Assessing the Preanalytical Variability of Plasma and Cerebrospinal Fluid Processing and Its Effects on Inflammation-Related Protein Biomarkers.

Proteomics studies are important for the discovery of new biomarkers as clinical tools for diagnosis and disease monitoring. However, preanalytical variations caused by differences in sample handling protocol pose challenges for assessing biomarker reliability and comparability between studies. The purpose of this study was to examine the effects of delayed centrifuging on measured protein levels in plasma and cerebrospinal fluid (CSF).

Inflammation-related plasma and CSF biomarkers for multiple sclerosis.

Effective biomarkers for multiple sclerosis diagnosis, assessment of prognosis, and treatment responses, in particular those measurable in blood, are largely lacking. We have investigated a broad set of protein biomarkers in cerebrospinal fluid (CSF) and plasma using a highly sensitive proteomic immunoassay. Cases from two independent cohorts were compared with healthy controls and patients with other neurological diseases.

Shrunken Pore Syndrome Is Associated With Increased Levels of Atherosclerosis-Promoting Proteins.

Introduction: Shrunken pore syndrome (SPS), originally defined by cystatin C-based estimated glomerular filtration rate (eGFR) being less than 60% of creatinine-based estimated glomerular filtration rate (eGFR) in the absence of extrarenal influences on the plasma levels of cystatin C or creatinine, is associated with a high increase in mortality, even in the absence of reduced glomerular filtration rate (GFR). The objective of the present study was to determine whether the proteome of patients with SPS shows differences from that of patients with normal or reduced measured GFR (mGFR) without SPS.

Methods: Four patient cohorts were included: 1 cohort with normal mGFR without SPS, 1 with normal mGFR with SPS, 1 with reduced mGFR without SPS, and 1 with reduced mGFR with SPS.

Preparation and evaluation of a Ga-labeled RGD-containing octapeptide for noninvasive imaging of angiogenesis: biodistribution in non-human primate.

Monitoring general disease marker such as angiogenesis may contribute to the development of personalized medicine and improve therapy outcome. Readily availability of positron emitter based imaging agents providing quantification would expand clinical positron emission tomography (PET) applications. Generator produced Ga provides PET images of high resolution and the half-life time frame is compatible with the pharmacokinetics of small peptides comprising arginine-glycine-aspartic acid (RGD) sequence specific to αβ integrin receptors.

Autoradiographic Mapping of 5-HT(1B/1D) Binding Sites in the Rhesus Monkey Brain Using [carbonyl-C]zolmitriptan.

Zolmitriptan is a serotonin 5-HT(1B/1D) receptor agonist that is an effective and well-tolerated drug for migraine treatment. In a human positron emission tomography study, [(11)C]zolmitriptan crossed the blood-brain barrier but no clear pattern of regional uptake was discernable. The objective of this study was to map the binding of [(11)C]zolmitriptan in Rhesus monkey brain using whole hemisphere in vitro autoradiography with [(11)C]zolmitriptan as a radioligand.

(18)F-labelled metomidate analogues as adrenocortical imaging agents.

Introduction: Two- and one-step syntheses of (18)F-labelled analogues of metomidate, such as 2-[(18)F]fluoroethyl 1-[(1R)-1-phenylethyl]-1H-imidazole-5-carboxylate (1), 2-[(18)F]fluoroethyl 1-[(1R)-1-(4-chlorophenyl)ethyl]-1H-imidazole-5-carboxylate (2), 2-[(18)F]fluoroethyl 1-[(1R)-1-(4-bromophenyl)ethyl]-1H-imidazole-5-carboxylate (3), 3-[(18)F]fluoropropyl 1-[(1R)-1-(4-bromophenyl)ethyl]-1H-imidazole-5-carboxylate (4) and 3-[(18)F]fluoropropyl 1-[(1R)-1-phenylethyl]-1H-imidazole-5-carboxylate (5) are presented.

Methods: Analogues 1-5 were prepared by a two-step reaction sequence that started with the synthesis of either 2-[(18)F]fluoroethyl 4-methylbenzenesulfonate or 3-[(18)F]fluoropropyl 4-methylbenzenesulfonate. These were used as (18)F-alkylating agents in the second step, in which they reacted with the ammonium salt of a 1-[(1R)-1-phenylethyl]-1H-imidazole-5-carboxylic acid.

[(18)F]Fluoroacetate is not a functional analogue of [(11)C]acetate in normal physiology.

Purpose: [(11)C]Acetate (C-AC) is a general PET tracer of cellular carbon flux and useful for clinical imaging in heart disease as well as prostate cancer and other tumours. C-AC has a high (70%) whole-body extraction fraction, proportional to blood flow in many organs. Trapping is related to organ-specific enzymatic activation and formation of [(11)C]-acetyl-CoA, the fate of which has been well characterized.

Restricted cortical and amygdaloid removal of vesicular glutamate transporter 2 in preadolescent mice impacts dopaminergic activity and neuronal circuitry of higher brain function.

A major challenge in neuroscience is to resolve the connection between gene functionality, neuronal circuits, and behavior. Most, if not all, neuronal circuits of the adult brain contain a glutamatergic component, the nature of which has been difficult to assess because of the vast cellular abundance of glutamate. In this study, we wanted to determine the role of a restricted subpopulation of glutamatergic neurons within the forebrain, the Vglut2-expressing neurons, in neuronal circuitry of higher brain function.

Species differences in blood-brain barrier transport of three positron emission tomography radioligands with emphasis on P-glycoprotein transport.

Species differences occur in the brain concentrations of drugs, but the reasons for these differences are not yet apparent. This study was designed to compare brain uptake of three radiolabeled P-glycoprotein (P-gp) substrates across species using positron emission tomography. Brain concentrations and brain-to-plasma ratios were compared; [(11)C]verapamil in rats, guinea pigs, and monkeys; [(11)C](S)-(2-methoxy-5-(5-trifluoromethyltetrazol-1-yl)-phenylmethylamino)-2(S)-phenylpiperidine (GR205171) in rats, guinea pigs, monkeys, and humans; and [(18)F]altanserin in rats, minipigs, and humans.

Species differences in 3-methylsulphonyl-DDE bioactivation by adrenocortical tissue.

The CYP11B1-activated adrenocortical toxicant 3-methylsulphonyl-DDE (3-MeSO2-DDE) is proposed as a lead compound for an improved chemotherapy for adrenocortical carcinoma. We compared the binding of 3-MeSO2-[14C]DDE in the adrenal cortex of four rodent species; hamster, guinea pig, mouse and rat, using a precision-cut adrenal slice culture system ex vivo. Localization and quantification of the bound radioactivity were carried out using light microscopy autoradiography and radioluminography.

Synthesis of two potential NK1-receptor ligands using [1-11C]ethyl iodide and [1-11C]propyl iodide and initial PET-imaging.

Background: The previously validated NK1-receptor ligand [O-methyl-11C]GR205171 binds with a high affinity to the NK1-receptor and displays a slow dissociation from the receptor. Hence, it cannot be used in vivo for detecting concentration changes in substance P, the endogenous ligand for the NK1-receptor. A radioligand used for monitoring these changes has to enable displacement by the endogenous ligand and thus bind reversibly to the receptor.

In vitro imaging techniques in neurodegenerative diseases.

Neurodegeneration induces various changes in the brain, changes that may be investigated using neuroimaging techniques. The in vivo techniques are useful for the visualization of major changes, and the progressing abnormalities may also be followed longitudinally. However, to study and quantify minor abnormalities, neuroimaging of postmortem brain tissue is used.

[11C]metomidate positron emission tomography of adrenocortical tumors in correlation with histopathological findings.

Context: Adrenal incidentalomas are common findings necessitating extensive laboratory work-up and repetitive radiological examinations. Positron emission tomography (PET) using (11)C-labeled metomidate (MTO) has previously been described as a tool for specific adrenocortical imaging.

Objective: We evaluated 212 MTO-PET examinations in 173 patients to identify its role in the management of adrenal tumors.

A new, fast and semi-automated size determination method (SASDM) for studying multicellular tumor spheroids.

Background: Considering the width and importance of using Multicellular Tumor Spheroids (MTS) in oncology research, size determination of MTSs by an accurate and fast method is essential. In the present study an effective, fast and semi-automated method, SASDM, was developed to determinate the size of MTSs. The method was applied and tested in MTSs of three different cell-lines.

Preparation and evaluation of (68)Ga-DOTA-hEGF for visualization of EGFR expression in malignant tumors.

Unlabelled: Detection of epidermal growth factor receptor (EGFR) overexpression in many carcinomas provides important diagnostic information, which can influence patient management. The use of PET may enable such detection in vivo by a noninvasive procedure with high sensitivity. The aim of this study was to develop a method for preparation of a positron-emitting tracer based on a natural ligand to EGFR, the recombinant human epidermal growth factor (hEGF), and to perform a preclinical evaluation of the tracer.

Irreversible binding of o,p'-DDD in interrenal cells of Atlantic cod (Gadus morhua).

Precision-cut tissue slices of the anterior kidney from Atlantic cod (Gadus morhua) were prepared with a Krumdieck tissue slicer and exposed to 2-(2-chlorophenyl)-2-(4-chloro-(14C)phenyl)-1,1-dichlorethane (o,p(')-[14C]DDD) in vitro. Microautoradiography revealed irreversible o,p(')-DDD-derived binding confined to the glucocorticoid producing interrenal cells (adrenocortical analogues). This cell-selective binding was confirmed by means of autoradiography at different levels of resolution on Atlantic cod administered o,p(')-[14C]DDD intragastrically.

Target cells for cytochrome p450-catalysed irreversible binding of 7,12-dimethylbenz[a]anthracene (DMBA) in rodent adrenal glands.

7,12-Dimethylbenz[a]anthracene (DMBA) is an adrenocorticolytic agent that causes apoplexy (haemorrhage) and massive necrosis in the adrenal cortex in rat. Several explanations regarding the origin of toxicity have been proposed. Huggins and Morii (J Exp Med 114:741-60, 1961) suggested that the cells of the inner adrenal cortex are the primary target, whereas Horváth and Kovács (Pathol Eur 8:43-59, 1973) suggested the vascular endothelium as being the origin of toxicity.

Cytochrome P450-catalyzed binding of 3-methylsulfonyl-DDE and o,p'-DDD in human adrenal zona fasciculata/reticularis.

3-Methylsulfonyl-2,2'-bis(4-chlorophenyl)-1,1'-dichloroethene (MeSO(2)-DDE) is a potent, tissue-specific toxicant that induces necrosis of the adrenal zona fasciculata following a local CYP11B1-catalyzed activation to a reactive intermediate in mice. Autoradiography was used to examine CYP11B1-catalyzed binding of MeSO(2)-[(14)C]DDE and the adrenocorticolytic drug 2-(2-chlorophenyl)-2-(4-chlorophenyl)-1,1-dichlorethane; (o,p'-[(14)C]DDD, Mitotane, Lysodren) in human adrenal tissue slice culture. Both compounds gave rise to a selective binding in the one sample of normal adrenal zona fasciculata/reticularis, leaving zona glomerulosa and the adrenal medulla devoid of binding.