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A Marchese

Publications and source records attributed to A Marchese.

At least 19 recordsLinked to original sources
PubMed2000

Cloning and characterization of additional members of the G protein-coupled receptor family.

A search of the expressed sequence tag (EST) database retrieved a human cDNA sequence which partially encoded a novel G protein-coupled receptor (GPCR) GPR26. A human genomic DNA fragment encoding a partial open reading frame (ORF) and a rat cDNA encoding the full length ORF of GPR26 were obtained by library screening. The rat GPR26 cDNA encoded a protein of 317 amino acids, most similar (albeit distantly related) to the serotonin 5-HT(5A) and gastrin releasing hormone BB2 receptors. GPR26 mRNA expression analysis revealed signals in the striatum, pons, cerebellum and cortex. HEK293 and Rh7777 cells transfected with GPR26 cDNA displayed high basal cAMP levels, slow growth rate of clonal populations and derangements of normal cell shape. We also used a sequence reported only in the patent literature encoding GPR57 (a.k.a. HNHCI32) to PCR amplify a DNA fragment which was used to screen a human genomic library. This resulted in the cloning of a genomic fragment containing a pseudogene, psiGPR57, with a 99.6% nucleotide identity to GPR57. Based on shared sequence identities, the receptor encoded by GPR57 was predicted to belong to a novel subfamily of GPCRs together with GPR58 (a.k.a. phBL5, reported only in the patent literature), putative neurotransmitter receptor (PNR) and a 5-HT(4) pseudogene. Analysis of this subfamily revealed greatest identities (approximately 56%) between the receptors encoded by GPR57 and GPR58, each with shared identities of approximately 40% with PNR. Furthermore, psiGPR57, GPR58, PNR and the 5-HT(4) pseudogene were mapped in a cluster localized to chromosome 6q22-24. PNR and GPR58 were expressed in COS cells, however no specific binding was observed for various serotonin receptor-specific ligands.

1-Methyl-3-isobutylxanthine↗
PubMed2000

Resistance patterns of lower respiratory tract pathogens in Europe.

Resistance to antimicrobial drugs in the major respiratory tract pathogens is known to vary profoundly depending on geographic location. In Europe high rates (>44%) of penicillin-resistance in pneumococci have been recorded in France and Spain, while countries like The Netherlands, the Czech Republic, Austria and Italy are only marginally affected. Similarly, the incidence of macrolide resistance differs widely among European nations with figures ranging from 45.9% (France) to 1.5% (The Netherlands). Significant percentages (>20%) of co-trimoxazole and doxycycline resistance have been found in France, Spain, Italy, Hungary, Poland and Belgium. The prevailing mechanism of resistance in Haemophilus influenzae is represented by beta-lactamase synthesis for which considerable variations (from 0 to 38.5%) have been evidenced. Ampicillin resistant beta-lactamase negative H. influenzae are very uncommon. Over 90% of Moraxella catarrhalis isolates are beta-lactamase producers without big differences among European countries.

Drug Resistance, Microbial↗
PubMed2000

Antibiotic susceptibility patterns and serotypes of antibiotic resistant and/or invasive Streptococcus pneumoniae strains circulating in Italy.

Antibiotic susceptibility patterns and serotypes of 397 Streptococcus pneumoniae recovered from 1994 to 1998 in Italy have been determined. This collection included 229 penicillin- and/or erythromycin-resistant strains and 168 isolates responsible for invasive infections. Among penicillin-resistant pneumococci, the most prevalent serotype was 23F, followed by 19F and 9V, while among erythromycin-resistant but penicillin-susceptible strains serotype 6B was predominant followed by 19A, 14, 19F, 15A, 15B, and 23F. The most common invasive serotypes were 6B, 19F, 23F, 3, 4, 14, 20, 15B, and 9N. The currently available 23-valent pneumococcal vaccine could cover 91% of noninvasive penicillin- and/or erythromycin-resistant strains, 84% of pneumococci isolated from sterile sites, and 83% of invasive antibiotic-resistant S. pneumoniae. Penicillin-resistant pneumococci also showed reduced susceptibility to other antimicrobial compounds. Against invasive pneumococci, amoxicillin, cefotaxime, ceftriaxone, imipenem, vancomycin, and rifampin were 100% effective. Penicillin, chloramphenicol, erythromycin, tetracycline, and co-trimoxazole resistance was 1.8%, 9.5%, 15.5%, 18.5%, and 21.4%, respectively.

Anti-Bacterial Agents↗
PubMed2000

Molecular typing of methicillin-resistant Staphylococcus aureus by pulsed-field gel electrophoresis: comparison of results obtained in a multilaboratory effort using identical protocols and MRSA strains.

Pulsed-field gel electrophoresis (PFGE) has become the gold standard of molecular methods in epidemiological investigations. In spite of its high resolving power, use of the method has been hampered by inadequate laboratory-to-laboratory reproducibility. In the project described here we have addressed this problem by organizing a multilaboratory effort in which the same bacterial strains (subtype variants of the Iberian and Brazilian methicillin-resistant Staphylococcus aureus--MRSA--clones) were analyzed by twenty investigators in thirteen different laboratories according to an indentical protocol, which is reproduced here in detail. PFGE patterns obtained were analyzed at a central laboratory in order to identify specific technical problems that produced substandard macrorestriction patterns. The results including the specific technical problems and their most likely causes are described in this communication. Also listed are seven major epidemic clones of MRSA which have been characterized by molecular fingerprinting techniques and the prototypes of which have been deposited at the American Type Culture Collection, from where they will be available for interested investigators for the purpose of typing MRSA isolates. It is hoped that this communication will contribute to the improvement of the reproducibility and technical/aesthetic quality of PFGE analysis.

Bacterial Typing Techniques↗
PubMed2000

Comparative in vitro potency of gemifloxacin against European respiratory tract pathogens isolated in the Alexander Project.

European isolates collected in 1998 for the Alexander Project were tested for their susceptibility to ciprofloxacin, ofloxacin and a novel fluoroquinolone, gemifloxacin, which has a spectrum of activity including common and atypical respiratory pathogens. MIC90s of gemifloxacin for Streptococcus pneumoniae, Haemophilus influenzae and Moraxella catarrhalis were 0.03, 0.06 and 0.015 mg/L, respectively. On the basis of MIC90s, gemifloxacin was the most potent antimicrobial tested against S. pneumoniae and M. catarrhalis. Against H. influenzae, gemifloxacin was one tube dilution more potent than ofloxacin and one tube dilution less potent than ciprofloxacin. As resistance to currently available antimicrobial agents increases, gemifloxacin offers potential as a promising new agent for the treatment of respiratory tract infection.

Anti-Infective Agents↗
PubMed2000

The evolving threat of antibiotic resistance in Europe: new data from the Alexander Project.

The Alexander Project was established in 1992 to examine the antimicrobial susceptibility of community-acquired lower respiratory tract bacterial pathogens to a range of compounds. Since then it has expanded both geographically and in the number of antimicrobial agents tested. Within Europe, the most recent data have confirmed that the prevalence of penicillin resistance among isolates of Streptococcus pneumoniae is high in France and Spain, with both intermediate (MIC 0.12-1 mg/L) and resistant (MIC > or = 2 mg/L) phenotypes, and combined resistance rates of >50%. Macrolide resistance is increasing generally both among penicillin-resistant and penicillin-susceptible isolates of S. pneumoniae and its prevalence now exceeds that of penicillin resistance, overall (16.5% and 10.4%, respectively, in 1996; 21.9% and 14.1% in 1997; 16.5% and 11.6% in 1998). Beta-lactamase production was the principal mechanism of resistance observed among isolates of Haemophilus influenzae and Moraxella catarrhalis.

Anti-Bacterial Agents↗
PubMed2000

Evolution of antibiotic resistance in gram-positive pathogens.

Staphylococcus aureus is a common cause of soft tissue infection, e.g. impetigo, cellulitis, or wound infection, and causes osteomyelitis, arthritis, bacteremia with metastatic infection, and scalded skin and toxic shock syndromes. Coagulase-negative staphylococci have become increasingly important causes of nosocomial bacteremia associated with invasive monitoring, intravascular catheters and prosthetic heart valves or joints. Most staphylococci produce b-lactamase and are resistant to penicillin. An increasing proportion of S. aureus have intrinsic resistance to methicillin (MRSA) and present major problems in hospitals for the control of cross infection. The glycopeptides, teicoplanin and vancomycin, are the antibiotics of first choice for treatment of these infections. After the first report describing a Japanese clinical isolate of vancomycin-resistant S. aureus (VRSA), several papers have documented the emergence of these microorganisms. Since the development and spreading of this phenomenon which is perceived as a fearsome threat to the already difficult therapy of nosocomial infections due to the prevalence of heterogeneous vancomycin resistance, we found the incidence of MRSA exceeds 35% in our hospital. Out of 179 methicillin-resistant S. aureus isolated during 1997-1998, two strains (1.1%) gave subclones with vancomycin MICs of 8 mg/L. PFGE showed identical restriction patterns for both isolates, suggesting transfer of a single clone between two different patients.

Anti-Bacterial Agents↗
PubMed2000

[Triple therapy of short-term with azithromycin, amoxycillin and omeprazole for the eradication of Helicobacter pylori].

BACKGROUND: The high cost and complexity of therapeutic schemes for the eradication of Helicobacter pylori has stimulated the search of simpler and cheaper treatment options. AIM: To evaluate the efficacy of 3 days of azithromycin 500 mg od, 7 days of amoxycillin 750 mg tid and omeprazole, 20 (Group A) or 40 mg (Group B) on randomization, as a treatment for Helicobacter pylori infection in patients with endoscopically diagnosed peptic ulcer. METHODS: H. pylori status of peptic ulcer patients was pathologically confirmed by the examination of five gastric biopsies using the Giemsa stain and by rapid urease testing in two gastric biopsies. H. pylori status was reassessed not less than 28 days after completing treatment. Adverse events and compliance were evaluated. RESULTS: Fifty four patients (29 men, 25 women, mean age 48 years) were enrolled, 28 in Group A and 27 in Group B. Per protocol the infection was cured in 58.8% of patients (30/51; 95% CI: 45-73%). On an intention to treat basis, H pylori infection was cured in 55%. Minor side effects including diarrhea and nausea were reported by 32% of patients. Ninety-five per cent of patients consumed more than 95% of prescribed medications. H. pylori was successfully eradicated in 61% of group A and 57% of group B patients (p = NS). CONCLUSION: Short term therapy with azithromycin was poorly effective in curing H. pylori infection. The compliance was excellent. Increasing Omeprazole from 20 to 40 mg/day did not improve treatment effectiveness.

Amoxicillin↗
PubMed1999

Trafficking of the HIV coreceptor CXCR4. Role of arrestins and identification of residues in the c-terminal tail that mediate receptor internalization.

The G protein-coupled chemokine receptor CXCR4 serves as the primary coreceptor for entry of T-cell tropic human immunodeficiency virus. CXCR4 undergoes tonic internalization as well as internalization in response to stimulation with phorbol esters and ligand (SDF-1alpha). We investigated the trafficking of this receptor, and we attempted to define the residues of CXCR4 that were critical for receptor internalization. In both COS-1 and HEK-293 cells transiently overexpressing CXCR4, SDF-1alpha and phorbol esters (PMA) promoted rapid internalization of cell surface receptors as assessed by both enzyme-linked immunosorbent assay and immunofluorescence analysis. Expression of GRK2 and/or arrestins promoted modest additional CXCR4 internalization in response to both PMA and SDF. Both PMA- and SDF-mediated CXCR4 internalization was inhibited by coexpression of dominant negative mutants of dynamin-1 and arrestin-3. Arrestin was also recruited to the plasma membrane and appeared to colocalize with internalized receptors in response to SDF but not PMA. We then evaluated the ability of CXCR4 receptors containing mutations of serines and threonines, as well as a dileucine motif, within the C-terminal tail to be internalized and phosphorylated in response to either PMA or SDF-1alpha. This analysis showed that multiple residues within the CXCR4 C-terminal tail appear to mediate both PMA- and SDF-1alpha-mediated receptor internalization. The ability of coexpressed GRK2 and arrestins to promote internalization of the CXCR4 mutants revealed distinct differences between respective mutants and suggested that the integrity of the dileucine motif (Ile-328 and Leu-329) and serines 324, 325, 338, and 339 are critical for receptor internalization.

Amino Acid Sequence↗
PubMed1999

Discovery of three novel orphan G-protein-coupled receptors.

We have discovered three novel human genes, GPR34, GPR44, and GPR45, encoding family A G-protein-coupled receptors (GPCRs). The receptor encoded by GPR34 is most similar to the P2Y receptor subfamily, while the receptor encoded by GPR44 is most similar to chemoattractant receptors. The receptor encoded by GPR45 is the mammalian orthologue of a putative lysophosphatidic acid receptor from Xenopus laevis. Partial sequence of GPR34 was discovered during a search of the GenBank database of expressed sequence tags (ESTs). This sequence information was used both to isolate the full-length translational open reading frame from a human genomic library and to assemble a contig from additional GPR34 EST cDNAs. Northern blot and in situ hybridization analyses revealed GPR34 mRNA transcripts in several human and rat brain regions. Also, we used polymerase chain reaction (PCR) to amplify human genomic DNA using degenerate oligonucleotides designed from sequences encoding transmembrane domains 3 and 7 of opioid and somatostatin receptors. Two PCR products partially encoding novel GPCRs, named GPR44 and GPR45, were discovered and used to isolate the full-length translational open reading frames from a human genomic library. Both GPR44 and GPR45 are expressed in the central nervous system and periphery. For chromosomal localization, fluorescence in situ hybridization analysis was performed to assign GPR34 to chromosomes 4p12 and Xp11. 3, GPR44 to chromosome 11q12-q13.3, and GPR45 to chromosome 2q11. 1-q12.

Amino Acid Sequence↗
PubMed1999

Epidemiology of resistance to antimicrobial drugs in the major respiratory pathogens circulating in Europe.

There is an overwhelming consensus on the fact that Streptococcus pneumoniae, Haemophilus influenzae and Moraxella catarrhalis represent the prevailing bacterial pathogens of community-acquired lower respiratory tract infections. Their specific incidence as causative agents of the more common syndromes is known to vary even profoundly depending on geographic location, and the same holds true for the rates of resistance to antimicrobial drugs. Europe does not escape the threat posed by the present pandemic spread of penicillin resistance in S. pneumoniae although, as expected, countries like Spain and France are greatly affected, while others including Germany, Italy, The Netherlands and the Scandinavian region are comparatively spared. In several sites multiple resistance has been described in S. pneumoniae and the most affected drugs include penicillin, the macrolides, co-trimoxazole and tetracycline. In H. influenzae synthesis of beta-lactamases the main trait of resistance is expressed. Lack of susceptibility to beta-lactams dictated by a different mechanism remains extremely rare. Considerable variations in the incidence of this characteristic are apparent when European countries are considered. France and Spain are again widely affected, while Germany, The Netherlands and Italy display rates of beta-lactamase-positive H. influenzae of about 10%. M. catarrhalis must be considered generally resistant to non-protected aminopenicillins since over 90% of these organisms produce beta-lactamases.

Anti-Bacterial Agents↗
PubMed1999

Novel GPCRs and their endogenous ligands: expanding the boundaries of physiology and pharmacology.

Nearly all molecules known to signal cells via G proteins have been assigned a cloned G-protein-coupled-receptor (GPCR) gene. This has been the result of a decade-long genetic search that has also identified some receptors for which ligands are unknown; these receptors are described as orphans (oGPCRs). More than 80 of these novel receptor systems have been identified and the emphasis has shifted to searching for novel signalling molecules. Thus, multiple neurotransmitter systems have eluded pharmacological detection by conventional means and the tremendous physiological implications and potential for these novel systems as targets for drug discovery remains unexploited. The discovery of all the GPCR genes in the genome and the identification of the unsolved receptor-transmitter systems, by determining the endogenous ligands, represents one of the most important tasks in modern pharmacology.

Animals↗
PubMed1999

Corrigendum

Explore the source record for details and available documents.

Journal Article↗
PubMed1999

Macrolide resistance mechanisms and expression of phenotypes among Streptococcus pneumoniae circulating in Italy.

In Italy, macrolide-resistant pneumococci have been isolated at a rate increasing from 6% in 1993 to 31.7% in 1998. A collection of 161 erythromycin-resistant Streptococcus pneumoniae recovered between 1993 and 1997 has now been phenotypically and genotypically characterized. Approximately 90% of these microorganisms possessed a constitutive MLS(B) mechanism of resistance. PCR detected ermB and mefE genes in strains showing MLS(B) and M phenotypes, respectively. Using pulsed-field gel electrophoresis of chromosomal DNA, one dominant restriction profile and its variations were detected in 51 S. pneumoniae isolates collected from different locations, indicating the circulation of a clone characterized by the possession of a great ability to spread.

Anti-Bacterial Agents↗
PubMed1998

Cloning genes encoding receptors related to chemoattractant receptors.

We report the cloning of a novel human gene (GPR32) encoding a putative G-protein-coupled receptor (GPCR) of 356 amino acids and a related pseudogene psi GPR32. The deduced amino acid sequence of GPR32 shares 35-39% identity with members of the chemoattractant receptor family. psi GPR32 shares 93% nucleotide identity with GPR32. We identified a mouse EST encoding a putative GPCR (GPR33) of 309 amino acids. The deduced amino acid sequence of GPR33 shares 30-35% identity with members of the chemoattractant receptor family and 36% identity with the receptor encoded by GPR32. The human orthologue of GPR33 contains a single basepair substitution with respect to the mouse, resulting in the presence of an in-frame stop codon within the predicted second intracellular loop, demonstrating that it is a pseudogene. Through fluorescence in situ hybridization and physical mapping of YACs, both GPR32 and psi GPR32 were mapped to chromosomal 19, region q13.3, while psi GPR33 was mapped to chromosome 14q12.

Amino Acid Sequence↗
PubMed1998

Discovery of three novel G-protein-coupled receptor genes.

We report here the molecular cloning, tissue distribution, and chromosomal localization of novel genes encoding G-protein-coupled receptors (GPCRs). A search of a mouse database of expressed sequence tags revealed an EST partially encoding a GPCR, which was used to screen a mouse genomic library to obtain the translational open reading frame (ORF). The resultant clone, GPR27, contained an intronless ORF, encoding a receptor of 379 amino acids. In an alternate strategy, human genomic DNA was subjected to polymerase chain reaction (PCR) amplification, using degenerate oligonucleotides based on GPR1. Two PCR products partially encoding GPCRs were isolated and used to screen a genomic library to obtain the translational ORF. One of the resultant clones, GPR30, contained an intronless ORF encoding a receptor of 375 amino acids. The other clone, GPR35, also contained an intronless ORF encoding a receptor of 309 amino acids. Transcripts corresponding to GPR27 and GPR30 were detected in several areas of human and rat CNS, While GPR35 expression was detected only in the rat intestine. Through fluorescence in situ hybridization analysis the gene encoding GPR30 was localized to chromosome 7p22 and GPR35 to chromosome 2q37.3.

Amino Acid Sequence↗
PubMed1998

Determination of Pranlukast and its metabolites in human plasma by LC/MS/MS with PROSPEKT on-line solid-phase extraction.

A highly sensitive and selective liquid chromatography/ionspray tandem mass spectrometry (LC/MS/MS) method was developed and validated for the determination of Pranlukast and its oxidative metabolites (SB 240103, SB 241484 and SB 218663) in human plasma in order to support pharmacokinetic studies. The method employed direct injection of human plasma into an on-line solid phase extraction (SPE) PROSPEKT instrument for isolation of the analytes followed by column switching to the LC/MS/MS. The use of on-line SPE resulted in reduced sample preparation time and cleaner extracts, therefore minimizing ion suppression and HPLC back-pressures issues. The use of a 20 mM ammonium acetate-methanol system and a step gradient yielded intense ion species, excellent separation between the polar metabolites and the parent drug and sufficient selectivity for baseline resolution of the two positional isomers, SB 240103 and SB 218663. Pranlukast, its metabolites and the internal standard (SK&F 108566) were quantified using a turbo-ionspray interface by negative ion selected reaction monitoring (SRM). The lower limit of quantification (LLQ) for the assay was 10.0 ng ml-1 for Pranlukast and 1.00 ng ml-1 for its metabolites based on a 100 microliters plasma aliquot. The calibration curves were linear for analyte concentrations ranging from 10.0 to 2000 ng ml-1 for Pranlukast and 1.00 to 200 ng ml-1 for the metabolites. The calculated intra- and inter-assay precision from quality control (QC) samples resulted in mean variability values of less than 12% for all analytes. Pranlukast and its metabolites were shown to be stable under routine analysis conditions for clinical trial samples. The method provides automated sample analysis in a total cycle time of 5 min with improved robustness, sensitivity, selectivity, accuracy and reproducibility compared to the existing methodology.

Chromatography, High Pressure Liquid↗