[Evaluation of the COPD Assessment Test in patients with stable COPD]. / Évaluation du COPD Assessment Test (CAT) chez des patients BPCO en état stable.

INTRODUCTION: The COPD Assessment Test (CAT) is a new simple tool developed for assessing health-related quality of life in patients with COPD. The characteristics of the score derived from the CAT as a function of various parameters of evaluation of the severity of COPD remain to be described. METHODS: The CAT was submitted prospectively to 213 consecutive stable ambulatory COPD patients assessed in a tertiary care hospital. The discriminative value of the CAT was analysed as well as its association with various parameters of interest. RESULTS: The progressive increase in the CAT score with the severity of the disease as assessed by the GOLD stages and the BODE index, as well as the level of dyspnoea, demonstrates the discriminative capacity of the CAT. In multivariate analysis, only the RV/TLC (residual volume/total lung capacity) and the 6-minute walk distance were significantly associated with the CAT score, explaining only 27 % of its variability. The inclusion of dyspnoea in the model explained 42 % of the CAT score variability, only dyspnoea and the RV/TLC ratio being significantly associated. CONCLUSION: The CAT has good discriminative characteristics that are similar to more complex tools designed to assess health-related quality of life in patients with COPD.

Interest of (18)F-FDG PET-CT scanning for staging and management of merkel cell carcinoma: a retrospective study of 15 patients.

BACKGROUND: The additional benefit of 18FDG-Positron Emission Tomography-Computed Tomography (FDG PET-CT) compared with conventional imaging is still a controversial issue in MCC. OBJECTIVES: This study was designed to evaluate the ability of FDG PET-CT to detect secondary lesions clinically inconspicuous and not shown by conventional imaging. METHODS: Clinical records of 15 MCC patients were retrospectively reviewed to investigate the specific interest of FDG PET-CT compared with X-computed tomography (CT). The main endpoint was the ability of FDG PET-CT to detect secondary lesions and the possible resulting changes in disease staging and management compared with pre-FDG PET-CT data including clinical examination, sentinel lymph node biopsy (SLNB), and diagnostic CT. RESULTS: FDG PET-CT was relevant with a single false negative result and led to significant changes in disease staging and management in 46% of patients compared with clinical examination alone. However, additional secondary lesions not detected by CT were evidenced during follow-up in a single patient with an already known metastatic disease, data which did not result in any change in staging and treatment. Sensitivity, specificity, positive predictive value and negative predictive value were respectively 0.66, 1, 1 and 0.8 for SLNB, 0.89, 1, 1 and 0.93 for CT and 0.89, 1, 1 and 0.93 for FDG PET-CT. No additional neoplasm was detected by FDG PET-CT. CONCLUSION: Although FDG PET-CT is of questionable value in MCC management when used in parallel with CT, it may be considered as a valuable option as a single whole-body survey procedure.

[Unusual axillary apocrine carcinoma of the skin: histological diagnostic difficulties]. / Carcinome apocrine cutané axillaire inhabituel : difficultés diagnostiques histologiques.

BACKGROUND: Apocrine carcinoma of the skin (ACS) is a rare adnexal neoplasm presenting as an indurated slow-growing dermal or subcutaneous plaque that often occurs in the axilla. Histological distinction between ACS and cutaneous metastases of breast carcinoma may be difficult. OBSERVATION: A 64-year-old man presented with a slowly growing left axillary mass, which he had noticed for 2 years, without any other functional or clinical symptoms. Histological examination of the skin biopsy showed dermal invasion with atypical cells in an "Indian file" pattern. The pattern of the tumour and immunohistochemical staining suggested a diagnosis of breast carcinoma metastasis. However, the history of a slow-growing tumour and negative initial testing for a primary adenocarcinoma supported the hypothesis of ACS. DISCUSSION: A 100 cases of ACS have been reported in the literature with the main site being the axillary area. The differential diagnostic between axillary ACS and metastasis of lobular breast carcinoma has been discussed recently. Diagnosis may be difficult since the pattern of the tumour can be misleading and immunomarkers are not always specific. CONCLUSION: We report a new case of axillary ACS histologically mimicking lobular breast carcinoma metastasis.

[Multiple Bowen disease of the lower limbs in elderly women: a rare clinical subset involving therapeutic difficulties]. / Maladies de Bowen multiples des membres inférieurs chez les femmes âgées : une forme clinique particulière et de traitement difficile.

BACKGROUND: Cutaneous Bowen's disease (CBD) is a form of intraepithelial squamous cell carcinoma that usually presents as a solitary lesion. We report four similar cases of a peculiar and well-delimited clinical subset of multiple Bowen's disease seen in the lower limbs in elderly women and associated with specific therapeutic problems. OBSERVATIONS: Four women aged over 70 years presented with multiple CBD limited to the lower limbs associated with squamous cell and superficial basal cell carcinomas along with actinic keratosis. No significant aetiological factors were present apart from chronic sun exposure other than one case possibly involving immunodeficiency. The four patients were treated using photodynamic therapy, and partial clinical response and good tolerance were observed. DISCUSSION: These four cases share numerous clinical similarities: elderly women, markers of chronic sun exposure, lack of other aetiological factors such as arsenic or irradiation, localization of the lesions (multiple and/or continuous layer pattern, restricted to the lower limbs in all cases) and a chronic course. The frequency of this subset is probably underestimated due to absence of biopsies or to inconclusive histology reports. Photodynamic therapy yields valuable results with a good efficacy/safety ratio compared to imiquimod or 5-fluorouracil. However, while this treatment could be considered a first-line option in multiple CBD, its therapeutic value requires more detailed evaluation.

[Thoracic hyperinflation and COPD. Beyond respiratory mechanics and dyspnea]. / Distension thoracique et BPCO, au-delà de la mécanique respiratoire et de la dyspnée.

INTRODUCTION: The interactions between thoracic hyperinflation and respiratory mechanics, as well as their importance in the development of dyspnoea, are now well understood. We discuss here other aspects of thoracic hyperinflation that are relevant in the context of COPD. BACKGROUND: Both clinical examination and imaging have a limited role in the detection of thoracic hyperinflation for which respiratory function tests remain the gold standard. Imaging, however, has led us to a better understanding of how the chest wall accommodates for hyperinflation, which mainly affects the diaphragm, particularly its vertical portion. More recently the adverse effects of hyperinflation on both pulmonary and systemic haemodynamics and life expectancy have been highlighted. VIEWPOINTS AND CONCLUSIONS: Thoracic hyperinflation affecting patients with COPD has important consequences that extend far beyond the framework of respiratory mechanics. In the future the importance of hyperinflation as a determinant of the prognosis should be confirmed and the most relevant parameter, in this context, defined. The potential links between thoracic hyperinflation and systemic inflammation should also be clarified.

Skeletal muscle force and functional exercise tolerance before and after lung transplantation: a cohort study.

We investigated the impact of lung transplantation and outpatient pulmonary rehabilitation after lung transplantation on skeletal muscle function and exercise tolerance. Skeletal muscle force (Quadriceps force, QF), exercise tolerance (six minute walking distance, 6MWD) and lung function were assessed in 36 patients before and after lung transplantation. Seventeen male and 19 female patients (age 57 +/- 4) showed skeletal muscle weakness before the transplantation. A further 32 +/- 21% reduction was seen 1.2 (interquartile range 0.9 to 2.0) months after LTX. The number of days on the intensive care unit was significantly related to the observed deterioration in muscle force after LTX. At this time point 6MWD was comparable to pre-LTX. Rehabilitation started 37 (IQR 29 to 61) days after LTX. 6MWD and QF improved significantly (140 +/- 91 m, and 35 +/- 48%, respectively; p < 0.05) with rehabilitation. QF remained below pre-LTX values. The evolution of the 6MWD with the transplantation and the subsequent rehabilitation was less in female compared to male subjects. We conclude that muscle strength deteriorates after lung transplantation, particularly in patients with long ICU stay. Outpatient pulmonary rehabilitation is feasible after lung transplantation and leads to recovery of skeletal muscle function. In female patients this recovery is significantly less compared to male recipients.

[Secretory immunity of the airways]. / Immunité sécrétoire des voies respiratoires.

INTRODUCTION: Continuous exposure of the respiratory tract to inhaled particles and microbes implies the presence of effective defence mechanisms at a bronchial and alveolar level. STATE OF ART: Among the mechanisms involved secretory mucosal immunity contributes considerably to the defence of the bronchial tree. This immunity depends essentially on the active trans-epithelial transport of IgA involved in both innate non-specific and acquired specific immunity. Recently an IgA receptor has been identified on the surface of phagocytes including alveolar macrophages, establishing a link between alveolar and bronchial defences. PERSPECTIVES: The respiratory mucosa represents a crucial interface between the host and its environment, and should provide in the future a new target for the development of diagnostic and therapeutic tools. CONCLUSIONS: Beyond its function as an anatomical barrier the bronchial epithelium possesses a secretory activity that is essential for the protection of the lung. Despite a better understanding of mucosal immunity this secretory activity and in particular the part played by IgA remains to be elucidated.

Unnatural enantiomers of 5-azacytidine analogues: syntheses and enzymatic properties.

2'-Deoxy-beta-L-5-azacytidine(L-Decitabine), beta-L-5-azacytidine, and derivatives were stereospecifically prepared starting from L-ribose or L-xylose. D- and L-enantiomers of 2'-deoxy-beta-5-azacytidine were weak substrates of human recombinant deoxycytidine kinase (dCK), whereas both enantiomers of beta-5-azacytidine or the L-xylo-analogues were not substrates of the enzyme. None of the reported derivatives of beta-L-5-azacytidine was a substrate of human recombinant cytidine deaminase (CDA).

Maedi-visna virus, a model for in vitro testing of potential anti-HIV drugs.

A series of beta-D- and beta-L-cytidine analogues were evaluated for their inhibitory effect on the replication of maedi-visna virus (MVV) strains KV1772 and MV1514 cultured on sheep choroid plexus cells and the sheep chondrocyte cell line G81092, respectively. Eleven cytidine analogues were selected for the anti-viral test. Five of them belong to the family of the 2',3'-dideoxycytidine analogues, well known for their activity against human immunodeficiency virus (HIV). The others, all newly synthesized, were potential anti-viral and/or anti-leukemic agents. None of the compounds under study had a toxic effect in both anti-viral assay systems up to a 300 microM concentration. Based on the cytopathic effects (CPE), the virus replication was completely inhibited by the five 2',3'-dideoxycytidine analogues at a concentration of 50 microM, whereas the others six newly synthesized compounds induced titre reductions of 4-5 log units. The effective concentration causing 50% reduction of CPE (EC50) was of 5 microM for the five 2',3'-dideooxycytidine analogues and for beta-L-XyloFc, whereas the value of 50 microM was found for the b-L-XyloC and the four 5-azacytidine compounds tested. All these data reveal a good correlation between inhibition of MVV replication by several nucleoside cytidine analogues and their reported anti-HIV activity.

The enantioselectivity of enzymes involved in current antiviral therapy using nucleoside analogues: a new strategy?

This review is primarily intended for synthetic bio-organic chemists and enzymologists who are interested in new strategies in the design of virus inhibitors. It is an attempt to assess the importance of the enzymatic properties of L-nucleosides and their analogues, particularly those that are active against viruses such as human immunodeficiency virus (HIV), hepatitis B virus (HBV), herpes simplex virus (HSV), etc. Only data obtained with purified enzymes have been considered and discussed. The examined enzymes include nucleoside- or nucleotide-phosphorylating enzymes, catabolic enzymes, viral target enzymes and cellular polymerases. The enantioselectivities of these enzymes were determined from existing data and are significant only when a sufficient number of enantiomeric pairs of substrates could be examined. The reported data emphasize the weak enantioselectivities of cellular or viral nucleoside kinases and some viral DNA polymerases. Thus, cellular deoxycytidine kinase has a considerably relaxed enantioselectivity with respect to a large number of nucleosides or their analogues, and it occupies a strategic position in the intracellular activation of the compounds. Similarly, HIV-1 reverse transcriptase often has a relatively weak enantioselectivity and can be inhibited by the 5-triphosphates of a large series of L-nucleosides and analogues. In contrast, degradation enzymes, such as adenosine or cytidine deaminases, generally demonstrate strict enantioselectivities favouring D-enantiomers and are used by chemists in asymmetric syntheses. The weak enantioselectivities of some enzymes involved in nucleoside metabolism are more or less pronounced, and one enantiomer or the other is favoured depending on the substrate. This suggests that the low enantioselectivity is fortuitous and does not result from evolutionary pressure, since these enzymes do not create or modify asymmetric centres in substrates. The combined enantioselectivities of the enzymes examined in this review strongly suggest that the field of L-nucleosides and their analogues should be systematically explored in the search for new virus inhibitors.

A semantic-based kernel for advanced health information systems.

This paper reports on the design and development of an infrastructure allowing one to share and exchange multimedia data in the context of a health network. A single technology exploiting a semantic model of the hospital universe provides users with information and data of diverse origins, generated by the various actors or departments of the health organization. Functions provided include act management and patient record management governed by domain semantics. The functionality has been validated through laboratory experiments against the requirements of protocol directed care and health networks. The functionality is integrated into a clinician workstation exploited in the Internet/Intranet environment thanks to a commercial browser. These results have been obtained with the support of several projects in the frame of the Health-Care Telematics Applications Programme of the European Community and of the Eurêka Programme.

Possible role of two phenylalanine residues in the active site of human cytidine deaminase.

Site-directed mutagenesis on human cytidine deaminase (CDA) was employed to mutate specifically two highly conserved phenylalanine residues, F36 and F137, to tryptophan; at the same time, the unique tryptophan residue present in the sequence at position 113 was mutated to phenylalanine. These double mutations were performed in order to have for each protein a single tryptophan signal for fluorescence studies relative to position 36 or 137. The mutant enzymes thus obtained, W113F, F36W/W113F and F137W/W113F, showed by circular dicroism and thermal stability an overall structure not greatly affected by the mutations. The titration of Trp residues by N-bromosuccinimide (NBS) suggested that residue W113 of the wild-type CDA and W36 of mutant F36W/W113F are buried in the tertiary structure of the enzyme, whereas the residue W137 of mutant F137W/W113F is located near the surface of the molecule. Kinetic experiments and equilibrium experiments with FZEB showed that the residue W113 seems not to be part of the active site of the enzyme whereas the Phe/Trp substitution in F36W/W113F and F137W/W113F mutant enzymes had a negative effect on substrate binding and catalysis, suggesting that F137 and F36 of the wild-type CDA are involved in a stabilizing interaction between ligand and enzyme.

Unnatural enantiomers of 5-azacytidine analogues: syntheses and enzymatic properties.

Although 2'-deoxy-beta-D-5-azacytidine (Decitabine) and beta-D-5-azacytidine display potent antileukemic properties, their therapeutic use is hampered by their sensitivity to nucleophiles and to deamination catalysed by cytidine deaminase. As shown earlier [Shafiee M., Griffon J.-F., Gosselin G., Cambi A., Vincenzetti S., Vita A., Erikson S., Imbach J.-L., Maury G., Biochem. Pharmacol. 56 (1998) 1237-1242], beta-L-enantiomers of cytidine derivatives are resistant to cytidine deaminase. We thus synthesized several 5-azacytosine beta-L-nucleoside analogues to evaluate their enzymatic and biological properties. 2'-Deoxy-beta-L-5-azacytidine (L-Decitabine), beta-L-5-azacytidine, 1-(beta-L-xylo-furanosyl)5-azacytosine, and 1-(2-deoxy-beta-L-threo-pentofuranosyl)5-azacytosine were stereospecifically prepared starting from L-ribose and L-xylose. D- and L-enantiomers of 2'-deoxy-beta-5-azacytidine were weak substrates of human recombinant deoxycytidine kinase (dCK) compared to beta-D-deoxycytidine, whereas both enantiomers of beta-5-azacytidine or the L-xylo-analogues were not substrates of the enzyme. As expected, none of the presently reported derivatives of beta-L-5-azacytidine was a substrate of human recombinant cytidine deaminase (CDA). The prepared compounds were tested for their activity against HIV and HBV and they did not show any significant activity or cytotoxicity. In the case of L-Decitabine, this suggests that the enantioselectivities of concerned enzymes other than dCK and CDA might not be favourable.

Low enantioselectivities of human deoxycytidine kinase and human deoxyguanosine kinase with respect to 2'-deoxyadenosine, 2'-deoxyguanosine and their analogs.

The antiviral activity of L-nucleoside analogs depends in part on the enantioselectivity of nucleoside kinases which catalyse their monophosphorylation. The substrate properties of human recombinant deoxycytidine kinase (dCK) and human recombinant deoxyguanosine kinase (dGK) with respect to L-adenosine and L-guanosine analogs, in the presence of saturating amounts of ATP and relatively high concentrations of substrates, demonstrated a marked lack of enantioselectivity of both these enzymes. Human dCK catalysed the phosphorylation of D- and L-enantiomers of beta-dA, beta-araA, and beta-dG with enantioselectivities favoring the unnatural enantiomer for the adenosine derivatives and the natural enantiomer for 2'-deoxyguanosine. No other tested L-adenosine or L-guanosine analog was a substrate of dCK. Similarly, D- and L-enantiomers of beta-dA, beta-araA, and beta-dG were substrates of human dGK but with different enantioselectivities compared to dCK, especially concerning beta-dA. The present results indicate that human dCK and dGK have similar properties including substrate properties, relaxed enantioselectivities, and possibly catalytic cycles.

Synthesis of new fluorescent nucleoside analogues and application to the study of human deoxycytidine kinase.

We have determined the affinity of human deoxycytidine kinase with respect to new fluorescent N-methylanthraniloyl cytidine derivatives or non fluorescent enantiomeric cytidine analogues. New results regarding the enantioselectivity and the mechanism of the enzyme are presented.

Derivatives of L-adenosine and L-guanosine as substrates for human deoxycytidine kinase.

A series of analogues of L-adenosine and of L-guanosine, including beta-L-dA, beta-L-Ado, beta-L-araA, and beta-L-dG, have been shown to be substrates of human deoxycytidine kinase thus demonstrating the complete lack of enantioselectivity of this enzyme.

A comparison of the enantioselectivities of human deoxycytidine kinase and human cytidine deaminase.

The stereoselectivities of recombinant human deoxycytidine kinase (EC 2.7.1.74) (dCK) and of recombinant human cytidine deaminase (EC 3.5.4.5) (CDA) were investigated with respect to a series of cytidine analogs, most of them having the unnatural L-stereochemistry. The enantioselectivity of dCK was always low and generally favored the L-enantiomers in the case of beta-2',3'-dideoxycytidine (beta-ddC), 5-fluoro-beta-2',3'-dideoxycytidine (beta-FddC) and beta-cytidine (beta-riboC). Concerning beta-2'-deoxycytidine, dCK showed a preference for the D-enantiomer. All other examined beta-L-cytidine analogs, [1-beta-L-lyxofuranosyl cytosine (beta-L-lyxoC), l-beta-L-xylofuranosyl cytosine (beta-L-xyloC), and 5-fluoro-1-beta-L-xylofuranosyl cytosine (beta-L-Fxylo C)], were substrates of dCK regardless of the nature of the pentose. None of the studied alpha-L-anomers (alpha-L-riboC, alpha-L-araC, alpha-L-lyxoC, or alpha-L-xyloC) was a substrate of dCK. Contrasting with the relaxed enantioselectivity of dCK, CDA had a strict requirement for D-cytidine analogs since none of the already listed beta-L- or alpha-L analogs was a substrate or an inhibitor of the enzyme. The conjunction of the preceding stereochemical properties of dCK and CDA confers to L-cytidine analogs important potentialities in antiviral and anticancer therapies.

Enzymatic properties of the unnatural beta-L-enantiomers of 2',3'-dideoxyadenosine and 2',3'-didehydro-2',3'-dideoxyadenosine.

The beta-L-enantiomers of 2',3'-dideoxyadenosine and 2',3'-didehydro-2',3'-dideoxyadenosine have been stereospecifically synthesized. In an attempt to explain the previously reported antiviral activities of these compounds, their enzymatic properties were studied with respect to adenosine kinase, deoxycytidine kinase, adenosine deaminase, and purine nucleoside phosphorylase. Adenosine deaminase was strictly enantioselective and favored beta-D-ddA and beta-D-d4A, whereas adenosine kinase and purine nucleoside phosphorylase had no apparent substrate properties for the D- or L-enantiomers of beta-ddA or beta-d4A. Human deoxycytidine kinase showed a remarkable inversion of the expected enantioselectivity, with beta-L-ddA and beta-L-d4A having better substrate efficiencies than their corresponding beta-D-enantiomers. Our results demonstrate the potential of beta-L-adenosine analogues as antiviral agents and suggest that deoxycytidine kinase has a strategic importance in their cellular activation.

Study of the substrate-binding properties of bovine liver adenosine kinase and inhibition by fluorescent nucleoside analogues.

Adenosine kinase (AK) catalyzes the phosphorylation of adenosine to AMP with ATP as phosphate donor. Intrinsic fluorescence of bovine liver AK was shown previously to be a sensitive probe to quantify the binding of substrates to the enzyme [Elaloui, A., Divita, G., Maury, G., Imbach, J.-L. & Goody, R. S. (1994) Eur. J Biochem. 221, 839-846]. AK contains two catalytic, sites: a high-affinity site, which binds adenosine and AMP selectively; and a site for ATP and ADP. In the present work, these two sites were characterized by combining the quenching of protein fluorescence induced by the binding of the ligands and the fluorescence enhancement observed upon binding of the N-methylanthraniloyl-derivated nucleotides or adenosine. A new fluorescent analog of adenosine, 5'-N-methylanthraniloyl-adenosine, was synthesized and shown to bind selectively to the high-affinity adenosine-binding site with an affinity similar to that of adenosine (Kd 1 microM). In contrast, 2'(3')-N-methylanthraniloyl derivatives of ATP, adenosine (5')tetraphospho(5')adenosine (Ap4A), and adenosine (5')pentaphospho(5')adenosine (Ap5A), bind to the enzyme at the ATP site. Methylantraniloyl derivatives of ATP and adenosine were used as tools for selective characterization of a series of adenosine analogues. The bisubstrate inhibitors Ap4A and Ap5A bind to the ATP site with high affinity and apparently not to the adenosine site, thus acting more as ATP analogues than true bisubstrate ligands. The binding properties of a series of adenosine analogues were strongly dependent on the structural modifications on adenosine. The analogues modified at positions 2' or 3' show similar affinities for AK as that of adenosine, whereas adenosine analogues modified at the base present a relatively low affinity for the enzyme.