Development of high throughput screening methods for inhibitors of ClpC1P1P2 from Mycobacteria tuberculosis

Tuberculosis affects about 100 million people worldwide and causes nearly 2 million deaths annually. It has been estimated that one third of all humans is infected with latent Mycobacterium tuberculosis (Mtb). Moreover, Mtb has become increasingly resistant to available antibiotics. Consequently, it is important to identify and characterize new therapeutic targets in Mtb and to synthesize selective inhibitors. ClpP1, ClpP2 and their associated regulatory ATPases, ClpX and ClpC1 are required for the growth of Mtb and for its virulence during murine infection and are highly attractive drug targets, especially since they are not present in the cytosol of mammalian cells, and they differ markedly from the mitochondrial ClpP complex. The importance of these proteins in Mtb is emphasized by the existence of several natural antibiotics targeting this system. In order to find new inhibitors of ClpC1P1P2 system, we developed an assay based on the ATP-dependent degradation of a fluorescent protein substrate. The hits obtained were further characterized with a set of secondary assays to identify precise targets within a complex. A large library of compounds was screened and led to the identification of a ClpC1 ATPase inhibitor demonstrating that this approach can be used in future searches for anti-TB agents.

Anti-heat shock protein 90β antibodies are detected in patients with multiple sclerosis during remission

Antibodies against heat shock protein 90beta (Hsp90beta) recognize the antigen on the surface of oligodendrocyte precursor cells and induce a decrease in the oligodendrocyte population of cell cultures. This study investigated the presence of anti-Hsp90beta antibodies in patients with multiple sclerosis (MS) during remission. Anti-Hsp90beta antibodies were detected in the cerebrospinal fluid (CSF) of patients with a specific and sensitive western blot procedure using Hsp90beta from cell membrane fraction. The number of patients with anti-Hsp90beta antibodies detected in the CSF was significantly greater in MS patients than in control patients with other neurological diseases, which included patients with other inflammatory neurological diseases. CSF anti-Hsp90beta antibody levels were significantly higher in MS patients than in control patients. The presence of anti-Hsp90beta antibodies in the CSF of MS patients during remission could suggest a potential pathogenic role for these autoantibodies in MS.

Detection of anti-heat shock protein 90 beta (Hsp90beta) antibodies in cerebrospinal fluid

Antibodies against heat shock protein 90 beta (Hsp90beta) recognize the antigen on the cell surface of the oligodendrocyte precursor cells and cause a decrease of oligodendrocyte population in cell cultures. These antibodies have been found in patients with multiple sclerosis (MS). This report describes an original and sensitive method to detect anti-Hsp90beta antibodies in cerebrospinal fluid (CSF) using a western blot procedure. We have developed the method for autoantibody detection using Hsp90beta from cell membrane fraction instead of commercial Hsp90beta as antigen. The presence of anti-Hsp90beta antibodies in CSF of MS patients may play a pathogenic role in MS, and a large-scale study is needed to establish a possible diagnostic value of these antibodies in MS patients.

Caspase inhibitors protect against neuronal apoptosis induced by cerebrospinal fluid from multiple sclerosis patients

Neuronal apoptosis has recently been implicated in multiple sclerosis (MS). Apoptotic cell death of neurons is induced in cultures exposed to cerebrospinal fluid (CSF) from MS patients. Since caspases are essential in the regulation of apoptosis, direct evidence was sought linking caspases to CSF-induced neuronal death. Caspase activity was measured in cell extracts from MS CSF-treated cultured neurons by the cleavage of caspase-1 and caspase-3 substrates. Caspase-3 activity, but not caspase-1, was induced in neuronal cultures in response to MS CSF treatment. This caspase-3 activity was inhibited in vitro by Ac-YVAD-cmk and Ac-DEVD-cmk caspase inhibitors. Treatment of MS CSF-incubated neuronal cells with these caspase inhibitors completely preserved neuronal survival and largely attenuated DNA fragmentation detected in situ. These findings show that neuronal cells are rescued from MS CSF-induced death by caspase inhibitors and suggest ways to treat MS.

Influence of water pressure on the final quality of arabica espresso coffee. Application of multivariate analysis

Water pressure is one of the most important factors which influence the final quality of espresso coffee (EC). However, few studies dealing with this issue have been found. The aim of this work was to study the effect of water pressure on the final quality of Arabica ECs as well as to classify ECs prepared at different pressures (7, 9, and 11 atm) according to their physicochemical and sensory characteristics, key odorants, by means of multivariate analysis. Statistically, principal component 1 (PC1) separated ECs prepared at 7 and 9 atm from ECs prepared at 11 atm and included the main foam and taste characteristics as well as some key odorants and flavor compounds. ECs prepared at 7 and 9 atm were separated by principal component 2 (PC2). Coffees prepared at 9 atm showed consistency of foam and a high percentage of key odorants related to freshness and fruity, malty, and buttery flavors. A simple discriminate function was obtained by discriminate analysis, allowing the classification of ECs prepared at three pressures into their respective groups with a success rate of 100%.

[The effect of cerebrospinal fluid on neurone culture: implications in the pathogenesis of multiple sclerosis]

In vitro studies have shown that the cerebrospinal fluid of patients with multiple sclerosis transports compounds which may affect the function or viability of central nervous system cell function. The presence of nerve ion channel blockers and other molecules, as yet unidentified, which may cause the death of nerve cells or oligodendrocytes has been shown, although their relevance and clinical correlation is still not clear. If their usefulness is proved, these methods may be useful in the search for inhibitors of the noxious effects of the substances mentioned.

Characterization of espresso coffee aroma by static headspace GC-MS and sensory flavor profile

The aromas of three espresso coffee (EC) samples from different botanical varieties and types of roast (Arabica coffee, Robusta natural blend, and Robusta Torrefacto blend (special roast by adding sugar)) were studied by static headspace GC-MS and sensory flavor profile analysis. Seventy-seven compounds were identified in all of the EC samples. Among them, 13 key odorants have been quantified and correlated with their flavor notes by applying multivariate statistical methods. Some correlations have been found in the EC samples: some aldehydes with fruity flavors, diones with buttery flavors, and pyrazines with earthy/musty, roasty/burnt, and woody/papery flavors. By applying principal component analysis (PCA), Arabica and Robusta samples were separated successfully by principal component 1 (60.7% of variance), and Torrefacto and Natural Robusta EC samples were separated by principal component 2 (28.1% of total variance). With PCA, the aroma characterization of each EC sample could be observed. A very simple discriminant function using some key odorants was obtained by discriminant analysis, allowing the classification of each EC sample into its respective group with a success rate of 100%.

Multivariate methods for characterization and classification of espresso coffees from different botanical varieties and types of roast by foam, taste, and mouthfeel

Three espresso coffee (EC) samples of different botanical varieties and types of roast were prepared in standard conditions using an experimental EC prototype: Arabica coffee, Robusta Natural blend, and Robusta Torrefacto blend (a special roast by adding sugar). The ECs were characterized with regard to the physical parameters, amount of total solids, total solids on filtrate, lipids, caffeine, trigonelline, and chlorogenic acids by HPLC, and sensory descriptive analysis related to foam appearance, taste, and mouthfeel. Principal component analysis (PCA) was applied to differentiate the EC samples. Arabica and Robusta samples were separated successfully by principal component 1 (55.3% of variance) including physicochemical and sensory parameters related to foam and taste of ECs. Torrefacto and Robusta Natural EC samples were separated by principal component 2 (20.7% of total variance) including mouthfeel and other attributes of color foam. Some interesting correlations among sensory and physicochemical variables were found. A very simple discriminate function was obtained by discriminate analysis allowing the classification of each EC sample into its respective group with a success rate of 100%.

Optimizing headspace temperature and time sampling for identification of volatile compounds in ground roasted Arabica coffee

Equilibration time and temperature were the factors studied to choose the best conditions for analyzing volatiles in roasted ground Arabica coffee by a static headspace sampling extraction method. Three temperatures of equilibration were studied: 60, 80, and 90 degrees C. A larger quantity of volatile compounds was extracted at 90 degrees C than at 80 or 60 degrees C, although the same qualitative profile was found for each. The extraction of the volatile compounds was studied at seven different equilibration times: 30, 45, 60, 80, 100, 120, and 150 min. The best time of equilibration for headspace analysis of roasted ground Arabica coffee should be selected depending on the chemical class or compound studied. One hundred and twenty-two volatile compounds were identified, including 26 furans, 20 ketones, 20 pyrazines, 9 alcohols, 9 aldehydes, 8 esters, 6 pyrroles, 6 thiophenes, 4 sulfur compounds, 3 benzenic compounds, 2 phenolic compounds, 2 pyridines, 2 thiazoles, 1 oxazole, 1 lactone, 1 alkane, 1 alkene, and 1 acid.

A homogeneous method to measure aminoacyl-tRNA synthetase aminoacylation activity using scintillation proximity assay technology

A new method to measure the aminoacylation of tRNA based upon the use of the scintillation proximity assay (SPA) technology has been developed. The assay detects incorporation of radiolabeled amino acids into cognate tRNA, catalyzed by a specific aminoacyl-tRNA synthetase (aaRS). Under acidic conditions, uncoated yttrium silicate SPA beads were found to bind tRNA aggregates, while the radiolabeled amino acid substrate remains in solution, resulting in good signal discrimination of these two species in the absence of any separation steps. The usefulness of this approach was demonstrated by measurement of steady-state kinetic constants and inhibitor binding constants for a range of aaRS enzymes in comparison with data from standard, trichloroacetic acid-precipitation-based assays. In all cases, the data were quantitatively comparable. Although the radioisotopic counting efficiency of the SPA method was less than that of standard liquid scintillation counting, the statistical performance (i.e., signal to background, variability, stability) of the SPA assays was at least equivalent to the separation-based methods. The assay was also shown to work well in miniaturized 384-well microtiter plate formats, resulting in considerable reagent savings. In summary, a new method to characterize aaRS activity is described that is faster and more amenable to high-throughput screening than traditional methods.

[Treatment of transformed refractory migraine with intravenous dihydroergotamine]

In this work we present our experience with a seven-day protocol of i.v. dihydroergotamine (DHE) in the treatment of 6 patients (7 treatments) suffering from intractable transformed migraine. All of them were admitted to hospital and treated for one week with a protocol which included DHE doses between 0.5-1 mg/8 h. One patient did not respond. The remaining 6 became free of pain in under 48 hours after the beginning of treatment. This positive effect remained for between 15 days and 3 months. All patients experienced adverse events; however, these were slight and ceased when the DHE dose was reduced. DHE is an effective and quick option for the short-term treatment of patients with severe transformed migraine resistant to other medications.

Design of a modified uniform redundant-array mask for portable gamma cameras

Uniform redundant-array masks have been reported as good lenses to form the image of gamma sources, with the correlation between the mask-aperture matrix and the shadows projected on a static position-sensitive detector. We present a modified uniform redundant-array configuration suitable for portable and small-size gamma cameras; its ability to reconstruct the image of several sources is analyzed. We have carried out a Montecarlo simulation of the gamma interactions in the mask, defining the expected response of the correlation process and comparing it with that achieved with the usual uniform redundant-array configurations.

Anaphylactic reaction after atropine

A 38-year-old woman developed symptoms of anaphylactic shock after intravenous atropine and required adrenaline to maintain perfusion pressure. A strongly positive response was obtained on intradermal testing. The Prausnitz-Kuestner test was also positive, which indicated the presence of drug specific IgE antibodies. No response was obtained after hyoscine.

Direct communication between the right pulmonary artery and the left atrium

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