[Prevalence and characteristics of Guillain-Barré syndromes associated with Campylobacter jejuni and cytomegalovirus in greater Paris]. / Prévalence et caractéristiques des syndromes de Guillain-Barré associés à Campylobacter jejuni et au cytomégalovirus en région parisienne.

AIM OF THE STUDY: We aimed to study prevalence and features of Campylobacter jejuni and cytomegalovirus (CMV)-associated Guillain-Barré syndromes (GBS) in a French care unit. PATIENTS AND METHODS: We studied 264 patients with GBS admitted at Raymond Poincaré hospital (Garches) between 1996 and 2001. Clinical data were obtained prospectively. Sera were collected at patients entry and tested retrospectively for anti-C. jejuni, anti-CMV and antigangliosides GM1 et GM2 antibodies. RESULTS: GBS associated with a serological evidence for a recent C. jejuni infection were the more frequent (58/264, 22%); they affected predominantly men of mature years (mean age: 51.3 years; sex-ratio M/F: 1.76), mostly after a gastrointestinal illness (52%); they were often pure motor forms (57%), were severe (mechanical ventilation: 40%) and associated to an anti-GM1 IgG and/or IgM response (44%). GBS cases involving a primary CMV infection were less frequent (40/264, 15%), but were severe too (mechanical ventilation: 37.5%); they occurred preferentially in young women (mean age: 35.9 years; sex-ratio MF: 0.82), often after respiratory tract symptoms (28%) or an influenza-like syndrome (15%) and were frequently associated with sensory loss (73%) and with an anti-GM2 IgM response (47%). CONCLUSION: C. jejuni and CMV proved to be major triggering agents of GBS in France. They are associated with distinct presentations, which are both severe.

A potent and selective NPY Y5 antagonist reduces food intake but not through blockade of the NPY Y5 receptor.

AIM: These studies were performed to test the hypothesis that endogenous neuropeptide Y (NPY) acting on the NPY Y(5) receptor subtype contributes to the control of food intake. The hypothesis was tested using S 25585-a newly synthesized NPY Y(5) receptor antagonist. METHODS AND RESULTS: S 25585 was shown to be a high-affinity antagonist of the NPY Y(5) receptor subtype (IC(50) 5 nM) with no significant affinity toward other NPY receptor subtypes and over 40 other receptors, channels or uptake systems. S 25585 (7.5 mg/kg, i.p.) did not induce a conditioned taste aversion, significantly alter need-induced sodium appetite or induce pica, suggesting that at this dose the compound did not induce illness or malaise. In satiated rats, S 25585 (5.0 and 7.5 mg/kg, i.p.) significantly decreased the overfeeding induced by i.c.v. injection of NPY (1 microg) and the highly selective NPY Y(5) receptor agonist [hPP(1-17), Ala(31), Aib(32)]NPY (0.7 microg). In rats fasted for 4 h immediately before the dark phase, analysis of the microstructure of feeding behavior revealed that S 25585 significantly increased latency to eat and significantly decreased the duration and size of the meals without altering the meal number or eating rate. Analysis of the behavioral satiety sequence at this time revealed that the animals passed through the normal pattern of feeding, grooming and resting. Although S 25585 appeared to be influencing a physiological system controlling appetite, this does not involve the NPY Y(5) receptor since the antagonist also markedly reduced food intake in the NPY Y(5) knockout mouse. CONCLUSIONS: The results presented do not support a role for the NPY Y(5) receptor in the control of food intake. The results further illustrate that it is imperative that the activity of any new NPY Y(5) antagonist be assessed in the NPY Y(5) knockout mouse before assuming that its effect on food intake is due to blockade of this receptor.

Second-line treatment for failure to eradicate Helicobacter pylori: a randomized trial comparing four treatment strategies.

AIM: To compare the efficacy of different regimens in patients in whom previous Helicobacter pylori eradication therapy has failed. METHODS: In this study named StratHegy patients (n=287) were randomized to receive one of three empirical triple therapy regimens or a strategy based on antibiotic susceptibility. The empirical regimens were omeprazole, 20 mg b.d., plus amoxicillin, 1000 mg b.d., and clarithromycin, 500 mg b.d., for 7 days (OAC7), clarithromycin, 500 mg b.d., for 14 days (OAC14) or metronidazole, 500 mg b.d., for 14 days (OAM14). In the susceptibility-based strategy, patients with clarithromycin-susceptible strains received OAC14, whilst the others received OAM14. The 13C-urea breath test was performed before randomization and 4-5 weeks after eradication therapy. RESULTS: In the intention-to-treat analysis, the eradication rates for empirical therapies were as follows: OAC7, 47.4% (27/57); OAC14, 34.5% (20/58); OAM14, 63.2% (36/57); it was 74.3% (84/113) for the susceptibility-based treatment (P<0.01 when compared with OAC7 and OAC14). In patients receiving clarithromycin, the eradication rates were 80% for clarithromycin-susceptible strains and 16% for clarithromycin-resistant strains; in patients receiving OAM14, the eradication rates were 81% for metronidazole-susceptible strains and 59% for metronidazole-resistant strains. CONCLUSIONS: Eradication rates of approximately 75% can be achieved with second-line triple therapy based on antibiotic susceptibility testing. If susceptibility testing is not available, OAM14 is an appropriate alternative.

Thrombin-induced platelet PAR4 activation: role of glycoprotein Ib and ADP.

Thrombin activates human platelets via the cleavage of two protease-activated G-protein coupled receptors (PARs), PAR1 and PAR4 that respond to low and high concentrations of thrombin, respectively. The aim of the present study was to examine the relative contributions of GPIbalpha and ADP receptors in response to thrombin-induced PAR1 and PAR4 stimulation. Platelet responses (aggregation, secretion and calcium mobilization) elicited by low thrombin concentrations were impaired when thrombin interaction with GPIbalpha was blocked. In contrast, blockade of thrombin interaction with GPIbalpha had no effect when PAR4-coupled responses were specifically elicited by high thrombin concentrations in the presence of PAR1 antagonists or after PAR1 desensitization. These results confirmed that unlike PAR1, PAR4 does not require GPIbalpha as a cofactor for thrombin-mediated activation. Both apyrase and selective antagonists of P2Y1 and P2Y12 inhibited PAR1-coupled responses but did not modify PAR4-coupled responses, indicating that in contrast to PAR1, PAR4 signals are not reinforced by ADP secretion and binding to the platelets. These results provide the direct evidence that, in human platelets, GPIbalpha and ADP act in synergy to amplify PAR1 coupled responses while PAR4 is activated independently of GPIbalpha and ADP.

[Helicobacter pylori infection: prospective study for asymptomatic Tunisian children]. / Infection à Helicobacter pylori: étude prospective chez les enfants tunisiens asymptomatiques.

UNLABELLED: The aim of this study was to specify epidemiologic particularities of Helicobacter pylori infection among asymptomatic Tunisian children. POPULATION AND METHODS: A sample of 191 Tunisian healthy children studied for a two-month-period of time in protection center for mothers and children in a Tunis area. The children had benefited of an oriented questionnaire and a serological study of Helicobacter pylori. RESULTS: The prevalence of Helicobacter pylori infection was 30.4% (58 of 191). This prevalence increased with age (21% < 5 years vs 69% > 6 years: p < 0.04). The low socio-economic level and the familial antecedents of peptic illness constitute the main risk factors of Helicobacter pylori infection (p < 0.05). Both ways of transmission: oro-oral and fecal-oral seem to coexist among children.

Validation of diffusion methods for macrolide susceptibility testing of Helicobacter pylori.

Helicobacter pylori resistance to macrolides is increasing, and the need for susceptibility testing has become crucial. The only standardized method is agar dilution, which is not adapted to clinical practice. The present work aimed: (1) to optimize the technical conditions and to assess the reproducibility of the E-test and disk diffusion method for macrolides susceptibility testing of H. pylori, and (2) to assess the performances of these two phenotypic methods in detecting strains harboring a resistance mechanism to macrolides. We used 191 isolates collected in nine centers of France and Belgium. Phenotypic tests were performed on Mueller-Hinton agar supplemented with 10% horse blood, inoculated with a 2-day-old H. pylori suspension (10(8) CFU/ml), and incubated for 72 hr at 37 degrees C under microaerophilic conditions. The reproducibility studied on two randomly selected strains was better for disk diffusion than for the E-test for both clarithromycin and erythromycin. For a subset of 10 strains, the MICs of erythromycin and clarithromycin did not differ from more than one two-fold dilution when determined by E-test or agar dilution method. The breakpoints were for MICs: 1 mg/L for both clarithromycin and erythromycin and for inhibition diameters, 22 mm for clarithromycin and 17 mm for erythromycin. There was a 100% concordance between susceptibility to erythromycin and clarithromycin. However, the susceptible and resistant populations were better separated by testing erythromycin. Of 34 resistant strains, two lacked the A2142G and A2143G point mutations in 23S rRNA by PCR-RFLP. None of 15 tested sensitive strains were positive for one of these two point mutations. For clinical practice, we recommend to assess macrolide susceptibility of H. pylori by using one of these two phenotypic methods under the described technical conditions.

Change of pneumococcal resistance to antibiotics in adults between 1995 and 1997: a study in eight French counties.

The main object of this study was to describe the evolution of antibiotic resistance in pneumococci from adults, in eight French counties of France between 1995 and 1997. Despite the high and increasing prevalence (23-35%) of pneumococci with diminished susceptibility to penicillin G (PSDP), resistance to amoxycillin (0.8-0.5%) and to cefotaxime (0-0.3%) was rare in both 1995 and 1997 respectively. The percentage of pneumococci resistant to penicillin G (PRP, minimum inhibitory concentration >1 mg/l) remained stable between the two periods. PSDP showed increased resistance to macrolides (30-41%), to cotrimoxazole (28-34%) and to tetracycline (19-25%). These figures are lower than those obtained over the same periods and the same regions in children. The distribution of PSDP serotypes isolated in adults was the same as that seen in children: by descending order serotypes 23, 14, 9 and 6. This study by the Regional Pneumococcal Observatories confirms the high prevalence and the main characteristics of antibiotic resistance among pneumococci with variations in levels of resistance with the age of patients, with the site of sampling and from one Observatory to another.

Appetite suppression based on selective inhibition of NPY receptors.

AIM: The aim of this review is to critically assess available evidence that blockade of the actions of NPY at one of the five NPY receptor subtypes represents an attractive new drug discovery target for the development of an appetite suppressant drug. RESULTS: Blockade of the central actions of NPY using anti-NPY antibodies, antisense oligodeoxynucleotides against NPY and NPY receptor antagonists results in a decrease in food intake in energy-deprived animals. These results appear to show that endogenous NPY plays a role in the control of appetite. The fact that NPY receptors exist as at least five different subtypes raises the possibility that the actions of endogenous NPY on food intake can be adequately dissociated from other effects of the peptide. Current drug discovery has produced a number of highly selective NPY receptor antagonists which have been used to establish the NPY Y(1) receptor subtype as the most critical in regulating short-term food intake. However, additional studies are now needed to more clearly define the relative contribution of NPY acting through the NPY Y2 and NPY Y5 receptors in the complex sequence of physiological and behavioral events that underlie the long-term control of appetite. CONCLUSIONS: Blockade of the NPY receptor may produce appetite-suppressing drugs. However, it is too early to state with certainty whether a single subtype selective drug used alone or a combination of NPY receptor selective antagonists used in combination will be necessary to adequately influence appetite regulation.

Synthesis, conformational analysis and biological activity of cyclic analogs of the octadecaneuropeptide ODN. Design of a potent endozepine antagonist.

The octadecaneuropeptide (ODN; QATVGDVNTDRPGLLDLK) and its C-terminal octapeptide (OP; RPGLLDLK), which exert anxiogenic activity, have been previously shown to increase intracellular calcium concentration ([Ca2+]i) in cultured rat astrocytes through activation of a metabotropic receptor positively coupled to phospholipase C. It has also been found that the [d-Leu5]OP analog possesses a weak antagonistic activity. The aim of the present study was to synthesize and characterize cyclic analogs of OP and [d-Leu5]OP. On-resin homodetic backbone cyclization of OP yielded an analog, cyclo1-8 OP, which was three times more potent and 1.4-times more efficacious than OP to increase [Ca2+]i in cultured rat astrocytes. Cyclo1-8 OP also mimicked the effect of both OP and ODN on polyphosphoinositide turnover. Conversely, the cyclo1-8 [d-Leu5]OP analog was totally devoid of agonistic activity but suppressed the effect of OP and ODN on [Ca2+]i and phosphoinositide metabolism in astrocytes. The structure of these cyclic analogs has been determined by two-dimensional 1H-NMR and molecular dynamics. Cyclo1-8 OP exhibited a single conformation characterized by a gamma turn comprising residues Pro2-Leu4 and a type III beta turn encompassing residues Leu5-Lys8. Cyclo1-8 [d-Leu5]OP was present as two equimolar conformers resulting from cis/trans isomerization of the Arg-Pro peptide bond. These pharmacological and structural data should prove useful for the rational design of non peptidic ODN analogs.

[Study of methicillin-resistant Staphylococcus aureus colonization among intermediate-care facility patients]. / Etude de la colonisation par Staphylococcus aureus résistant à la méticilline dans des services de soins de suite.

PURPOSE: Prevalence of methicillin-resistant Staphylococcus aureus is high in the Poitiers teaching hospital, particularly in the intermediate care facilities. We performed a survey of methicillin-resistant Staphylococcus aureus colonization in the intermediate care facilities and 265 patients were included. METHODS: Nasal, cutaneous and wound swab cultures were done at the time of admission and at the time of the patients' departure. A decolonization procedure of methicillin-resistant Staphylococcus aureus carriers was performed using nasal application of fusidic acid and different soaps for the skin. At entry, 17.7% of patients were methicillin-resistant Staphylococcus aureus carriers (of at least one location). At departure, 30.4% were methicillin-resistant Staphylococcus aureus carriers. Among methicillin-resistant Staphylococcus aureus non-carriers at entry, 24.3% became methicillin-resistant Staphylococcus aureus carriers. RESULTS: The principal risk factor of carriage was the initial presence of a wound (RR = 3.6). The incidence rate of methicillin-resistant Staphylococcus aureus infection among the 265 patients included was 3%. CONCLUSION: The systematic screening of patients at the time of admission is expensive and isolation technically hard to manage in the intermediate care facilities. The risk factor we found in this study allow us to propose a 'light' screening limited to patients with wounds.

Quality assessment of combinatorial pooled libraries using mass spectrometry.

Parallel synthesis techniques aim to prepare collections of single compounds which, once tested, can easily be identified by their sole location in the synthesic array. On the other hand, true combinatorial chemistry produces libraries of compounds as mixtures of variable size which require a deconvolution procedure for identification of the active hits or leads. In the latter case, analytical methods are crucial for the success of the strategy and mass spectrometry plays a major role. If the goal is to identify all the library components, including expected products as well as by-products, various mass spectrometric techniques may be necessary. Library components can be separated according to their mass by increasing mass resolution or by their elution time by coupling liquid chromatography and mass spectrometry. The efficiency of such separation techniques are discussed as a function of the size and the degeneracy of the library. Library members possess common structural features which impart similar fragmentation patterns after ionization in the gas phase. This feature can be exploited by tandem mass spectrometry to specifically detect subfamilies of products. Examples of precursor ion scans, product ion scans and constant neutral loss scans will be shown that facilitate partial characterization of libraries. To solve the difficult problem of the quantitative analysis of libraries, i.e., to evaluate their equimolarity, the use of an evaporative light scattering detector (ELSD) or a chemiluminescent nitrogen detector (CLND) is suggested as more appropriate.

Parallel synthesis and pharmacological screening of nonpeptide ligands of the neuropeptide Y receptor subtype Y5.

Several series of low-molecular-mass ligands of the neuropeptide receptor subtype Y5 were prepared using a mixed strategy of synthesis on solid phase and in solution. Collections of single compounds were obtained by an automated parallel procedure which allowed quick variation and investigation of the central spacer moiety, as well as of the aromatic substituents on each side. The strategy of parallel synthesis and screening of partially purified analogs helped to select rapidly potent and selective leads which displayed comparable antagonistic potency against neuropeptide Y activity on the Y5 receptor and better receptor selectivity than the original reference compounds.

[125I]-S36057: a new and highly potent radioligand for the melanin-concentrating hormone receptor.

Shortened, more stable and weakly hydrophobic analogues of melanin-concentrating hormone (MCH) were searched as candidates for radioiodination. Starting from the dodecapeptide MCH(6 - 17), we found that: (1) substitution of Tyr(13) by a Phe residue; (2) addition of a 3-iodo-Tyr residue at the N-terminus; and (3) addition of a hydrophilic spacer 8-amino-3,6-dioxyoctanoyl between the 3-iodo-Tyr and MCH(6 - 17) (compound S36057), led to an agonist more potent than MCH itself in stimulating [35S]-GTPgammaS binding at membranes from HEK293 cells stably expressing the human MCH receptor. Specific binding of [125I]-S36057 was found in HEK293 and CHO cell lines stably expressing the human MCH receptor. This radioligand recognized a similar number of binding sites (ca. 800 fmol mg(-1)) than [125I]-[3-iodo Tyr(13)]-MCH. However, the K(D) for [125I]-S36057 obtained from saturation studies (0.037 nM) or from binding kinetics (0.046 nM) was at least 10 fold higher to that of [125I]-[3-iodo Tyr(13)]-MCH (0.46 nM). Affinities determined for a series of MCH analogues were similar with both radioligands, S36057 being the most potent compound tested (K(i)=0.053 nM). Finally, [125I]-S36057 also potently labelled the MCH receptor in membranes from whole rat brain (K(D) 0.044 nM, B(max)=11 fmol mg(-1)). In conclusion, [125I]-S36057 is a more potent and more stable radioligand than [125I]-[3-iodo Tyr(13)]-MCH that will represent a reliable tool for binding assays in the search of novel MCH ligands. It should also provide great help for autoradiographic studies of the MCH receptor distribution in the central nervous system.

Structure-activity relationship studies of melanin-concentrating hormone (MCH)-related peptide ligands at SLC-1, the human MCH receptor.

Melanin-concentrating hormone (MCH) is a cyclic nonadecapeptide involved in the regulation of feeding behavior, which acts through a G protein-coupled receptor (SLC-1) inhibiting adenylcyclase activity. In this study, 57 analogues of MCH were investigated on the recently cloned human MCH receptor stably expressed in HEK293 cells, on both the inhibition of forskolin-stimulated cAMP production and guanosine-5'-O-(3-[(35)S]thiotriphosphate ([(35)S]- GTPgammaS) binding. The dodecapeptide MCH-(6-17) (MCH ring between Cys(7) and Cys(16), with a single extra amino acid at the N terminus (Arg(6)) and at the C terminus (Trp(17))) was found to be the minimal sequence required for a full and potent agonistic response on cAMP formation and [(35)S]- GTPgammaS binding. We Ala-scanned this dodecapeptide and found that only 3 of 8 amino acids of the ring, namely Met(8), Arg(11), and Tyr(13), were essential to elicit full and potent responses in both tests. Deletions inside the ring led either to inactivity or to poor antagonists with potencies in the micromolar range. Cys(7) and Cys(16) were substituted by Asp and Lys or one of their analogues, in an attempt to replace the disulfide bridge by an amide bond. However, those modifications were deleterious for agonistic activity. In [(35)S]- GTPgammaS binding, these compounds behaved as weak antagonists (K(B) 1-4 microm). Finally, substitution in MCH-(6-17) of 6 out of 12 amino acids by non-natural residues and concomitant replacement of the disulfide bond by an amide bond led to three compounds with potent antagonistic properties (K(B) = 0.1-0.2 microm). Exploitation of these structure-activity relationships should open the way to the design of short and stable MCH peptide antagonists.

implication of the structure of the Helicobacter pylori cag pathogenicity island in induction of interleukin-8 secretion.

Helicobacter pylori virulence is associated with the presence of the cag pathogenicity island (PAI). The cag PAI is involved in the ability to induce interleukin-8 (IL-8) secretion by human cells, which is implicated in the inflammatory response of the gastric mucosa to H. pylori infection. The aim of this study was to determine whether the genetic structure of the cag PAI is conserved and whether it is linked to IL-8 induction ability. Detection of specific markers (cagA, picB, cag13-cag14, virD4, and IS605) by PCR and dot blot hybridization and long-distance PCR determination of the presence of cagI, cagII, and the middle region of the cag PAI were performed on 153 strains isolated from adults suffering from ulcers (n = 79) or gastritis (n = 74). IL-8 induction ability was evaluated by coculture of the strains with HEp-2 cells. Eighty-three strains (54.3%) had an entire cag PAI, 12 strains (7.8%) had the cag PAI split in two, 49 strains (32%) had no cag PAI, and 9 strains exhibited other structural combinations. The presence of an entire cag PAI was statistically correlated with the presence of IS605 (P = 0.006) and the ability to induce IL-8 secretion but not with clinical presentation of the infection. The structure of the cag PAI appears to be rather conserved and is related to the proinflammatory power of a strain. The existence of strains inducing IL-8 secretion regardless of the cag PAI structure suggests that this region is not the only requirement for IL-8 secretion.

From peptide libraries to optimized nonpeptide ligands in the search for S-farnesyltransferase inhibitors.

A complete 331,776-member library of tetrapeptides made of 24 amino acid building blocks was synthesized robotically on solid phase and subjected to a deconvolution based on the inhibitory potency of the sublibraries in a HPLC assay of the S-farnesyltransferase activity in vitro. One of the non-natural peptide and noncysteine-containing leads Nip-Trp-Phe-His (Nip=p-nitrophenyl-L-alanine) was optimized chemically to give a proteolytically stable pseudopeptide with a 200-fold potency compared with the original lead. The final compound was converted to the C-terminal ethyl ester: p-F-C6H4-CO(CH2)2-CO-Bta-D-Phepsi[CH2NH]His-OEt (Bta = benzothienyl-L-alanine) and shown to behave as a prodrug which was hydrolyzed back to the C-terminal acid following cell penetration. The method confirmed that several structurally original leads can be discovered in large libraries when deconvolution relies upon a highly specific assay and that these leads can be optimized by chemical modification to impart the final compound the desired pharmacological and pharmacokinetic properties.

[Effect of age on the prognosis of infectious endocarditis]. / Influence de l'âge sur le pronostic de l'endocardite infectieuse.

The aim of this study was to evaluate the influence of age on the prognosis of infectious endocarditis. A retrospective study from 1987 to 1997 of 136 patients with infectious endocarditis on native, prosthetic valves or cardiac pacing catheter was performed. The outcome was analysed with the help of general practitioners. Two groups of patients were compared: 87 patients of 65 years of age or more (Group 1) and 49 patients under 65 years of age (Group 2). With a follow-up period of 5 years, the global mortality was 35%, but greater in Group 1 (p = 0.06). Cardiac failure was the main cause of death. The mortality was significantly higher in patients who were not operated (p < 0.002). The authors conclude that age of over 65 does not significantly worsen the prognosis of infectious endocarditis. The absence of surgery seems to be an indirect factor of a poor prognosis. Long-term follow-up of patients is necessary to diagnose and treat cardiac failure at an early stage and to consider referral for surgery.

Helicobacter pylori and stomach cancer: a case-control study in Venezuela.

The role of Helicobacter pylori infection in gastric cancer was evaluated in a high-risk population in Venezuela using serological assays in a study of 302 cases and 483 neighborhood controls. To investigate the claim that assays for H. pylori should use antigens derived from local strains, four different assays derived from Venezuelan and European strains were used. Prevalence of IgG H. pylori antibodies in controls was very high, with estimates between 72 and 92%. Prevalence was similar in cases and controls. However, cases had lower antibody titers. This effect was observed only in subjects with low pepsinogen (PG) levels PGI/PGII <3.0), which suggested that extensive atrophy in cases causes a loss of H. pylori infection, with a consequent reduction in antibody titer. In addition, advanced cases (stage II or higher) had lower antibody titers than less advanced cases, which indicated that the lower antibody titers in cases may be attributable partially to a diminished immune response. All of the four assays for anti-H. pylori antibodies gave similar results. No evidence was found for the superiority of the assay based on Venezuelan strains. These results are consistent with other case-control studies in high-risk populations and highlight the difficulties of investigating H. pylori infection in retrospective studies.

[Muco-cutaneous colonization and nosocomial infections caused by methicillin-resistant Staphylococcus aureus and Acinetobacter baumanii in intensive care patients]. / Colonisation cutaneo-muqueuse et infections nosocomiales à Staphylococcus aureus meticilline résistant et à Acinetobacter baumanii chez des malades en réanimation médicale.

This study was designed to assess the frequency and risk factors for colonization with MRSA and A. baumanii in the intensive care unit, and to analyse the relationship between colonization and infection with MRSA or A. baumanii. During a 24-day survey period, colonization was studied weekly with nasal, throat and digit skin swabs; nosocomial infections were routinely monitored according to CDC recommendations. Clinical data and invasive procedures were registered during a one-year non-epidemic period; 103 ICU patients hospitalized for more than 7 days were prospectively included. We investigated acquired colonization and nosocomial infection with SAMR or A. baumanii for 87 patients not colonized by SAMR or A. baumanii on admission. The colonization acquisition rate was 56% for MRSA and 27% for A. baumanii. Infection incidence (cases per 1,000 patient-days) was 6.46 for MRSA and 1.61 for A. baumanii. On univariate analysis, acquired MRSA colonization was associated with longer ICU stays, longer mechanical ventilation and longer central venous catheterization. Multivariate analysis only showed an association with longer ICU stay. Acquired A. baumanii colonization was associated with SAPSII, longer mechanical ventilation, and longer central venous catheterization in univariate analysis. Multivariate analysis only showed an association with SAPSII and longer mechanical ventilation. In this study, SAMR or A. baumanii infections were not associated with colonization or clinical setting or invasive procedures.

Identification of the melatonin-binding site MT3 as the quinone reductase 2.

The regulation of the circadian rhythm is relayed from the central nervous system to the periphery by melatonin, a hormone synthesized at night in the pineal gland. Besides two melatonin G-coupled receptors, mt(1) and MT(2), the existence of a novel putative melatonin receptor, MT(3), was hypothesized from the observation of a binding site in both central and peripheral hamster tissues with an original binding profile and a very rapid kinetics of ligand exchange compared with mt(1) and MT(2). In this report, we present the purification of MT(3) from Syrian hamster kidney and its identification as the hamster homologue of the human quinone reductase 2 (QR(2), EC ). Our purification strategy included the use of an affinity chromatography step which was crucial in purifying MT(3) to homogeneity. The protein was sequenced by tandem mass spectrometry and shown to align with 95% identity with human QR(2). After transfection of CHO-K1 cells with the human QR(2) gene, not only did the QR(2) enzymatic activity appear, but also the melatonin-binding sites with MT(3) characteristics, both being below the limit of detection in the native cells. We further confronted inhibition data from MT(3) binding and QR(2) enzymatic activity obtained from samples of Syrian hamster kidney or QR(2)-overexpressing Chinese hamster ovary cells, and observed an overall good correlation of the data. In summary, our results provide the identification of the melatonin-binding site MT(3) as the quinone reductase QR(2) and open perspectives as to the function of this enzyme, known so far mainly for its detoxifying properties.