Multiplexed Assays by High-Content Imaging for Assessment of GPCR Activity

G-protein-coupled receptors (GPCR) participate in many disease pathways and represent the largest family of therapeutic targets. Thus, great investments are made to discover drugs modulating GPCR-mediated events. Among functional assays for screening GPCRs, the Transfluor®imaging assay is based on redistribution of cytosolic β-arrestin to an activated GPCR and has become widely used in high-content screening. However, assessing Transfluor®alone has limitations: relying on a single mechanistic step of β-arrestin redistribution during GPCR activation, providing no information on the stimulated GPCR's intracellular fate, and using only a single fluorescent color (green fluorescent protein). Taking full advantage of high-content imaging to screen approximately 2000 compounds, the authors multifplexed the Transfluor®assay with an immunofluorescence-based quantification of GPCR internalization. This approach identified and classified 377 compounds interfering with agonist-induced activation of the Transfluor®assay, receptor internalization, or both. In addition, a subset of compounds was analyzed for their performance across imaging, cell-based calcium release (fluorometric imaging plate reader [FLIPR]), and biochemical receptor binding assays (scintillation proximity assay). This indicated that the imaging assays have even better predictive power for direct inhibition of receptor binding than the FLIPR assay. In conclusion, compounds inducing unique responses can suggest novel mechanisms of action and be used as tools to study GPCR activation and internalization. ( Journal of Biomolecular Screening 2008:449-455)

Non-invasive ventilation in the weaning process

Patients with chronic airflow obstruction and difficulty in weaning from mechanical ventilation are at increased risk for intubation-associated complications and mortality because of prolonged invasive mechanical ventilation. Non-invasive ventilation (NIV) may avert most of the pathophysiologic mechanisms associated with weaning failure in these patients. Several randomised controlled trials have shown that the use of NIV in order to advance extubation in difficult patients can result in reduced periods of endotracheal intubation, complication rates and survival. The published data with the outcome as a primary variable are nearly exclusively from patients who had pre-existing lung disease. In addition, the patients were hemodynamically stable, with a normal level of consciousness, no fever and a preserved cough reflex. The use of NIV in the management of respiratory failure after extubation did not show clinical benefits, although clinical trials included a small proportion of chronic respiratory patients. In contrast, NIV immediately after extubation is effective in avoiding respiratory failure after extubation in patients at risk for this complication, particularly those with chronic respiratory disorders and hypercapnic respiratory failure.

Light-driven novel properties of TiO2-modified polypropylene-based nanocomposite films

Nanocomposite films obtained by TiO2 incorporation into a polypropylene (PP) polymer matrix were prepared via a straightforward melting process. The structural characteristics of the nanocomposite materials were examined by a multitechnique approach showing the outstanding morphological uniformity of the films. TiO2 incorporation into the polymer matrix renders self-sterilized and self-degradable materials which showed an impressive performance against gram-positive, gram-negative, coccus and yeast micro-organisms. Optimization of the novel properties of TiO2-PP nanocomposite films is reached with a 2 wt% of oxide content loading. The physico-chemical bases of this optimum are discussed.

Orchidectomy increases the formation of non-endothelial thromboxane A2 and modulates its role in the electrical field stimulation-induced response in rat mesenteric artery

The aim of this study was to analyze whether endogenous male sex hormones influence the release of thromboxane A2(TXA2) and its role in the electrical field stimulation (EFS)-induced response, as well as the mechanism involved. For this purpose, endothelium-denuded mesenteric arteries from control and orchidectomized male Sprague-Dawley rats were used to measure TXA2 release; EFS-induced response, nitric oxide (NO), norepinephrine (NA), and prostaglandin (PG) I2 release were also measured in the presence of the TXA2 synthesis inhibitor furegrelate. Orchidectomy increased basal and EFS-induced TXA2 release. Furegrelate decreased the EFS-induced contraction in arteries from control rats, but did not modify it in arteries from orchidectomized rats. The EFS-induced neuronal NO release and vasodilator response were increased by furegrelate in arteries from control rats, but were not modified in arteries from orchidectomized rats. Furegrelate did not modify the EFS-induced NA release or vasoconstrictor response in arteries from either control or orchidectomized rats. The EFS-induced PGI2 release was not modified by furegrelate in arteries from control rats, but was increased in arteries from orchidectomized rats. The results of the present study show that endogenous male sex hormone deprivation i) increases non-endothelial TXA2 release and ii) regulates the effect of endogenous TXA2 on the EFS-induced response through different mechanisms that, at the least, involve the NO and PGI2 systems. In arteries from control rats, inhibition of TXA2 formation decreases the EFS-induced response by increasing neuronal NO release. In arteries from orchidectomized rats, the EFS-induced response is unaltered after the inhibition of TXA2 formation, by increasing PGI2 release.

Effect of oat's soluble fibre (β-glucan) as a fat replacer on physical, chemical, microbiological and sensory properties of low-fat beef patties

This study evaluated the effect of adding oat fibre source of β-glucan (13.45%) on physical, chemical, microbiological and sensory traits of low-fat (<10%) beef patties as compared to 20% fat control patties. Significant (p<0.05) improvements in cooking yield (74.19%), and retentions of fat (79.74%) and moisture (48.41%) of low-fat patties were attributed to the water binding ability of β-glucan. Because of larger water retentions moisture contents of raw and cooked low-fat patties were higher (p<0.05) than those of the control patties. Cholesterol content was similar across formulations. Low-fat and control beef patties remained stable in microbiological quality during 60days frozen storage. Low-fat patties were found to be of lower degree of likeness in the taste but juicer than control (p<0.05). Besides appearance, tenderness and colour were not affected by the addition of oat's soluble fibre. Oat fibre can be used successfully as a fat substitute in low-fat beef patties.

Adaptation and validation of the Spanish version of the Chronic Urticaria Quality of Life Questionnaire (CU-Q2oL)

OBJECTIVES

The aim of this study was to develop a Spanish version of the Chronic Urticaria Quality of Life Questionnaire (CU-Q2oL) and to test its acceptability, reliability, validity, and sensitivity to change.

METHODS

Forward and back translation by bilingual translators followed by pilot testing in patients with urticaria was used to adapt the questionnaire. The Spanish version of the CU-Q2oL was self-administered alongside the Skindex-29 in an observational, longitudinal, multicenter study. Feasibility was assessed by analyzing missing responses and ceiling and floor effects. Reliability was tested by examining internal consistency (Cronbach alpha). Construct validity was analyzed by examining convergent and discriminant validity with the Skindex-29 and by evaluating the ability of the CU-Q2oL to discriminate between patients according to a clinical classification of severity. Sensitivity to change was analyzed in a subgroup of patients who completed a second visit 4 weeks after baseline.

RESULTS

A total of 695 patients were included in the analysis. Mean (SD) age was 42.4 (15.0) years and 62.1% of the sample was female. All of the items on the CU-Q2oL were answered by 91.9% of the sample. Over 15% of patients scored at the floor (best possible health) on 5 of the 6 dimensions. Cronbach alpha coefficients were > 0.80 for all dimensions of the CU-Q2oL, and 0.86 for the overall score. Construct validity was supported by correlations between the CU-Q2oL and the Skindex-29, which generally fulfilled hypotheses, and by the questionnaire's ability to discriminate between groups with different severities of urticaria.The questionnaire was sensitive to change, with an effect size of 1.0 for the overall score in patients reporting an improvement on the health transition scale.

CONCLUSIONS

The Spanish version of the CU-Q2oL has shown satisfactory reliability, validity, and sensitivity to change. It is suitable for use as an outcome measure for chronic urticaria patients in clinical and research settings.

Health-related quality of life in allergic rhinitis: comparing the short form ESPRINT-15 and MiniRQLQ questionnaires

BACKGROUND

We compared the psychometric properties of the ESPRINT-15, the short form of a new Spanish instrument to measure health-related quality of life in allergic rhinitis (AR) patients, with those of the Mini-Rhinoconjunctivitis Quality of Life Questionnaire (MiniRQLQ).

METHODS

The questionnaires were compared in Spanish patients with intermittent allergic rhinitis (IAR) or persistent AR in a prospective, observational study. Floor and ceiling effects, internal consistency (Cronbach's alpha), test-retest reliability (intraclass correlation coefficient; ICC), convergent and known groups validity, and sensitivity to change (standardized response means; SRMs) were compared.

RESULTS

In terms of content, while the MiniRQLQ has a dimension covering practical problems and places more emphasis on symptoms, the ESPRINT-15 has two dimensions (Sleep and Psychological impact) which are not included in the MiniRQLQ. In the validation study, 400 patients were included and 59% of the sample had persistent AR. There were no significant floor or ceiling effects on any dimension on either questionnaire. Cronbach's alpha values for the ESPRINT-15 and MiniRQLQ overall scores were 0.92 and 0.90, respectively. In 48 clinically stable patients, ICCs were 0.80 and 0.77, respectively. Both instruments discriminated between patients with IAR and persistent AR. Correlations with symptom scores and generic measures were moderate to strong. SRMs for overall scores and individual dimensions on the two questionnaires in the 197 patients reporting a change in health status ranged from 0.7 to 1.3.

CONCLUSIONS

Both questionnaires performed well in psychometric terms. The ESPRINT-15 is particularly recommended for use in Spanish-speaking populations.

[Spanish version of the Functional Outcomes of Sleep Questionnaire: scores of healthy individuals and of patients with sleep apnea-hypopnea syndrome]

OBJECTIVE

The main symptom of sleep apnea-hypopnea syndrome (SAHS) is excessive daytime sleepiness. The self-administered Functional Outcomes of Sleep Questionnaire (FOSQ) was designed to evaluate the impact of sleepiness on a patient's daily life. The aim of this study was to determine the scores of patients with SAHS and of healthy individuals on the Spanish version of the FOSQ and to assess its usefulness for evaluating the impact of excessive sleepiness in patients with suspected SAHS.

POPULATION AND METHODS

Thirty-one patients with SAHS diagnosed by conventional polysomnography and 31 healthy individuals were included in the study. The following data were collected: patient information; use of tobacco, alcohol, or street drugs; blood pressure; and sleep schedule. Sleepiness was assessed on the Epworth Sleepiness Scale and the impact of sleepiness on activities of daily living by the FOSQ.

RESULTS

Patients with SAHS (apnea-hypopnea index, 57) had a mean FOSQ total score of 88.7; healthy individuals had a mean score of 110.9 (P< .001) Significant differences were found between the 2 groups on all the FOSQ subscales, except for the one that measured social outcome. There was a moderate correlation between the 2 questionnaires (r=--0.54; P=.01) and between FOSQ and the AHI (r=--0.39; P=.05). While the capacity to predict SAHS, based on receiver operating characteristic curves was greater for the Epworth Sleepiness Scale than for the FOSQ (area under the curve, 0.91 and 0.77, respectively), the diagnostic yield increased when both questionnaires were considered together.

CONCLUSIONS

We obtained FOSQ reference scores for Spanish patients with SAHS and for healthy individuals. The study showed that the Spanish version of the FOSQ is a good instrument for assessing the impact of excessive sleepiness on activities of daily living in patients with suspected SAHS.

Sequential measurements of procalcitonin levels in diagnosing ventilator-associated pneumonia

The utility of procalcitonin levels to improve the accuracy of clinical and microbiological parameters in diagnosing ventilator-associated pneumonia (VAP) was evaluated. Sequential measurement of procalcitonin and C-reactive protein levels and the calculation of the simplified Clinical Pulmonary Infection Scores (CPIS) were performed in 44 patients mechanically-ventilated for >48 h with neither active infection for the duration or suspicion of VAP. Patients who developed extrapulmonary infection were excluded. In total, 20 cases were suspected of having VAP and diagnosis was microbiologically confirmed in nine. In patients with confirmed VAP, procalcitonin levels were higher than in those without VAP. C-reactive protein levels and CPIS were lower in patients without suspected VAP, but could not discriminate confirmed and nonconfirmed suspicion of VAP. The best sensitivity and specificity (78 and 97%, respectively) corresponded to procalcitonin. The CPIS resulted in the same sensitivity, but had a lower specificity (80%). C-reactive protein had the worst sensitivity (56%), but a good specificity (91%). A CPIS >or=6 combined with serum levels of procalcitonin >or=2.99 ng.mL(-1) did not improve the sensitivity (67%), but resulted in 100% specificity. Procalcitonin might be useful in the diagnosis of ventilator-associated pneumonia. Combined values of Clinical Pulmonary Infection Scores and procalcitonin below the cut-off points excluded false-positive diagnoses of ventilator-associated pneumonia.

DNA interaction and antiproliferative behavior of the water soluble platinum supramolecular squares [(en)Pt(N–N)]4(NO3)8 (en=ethylenediamine, N–N=4,4′-bipyridine or 1,4-bis(4-pyridyl)tetrafluorobenzene)

The interaction with DNA of two water soluble platinum supramolecular squares [(en)Pt(N-N)]4(NO3)8 (en=ethylenediamine, N-N=1,4-bis(4-pyridyl)tetrafluorobenzene, compound 1, N-N=4,4'-bipyridine, compound 2) has been studied by circular dichroism, electrophoretic mobility and atomic force microscopy. the two complexes drastically modify the second and tertiary structures of DNA, but compound 2 does it strongly due probably to its smaller size by comparison with compound 1 and its more suitable structural features for intercalation between base pairs. The two supramolecular squares were assayed against the HL-60 tumor cell line for 24 and 72 h. The IC50 values for 24 h are smaller than that of cisplatin for this time, however for 72 h the IC50 have higher values being the corresponding to compound 2 comparable to that of cisplatin. Apoptotic assays were also carried out for the compounds 1 and 2 against the tumor cell line.

Self-Assembly Reactions between the Cis-Protected Metal Corners (N−N)MII (N−N = Ethylenediamine, 4,4‘-Substituted 2,2‘-Bipyridine; M = Pd, Pt) and the Fluorinated Edge 1,4-Bis(4-pyridyl)tetrafluorobenzene

The self-assembly reactions between the fluorinated ditopic ligand 1,4-bis(4-pyridyl)tetrafluorobenzene (A) and different nitrogen-protected palladium(II) and platinum(II) complexes have been investigated. While dynamic equilibria between molecular triangles and squares were observed when the diimine compounds 4,4'-R2bipy (bipy = 2,2'-bipyridine; R = H, Me, t-Bu) were employed as ancillary ligands, only square species were obtained from ethylenediamine (en) derivatives. Characterization of the obtained metallomacrocycles was accomplished by 1H and 19F NMR spectroscopy in combination with electrospray ionization Fourier transform ion cyclotron resonance mass spectrometry (ESI-FT-ICR). Molecular dynamics simulations (UFF) have been performed to interpret the influence of the fluorinated ring on the square/triangle relative stability. Density functional calculations using the GIAO method have been employed for the interpretation of the chemical shift assignments. The study of the ability of these compounds to act as hosts of electron-rich aromatic guests has shown that the palladium ethylenediamine square is capable of establishing this type of intermolecular interaction exclusively in aqueous media. The host-guest stoichiometry and association constants have been determinated by 1H NMR spectroscopy.

Chronic urticaria: what is new, where are we headed

Chronic urticaria can be defined as the occurrence of widespread daily or nearly daily wheals for at least 6 weeks, which may be accompanied by angioedema. It is a disease with a considerable impact on patients' quality of life. Furthermore, these patients may undergo extensive laboratory evaluations seeking a cause only to be frustrated when none is found. There is no curative treatment for this disorder and we do not understand the mechanisms that lead to the onset of disease. However, in recent years there have been significant advances in the understanding of some of the molecular mechanisms that cause cutaneous inflammation that is manifest as urticaria and angioedema. In this review we will summarize our recent contributions to this field and try to offer insights regarding future directions for research.