Rapid discrimination of multiple myeloma patients by artificial neural networks coupled with mass spectrometry of peripheral blood plasma.

Multiple myeloma (MM) is a highly heterogeneous disease of malignant plasma cells. Diagnosis and monitoring of MM patients is based on bone marrow biopsies and detection of abnormal immunoglobulin in serum and/or urine. However, biopsies have a single-site bias; thus, new diagnostic tests and early detection strategies are needed.

Clusters of Monoisotopic Elements for Calibration in (TOF) Mass Spectrometry.

Precise calibration in TOF MS requires suitable and reliable standards, which are not always available for high masses. We evaluated inorganic clusters of the monoisotopic elements gold and phosphorus (Au /Au and P /P ) as an alternative to peptides or proteins for the external and internal calibration of mass spectra in various experimental and instrumental scenarios. Monoisotopic gold or phosphorus clusters can be easily generated in situ from suitable precursors by laser desorption/ionization (LDI) or matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS).

Use of flower-like gold nanoparticles in time-of-flight mass spectrometry.

Rationale: Many kinds of nanoparticles (NPs) have been used for mass spectrometry (MS) so far. Here we report the first use of flower-like gold nanoparticles (AuNPs) as a mediator to enhance ionization in MS of peptides and proteins.

Methods: Flower-like AuNPs were characterized using transmission and scanning electron microscopy, UV-VIS spectrophotometry, and laser desorption/ionization (LDI)-MS and compared with polyhedral AuNPs.

Characterization of Ni(II) complexes of Schiff bases of amino acids and (S)-N-(2-benzoylphenyl)-1-benzylpyrrolidine-2-carboxamide using ion trap and QqTOF electrospray ionization tandem mass spectrometry.

This work demonstrates the application of electrospray ionization mass spectrometry (ESI-MS) using two different mass analyzers, ion trap and hybrid quadrupole time-of-flight (QqTOF) mass analyzer, for the structural characterization of Ni(II) complexes of Schiff bases of (S)-N-(2-benzoylphenyl)-1-benzylpyrrolidine-2-carboxamide with different amino acids. ESI enables the determination of molecular weight on the basis of rather simple positive-ion ESI mass spectra containing only protonated molecules and adducts with sodium or potassium ions. Fragmentation patterns are characterized by tandem mass spectrometric experiments, where both tandem mass analyzers provide complementary information.

Comparison of negative ion electrospray mass spectra measured by seven tandem mass analyzers towards library formation.

A library of negative ion electrospray ionization mass spectra and tandem mass spectra (MS/MS) of sulfonated dyes has been developed for fast identification purposes. The uniform protocol has been elaborated and applied to the measurements of more than 50 anionic dyes. Three collision energies are selected in our protocol which ensures that at least one of them provides a suitable ratio of product ions to the precursor ion.

Electrospray ionization-multistage tandem mass spectrometry of complex multitin organometallic compounds.

The series of 14 complex organotin(IV) compounds containing many tin atoms and noncovalent bonds in the structure was characterized by electrospray ionization multistage tandem mass spectrometry (ESI-MS(n)). The mass spectra were measured in both polarity modes to obtain complementary structural information. The characteristic pattern of ten natural tin isotopes allowed the determination of the number of tin atoms in the molecular adducts and fragment ions by comparing theoretical and experimental isotopic distributions.

Metabolic profiling of a potential antifungal drug, 3-(4-bromophenyl)-5-acetoxymethyl-2,5-dihydrofuran-2-one, in mouse urine using high-performance liquid chromatography with UV photodiode-array and mass spectrometric detection.

3-(4-bromophenyl)-5-acetyloxymethyl-2,5-dihydrofuran-2-one (LNO-18-22) is a representative member of a novel group of potential antifungal drugs, derived from a natural 3,5-disubstituted butenolide, (-)incrustoporine, as a lead structure. This lipophilic compound is characterized by high in vitro antifungal activity and low acute toxicity. For the purpose of in vivo studies, a new bioanalytical high-performance liquid chromatographic method with UV photodiode-array and mass spectrometric detection (HPLC-PDA-MS), involving a direct injection of diluted mouse urine was developed and used in the evaluation of the metabolic profiling of this drug candidate.

Structural analysis of ionic organotin(IV) compounds using electrospray tandem mass spectrometry.

A novel electrospray ionization (ESI) mass spectrometric approach for the structure elucidation of ionic organotin(IV) compounds or complexes with weakly bonded ligands as for example monodentate carboxylates or sulfonates is proposed using both positive-ion and negative-ion ESI tandem mass spectra. The ionization mechanism of organotin(IV) compounds involves the cleavage of the most labile bond with an ionic character yielding two complementary ions, [Cat]+ and [An]-. Positively charged species containing tin atom, [Cat]+, are analyzed in the positive-ion mode and negatively charged species without the tin atom, [An]-, in the negative-ion mode.

Two-dimensional liquid chromatography normal-phase and reversed-phase separation of (co)oligomers.

Many samples contain compounds with various numbers of two or more regular structural groups. Such "multidimensional" samples (according to the Giddings' notation) are best separated in orthogonal chromatographic systems with different selectivities for the individual repeat structural groups, described by separation factors. Correlations between the repeat group selectivities characterize the degree of orthogonality and suitability of chromatographic systems for two-dimensional (2D) separations of two-dimensional samples.

Phase system selectivity and two-dimensional separations in liquid column chromatography.

Correlations between the separation selectivity in aqueous and non-aqueous reversed-phase systems and in normal-phase LC systems were investigated for samples containing different numbers of two repeat structural elements. Such samples are best separated in "orthogonal" two-dimensional chromatographic systems, showing selectivity for one type of the repeat structural element only in the first dimension and for the other structural element only in the second dimension. The number of resolved compounds improves as the degree of orthogonality of the separation systems increases with decreasing correlation between the selectivities for the sample structural distribution in the two dimensions.

Structural analysis of 2,6-[bis(alkyloxy)methyl]-phenyltin derivatives using electrospray ionization mass spectrometry.

Electrospray ionization (ESI) mass spectrometry was applied to the structural analysis of 23 2,6-[bis(alkyloxy)methyl]phenyltin(IV) derivatives. The mass spectra were measured in both polarity modes and multistage tandem mass spectrometric (MS(n)) measurements were performed on the ion trap analyser for positively charged tin-containing ions. The sum of complementary ions observed in the positive-ion mode (i.

Respiratory viruses and severe lower respiratory tract complications in hospitalized patients.

Background: Acute respiratory viral infections are generally self-limited in healthy subjects but can lead to severe complications in immunocompromised hosts. We report the clinical impact of acute lower respiratory tract viral infections in hospitalized patients.

Materials And Methods: Of 1,001 fiberoptic bronchoscopies performed during a period of 5 years, 33 BAL samples were positive for respiratory viruses by cell culture.

Secular trends of candidemia over 12 years in adult patients at a tertiary care hospital.

The incidence of fungal infections has been increasing for the last 3 decades, especially among neutropenic, cancer, and critically ill patients. These infections are associated with high mortality rates. We retrospectively reviewed medical charts of adult patients with fungemia from 1989 to 2000 at our institution.

Improved monitoring of cytomegalovirus infection after allogeneic hematopoietic stem cell transplantation by an ultrasensitive plasma DNA PCR assay.

Cytomegalovirus (CMV) DNA amplification assays in plasma have shown limited sensitivity compared to the detection of pp65 antigen in leukocytes. Our goal was to increase the sensitivity of a commercial CMV DNA PCR quantitative assay. After modification, the new assay was able to reproducibly detect 20 CMV DNA copies/ml of plasma.

Exon 1 polymorphism of the B2BKR gene does not influence the clinical status of patients with hereditary angioedema.

Polymorphic variants of B2 receptors for bradykinin (B2BKR) have been postulated to influence a clinical manifestation of hereditary angioedema. In this study, exon 1 nonanucleotide deletion polymorphism in the B2BKR gene was examined in 37 patients with hereditary angioedema. The patients were grouped according to disease severity or the age of the first clinical manifestation of disease.

Five novel mutations in the C1 inhibitor gene (C1NH) leading to a premature stop codon in patients with type I hereditary angioedema.

Hereditary angioedema (HAE) is a disorder characterised by recurrent attacks of localized subcutaneous or submucosal edema. It is inherited in an autosomal dominant fashion and caused by a deficiency of C1 inhibitor (C1 inh, or C1NH). Most patients with HAE have an absolute deficiency of C1 inh (type I HAE) while the rest (15% of kindreds) synthetize a dysfunctional C1 inh protein (type II HAE).