energy (ME) will have a preference. The principles of an energetic feed evaluation system with ME as parameter are explained according to which the subsystems for all species of animals should be worked out uniformly. The subsystems for the most important farm animals integrate themselves in addition to ME for predicting the energy and food needs of the animal also the net energy (NE) by taking a standard feedstuff to characterise the relative energetic feed value of the feedstuffs for one or more partial performances of the animal species concerned.

First report on the identification of microcystin in a water bloom collected in Belgium

A toxic cyanobacterial bloom dominated by Microcystis aeruginosa occurred in 1995 in three adjacent ponds near Liège (Belgium) where at the same time conspicuous bird deaths were observed. The toxicity assay using primary rat hepatocytes indicated a high hepatoxicity. A 4 h incubation yielded a LD50 of 0.23 mg bloom material (dry weight)/ml cell culture medium. Toxicity was due to hepatotoxins of the microcystin class, microcystin-LR and-RR being the major microcystins present as determined by RP-HPLC absorption spectra, 1H NMR, and ESMS spectra. Additionally, the bloom sample contained small amounts of microcystin-YR. The microcystin content of the dry bloom biomass was 870 micrograms/g (on the basis of the hepatotoxicity assay) and 556 micrograms/g (on the basis of the RP-HPLC peak area). A higher yield of microcystins was obtained by acetic acid extraction instead of methanol extraction, whereas different extraction temperatures (20 degrees C, 40 degrees C) had no effect on the yield.