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Внаслідок швидкого розвитку сучасної науки ми постійно, день у день, удосконалюємо наші знання про патогенез і морфологію захворювань. У зв’язку з настанням ери наукомік, таких як геноміка, транскріптоміка та протеоміка, є велика необхідність у розумінні молекулярних механізмів хвороб і організмів. Кінцевими цілями повинні бути такі: більш успішні діагностика та прогноз, виявлення потенційних терапевтичних мішеней і прогнозування відповіді на лікування. Хронічна хвороба нирок (ХХН) є всесвітньою проблемою охорони здоров’я, що характеризується швидкозростаючою захворюваністю, a сам термін «ХХН» охоплює велику підмножину захворювань. Останнім часом для вивчення ХХН використовуються сучасні технології протеоміки, такі як мас-спектрометрія з матрично-активованою лазерною десорбцією/іонізацією. Незважаючи на ранній етап розвитку подібних методик, уже існує значна кількість досліджень і публікацій, присвячених цій темі.

Human platelet lysate (hPL) is considered a valid substitute to fetal bovine serum (FBS) in the expansion of mesenchymal stromal cells (MSC), and it is commonly produced starting from intermediate side products of whole blood donations. Through freeze–thaw cycles, hPL is highly enriched in chemokines, growth factors, and adhesion and immunologic molecules. Cell therapy protocols, using hPL instead of FBS for the expansion of cells, are approved by regulatory authorities without concerns, and its administration in patients is considered safe. However, published data are fairly difficult to compare, since the production of hPL is highly variable. This study proposes to optimize and standardize the hPL productive process by using instruments, technologies, and quality/safety standards required for blood bank activities and products. The quality and improved selection of the starting material (i.e., the whole blood), together with the improvement of the production process, guarantee a product characterized by higher content and quality of growth factors as well as a reduction in batch-to-batch variability. By increasing the number of freeze/thaw cycles from one (hPL1c) to four (hPL4c), we obtained a favorable effect on the release of growth factors from platelet α granules. Those changes have directly translated into biological effects leading to a decreasing doubling time (DT) of MSC expansion at 7 days (49.41 ± 2.62 vs. 40.61 ± 1.11 h, p < 0.001). Furthermore, mass spectrometry (MS)-based evaluation has shown that the proliferative effects of hPL4c are also combined with a lower batch-to-batch variability (10–15 vs. 21–31%) at the proteomic level. In conclusion, we have considered lot-to-lot hPL variability, and by the strict application of blood bank standards, we have obtained a standardized, reproducible, safe, cheap, and ready-to-use product.

Gelatin–dextran hydrogel scaffolds (G-PEG-Dx) were evaluated for their ability to activate the bone marrow human mesenchymal stromal cells (BM-hMSCs) towards mineralization. G-PEG-Dx1 and G-PEG-Dx2, with identical composition but different architecture, were seeded with BM-hMSCs in presence of fetal bovine serum or human platelet lysate (hPL) with or without osteogenic medium. G-PEG-Dx1, characterized by a lower degree of crosslinking and larger pores, was able to induce a better cell colonization than G-PEG-Dx2. At day 28, G-PEG-Dx2, with hPL and osteogenic factors, was more efficient than G-PEG-Dx1 in inducing mineralization. Scanning electron microscopy (SEM) and Raman spectroscopy showed that extracellular matrix produced by BM-hMSCs and calcium-positive mineralization were present along the backbone of the G-PEG-Dx2, even though it was colonized to a lesser degree by hMSCs than G-PEG-Dx1. These findings were confirmed by matrix-assisted laser desorption/ionization mass spectrometry imaging (MALDI-MSI), detecting distinct lipidomic signatures that were associated with the different degree of scaffold mineralization. Our data show that the architecture and morphology of G-PEG-Dx2 is determinant and better than that of G-PEG-Dx1 in promoting a faster mineralization, suggesting a more favorable and active role for improving bone repair.

The association between lipid metabolism and long-term outcomes is relevant for tumor diagnosis and therapy. Archival material such as formalin-fixed and paraffin embedded (FFPE) tissues is a highly valuable resource for this aim as it is linked to long-term clinical follow-up. Therefore, there is a need to develop robust methodologies able to detect lipids in FFPE material and correlate them with clinical outcomes. In this work, lipidic alterations were investigated in patient-derived xenograft of breast cancer by using a matrix-assisted laser desorption ionization mass spectrometry (MALDI MSI) based workflow that included antigen retrieval as a sample preparation step. We evaluated technical reproducibility, spatial metabolic differentiation within tissue compartments, and treatment response induced by a glutaminase inhibitor (CB-839). This protocol shows a good inter-day robustness (CV = 26 ± 12%). Several lipids could reliably distinguish necrotic and tumor regions across the technical replicates. Moreover, this protocol identified distinct alterations in the tissue lipidome of xenograft treated with glutaminase inhibitors. In conclusion, lipidic alterations in FFPE tissue of breast cancer xenograft observed in this study are a step-forward to a robust and reproducible MALDI-MSI based workflow for pre-clinical and clinical applications.

Formalin-fixed paraffin-embedded (FFPE) tissue represents the primary source of clinical tissue and is routinely used in MALDI-MSI studies. However, it is not particularly suitable for lipidomics imaging given that many species are depleted during tissue processing. Irrespective, a number of solvent-resistant lipids remain, but their extraction may be hindered by the cross-link between proteins. Therefore, an antigen retrieval step could enable the extraction of a greater number of lipids and may provide information that is complementary to that which can be obtained from other biomolecules, such as proteins. In this short communication, we aim to address the effect of performing antigen retrieval prior to MALDI-MSI of lipids in FFPE tissue. As a result, an increased number of lipid signals could be detected and may have derived from lipid species that are known to be implicated in the lipid-protein cross-linking that is formed as a result of formalin fixation. Human renal cancer tissue was used as a proof of concept to determine whether using these detected lipid signals were also able to highlight the histopathological regions that were present. These preliminary findings may highlight the potential to enhance the clinical relevance of the lipidomic information obtained from FFPE tissue.

This study presents the matrix-assisted laser desorption/ionization (MALDI) mass spectrometry imaging (MSI) as a unique technology for the in-situ detection of N-glycans and proteins from the same formalin-fixed paraffin-embedded (FFPE) tissue section.

Recurrent somatic mutations in ETNK1 (Ethanolamine-Kinase-1) were identified in several myeloid malignancies and are responsible for a reduced enzymatic activity. Here, we demonstrate in primary leukemic cells and in cell lines that mutated ETNK1 causes a significant increase in mitochondrial activity, ROS production, and Histone H2AX phosphorylation, ultimately driving the increased accumulation of new mutations. We also show that phosphoethanolamine, the metabolic product of ETNK1, negatively controls mitochondrial activity through a direct competition with succinate at mitochondrial complex II. Hence, reduced intracellular phosphoethanolamine causes mitochondria hyperactivation, ROS production, and DNA damage. Treatment with phosphoethanolamine is able to counteract complex II hyperactivation and to restore a normal phenotype., ETNK1 mutations are recurrent in leukemia but how they contribute to oncogenesis is still unclear. Here, the authors show that ETNK1 mutations increase mitochondrial activity, ROS and H2AX levels and that these effects can be rescued upon phosphoethanolamine supplementation.

Bone marrow and adipose tissue human mesenchymal stem cells were seeded in highly performing 3D gelatin–chitosan hybrid hydrogels of varying chitosan content in the presence of human platelet lysate and evaluated for their proliferation and osteogenic differentiation. Both bone marrow and adipose tissue human mesenchymal stem cells in gelatin–chitosan hybrid hydrogel 1 (chitosan content 8.1%) or gelatin–chitosan hybrid hydrogel 2 (chitosan 14.9%) showed high levels of viability (80%–90%), and their proliferation and osteogenic differentiation was significantly higher with human platelet lysate compared to fetal bovine serum, particularly in gelatin–chitosan hybrid hydrogel 1. Mineralization was detected early, after 21 days of culture, when human platelet lysate was used in the presence of osteogenic stimuli. Proteomic characterization of human platelet lysate highlighted 59 proteins mainly involved in functions related to cell adhesion, cellular repairing mechanisms, and regulation of cell differentiation. In conclusion, the combination of our gelatin–chitosan hybrid hydrogels with hPL represents a promising strategy for bone regenerative medicine using human mesenchymal stem cells.

MALDI-MSI represents an ideal tool to explore the spatial distribution of proteins directly in situ, integrating molecular and cytomorphological information, enabling the discovery of potential diagnostic markers in thyroid cytopathology. However, red cells present in the fine needle aspiration biopsy (FNAB) specimens caused ion suppression of other proteins during the MALDI-MSI analysis due to large amount of haemoglobin. Aim of this study was to set up a sample preparation workflow able to manage this haemoglobin interference. Three protocols were compared using ex vivo cytological samples collected from fresh thyroid nodules of 9 patients who underwent thyroidectomy: (A) conventional air-dried smears, (B) cytological smears immediately fixed in ethanol, and (C) ThinPrep liquid-based preparation. Protocols C and A were also evaluated using real FNABs. Results show that protocol C markedly decreased the amount of haemoglobin, with respect to protocols A and B. Protein profiles obtained with protocols A and B were characterised by high inter-patient variability, probably related to the abundance of the haemoglobin, whereas similar spectra were observed for protocol C, where haemoglobin contents were lower. Our findings suggest protocol C as the sample preparation method for MALDI-MSI analysis. Graphical abstract.

Purpose Matrix-assisted laser desorption/ionization mass spectrometry imaging (MALDI-MSI) technology has advanced rapidly during recent years with the development of instruments equipped with low-diameter lasers that are suitable for high spatial resolution imaging. This may provide significant advantages in certain fields of molecular pathology where more specific protein fingerprints of individual cell types are required, such as renal pathology. Experimental design Here MALDI-MSI analysis of a cohort of membranous nephropathy (MN) patients is performed among which patients either responded favorably (R; n = 6), or unfavorably (NR; n = 4), to immunosuppressive treatment (Ponticelli Regimen), employing a 10 µm laser spot diameter. Results Specific tryptic peptide profiles of the different cellular regions within the glomerulus can be generated, similarly for the epithelial cells belonging to the proximal and distal tubules. Conversely, specific glomerular and sub-glomerular profiles cannot be obtained while using the pixel size performed in previous studies (50 µm). Furthermore, two proteins are highlighted, sonic hedgehog and α-smooth muscle actin, whose signal intensity and spatial localization within the sub-glomerular and tubulointerstitial compartments differ between treatment responders and non-responders. Conclusions and clinical relevance The present study exemplifies the advantage of using high spatial resolution MALDI-MSI for the study of MN and highlights that such findings have the potential to provide complementary support in the routine prognostic assessment of MN patients.

Renal tubular cells release urinary extracellular vesicles (uEV) that are considered a promising source of molecular markers for renal dysfunction and injury. We investigated uEV proteomes of patients with hereditary salt-losing tubulopathies (SLTs), focusing on those caused by Gitelman and Bartter (BS) syndromes, to provide potential markers for differential diagnosis. Second morning urine was collected from patients with genetically proven SLTs and uEV were isolated by the ultracentrifugation-based protocol. The uEV proteome was run through a diagonal bidimensional electrophoresis (16BAC/SDS-PAGE), to improve hydrophobic protein resolution. Sixteen differential spots from the proteome of two variants (BS2 and BS3) were analysed by nLC-ESI-MS/MS after in-gel tryptic digestion. A total of 167 protein species were identified from 7 BS2 spots and 9 BS3 spot. Most of these proteins were membrane-associated proteins, in particular transmembrane proteins, and were related to typical renal functions. The differential content of some uEV was then validated by immunoblotting. Our work suggests that uEV proteomics represents a promising strategy for the identification of differential SLT proteins. This could play a role in understanding the pathophysiological disease mechanisms and may support the recognition of different syndromes.

Protein N-glycosylation is one of the most important post-translational modifications and is involved in many biological processes, with aberrant changes in protein N-glycosylation patterns being closely associated with several diseases, including the progression and spreading of tumours. In light of this, identifying these aberrant protein glycoforms in tumours could be useful for understanding the molecular mechanism of this multifactorial disease, developing specific biomarkers and finding novel therapeutic targets. We investigated the urinary N-glycoproteome of clear cell renal cell carcinoma (ccRCC) patients at different stages (n = 15 at pT1 and n = 15 at pT3), and of non-ccRCC subjects (n = 15), using an N-glyco-FASP-based method. Using label-free nLC-ESI MS/MS, we identified and quantified several N-glycoproteins with altered expression and abnormal changes affecting the occupancy of the glycosylation site in the urine of RCC patients compared to control. In particular, nine of them had a specific trend that was directly related to the stage progression: CD97, COCH and P3IP1 were up-expressed whilst APOB, FINC, CERU, CFAH, HPT and PLTP were down-expressed in ccRCC patients. Overall, these results expand our knowledge related to the role of this post-translational modification in ccRCC and translation of this information into pre-clinical studies could have a significant impact on the discovery of novel biomarkers and therapeutic target in kidney cancer.

Hematuria is a common sign of many renal and urologic pathologic conditions and it may affect the proteomic analysis of urinary extracellular vesicles (UEv), nanovesicles released from all cells in contact with the urinary space. This condition hinders UEv based proteomic studies aiming to discover biomarkers. Therefore, we studied the effects of hematuria on the proteome of UEv and introduced a possible solution to reduce its misleading impact. We mimicked hematuria by adding increasing amount of blood to nonaffected urine and investigated its effects on UEv isolation, purity, and proteomic composition. We proposed a trypsin treatment able to reduce the impact of hematuria on UEv. The effects of the treatment were investigated by evaluating the UEv proteomic profile, the enrichment of known UEv markers, and by assessing differential protein content by MS-based label-free quantification. Results showed that as the blood contamination increased, it affected both the proteome profile and the yield of UEv isolated from urine. Our treatment with trypsin was able to counteract completely these effects for low/medium levels of hematuria, which are most commonly encountered. This promising finding could lead to the reliable use of hematuria samples for UEv proteomic investigation.

Proteomics and bioinformatics are a useful combined technology for the characterization of protein expression level and modulation associated with the response to a drug and with its mechanism of action. The folate pathway represents an important target in the anticancer drugs therapy. In the present study, a discovery proteomics approach was applied to tissue samples collected from ovarian cancer patients who relapsed after the first-line carboplatin-based chemotherapy and were treated with pemetrexed (PMX), a known folate pathway targeting drug. The aim of the work is to identify the proteomic profile that can be associated to the response to the PMX treatment in pre-treatement tissue. Statistical metrics of the experimental Mass Spectrometry (MS) data were combined with a knowledge-based approach that included bioinformatics and a literature review through ProteinQuest™ tool, to design a protein set of reference (PSR). The PSR provides feedback for the consistency of MS proteomic data because it includes known validated proteins. A panel of 24 proteins with levels that were significantly different in pre-treatment samples of patients who responded to the therapy vs. the non-responder ones, was identified. The differences of the identified proteins were explained for the patients with different outcomes and the known PMX targets were further validated. The protein panel herein identified is ready for further validation in retrospective clinical trials using a targeted proteomic approach. This study may have a general relevant impact on biomarker application for cancer patients therapy selection.

Calcium homeostasis is crucial to eukaryotic cell survival. By acting as an enzyme cofactor and a second messenger in several signal transduction pathways, the calcium ion controls many essential biological processes. Inside the endoplasmic reticulum (ER) calcium concentration is carefully regulated to safeguard the correct folding and processing of secretory proteins. By using the model organism Saccharomyces cerevisiae we show that calcium shortage leads to a slowdown of cell growth and metabolism. Accumulation of unfolded proteins within the calcium-depleted lumen of the endoplasmic reticulum (ER stress) triggers the unfolded protein response (UPR) and generates a state of oxidative stress that decreases cell viability. These effects are severe during growth on rapidly fermentable carbon sources and can be mitigated by decreasing the protein synthesis rate or by inducing cellular respiration. Calcium homeostasis, protein biosynthesis and the unfolded protein response are tightly intertwined and the consequences of facing calcium starvation are determined by whether cellular energy production is balanced with demands for anabolic functions. Our findings confirm that the connections linking disturbance of ER calcium equilibrium to ER stress and UPR signaling are evolutionary conserved and highlight the crucial role of metabolism in modulating the effects induced by calcium shortage.

Matrix-Assisted Laser Desorption/Ionization (MALDI) Imaging Mass Spectrometry (IMS) is a molecular technology that allows simultaneous investigation of the content and spatial distribution of molecules within tissue. In this work, we examine different classes of detergents, the anionic sodium dodecyl sulfate (SDS), the nonionic detergents Triton X-100, Tween 20 and Tween 80, and the zwitterionic 3-[(3-cholamidopropyl)dimethylammonio]-1-propanesulfonate (CHAPS) for use in MALDI IMS of analytes above m/z 4000. These detergents were found to be compatible with MALDI MS and did not cause signal suppression relative to non-detergent applications and did not produce interfering background signals. In general, these detergents enhanced signal acquisition within the mass range m/z 4-40 000. Adding detergents into the matrix was comparable with the separate application of detergent and matrix. Evaluation of spectra collected from organ-specific regions of a whole mouse pup section showed that different detergents perform optimally with different organs, indicating that detergent selection should be optimized on the specific tissue for maximum gain. These data show the utility of detergents towards enhancement of protein signals for on-tissue MALDI IMS analysis.

The biological functions of prion protein (PrP(C)) and its possible interaction with other specific molecular membrane partners remain largely unknown. The aim of this study is to gain information on the molecular environment of PrP(C) by analyzing the lipid and protein composition of a PrP(C)-enriched membrane subfraction, called prion domain, PrD. This domain was obtained by immunoprecipitation of detergent-resistant microdomains (DRM) of rat cerebellar granule cells under conditions designed to preserve lipid-mediated membrane organization. The electrophoretic pattern of PrD, after staining with Coomassie blue, showed the enrichment of some protein bands in comparison with DRM. microLiquid chromatography-electrospray ionization-mass spectrometry (microLC-ESI-MS)/MS analysis showed that Thy-1 and different types of myosin were strongly enriched in PrD and, in a lesser extent, also OBCAM, LSAMP and tubulin, present altogether in a single band. Experiments using the chemical cross-linker BS(3) suggested the existence of an interaction between PrP(C) and neural cell adhesion molecule (NCAM). Concerning lipids, the comparison between PrD and DRM showed a similar phospholipid/sphingolipid ratio, a phospholipid/cholesterol ratio doubled, and a strong decrease of plasmenilethanolamine (19.7 +/- 3.5% vs. 38.3 +/- 1.2%). In conclusion, the peculiar lipid composition and in particular the presence of proteins involved in synaptic plasticity, cell adhesion, cytoskeleton regulation and signalling, suggest an important physiological role in neurons of Prion Domain.

Standards and des -methyl precursors of ( R )- and ( S )-thionisoxetine, potent and selective norepinephrine reuptake inhibitors, were synthesized and radiolabeled with carbon-11. Both enantiomers of the N -methyl-3-(2-thiomethylphenoxy)-3-phenylpropanamine and the 3-(2-thiomethylphenoxy)-3-phenylpropylamine were obtained via multi-step syntheses, while the radiosyntheses were carried out using [ 11 C]CH 3 I. The radiochemical yields were 26%, decay corrected and the specific radioactivity ranging from 2 to 3 Ci/μmol. The HPLC analyses were performed using a chiral column: during the radiolabeling, no racemization occurred and the isomers were synthesized with high enantiomeric purity.

The selective dopamine D(3) receptor ligands N-4-[4-[(2,3-dichlorophenyl)piperazin-1-yl]butyl]1-methoxy-2-naphthalencarboxamide (1) and N-4-[4-[(2,3-dichlorophenyl)piperazin-1-yl]butyl]-7-methoxy-2-benzofurancarboxamide (2) were labeled with (11)C (t(1/2) = 20.4 min) as potential radioligands for the noninvasive assessment of the dopamine D(3) neurotransmission system in vivo with positron emission tomography (PET). The radiosynthesis consisted in an O-methylation of the des-methyl precursors N-[4-[4-(2,3-dichlorophenyl)piperazin-1-yl]butyl]-1-hydroxy-2-naphthalenecarboxamide (3) and N-[4-[4-(2,3-dichlorophenyl)piperazin-1-yl]butyl]-7-hydroxy-2-benzofurancarboxamide (4) with [(11)C]methyl iodide using tBuOK/HMPA and KOH/DMSO, respectively. The radiotracers [(11)C]1 and [(11)C]2 were obtained in 35 min with over 99% radiochemical purity, 74 +/- 37 GBq/mumol of specific radioactivity, 13% and 26% radiochemical yield (EOB, decay-corrected). Distribution studies in rats demonstrated that the new tracers [(11)C]1 and [(11)C]2 cross the blood-brain barrier and localize in the brain. However, the kinetics of cerebral uptake did not reflect the regional expression of the D(3) receptors. Despite their in vitro pharmacological profile, [(11)C]1 and [(11)C]2 do not display an in vivo behavior suitable to image D(3) receptor expression using PET.

OBJECTIVE: The purpose of this study was (a) to study whether a folate and vitamin B12 treatment, aimed at decreasing homocysteine levels, might ameliorate insulin resistance and endothelial dysfunction in patients with metabolic syndrome according to the National Cholesterol Education Program-Adult Treatment Panel-III criteria and (b) to evaluate whether, under these metabolic conditions, there is a relationship between hyperhomocysteinemia and insulin resistance. DESIGN AND METHODS: A double-blind, parallel, identical placebo-drug, randomized study was performed for 2 months in 50 patients. Patients were randomly allocated to two groups. In group 1, patients were treated with diet plus placebo for 2 months. In group 2, patients were treated with diet plus placebo for 1 month, followed by diet plus folic acid (5 mg/day) plus vitamin B12 (500 microg/day) for another month. RESULTS: In group 2, folate treatment significantly decreased homocysteine levels by 27.8% (12.2+/-1.2 vs 8.8+/-0.7 micromol/l; P

(4 S )-1-[( S )-3-Mercapto-2-methylpropanoyl]-4-phenylthio- l -proline (Zofenoprilat, 2 ), the active metabolite of the potent ACE inhibitor Zofenopril Calcium ( 1 ), was labelled with carbon-11 ( t 1/2 =20.4 min) to evaluate its pharmacokinetics behaviour in human body using Positron Emission Tomography (PET). [ 11 C]2 labelling procedures were based on the use of immobilized Grignard reagent and the acylation of ( S )-4-phenylthio- l -proline methyl ester ( 5 ) with 11 C-labelled methacryloyl chloride, followed by a Michael addition with thiobenzoic acid. The radiochemical yield was 5–10% (EOB, decay corrected) and specific radioactivity ranged from 0.5 to 1.5 Ci/μmol (18.5–55.5 GBq/μmol). Preliminary in vivo human evaluation of [ 11 C] 2 showed that the drug accumulates in organs which express high levels of ACE, like lungs and kidneys, and in organs involved in drug metabolism such as the liver and gall bladder. Results of the distribution of [ 11 C] 2 showed a measurable concentration of the drug in the target tissues such as the kidney and to a minor extent, the heart, where it can afford organ protection.

Lipids extracted from detergent-resistant membrane fractions, thought to derive from membrane domains, were analyzed for fatty acid composition. The proportion of palmitic acid in fractions isolated from neurons (cerebellar granule cells) and from neural-like cell lines (neuroblastomaglioma NG108-15) nearly doubled (reaching about 54% of total fatty acids) with respect to cell WCL, indicating their enrichment in palmitic acid-carrying lipids. The proportion of palmitic acid in detergent-resistant fractions obtained from caveolin-transfected NG108-15 cells was comparable with that obtained from caveolin-negative cells, ruling out a specific role of this protein in recruiting palmitoylated lipid species. The enrichment in palmitic acid was remarked also in membrane fractions isolated from non-neuronal cell lines (A431) using either detergents or detergent-free techniques. Lipid fractionation and mass spectrometry experiments show that palmitic acid-rich phosphatidylcholine species are responsible of the peculiar fatty acid composition of these fractions. All together these results suggest that the enrichment in palmitic acid-rich phosphatidylcholine species is a common feature of neural and non-neural cell lines and may play a major role in the biogenesis of membrane domains.

Matrix-assisted laser desorption ionization time-of-flight (MALDI-TOF)—profiling and imaging mass spectrometry (MSI) are promising technologies for measuring hundreds of different molecules directly on tissues. For instance, small molecules, drugs and their metabolites, endogenous lipids, carbohydrates and complex peptides/proteins can be measured at the same time. In the most advanced instruments, it is achieved without significant disruption of sample integrity. MSI is a unique approach for assessing the spatial distribution of molecules using graphical multidimensional maps of their constituent analytes, which may for instance be correlated with histopathological alterations in patient tissues. MALDI-TOFMSI technology has been implemented in hospitals of several countries, where it is routinely used for quick pathogen(s) identification, a task formerly accomplished by laborious and expensive DNA/RNA-based PCR (polymerase chain reaction) screening.In this chapter, we describe how MSI is performed, what is required from the researcher, the instrument vendors and finally what can be achieved with MSI. We restrict our descriptions only to MALDI- MSI although several other MS techniques of ionization can easily be linked to MSI.

Renal Cell Carcinoma (RCC) is typically asymptomatic and surgery usually increases patient's lifespan only for early stage tumours. Moreover, solid renal masses cannot be confidently differentiated from RCC. Therefore, markers to distinguish malignant kidney tumours and for their detection are needed. Two different peptide signatures were obtained by a MALDI-TOF profiling approach based on urine pre-purification by C8 magnetic beads. One cluster of 12 signals could differentiate malignant tumours (n = 137) from benign renal masses and controls (n = 153) with sensitivity of 76% and specificity of 87% in the validation set. A second cluster of 12 signals distinguished clear cell RCC (n = 118) from controls (n = 137) with sensitivity and specificity values of 84% and 91%, respectively. Most of the peptide signals used in the two models were observed at higher abundance in patient urines and could be identified as fragments of proteins involved in tumour pathogenesis and progression. Among them: the Meprin 1α with a pro-angiogenic activity, the Probable G-protein coupled receptor 162, belonging to the GPCRs family and known to be associated with several key functions in cancer, the Osteopontin that strongly correlates to tumour stages and invasiveness, the Phosphorylase b kinase regulatory subunit alpha and the SeCreted and TransMembrane protein 1.

The novel quinoline-2-carboxamide derivatives N-[methyl-C-11]-3-methyl-4-phenyl-N-(phenyl-methyl)quinoline-2-carboxamide ([C-11]4), (+/-)-N-[methyl-C-11]-3-methyl-N-(1-methylpropyl)-4- phenylquinoline-2-carboxamide ([C-11]5), and (+/-)-N-[methyl-C-11]-3-methyl-4-(2-fluorophenyl)-N-(1-methylpropyl)quinoline-2-carboxamide ([C-11]6) were labeled with carbon-11 (t(1/2) = 20.4 min, beta (+) = 99.8%) as potential radioligands for the noninvasive assessment of peripheral benzodiazepine type receptors (PBR) in vivo with positron emission tomography (PET). The radiosynthesis consisted of N-methylation of the desmethyl precursors 3-methyl-4-phenyl-N-(phenylmethyl)quinoline-2-carboxamide (4a), (+/-)-3-methyl-N-(1-methylpropyl)-4-phenylquinoline-2-carboxamide (5a), and (+/-)-4-(2-fluorophenyl)-3-methyl-N-(1-methylpropyl)quinoline-2-carboxamide (6a) with either [C-11]methyl iodide or [C-11]methyl triflate in the presence of tetrabutylammonium hydroxide or potassium hydroxide in dimethylformamide. The radioligands [C-11]4, [C-11]5, and [C-11]6 were synthesized with over 99% radiochemical purity in 30 min, 30 +/- 5% radiochemical yield, calculated at the end of synthesis (EOS) non-decay-corrected, and 2.5 +/- 1.2 Ci/mu mol of specific radioactivity. Inhibition studies in rats following intravenous pre-administration of 1-(2-chlorophenyl)-N-methyl-N-(1-methylpropyl)-3-isoquinolinecarboxamide (PK 11195, 1) showed high specific binding to PER of [C-11]4, [C-11]5, and [C-11]6 in heart, lung, kidney, adrenal gland, spleen, and brain. The biological data suggest that [C-11]5, [C-11]6, and particularly [C-11]4 are promising radioligands for PER imaging in vivo with PET.

Therapy with cyclosporin A (CsA) for immunosuppression after organ transplantation requires monitoring of its levels in blood owing to the narrow therapeutic index of the drug and to the high inter-individual variability of the drug absorption and metabolism. We describe the preparation of CsA labelled with stable isotopes (13C and 2H) with an isotopic enrichment of about 99% using labelled glucose and its use as internal standard for quantification of CsA blood levels by isotope dilution/electrospray ionization mass spectrometry. The method was found to be linear in the tested range (1–1000 ng) with and without the matrix. The accuracy of the bracketting calibration curves prepared using 100 ng ml−1 labelled CsA was within ±1.7% (bias). The results confirmed the usefulness of the procedure as a reference method for the external quality assessment of the field methods for the evaluation of CsA blood concentration, the imprecision (relative standard deviation) and accuracy (bias) being

Previous studies showed that chromogranin A (CgA), a glycoprotein stored and co-released with various hormones by neuroendocrine cells and neurons, can modulate cell adhesion. We have investigated the structure-activity relationships of CgA using fibroblasts and coronary artery smooth muscle cells in adhesion assays. A recombinant CgA fragment 1-78 and a peptide 7-57 containing reduced and alkylated cysteines (Cys(17) and Cys(38)) induced cell adhesion after adsorption onto solid phases at 50-100 nm. Peptides lacking the disulfide loop region, including residues 47-68, 39-59, and 39-68, induced cell adhesion, either bound to solid phases at 200-400 nm or added to the liquid phase at 5-10 microm, whereas peptide 60-68 was inactive, suggesting that residues 47-57 are important for activity. The effect of CgA-(1-78) was blocked by anti-CgA antibodies against epitopes including residues Arg(53), His(54), and Leu(57). Substitutions of residues His(54), Gln(55), and Asn(56) with alanine decreased the cell adhesion activity of peptide 47-68. These results suggest that the region 47-57 (RILSILRHQNL) contains a cell adhesion site and that the disulfide bridge is not necessary for the proadhesive activity. The ability of soluble peptides to elicit proadhesive effects suggests an indirect mechanism. The high sequence conservation and accessibility to antibodies suggest that this region is important for the physiological role of CgA.

This paper describes the radiosynthesis of [C-11]CGP62349, a potential ligand to assess GABA, receptors in vivo. C-11 was introduced by O-methylation of the corresponding des-methyl precursor, namely CGP67780. The final product was obtained with a reliable method in good yield. The radioligand was tested in monkey, revealing negligible blood brain barrier penetration and brain uptake, thus prompting us to search for a new target structure with a better lipophilicity. NUCL MED BIOL 27;6:565-569, 2000. (C) 2000 Elsevier Science Inc. All rights reserved.

(3-Methoxy-naphthalen)2-yl-(1-benzyl-piperidin)4-yl-acetate (SB-235753) was labelled with 11C (t1/2=20·4 min) as a putative radioligand for the non-invasive assessment of Dopamine D4 receptors in vivo with positron emission tomography (PET). The precursor for the radiosynthesis 3-hydroxynaphthyl-2-[N-benzyl)-piperidyl]-acetate hydrochloride was prepared by a four-step synthesis starting from ethyl-4-pyridyl acetate. The radiolabelling consisted of methylation with [11C]methyltriflate in dimethylformamide in the presence of potassium hydroxide. [11C]SB-235753, was synthesised in 30 min with a radiochemical yield of 10±5% (EOS, non-decay corrected) with 99% radiochemical purity and specific radioactivity of 10±3 Ci/μmol. Biodistribution studies in rats with [11C]SB-235753 showed the uniform distribution of the tracer within different areas of the murine brain. At 30 min after injection 99% of the radioligand in plasma and 100% in cerebellum was metabolised. These findings suggest that [11C]SB-235753 can not be a suitable tracer for dopamine D4 receptor studies with PET. Copyright © 2000 John Wiley & Sons, Ltd.

The aim of the study was to investigate the acute effect of GH per se, independent from its lipolytic activity, on glucose and lipid oxidation and glucose turnover in seven healthy subjects. Five tests lasting 360 min were performed. Each test consisted of a 4-h equilibration period followed by a euglycemic hyperinsulinemic (25 mU/kg x h) clamp lasting 2 h. In test 1 (control experiment) saline was infused, leaving GH and FFA at basal levels. In tests 2, 3, and 4, GH was infused (80 ng/kg x min) to increase GH levels. Whereas in test 2 FFA levels were free to increase due to GH lipolytic activity, in test 3 FFA elevation was prevented by using an antilipolytic compound (Acipimox) that allowed evaluation of the effect of GH at low FFA levels. In test 4 (GH+Acipimox+heparin) GH infusion was associated with the administration of Acipimox and heparin to maintain FFA at the basal level to evaluate the effect of GH per se independent from GH lipolytic activity. In test 5 Acipimox and a variable heparin infusion were given to evaluate possible effects of Acipimox other than the inhibition of lipolysis. During the euglycemic hyperinsulinemic clamp in the presence of high GH and FFA levels (test 2), glucose oxidation was significantly lower and lipid oxidation was significantly higher than in tests 1, 3, 4, and 5. During the same period, hepatic glucose production was completely suppressed in the control study (test 1; 94%) and in test 5 (99.6%), whereas it was significantly less inhibited (65%, 74%, and 73%) when GH was administered in tests 2, 3, and 4. In conclusion, these results suggest that GH directly mediates the reduction of insulin's effect on the liver. In addition, the effect of GH on glucose and lipid oxidation is not direct, but is mediated by its lipolytic activity.

The mature hen avidin encoded by a synthetic cDNA was expressed in Escherichia coli in an insoluble form. After resolubilization, renaturation and purification, a recovery of about 20 mg/l cell culture was obtained. ELISA assays indicated no apparent differences in biotin binding between the natural and recombinant avidins. In addition, an acidic avidin mutant, bearing the substitutions Lys3-->Glu, Lys9-->Glu, Arg26-->Asp and Arg124-->Leu of four exposed basic residues, was produced. The protein, expressed and renatured as wild-type avidin, showed unaltered biotin-binding activity. The acidic pi (approximate to 5.5) and lack of aggregation of the mutant allowed easy electrophoretic analysis under non-denaturing conditions of the protein alone and of its complexes with biotin, biotinylated transferrin or peroxidase. Analysis of the sera from sensitized subjects revealed that the avidin mutant has altered antigenicity. Both recombinant avidins were crystallized and the three-dimensional structures solved by molecular replacement and re fined to 0.22 nm resolution. The three-dimensional structures of the two recombinant molecules, in the absence of biotin and of glycosylation, are fully comparable with those of the natural hen avidin previously reported.

Isocyclosporins are isomers of cyclosporins deriving from an N,O-acyl transfer occurring under acidic conditions. For the identification by 1 H NMR of isocyclosporins prepared in organic solvents the signal at 2.3 ppm assigned to three hydrogens of the NHCH 3 group is considered. Results reported here show that the 1 H NMR spectrum of isocyclosporin A prepared in aqueous acidic conditions lacks of the above signal and profoundly differs from that of isocyclosporin A prepared in organic solvents, despite the identity of the primary structures determined on the basis of mass spectrometric analysis.

MALDI imaging mass spectrometry (IMS) is a unique technology to explore the spatial distribution of biomolecules directly on tissues. It allows the in situ investigation of a large number of small proteins and peptides. Detection of high molecular weight proteins through MALDI IMS still represents an important challenge, as it would allow the direct investigation of the distribution of more proteins involved in biological processes, such as cytokines, enzymes, neuropeptide precursors and receptors. In this work we compare the traditional method performed with sinapinic acid with a comparable protocol using ferulic acid as the matrix. Data show a remarkable increase of signal acquisition in the mass range of 20k to 150k Th. Moreover, we report molecular images of biomolecules above 70k Th, demonstrating the possibility of expanding the application of this technology both in clinical investigations and basic science.

The aim of the study was to evaluate the effects of an acute increase in triglyceride levels induced by Intralipid (Kabivitrum, Stockholm, Sweden) infusion on forearm glucose uptake, glucose oxidative metabolism, and hepatic glucose production independent of circulating free fatty acid (FFA) levels in man. Six normal subjects underwent three different tests in random order. Each test consisted of a control period of 120 minutes followed by a euglycemic, hyperinsulinemic clamp lasting 120 minutes. In test 1, a high-dose intravenous Intralipid infusion was performed to increase triglyceride and FFA levels. In test 2, heparin (30 U/min) plus low-dose Intralipid infusions were performed to maintain triglyceride at normal levels and increase only FFA levels. Test 3 was performed as a control study. During the 120-minute control period, forearm glucose uptake and hepatic glucose production were not affected by increasing only FFA levels (test 2) or FFA and triglyceride levels (test 1) as compared with the control study. On the contrary, glucose oxidation was significantly decreased as compared with the control study during tests 1 and 2, without a further significant decrease during simultaneously increased FFA and triglyceride levels. Concomitantly, lipid oxidation was similar in tests 1 and 2, at values significantly greater than in test 3. During the euglycemic clamp, forearm glucose uptake and glucose oxidation were significantly lower during tests 1 and 2 than test 3. At variance with the control period, the increase of triglyceride levels during test 1 caused a significant 30% to 40% decrease of both parameters as compared with test 2. Opposite results were found for lipid oxidation, which remained unchanged during test 1 as compared with the control period but significantly decreased during tests 2 and 3. Hepatic glucose production was less inhibited during test 1 than during tests 2 and 3, and less so during test 2 than test 3. In conclusion, at least under these particular conditions, acute hypertriglyceridemia induced by Intralipid infusion seems to decrease forearm glucose uptake, glucose oxidation, and insulin-induced suppressibility of hepatic glucose production. Taking our results together, it seems that the triglyceride effect on carbohydrate metabolism occurs via triglyceride hydrolysis using the intracellular pathways of FFA without interference with the circulating FFA pool. © 1995.

We have previously reported that treatment of CsA with aqueous HCl gives rise to the formation of a number of water-soluble compounds. Two of these were identified from their FAB-MS MS spectra as open-chain nona- and decapeptides. We describe here the identification of two other main compounds deriving from the same treatment. Identification was rendered possible from the comparison of their FAB-MS MS spectra with those of methyl and acetyl derivatives. The two compounds are water-soluble, open-chain undecapeptides corresponding to 1,11 seco-CsA and of 4,5 seco-isoCsA, respectively.

Urinary exosomes are released from every renal epithelial cell type facing the urinary space and therefore, they may carry molecular markers of renal dysfunction and structural injury. Here, we present a hyphenated microLC-Q-TOF-MS platform for lipidomics studies applied to investigate the urinary exosome lipid repertoire. Lipids were separated by reversed-phase chromatography using a linear gradient of formic acid 0.2% and tetrahydrofuran, in 40 min of analysis. Features (m/z with associated own retention time) were extracted by MarkerLynx(TM) (Waters) and processed, demonstrating good analytical performance in terms of repeatability and mass accuracy of the microLC Q-TOF MS platform. In particular, a stable retention time (RSD less than 4%) and relative intensity (RSD from 2.9% to 11%) were observed. Moreover, the method takes advantages by the use of a lock spray interface (Waters) that allows readjusting the m/z data after acquisition, obtaining inaccuracy below 6 ppm in measuring the m/z value of the reference compound during chromatographic run. The method was employed in a preliminary application to perform comparative analysis from healthy control subjects and renal cell carcinoma (RCC) patients, in order to possibly highlight differences in lipid composition to be exploited as potential tumor biomarker. Differential lipid composition in RCC urinary exosomes was achieved and tentatively identified by accurate mass, providing a preliminary indication of a relationship between lipid composition of urinary exosomes and RCC disease. Among the total features significantly different in RCC exosomes, the ion at m/z 502.3 was taken as an example for molecular confirmation by MS/MS fragmentation analysis.

Mass Spectrometry (MS)-based technologies represent a promising area of research in clinical analysis. They are primarily concerned with measuring the relative intensity (i.e., signals) of many protein/peptide molecules associated with their mass-to-charge ratios. These measurements provide a huge amount of information which requires adequate tools to be interpreted. Following the methodology for testing hypotheses, we investigate the proteomic signals of the most common type of Renal Cell Carcinoma, the Clear Cell variant (ccRCC) [1]. By using mutual information, we detect changes in dependence values between signals from control to case groups (ccRCC or non-ccRCC). To this end, we sample and represent each population group through graphs, thus providing the observed dependence structures (many real domains are best described by relational models [2]). This way, graphs establish abstract frames of reference in our analysis giving the opportunity to test hypotheses over their properties. In other words, changes are detected by testing graph property modifications from group to group. We report the mass-to-charge values which identify bounded regions where changes have been detected. The main interest in handling such regions is to perceive which signal ranges are associated with some specific factors of interest (e.g., studying differentially expressed peaks between cases and controls) and thus, to suggest potential biomarkers for future analysis [3]. This study has been applied to samples collected at the "Ospedale Maggiore Policlinico" Foundation (Milano, Italy) using a standardized protocol. All samples were analyzed using an UltraFlex II MALDI-TOF/TOF MS instrument and mass spectra were acquired in the m=z range of 1000-12000. The samples cohort consists of 85 control subjects and 102 Renal Cell Carcinoma patients. It was possible to classify pathological group in patients affected by clear cell (ccRCC) and other different histological subtypes (respectively 79 ccRCC and 23 non-ccRCC). Table I reports the selected rejection regions (i.e., tests reject the null) at the 5% significance level. Testing hypotheses suggested by the data may induce statistical bias. For this reason, we evaluate the results to independent samples. We investigate whether test decisions are statistically independent from the region's property (i.e., distinguishing (DR) or non-distinguishing (ND) regions) when new samples are given. In other words, we want to know whether the property of a region can be statistically associated to test decisions when new samples are available. After that a new sample is provided, we verify test decisions over both the detected distinguishing regions and these regions out of the m=z bounding values previously detected. Table II summarizes the (Fisher's exact test) results confirming a significant association (a = 0.05 level) between decisions and region's property for both the class of tests. This work was supported by grants from the Italian Ministry of University and Research (PRIN n. 69373, FIRB n. RBRN07BMCT 011, FAR 2006 -- 2011), EuroKUP COST Action (BM0702) and the NEDD project ("Regione Lombardia").

A sensitive method for the simultaneous analysis of plasma alpha-ketoisocaproic acid (KIC) and leucine using GC-MS is described. Plasma was deproteinized after addition of both alpha-ketovaleric acid and norleucine as internal standards. Derivatization of the compounds involved protection of the keto groups with methoxyamine and tert-butyldimethylsilylation under optimized conditions. Mass spectral analyses were carried out in electron impact ionization mode and the gas chromatographic conditions selected prevented interference by other keto acids and amino acids normally present in plasma or by the biological matrix. Determination of both plasma levels and isotopic enrichment of KIC and leucine required a single injection and was easily accomplished in 7-9 min. The good reproducibility of the method, in addition to rapidity and simplicity, permits several samples to be accurately analyzed daily. Therefore, the method is particularly useful for studies on the metabolism of amino acids.

The paper presents preliminary experimental analyses of combustion processes for crude oil. The research is started from investigation of combustion of gas in a strong swirl flow as is intended to be an introductory step in studying the mechanism of stability and emission of pollutants in combustion of crude oil occurring in gas turbines. The areas of recirculation and pollutant emission in a strong swirl flow have been studied for the following three cases: - isothermal flow without combustion; - combustion of gas mixture with CH4 and N2 differently composed; - combustion of crude oil. All experiments are performed in the atmospheric test rig of a top-mounted combustor, briefly described in the paper. The velocity field in the combustion chamber is measured by laser doppler anemometry. The measured profiles of temperature and molar fraction of NOx , CO, CO2 , O2 are discussed for natural gas and crude oil. Depending on the degree of the swirl of the flow and on the temperature of entering air, the distribution of molar fraction of most important chemical species has been established. This allows for better understanding the process of combustion in a strong swirl flow. The established characteristics of the flame blow-out make it possible to calculate the limits of capacity power generation available from a given size of a gas burner. For the burner geometry, similar to that with the know characteristic of gas combustion, the parameters for CO and NOx have been established for crude oil. Also, characteristics have been found for a specially designed oil nozzle with a large spray angle — sufficiently large for the optimum supply of fuel into the area of strong swirl flow with combustion established on the basis of the analysis of the burning of gas. It has been found that in cases of combustion crude oil a relatively small increase of the temperature of air supplied for combustion results in a significant drop in CO emission what has an impact on lower NOx emission.Copyright © 2010 by ASME and Alstom Technology, Ltd.

The effects of streptozotocin-induced diabetes on the various forms of 3-hydroxy-3-methylglutaryl coenzyme A reductase (HMGCoA reductase), phosphorylated/dephosphorylated and thiolic/disulphide, were studied in rat liver. Animals were treated twice with 65 mg/kg intraperitoneally of streptozotocin to induce diabetes and sacrificed after 5 days. The relative amounts of the four possible forms of the enzyme were determined in control and diabetic rats. As determined from the total activity, and in agreement with previous reports, the enzyme protein was significantly decreased in streptozotocin-treated rats. However, the percentage of the active thiolic dephosphorylated form was higher in these animals than in controls, suggesting a response of the liver to the decrease both total and specific activity of HMGCoA reductase.

We report a rather simple method to determine glucose concentration in serum, using isotope dilution mass spectrometry and [13C6]glucose as internal standard. The procedure involves a single step of sample purification and the conversion of the analyte into its aldononitrile pentaacetate. The between-day and within-day contribution to total variance for a single measurement was determined by assaying Standard Reference Material (SRM) 909 serum. The method was then applied to measurement of glucose concentration in three lyophilized sera: SRM 909 and two other commercially available sera. In the two studies, the concentration of SRM 909 serum was found to be 0.8% above and 0.3% below the reported value (6.25 mmol/L), respectively; the overall coefficient of variation for determinations in all sera ranged from 0.37% to 0.56%. The precision and the accuracy of the method satisfy the requirements for a Definitive Method.

Aquaporin (AQP)1 belongs to a ubiquitous family of water channel proteins characterized by sequence similarity and the presence of two NPA (Asp-Pro-Ala) motifs existing in almost all organs and tissues. Currently, 13 human AQPs are known and they are divided into two subgroups according to their ability to transport only water molecules, such as AQP1, or also glycerol and other small solutes. The genomic, structural and functional aspects of AQP1 are briefly described. An in-depth discussion is devoted to proteomic approaches that are useful for identifying and characterizing AQP1, mainly through electrophoretic techniques combined with different extraction procedures followed by mass spectrometry analysis. Moreover, the relevance of AQP1 in human diseases is also explained. Its role in human tumors and, in particular, those of the kidney (e.g., clear cell renal carcinoma) is discussed.

This study showed that the 1-O-hexadecyl form of platelet-activating factor (PAF) is released along with 6-keto-prostacyclin1 alpha (6-keto-PGF1 alpha) in the perfusates of ischemic-isolated rabbit heart. During the early phase of the reperfusion, the release of PAF and 6-keto-PGF1 alpha was particularly increased (PAF, from 5.4 +/- 1.2 to 19.7 +/- 2.0 ng/min; 6-keto-PGF1 alpha, from 2.3 +/- 0.1 to 27.4 +/- 1.8 ng/min) and this event was coupled with the characteristic mechanical alterations of myocardial performance and perfusion pressure (PP). These changes were effectively antagonized by pretreatment of the hearts with both prostacyclin (PGI2, 20 ng/ml) and the PGI2-releaser defibrotide (400 micrograms/ml). The protecting activity observed with PGI2 was paralleled by a reduction in the rate of PAF release during reperfusion (from 19.7 +/- 2.0 to 6.8 +/- 0.2 ng/min). In defibrotide-treated preparations, inhibition of PAF formation was associated with a pronounced stimulation of 6-keto-PGF1 alpha generation, which was particularly marked on reperfusion (from 27.4 +/- 1.8 to 197.5 +/- 8.2 ng/min). Indomethacin (1 microgram/ml) ablated the antiischemic effect of defibrotide but did not potentiate the rate of formation of PAF despite inhibition of 6-keto-PGF1 alpha biosynthesis. From these results, we conclude that in a model of severe myocardial ischemia, in which the major determinants of cardiac performance are under control, generation of PAF and PGI2 appears to play an important biologic role in determination of the severity of myocardial ischemic damage.

Bamifylline, a 7–8 disubstituted theophylline derivative, reduces in a dose dependent way (1 × 10−5 m , 1 × 10−4 m and 1 × 10−3 m ) the release of histamine, TXB2 (measured also as TXA2-like material) and SRS -A (as LTD4 like material) during the immunological challenge of actively sensitized guinea-pig lungs perfusedin vitro. Theophylline was significantly less potent than bamifylline and particularly, at the higher concentrations used (1 × 10−3 m ), bamifylline was 2 · 7 times more potent than theophylline in reducing the immunological release of histamine and 1 · 6 and 1 · 5 times more potent in inhibiting the production of TXB2 and SRS-A, respectively. These data suggest that the ability of the two xanthine derivatives to control the immunological release of histamine represents an important point in understanding the mechanism of their anti-anaphylactic activity.

Human aquaporin-1 (AQP1) is the most studied member of the aquaporin family, acting as molecular water channel. It is also considered a differentiation marker for proximal renal tubular cells, from which clear cells renal cell carcinoma (RCC) originates, playing an important role in urine formation. We therefore studied AQP1 expression at the proteomic level in RCC and normal tissues, mainly focusing on microdomain-enriched membranes in which AQP1 is highly concentrated. Subcellular fractions were prepared through differential centrifugation, and microdomain-enriched fractions were purified from a plasma membrane-enriched fraction by 1% Triton X-100 treatment followed by ultracentrifugation in sucrose gradient. After SDS-PAGE and Western blot analyses with antibodies against AQP1, lower expression levels of AQP1 isoforms were observed in each subcellular fraction of RCC compared to fractions from normal kidney tissues. The presence of AQP1 in the immunoreactive bands was verified by MALDI-TOF-MS and LC-ESI-MS/MS analysis. Glycosylation of AQP1 was also investigated using N-glycosidase F, confirming the presence of a N-glycosylated isoform of AQP1 in the 35-45-kDa region. These results highlight an under-expression of AQP1 protein and its glycosylated isoforms in homogenate and subcellular fraction obtained from RCC tissue compared to adjacent normal cortex. © 2007 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Oxidative stress, linked to Abeta-lipid interactions, plays a pathogenetic role in Alzheimer's disease. We investigated modifications of lipid peroxidation products in plasma of 52 AD patients, 42 healthy controls and 16 patients with amyotrophic lateral sclerosis, a neurodegenerative disease where oxidative stress also plays a pathogenetic role. Final lipid peroxidation products were measured in plasma by thiobarbituric acid reactive substances (TBARS) assay before and after ex vivo oxidative stress catalysed by copper. There were no significant changes at basal conditions, but after copper-induced oxidation TBARS levels were higher in AD patients (19.0 microM +/- 2.2) versus both controls (5.2 microM +/- 0.8, p

An improved synthesis of the precursor acetic acid-piperidine-4-yl ester by acetylation of 4-hydroxypiperidine hydrochloride in anhydrous chloroform was developed. A procedure for fast evaluation and characterization of products originated by acetylation of the 4-piperidinol using LC-APCI/MS with an acetonitrile-water gradient method on a Merck Purosphere RP-18 column was also developed. The highly purified precursor allowed the production of [C-11]MP4A for PET studies of acethylcholine neurotransmission system. The tracer was produced with > 98% radiochemical purity, with yields ranging 20-60% (decay-corrected) from EOB. (c) 2005 Elsevier Ltd. All rights reserved.