Analytical methods for measuring collagen XIX in human cell cultures, tissue extracts, and biological fluids.

Type XIX collagen is a minor collagen associated with basement membranes in vascular, neuronal, mesenchymal, and epithelial tissues. We demonstrated that the NC1, C-terminal, domain of collagen XIX inhibits the migration capacities of tumor cells and exerts a strong inhibition of tumor growth. Other basement membrane collagens or derived fragments were measured in biological fluids such as blood and urine of patients and appeared to be useful for diagnosis, prognosis, or treatment monitoring. The aim of this study was to develop and validate methods to measure collagen XIX and its fragments in human cell cultures, tissue extracts, and human biological fluids. For that purpose, we developed real-time PCR, Western blot, and competitive enzyme-linked immunosorbent assays. We demonstrated that the methods developed in this paper are specific for collagen XIX. We showed that it is expressed in human cell cultures, tissue extracts, and various biological fluids. These methods may be used in various human tissue extracts and biological fluids such as serum, amniotic fluid, cord blood, and many other fluids. Collagen XIX or its fragments could constitute new biomarkers for human diseases as well as for diagnosis and/or prognosis.

The very low penetrance of cystic fibrosis for the R117H mutation: a reappraisal for genetic counselling and newborn screening.

BACKGROUND: Cystic fibrosis (CF) is caused by compound heterozygosity or homozygosity of CF transmembrane conductance regulator gene (CFTR) mutations. Phenotypic variability associated with certain mutations makes genetic counselling difficult, notably for R117H, whose disease phenotype varies from asymptomatic to classical CF. The high frequency of R117H observed in CF newborn screening has also introduced diagnostic dilemmas. The aim of this study was to evaluate the disease penetrance for R117H in order to improve clinical practice. METHODS: The phenotypes in all individuals identified in France as compound heterozygous for R117H and F508del, the most frequent CF mutation, were described. The allelic prevalences of R117H (p(R117H)), on either intron 8 T5 or T7 background, and F508del (p(F508del)) were determined in the French population, to permit an evaluation of the penetrance of CF for the [R117H]+[F508del] genotype. RESULTS: Clinical details were documented for 184 [R117H]+[F508del] individuals, including 72 newborns. The disease phenotype was predominantly mild; one child had classical CF, and three adults' severe pulmonary symptoms. In 5245 healthy adults, p(F508del) was 1.06%, p(R117H;T7) 0.27% and p(R117H;T5)<0.01%. The theoretical number of [R117H;T7]+[F508del] individuals in the French population was estimated at 3650, whereas only 112 were known with CF related symptoms (3.1%). The penetrance of classical CF for [R117H;T7]+[F508del] was estimated at 0.03% and that of severe CF in adulthood at 0.06%. CONCLUSIONS: These results suggest that R117H should be withdrawn from CF mutation panels used for screening programmes. The real impact of so-called disease mutations should be assessed before including them in newborn or preconceptional carrier screening programmes.

RISA-HPLC analysis of lung bacterial colonizers of cystic fibrosis children.

Microbiological analysis of sputum samples, from children affected by cystic fibrosis (CF) and showing signs of acute or chronic infections, is routinely performed by culture-dependent approaches involving selective media and biochemical tests. These identification schemes are time-consuming, and may lead to false negative results. The aim of this work was to evaluate the efficacy of a Ribosomal Intergenic Spacer Analysis (RISA) coupled to high performance liquid chromatography (HPLC) for the detection and monitoring of CF lung microbial colonizers including Staphylococcus aureus, Haemophilus influenzae, Pseudomonas aeruginosa, the Burkholderia cepacia complex, Stenotrophomonas maltophilia, and Achromobacter xylosoxidans. These RISA-HPLC analyses were performed over a 10-months period on infants (below 18 months) and children that were or were not yet known to be colonised by P. aeruginosa. The RISA-HPLC profiles were found specific of the patients' microbial communities. A specific P. aeruginosa RISA-HPLC peak corresponding to 550 bp PCR products was recorded, and used to investigate P. aeruginosa persistence through time and after various therapeutic treatments. The RISA-HPLC profiles showed the CF children to be colonized by few bacterial species, and sometimes revealed peaks corresponding to bacterial species that were not detected by the selective plating approaches. Significant RISA-HPLC infra-specific variations were observed for most bacterial colonizers of CF lungs except P. aeruginosa. These species could yield as much as 5 distinct RISA-HPLC peaks, with some of these profiles being strain-specific. RISA-HPLC shows a great potential for revealing colonization by novel emerging pathogens, and for evaluating the efficacy of therapeutic treatments on the global bacterial community of CF lungs.

Elastokine-mediated up-regulation of MT1-MMP is triggered by nitric oxide in endothelial cells.

Membrane-type I matrix metalloproteinase (MT1-MMP) has been previously reported to be up-regulated in human microvascular endothelial cell-1 line (HMEC) by elastin-derived peptides (elastokines). The aim of the present study was to identify the signaling pathways responsible for this effect. We showed that elastokines such as (VGVAPG)(3) peptide and kappa elastin induced nitric oxide (NO) production in a time-, concentration- and receptor-dependent manner as it could be abolished by lactose and a receptor-derived competitive peptide. As evidenced by the use of NO synthase inhibitors, elastokine-mediated up-regulation of MT1-MMP and pseudotube formation on Matrigel required NO production through activation of the PI(3)-kinase/Akt/NO synthase and NO/cGMP/Erk1/2 pathways. Elastokines induced both PI(3)-kinase p110gamma sub-unit, Akt and Erk1/2 activation, as shown by a transient increase in phospho-Akt and phospho-Erk1/2, reaching a maximum after 5 and 15 min incubation, respectively. Inhibitors of PI(3)-kinase and MEK1/2 suppressed elastokine-mediated MT1-MMP expression at both the mRNA and protein levels, and decreased the ability of elastokines to accelerate pseudotube formation. Besides, elastokines mediated a time- and concentration-dependent increase of cGMP, suggesting a link between NO and MT1-MMP expression. This was validated by the use of a guanylyl cyclase inhibitor, a NO donor and a cGMP analog. The guanylyl cyclase inhibitor abolished the stimulatory effect of elastokines on MT1-MMP expression. Inversely, the cGMP analog, mimicked the effect of both elastokines and NO donor in a concentration- and time-dependent manner. Overall, our results demonstrated that such elastokine properties through NO and MT1-MMP may be of importance in the context of tumour progression.

Contribution of CT-assisted navigation and microdebriders to endoscopic sinus surgery in cystic fibrosis.

OBJECTIVE: To demonstrate the interest of CT-assisted navigation and the microdebrider in rhino-sinus surgery for cystic fibrosis. METHODS: A retrospective study included 20 patients with cystic fibrosis who had undergone endoscopic sinus surgery using CT-assisted navigation and microdebrider between 1998 and 2006. RESULTS: Surgery was indicated for the following symptoms resistant to medical management: incapacitating nasal obstruction (n=18, 90%) and headache or periorbital pain (n=14, 70%). At 3 years follow-up, six patients (30%) were symptom-free, six (30%) had required re-operation, and symptoms were well controlled by medication in the other eight (40%). Mean initial bilateral surgery time was 61 min. There were no complications. CONCLUSION: The advent of microdebriders and CT-based navigation has improved endoscopic sinus surgery in cystic fibrosis. It has permitted the control of medication-resistant symptoms, especially nasal obstruction and pain. Precision is satisfactory, with reduced surgery time. No major complications have been observed. Two- or three-step surgery is possible where endoscopic anatomic landmarks have suffered alteration. The resultant control of symptoms encourages extending indications, with repeat procedures, in view of improving patients' quality of life. Further assessment on a larger series will be needed.

[Capnocytophaga sputigena pleuropneumonitis: a case report]. / Pleuropneumopathie àCapnocytophaga sputigena : à propos d'un cas.

Community-acquired pneumonia is complicated by purulent pleural effusion in approximately 28% of affected children. Its incidence has increased over the last decade. Streptococcus pneumoniae is the most frequent causal microorganism, encountered in roughly 80% of cases. We report the case of an immunocompetent 13-year-old teenager wearing orthodontic braces who suffered from pleuropneumonia due to Capnocytophaga sputigena. To date, this Gram-negative bacillus, a commensal of the buccal cavity, had never been reported to be responsible for pleural or lung infection. The clinical presentation is similar to that observed with usual bacteria, while bacterial sensitivity to betalactam antibiotics is excellent.

In vivo stimulation of connective tissue accumulation by the tripeptide-copper complex glycyl-L-histidyl-L-lysine-Cu2+ in rat experimental wounds.

The tripeptide-copper complex glycyl-L-histidyl-L-lysine-Cu2+ (GHK-Cu) was first described as a growth factor for differentiated cells. Recent in vitro data showed that it possesses several properties of a potential activator of wound repair. We investigated the effects of GHK-Cu in vivo, using the wound chamber model described previously (Schilling, J.A., W. Joel, and M.T. Shurley, 1959. Surgery [St. Louis]. 46:702-710). Stainless steel wire mesh cylinders were implanted subcutaneously on the back of rats. The animals were divided into groups that received sequential injections into the wound chamber of either saline (control group) or various concentrations of GHK-Cu. At the end of the experiments, rats were killed, wound chambers were collected, and their content was analyzed for dry weight, total proteins, collagen, DNA, elastin, glycosaminoglycans, and specific mRNAs for collagens and TGF beta. In the GHK-Cu-injected wound chambers, a concentration-dependent increase of dry weight, DNA, total protein, collagen, and glycosaminoglycan contents was found. The stimulation of collagen synthesis was twice that of noncollagen proteins. Type I and type III collagen mRNAs were increased but not TGF beta mRNAs. An increase of the relative amount of dermatan sulfate was also found. A control tripeptide, L-glutamyl-L-histidyl-L-proline, had no significant effect. These results demonstrate that GHK-Cu is able to increase extracellular matrix accumulation in wounds in vivo.

Macroscopic-microscopic characterization of the passive mechanical properties in rat soleus muscle.

The purpose of the study was to investigate changes in passive mechanical properties of the soleus muscle of the rat during the first year of life. These mechanical changes were quantified at a macroscopic (whole muscle) and a microscopic level (fiber) and were correlated with biochemical and morphological properties. Three passive mechanical tests (a relaxation test, a ramp stretch test and a stretch release cycle test) with different amplitudes and velocities were performed on isolated soleus muscles and fibers in rats at ages 1 (R1), 4 (R4) and 12 (R12) months. Mechanical parameters (dynamic and static forces, stresses and normalized stiffness) were recorded and measured. The morphological properties (size of fibers and muscles) for the three groups of rats were assessed by light microscopy which allowed us to observe the evolution of the fiber type (I, IIc and IIa) in the belly region and along the longitudinal axis of the muscle. In addition, biochemical analyses were performed at the level of the whole muscle in order to determine the collagen content. The results of the passive mechanical properties between the macroscopic (muscle) and microscopic (fiber) levels showed a similar evolution. Thus, an increase of the dynamic and static forces appeared between 1 and 4 months while a decrease of the passive tension occurred between 4 and 12 months. These mechanical changes were correlated to the morphological properties. In addition, the size of the three fibers type which grew with age could explain the increase of forces between 1 and 4 months. Furthermore, the biochemical analysis showed an increase of the collagen content during the same period which could also be associated with the increase of the passive forces. After 4 months, the passive tension decreased while the size of the fiber continued to increase. The biochemical analysis showed a decrease of the collagen content after 4 months, which could explain the loss of passive tension in the whole muscle. Concerning the similar loss at the fiber level, other assumptions are required such as a myofibril loss process and an increase of intermyofibrillar spaces. The originality of this present study was to compare the passive mechanical properties between two different levels of anatomical organization within the soleus muscle of the rat and to explain these mechanical changes in terms of biochemical and morphological properties.

[Rib fractures after chest physiotherapy: a report of 2 cases]. / Fractures costales au cours des bronchiolites aiguës virales: à propos de 2 cas.

The 2000 French consensus conference for acute viral bronchiolitis management underlined the fundamental role of chest physiotherapy. According to Chalumeau and al., rib fractures were found out in 1/1000 children hospitalized for bronchiolitis or pneumonia. However, such complication of chest physiotherapy is exceptional. We report 2 cases with third to sixth lateral rib fractures after chest physiotherapy in infants with bronchiolitis. Despite the rarity of these complications, clinicians must keep in mind this etiology while facing rib fractures in infants.

Identification of CD47/integrin-associated protein and alpha(v)beta3 as two receptors for the alpha3(IV) chain of type IV collagen on tumor cells.

Previous studies from our laboratories demonstrated that a peptide from the noncollagenous domain of the alpha3 chain of basement membrane collagen (COL IV), comprising residues 185-203, inhibits polymorphonuclear leukocyte activation and melanoma cell proliferation independently of its ability to promote cell adhesion; these properties require the presence of the triplet -SNS- at residues 189-191 (J. C. Monboisse et al., J. Biol. Chem., 269: 25475-25482, 1994; J. Han et al., J. Biol. Chem., 272: 20395-20401, 1997). More recently, we demonstrated that native COL IV and -SNS-containing synthetic peptides (10 microg/ml) added to culture medium inhibit the proliferation of not only melanoma cells but also breast, pancreas, and stomach tumor cells up to 82% and prostate tumor cells by 15%. This inhibition was shown to be dependent on a COL IV- or peptide-induced increase in intracellular cAMP (T. A. Shahan et al., Connect. Tissue Res., 40: 221-232, 1999). Attempts to identify the putative receptor(s) on tumor cells led to the isolation of five proteins (Mr 33,000, 52,000, 72,000, 95,000, and 250,000) from melanoma and prostate cells by affinity purification with the alpha3(IV)179-208 peptide. The Mr 52,000, 95,000, and 250,000 proteins were shown to be CD47/integrin-associated protein(IAP), the integrin beta3 subunit, and the alpha(v)beta3 integrin complex, respectively. The Mr 33,000 and 72,000 proteins have not yet been identified. To confirm the specificity of ligand binding to the receptors, cell membranes from either melanoma or prostate tumor cells were pretreated with the unlabeled ligand alpha3(IV)187-191 (-YYSNS-); alternatively, the peptide was pretreated with a peptide-reactive monoclonal antibody (A5D7) before receptor isolation. These treatments inhibited the purification of CD47/IAP, the integrin beta3 subunit, and the alpha(v)beta3 integrin complex from tumor cells. Furthermore, cells treated with CD47/IAP- or the alpha(v)beta3 integrin-reactive antibodies prevented the alpha3(IV)185-203 peptide from inhibiting cell proliferation and the subsequent rise in intracellular cAMP. Pretreating cells with the alpha3(IV)187-191 (-YYSNS-) peptide also inhibited their adhesion to the alpha3(IV)185-203 peptide substrate, whereas the inactive alpha1(IV)185-203 peptide, from the same region of the alpha1 chain as the alpha3(IV)185-203 peptide, had no effect. Incubation of cells with either CD47/IAP and/or alpha(v)beta3 integrin-reactive antibodies inhibited their adhesion to the alpha3(IV)185-203 peptide, whereas antibodies to the beta1 and beta2 integrin subunits were without effect. These data suggest that ALC-COL IV, through its alpha3(IV) chain, inhibits tumor cell proliferation using the receptors CD47/IAP and the alpha(v)beta3 integrin.

A specific sequence of the noncollagenous domain of the alpha3(IV) chain of type IV collagen inhibits expression and activation of matrix metalloproteinases by tumor cells.

The invasive properties of melanoma cells correlate with the expression of matrix metalloproteinases (MMPs) and their physiological modulators (tissue inhibitors of metalloproteinase and membrane-type MMPs) and with that of the alphaVbeta3 integrin. We investigated the effect of anterior lens capsule type IV collagen and of the alpha3(IV) collagen chain on the invasive properties of various tumor cell lines (HT-144 melanoma cells, HT-1080 fibrosarcoma cells). We demonstrated that anterior lens capsule type IV collagen or specifically the synthetic peptide alpha3(IV) 185-203 inhibited both the migration of melanoma or fibrosarcoma cells as well as the activation of membrane-bound MMP-2 by decreasing the expressions of MT1-MMP and the beta3 integrin subunit.

Intercomparison of methods of coupling between convection and large-scale circulation: 2. Comparison over nonuniform surface conditions.

As part of an international intercomparison project, the weak temperature gradient (WTG) and damped gravity wave (DGW) methods are used to parameterize large-scale dynamics in a set of cloud-resolving models (CRMs) and single column models (SCMs). The WTG or DGW method is implemented using a configuration that couples a model to a reference state defined with profiles obtained from the same model in radiative-convective equilibrium. We investigated the sensitivity of each model to changes in SST, given a fixed reference state. We performed a systematic comparison of the WTG and DGW methods in different models, and a systematic comparison of the behavior of those models using the WTG method and the DGW method. The sensitivity to the SST depends on both the large-scale parameterization method and the choice of the cloud model. In general, SCMs display a wider range of behaviors than CRMs. All CRMs using either the WTG or DGW method show an increase of precipitation with SST, while SCMs show sensitivities which are not always monotonic. CRMs using either the WTG or DGW method show a similar relationship between mean precipitation rate and column-relative humidity, while SCMs exhibit a much wider range of behaviors. DGW simulations produce large-scale velocity profiles which are smoother and less top-heavy compared to those produced by the WTG simulations. These large-scale parameterization methods provide a useful tool to identify the impact of parameterization differences on model behavior in the presence of two-way feedback between convection and the large-scale circulation.

Human type VI collagen: isolation and characterization of alpha 1 and alpha 2 chains by two-dimensional preparative gel electrophoresis.

Two 140 kDa collagenous glycoproteins were isolated from 5 M guanidinium chloride extracts of human uterine leiomyoma by two-dimensional preparative gel electrophoresis. The glycoproteins represented the major concanavalin A binding fraction of the extract and were also present in adult human skin. On two-dimensional gel electrophoresis the glycoproteins appeared as elongated spots, indicating variations of their isoelectric points from 5 to 6. These glycoproteins were disulfide-bonded components of high molecular mass protein and, after reduction, became sensitive to collagenase treatment that generated peptides corresponding in size to those of the noncollagenous domains of type VI collagen. Antisera raised against these purified glycoproteins reacted with either pepsin-derived alpha 1(VI) or pepsin-derived alpha 2(VI) chains but not with alpha 3(VI) chain of human type VI collagen. Reciprocally, these glycoproteins reacted with monoclonal antibodies against type VI collagen. These results indicate that the glycoproteins represent the integral alpha 1 and alpha 2 chains of type VI collagen. The globular domains of alpha 1(VI) and alpha 2(VI) chains remaining after collagenase treatment appeared on two-dimensional gel electrophoresis as elongated spots, suggesting that the noncollagenous portions determine the well known microheterogeneity of the molecule. The differences in isoelectric points between and within alpha chains may facilitate the formation of microfibrillar network.

Effects of preformed proline and proline amino acid precursors (including glutamine) on collagen synthesis in human fibroblast cultures.

A technique of derivatizing proline and 4-hydroxyproline with 7-chloro-4-nitrobenzo-2-oxa-1,3-diazole was used to measure the radioactivities, concentrations and specific activities of proline and hydroxyproline. The technique was used to study the conditions of procollagen synthesis in cultured human foreskin fibroblasts. Procollagen synthesis appeared to be independent of the proline concentration in the medium, in the presence of glutamine, when monitored by the assay of non-dialyzable hydroxyproline, but not when monitored by [14C]proline incorporation. In the absence of unlabelled proline added to labelled proline in the medium, the specific activity of the secreted procollagen did not reach a plateau over a 24-h period. When the medium was supplemented with glutamine, glutamic acid, or aspartic acid, both the radioactivity and concentration of intracellular free proline decreased. Pyrrolidone-2-carboxylic acid and ornithine both induced a slight increase in concentration of the intracellular free proline. Glutamine competed with [14C]proline for incorporation into prolyl-tRNA and procollagen, independently of free intracellular proline, and it stimulated the biosynthesis of procollagen (expressed as non-dialyzable hydroxyproline) by a factor of 2.3.

Glutamine increases collagen gene transcription in cultured human fibroblasts.

We have previously shown that glutamine stimulates the synthesis of collagen in human dermal confluent fibroblast cultures (Bellon, G. et al. [1987] Biochim. Biophys. Acta, 930, 39-47). In this paper, we examine the effects of glutamine on collagen gene expression. A dose-dependent effect of glutamine on collagen synthesis was demonstrated from 0 to 0.25 mM followed by a plateau up to 10 mM glutamine. Depending on the cell population, collagen synthesis was increased by 1.3-to 2.3-fold. The mean increase in collagen and non-collagen protein synthesis was 63% and 18% respectively. Steady-state levels of alpha 1(I) and alpha 1(III) mRNAs, were measured by hybridizing total RNA to specific cDNA probes at high stringency. Glutamine increased the steady-state level of collagen alpha 1(I) and alpha 1(III) mRNAs in a dose-dependent manner. At 0.15 mM glutamine, collagen mRNAs were increased by 1.7-and 2.3-fold respectively. Nuclear run-off experiments at this concentration of glutamine indicated that the transcriptional activity was increased by 3.4-fold for the pro alpha 1(I) collagen gene. The effect of glutamine on gene transcription was also supported by the measurement of pro alpha 1(I) collagen mRNA half-life since glutamine did not affect its stability. Protein synthesis seemed to be required for the glutamine-dependent induction of collagen gene expression since cycloheximide suppressed the activation. The effect of glutamine appeared specific because analogues and/or derivatives of glutamine, such as acivicin, 6-diazo-5-oxo-L-norleucine, homoglutamine, ammonium chloride and glutamate did not replace glutamine. The influence of amino acid transport systems through plasma membrane was assessed by the use of 2(methylamino)-isobutyric acid and beta 2-aminobicyclo-(2.2.1)-heptane-2-carboxylic acid. The glutamine-dependent induction of collagen gene expression was found to be independent of transport system A but dependent on transport system L whose inhibition induced a decrease in pro alpha 1(I) collagen gene transcription by an unknown mechanism. Thus, glutamine, at physiological concentrations, indirectly regulates collagen gene expression.

Quantification of collagen synthesis by cultured human glomerular cells.

This study examines the amount of total collagen and its different fractions synthesized by cultured human glomerular epithelial and mesangial cells. Two quantitative techniques were used, namely estimation of proline (Pro) plus hydroxyproline (Hyp) present in the collagenase-sensitive proteins and ELISA or RIA of the different types of collagen. In addition, the pattern of collagen synthesis for both cell types was further examined using immunofluorescence methods and polyacrylamide gel electrophoresis. Glomerular epithelial cells synthesized mainly type IV collagen and it was, for the better part, cell-associated. Mesangial cells synthesized approx. 4-times more collagen than epithelial cells. Type I collagen was predominant, but there were also type IV and III collagens. Secreted and cell-associated collagens were present in roughly equivalent amounts. In both cell lines 10-14% of the newly synthesized collagen had been degraded within the cells. These results provide quantitative data on collagen synthesis by human glomerular cells in vitro and represent the first necessary stage before studying which factors mediate the development of glomerular sclerosis.

Matrikines in the regulation of extracellular matrix degradation.

The term "matrikines" was coined for designating peptides liberated by partial proteolysis of extracellular matrix macromolecules, which are able to regulate cell activities. Among these peptides, some of them may modulate proliferation, migration, protease production, or apoptosis. In this review, we summarize the activity of matrikines derived from elastin and interstitial or basement membrane collagens on the regulation of matrix metalloproteinases expression and/or activation, and on the plasminogen/plasmin system. Due to their activity, matrikines may play a significant role in physiological or pathological processes such as wound healing or tumor invasion.

A peptide of the alpha 3(IV) chain of type IV collagen modulates stimulated neutrophil function via activation of cAMP-dependent protein kinase and Ser/Thr protein phosphatase.

Previous reports from our laboratories showed that type IV collagen from anterior lens capsule (ALC) inhibited stimulated neutrophil function. This property was shown to reside in the region comprising residues 185-203 of the non-collagenous domain (NC1) of the alpha 3(IV) chain. We also reported that ALC-type IV collagen or the synthetic alpha 3(IV) 185-203 peptide, induced a rise in intracellular cAMP which persisted for up to 60 minutes. In the present work we extend our previous studies on signal transduction by alpha 3(IV) 185-203 and we provide new data showing the involvement of cAMP-dependent PKA and protein phosphatases. The data also show that the alpha 3(IV) peptide triggered a rise in intracellular calcium that was dependent on phospholipase C activation. Inhibitors of the Ca(2+)/calmodulin system suppressed both the alpha 3(IV) 185-203 peptide-induced cAMP increase and the inhibitory activity of the peptide on f-Met-Leu-Phe triggered O(2)(-) generation. When alpha 3(IV) 185-203 peptide-induced calcium mobilization was blocked by U-73122, an inhibitor of phospholipase C activation, or by BAPTA/AM, a chelator of intracellular calcium, the inhibitory effect of the peptide on PMA-triggered O(2)(-) production was also abolished. These findings provide evidence that signal transduction by the alpha 3(IV) peptide occurs via pathways which involve calcium. Indeed, the cAMP increase was shown to be mediated by adenosine and adenosine A2 receptors and required calcium elevation, since adenosine deaminase, theophilline, dimethylpropargylxanthine, trifluoperazine or autocamtide-2 related inhibitory peptide, suppressed the activity of the alpha 3(IV) peptide. The inhibitory effect of the peptide on f-Met-Leu-Phe-induced O(2)(-) generation was slightly affected by 1 microM KT5720 or H89, two inhibitors of cAMP-dependent PKA, but was completely suppressed by 10 nM calyculin A or 10 microM okadaic acid, two inhibitors of ser/thr phosphatases. These results suggest that Ser/Thr protein phosphatases and/or cAMP-dependent PKA are involved in signal transduction by the alpha 3(IV) 185-203 peptide and is consistent with the concept that adenosine receptor occupancy modulates neutrophil function.

[Kidney transplanted child and sport practices]. / Enfant transplanté rénal et pratiques sportives.

OBJECTIVE: Evaluation of physical capacity in kidney transplanted children for sport practice adequacy. POPULATION AND METHODS: A retrospective study was carried out in 32 children transplanted at least one year before evaluation. We studied auxology, respiratory function testing, cardiovascular parameters at rest and after exercise, and aerobic capacity performed during a triangular effort test. RESULTS: Kidney transplanted children were smaller and had a higher body mass index (IMC). Breathing parameters and cardiac ultrasound examinations were normal in all but one child. After exercise, four children had high systolic blood pressure requiring a treatment adaptation. Lower values of maximal aerobic power (Pmax) and oxygen maximal uptake (VO2max) were noticed, mainly in girls. CONCLUSION: Kidney transplanted children have a good physical exercise tolerance. Therefore they can be allowed to practise sports at school or in a club after a normal effort test (taking into account the risk of transplant trauma).

[Sudden unexpected death of cardiac origin in the 6 to 18 years population. Pathologic data. Role of sports? How can we prevent it?]. / Mort subite inopinée d'origine cardiaque entre 6 et 18 ans. Données anatomopathologiques. Rôle du sport ? Prévention ?

UNLABELLED: There is only a few data on sudden unexpected death (SUD) in the pediatric population, as well as the role of sport. MATERIALS AND METHODS: Between 1980 and 2003, 2220 autopsies were performed at the Lyon's forensic institute for SUD (all ages) as defined by world health organization. RESULTS: Fifty-seven cases of SUD of cardiac origin concerned 6 to 18-year-old children. Hypertrophic cardiomyopathy and arrhythmogenic right ventricular cardiomyopathy remained the main causes of SUD. Mitral valve prolapse were frequently observed and for the most part of the cases associated with other diseases. Twenty-four were observed during physical activity. CONCLUSION: Our study confirms the low incidence of SUD and its male predominance in the pediatric population (47 males, 10 females). It seems that physical activity is not the decisive factor for SUD. The authors emphasized the necessity to get a rapid access to cardiac resuscitation devices, as well as the formation of collaborators. Some preventive measures could be done.