Quantitative Clinical Chemistry Proteomics (qCCP) using mass spectrometry: general characteristics and application

Proteomics studies typically aim to exhaustively detect peptides/proteins in a given biological sample. Over the past decade, the number of publications using proteomics methodologies has exploded. This was made possible due to the availability of high-quality genomic data and many technological advances in the fields of microfluidics and mass spectrometry. Proteomics in biomedical research was initially used in ‘functional' studies for the identification of proteins involved in pathophysiological processes, complexes and networks. Improved sensitivity of instrumentation facilitated the analysis of even more complex sample types, including human biological fluids. It is at that point the field of clinical proteomics was born, and its fundamental aim was the discovery and (ideally) validation of biomarkers for the diagnosis, prognosis, or therapeutic monitoring of disease. Eventually, it was recognized that the technologies used in clinical proteomics studies [particularly liquid chromatography-tandem mass spectrometry (LC-MS/MS)] could represent an alternative to classical immunochemical assays. Prior to deploying MS in the measurement of peptides/proteins in the clinical laboratory, it seems likely that traditional proteomics workflows and data management systems will need to adapt to the clinical environment and meet in vitro diagnostic (IVD) regulatory constraints. This defines a new field, as reviewed in this article, that we have termed quantitative Clinical Chemistry Proteomics (qCCP

CFTR Cl− channel function in native human colon correlates with the genotype and phenotype in cystic fibrosis

BACKGROUND & AIMS: Cystic fibrosis (CF) is caused by over 1000 mutations in the cystic fibrosis transmembrane conductance regulator (CFTR) gene and presents with a widely variable phenotype. Genotype-phenotype studies identified CFTR mutations that were associated with pancreatic sufficiency (PS). Residual Cl- channel function was shown for selected PS mutations in heterologous cells. However, the functional consequences of most CFTR mutations in native epithelia are not well established. METHODS: To elucidate the relationships between epithelial CFTR function, CFTR genotype, and patient phenotype, we measured cyclic adenosine monophosphate (cAMP)-mediated Cl- secretion in rectal biopsy specimens from 45 CF patients who had at least 1 non-DeltaF508 mutation carrying a wide spectrum of CFTR mutations. We compared CFTR genotypes and clinical manifestations of CF patients who expressed residual CFTR-mediated Cl- secretion with patients in whom Cl- secretion was absent. RESULTS: Residual anion secretion was detected in 40% of CF patients, and was associated with later disease onset (P < 0.0001), higher frequency of PS (P < 0.0001), and less severe lung disease (P < 0.05). Clinical outcomes correlated with the magnitude of residual CFTR activity, which was in the range of approximately 12%-54% of controls. CONCLUSIONS: Specific CFTR mutations confer residual CFTR function to rectal epithelia, which is related closely to a mild disease phenotype. Quantification of rectal CFTR-mediated Cl- secretion may be a sensitive test to predict the prognosis of CF disease and identify CF patients who would benefit from therapeutic strategies that would increase residual CFTR activity

Reduktion von Bremskraftschwingungen mithilfe reibkraftgeregelter Bremsen

The research presented in this work analyses two friction force-controlled brakes regarding their ability to influence and actively reduce occurring brake force oscillations. Based on the state of the art, the prototype of a self-energized electrohydraulic brake (SEHB) and the corresponding test bench are introduced. Brake tests carried out prove the occurrence of the vibration phenomenon of brake judder. A detailed 1D-simulation model of the SEHB reproduces the vibration behaviour of occurring forces and has been validated by measurement results. Both measurements and simulation results show that the compensatory capacity of the prototype is limited regarding friction-induced vibrations. In the following, the simulation model is used to derive innovative control structures, analyse the results and validate them on the test bench. A derivative feedforward control successfully compensates frictional force oscillations. Observed vibration amplitudes can be actively reduced up to 86 % depending on the brake disc speed by adjusting the actuation of the SEHB both at constant speeds and when driving through speed ramps. Subsequently, the work concentrates on a hydraulic-mechanically controlled brake, which is characterized by its simple retrofittability into an uncontrolled brake that has already been used in practice. A comprehensive 1D-simulation model of the brake system is followed by an analysis and optimization of the compensating capacity of brake force oscillations. Compensation rates of almost 90 % can also be determined for the hydraulic-mechanically controlled brake in wide operating ranges. Overall, the results of the work show the promising potential of friction forcecontrolled brakes regarding the compensation of brake force oscillations and the phenomenon of brake judder in particular. The further development of such brake systems up to their industrial implementation therefore appears promising, as these brake systems are able to meet increased demands for the required performance, sensitivity and reproducibility of braking processes

Matrix-assisted laser desorption/ionization imaging mass spectrometry of oxaliplatin derivatives in heated intraoperative chemotherapy (HIPEC)-like treated rat kidney.

The authors are grateful to F. Boissière and A. Denouel (Department of Anatomopathology CRLC Val d'Aurelle) for help in preparing tissues slices. Thanks are due to Drs. P. Martineau, F. Quenet and. F. Pinguet for helpful discussions and to Pr. JB Dubois for continuous support.International audienceOxaliplatin [1,2-diaminocyclohexane (dach)-Pt complex] is a platinum anticancer drug which is mainly used in the treatment of advanced colorectal cancer, particularly in Heated Intraoperative Chemotherapy (HIPEC) for the treatment of colorectal peritoneal carcinomatosis. In order to better understand the penetration of oxaliplatin in treated tissues we performed a direct imaging of tissue sections from HIPEC-like treated rat kidney using matrix-assisted laser desorption/ionization (MALDI) mass spectrometry. This procedure allowed the detection and localization of oxaliplatin and its metabolites, the monocysteine and monomethionine complexes, in kidney sections. Specifically, oxaliplatin and its metabolites were localized exclusively in the kidney cortex, suggesting that it did not penetrate deeply into the organ. Based on these results, an imaging analysis of human tumors collected after HIPEC is currently in progress to assess the distribution of oxaliplatin and/or metabolites with the aim of defining clinical conditions to improve drug penetration

How personality influences health outcomes and quality of life in adult patients with cystic fibrosis

Abstract Background The present study evaluates personality traits in adult patients with cystic fibrosis (CF) and correlates these results with health-related quality of life (HRQoL) and other clinical parameters indicative of disease severity. Methods Seventy adults completed the Cystic Fibrosis Questionnaire-Revised (CFQ-R 14+), a CF-specific measure of HRQoL, and a self-administered questionnaire about personality traits and disorders. Mean subscale scores and the prevalence of extreme personality traits on the `Persönlichkeits-Stil- und Störungs-Inventar (PSSI)´ were compared to the norming sample. Moreover, a cluster analysis was conducted to identify personality styles among people with cystic fibrosis (pwCF). The relationship between mean PSSI subscale scores and personality clusters with HRQoL and clinical outcomes, e.g., percent predicted forced expiratory volume in one second (ppFEV1), and body mass index (BMI), was studied by regression analysis considering important confounders. Results On several of the subscales of the personality questionnaire, people with cystic fibrosis (pwCF) showed either significantly higher or lower scores than the norm sample. In further analyses, two personality clusters could be identified. PwCF from the cluster with predominantly low scores on the subscales ‘negativistic’, ‘schizoid’, ‘borderline’, ‘depressed’, and ‘paranoid’ showed better HRQoL than pwCF from the other cluster with mainly high normal or elevated scores. The studied health outcomes proved to be independent of the respective personality clusters. Conclusions In pwCF, HRQoL is mainly determined by psychological factors, including personality. Since more recent personality theories assume that personality is modifiable, our findings imply that patients with accentuated personality traits may benefit from psychosocial support

Real-life impact of highly effective CFTR modulator therapy in children with cystic fibrosis

Introduction: Recently, cystic fibrosis transmembrane regulator modulator therapy with elexacaftor/tezacaftor/ivacaftor has become available for children with cystic fibrosis (CF) carrying at least one F508del mutation.Objective: To assess the intermediate term effects of elexacaftor/tezacaftor/ivacaftor in children with cystic fibrosis in a real-world setting.Methods: We performed a retrospective analysis of records of children with cystic fibrosis, who started elexacaftor/tezacaftor/ivacaftor between 8/2020 and 10/2022. Pulmonary function tests, nutritional status, sweat chloride and laboratory data were assessed before, 3 and 6 months after the start of elexacaftor/tezacaftor/ivacaftor respectively.Results: Elexacaftor/tezacaftor/ivacaftor was started in 22 children 6–11 years and in 24 children 12–17 years. Twenty-seven (59%) patients were homozygous for F508del (F/F) and 23 (50%) patients were transitioned from ivacaftor/lumacaftor (IVA/LUM) or tezacaftor/ivacaftor (TEZ/IVA) to elexacaftor/tezacaftor/ivacaftor. Overall, mean sweat chloride concentration decreased by 59.3 mmol/L (95% confidence interval: −65.0 to −53.7 mmol/L, p &lt; 0.0001) under elexacaftor/tezacaftor/ivacaftor. Sweat chloride concentration also decreased significantly after transition from IVA/LUM or TEZ/IVA to elexacaftor/tezacaftor/ivacaftor (−47.8 mmol/l; 95% confidence interval: −57.6 to −37.8 mmol/l, n = 14, p &lt; 0.0001). Sweat chloride reduction was more marked in children with the F/F than in those with the F/MF genotype (69.4 vs 45.9 mmol/L, p &lt; 0.0001). At 3 months follow-up, body-mass-index-z-score increased by 0.31 (95% CI, 0.2–0.42, p &lt; 0.0001) with no further increase at 6 months. BMI-for-age-z-score was more markedly improved in the older group. Overall pulmonary function (percent predicted FEV1) at 3 months follow-up increased by 11.4% (95% CI: 8.0–14.9, p &lt; 0.0001) with no further significant change after 6 months. No significant differences were noted between the age groups. Children with the F/MF genotype had a greater benefit regarding nutritional status and pulmonary function tests than those with the F/F genotype. Adverse events led to elexacaftor/tezacaftor/ivacaftor dose reduction in three cases and a temporary interruption of therapy in four cases.Conclusion: In a real-world setting, elexacaftor/tezacaftor/ivacaftor therapy had beneficial clinical effects and a good safety profile in eligible children with cystic fibrosis comparable to previously published data from controlled clinical trials. The positive impact on pulmonary function tests and nutritional status seen after 3 months of elexacaftor/tezacaftor/ivacaftor therapy was sustained at 6 months follow-up