We report on a 36 year old patient who collapsed at home and was resuscitated by prehospital medical emergency services. He presented on scene unconscious with severe ST-elevations on the ECG and hardly palpable pulses. His previous medical history included only idiopathic hypertension and his professional background as manager of a company was associated with high stress levels. The prehospital diagnosis was myocardial infarction with cardiogenic shock. A hypovolemic shock was excluded from the differential diagnosis because of the age of the patient, lack of a precipitating trauma and inconsistent symptoms.The patient died after terminating prolonged resuscitation. A post mortem showed as cause of death the rupture of a splenic artery aneurysm. We emphasize that a cardiovascular collapse in a young patient without specific history or trauma still can be caused by hypovolemic shock due to intra-abdominal or -thorac bleeding.

Surface chemical processes of UO2 are investigated on a nanoscopic scale by electrochemical atomic force microscopy (ECAFM) using a home-developed electrochemical cell. Dissolution reactions of the solid surface and subsequent remineralization are observed at the solid–water interface under different redox conditions and carbonate concentrations. The local dissolution rates vary between different grain faces, grain boundaries and etch pits. A correlation between dissolution rates and the grain orientations relative to the specimen surface can be demonstrated by electron backscatter diffraction (EBSD). Remineralization under oxidizing conditions occurs mainly at grain faces with higher dissolution rates. The remineralized products are particles of 200–900 nm in diameter and exhibit a tabular morphology. Profound knowledge of the UO2 surface chemistry on a nanoscale may help to clarify the related mechanisms explaining the macroscopically observed dissolution rates.

16Alpha-fluoroestradiol-3,17beta-disulfamate (FESDS) strongly inhibits estrone sulfatase (ES), an enzyme which is also present in the brain. The enzyme is probably involved in important regulatory functions of neurosteroids which may be disturbed in certain brain diseases. In the present study, [18F]FESDS was used to measure the amount of ES in various rat brain regions using quantitative in vitro autoradiography. The obtained values vary between 0.29 pmol (mg protein)(-1) (pons) and 11.5 pmol (mg protein)(-1) (striatum). They are positively correlated with the enzyme activity measured in homogenates of the corresponding regions. Because this radiotracer binds also to carbonic anhydrase in the brain it is only of limited use for in vivo imaging studies.

Based on a high affinity to the enzyme estrone sulfatase (ES), 16alpha-[F-18]fluoroestradiol-3,17beta-disulfamate ([F-18]FESDS) has been suggested as a potential PET radiotracer for imaging steroid-dependent breast tumours. The distribution of [F-18]FESDS was studied in rats, tumour-bearing nude mice and piglets. In all species evidence for binding to a second target, the enzyme carbonic anhydrase (CA), was obtained. ES and CA inhibitors significantly reduced the radiotracer uptake in various organs but not in tumours. It is concluded that [F-18]FESDS binds to ES and CA in vivo but this binding is not strong enough to allow tumour imaging with positron emission tomography (PET). (C) 2002 Elsevier Science Ltd. All rights reserved.

Groundwater colloids from the Gorleben site (Lower Saxony, Germany) are characterized in the presence of Eu(III) by tapping-mode atomic force microscopy (AFM) with phase contrast imaging. Using a liquid cell the method allows investigations of samples being in contact with aqueous solution. This ensures that complex structures are kept in their native hydrated state. Different types of colloids and aggregates are found by AFM, e.g., spherical particles, fibrous structures, and structures which appear to be hollow. A partial coating of the edges of clay particles with humic colloids can be assumed from phase contrast images. Therefore, aquatic colloids and their aggregates found in Gorleben groundwater can be characterized as a complex mixture of components, which may influence the migration of groundwater contaminants in different processes.

Based on a high affinity to the enzyme estrone sulfatase (ES), 16alpha-[18F]fluoroestradiol-3,17beta-disulfamate ([18F]FESDS) has been suggested as a potential PET radiotracer for imaging steroid-dependent breast tumours. The distribution of [18F]FESDS was studied in rats, tumour-bearing nude mice and piglets. In all species evidence for binding to a second target, the enzyme carbonic anhydrase (CA), was obtained. ES and CA inhibitors significantly reduced the radiotracer uptake in various organs but not in tumours. It is concluded that [18F]FESDS binds to ES and CA in vivo but this binding is not strong enough to allow tumour imaging with positron emission tomography (PET).

AbstractThe procedure described can simultaneously provide about 3GBq 16α‐[18F]fluoroestradiol‐3‐sulphamate and about 1 GBq 16α‐[18F]fluoroestradiol‐17β‐sulphamate of high radiochemical purity. By treating 16α‐[18F]fluoroestradiol‐3, 17β‐disulphamate with Kryptofix 2.2.2 and potassium carbonate as a base, 16α‐[18F]fluoro‐estradiol‐17β‐sulphamate became accessible with a still higher radioactivity level.

After successfully synthesizing 16 alpha-[F-18]fluoroestradiol-3,17 beta -disulphamate in an automatic procedure, we studied the conditions for obtaining 16 alpha-[F-18]fluoroestradiol-monosulphamates in a similar manner. The described procedure can simultaneously provide approximately 3 GBq of 16 alpha-[F-18]fluoroestradiol-3-sulphamate and 1 GBq of 16 alpha-[F-18]fluoroestradiol-17 beta -sulphamate of high radiochemical purity. By treating 16 alpha-[F-18]fluoroestradiol-3,17 beta -disulphamate with Kryptofix 2.2.2 and potassium carbonate, 16 alpha-[F-18]fluoroestradiol-17 beta -sulphamate also becomes available at high radioactivity. Copyright (C) 2001 John Wiley & Sons, Ltd. Copyright 2001 John Wiley & Sons, Ltd.

The importance of humic colloids influencing mobilization or immobilization of metal ions, i.e. actinides, in natural aquatic systems has been emphasized in the context of safety aspects of nuclear waste repositories. The influence of polyvalent cations, i.e. Eu(III) as a homologue for trivalent actinides, on the adsorption of humic acid (HA) onto the basal plane of cleaved muscovite is studied by atomic force microscopy (AFM). To avoid denaturation of sorbed HA by drying procedures, the investigation is performed in aqueous medium by applying non-contact-mode AFM (also called fluid-tapping-mode AFM). Nanostructure, surface coverage and dimensions of sorbed HA are found to be influenced by Eu(III) ions. To get a basic understanding of the interaction between HA and the mica crystalline plane, force spectroscopy experiments are performed. Force versus distance curves are recorded with and without the presence of Eu(III) ions using AFM tips covered with HA. It is found that in the presence of Eu(III) binding forces between HA and the mica surface increase by about one order of magnitude. This effect is partly reversible in deionized water and fully reversible in EDTA solution. On the basis of these observations, polyvalent cation bridges can be favoured as the binding mechanism between HA and mica planes. Copyright © 2000 John Wiley & Sons, Ltd.

An iterative mathematical procedure for the alignment of sequentially recorded atomic force microscope images (AFM) is presented. The computer program is able to correct commonly observed drifts in vertical and lateral directions, rotations around a vertical or lateral axis and differences in scale. This method is applied on dissolution experiments of uranium dioxide (UO2) surfaces. Images recorded during in situ experiments, which are shifted probably due to thermal fluctuations, can be aligned with good accurancy. In a further approach the UO2 surface is marked by electron-beam-induced deposition (EBD or EBID) with microstructured reference points. The alignment can be distinctly improved using marked sample surfaces because of the characteristic shape of the markings, which do not change during the experiment. Furthermore, the markings can be used to find again a domain on a sample surface. Therefore, AFM images recorded before and after an ex situ experiment (e.g. treatment in corrosive medium for a longer period of time) can be aligned with a nanometer spatial resolution.

The synthesis of 16 alpha-[F-18]fluoroestradiol-3,17 beta-disulphamate ([F-18]FESDS) is described. 16-alpha[F-18]Fluoroestradiol ([F-18]FES) is converted using excess sulphamoyl chloride in absolute acetonitrile in the presence of Kryptofix 2.2.2 and potassium carbonate using an automatically operating module. The required time for the synthesis related to end of bombardment is 3h, the maximum yield is 6%, and the maximum decay-corrected yield is 20%. The radiochemical purity of [F-18]FESDS is > 99%. The specific radioactivity of [F-18]FESDS is found to be between 150 and 200 GBq/mu mol.

Humic acid colloids adsorbed on the basal plane of cleaved muscovite are investigated under in situ conditions by non-contact mode atomic force microscopy (AFM) in liquid (also called fluid tapping-mode AFM). Structures are found to be of nanometer scale, consisting of hat particles (8-13 nm in diameter), aggregates of particles (20-100 nm), chain-like assemblies, networks and torus-like structures. In contrast to former investigations colloids are investigated in aquatic solution and structures are not influenced by sample preparation. Nanostructure, surface coverage and particle sizes are found to depend on solution pH. Humic colloids can be distinguished from surface roughness and background noise by image processing. Furthermore, an approach to quantify the surface coverage is discussed. Therefore, non-contact mode AFM in liquid is shown to be a powerful method to study the interaction of colloids at solid-liquid interfaces. (C) 1999 Elsevier Science B.V. All rights reserved.

Estradiols are able to form two monosulphamates and one disulphamate. In the present work all the sulphamates of 17 alpha-estradiol, 17 beta-estradiol and 16 alpha-fluoroestradiol were synthesized and characterized. For characterization NMR spectroscopy was used first of all. Because of its high sulphatase inhibitory efficiency 16 alpha-fluoroestradiol-3,17-beta-disulphamate found a special interest among the new sulphamates. Just the binding between sulphamate and sulphatase favoured 16 alpha-[F-18] fluorestradiol-3, 17-beta-disulphamate to a new radio-pharmaceutical which should be appropriate to image the active sites of sulphatase by positron emission tomography. The preparation of 16a-[F-18]fluoroestradiol-3,17-beta-disulphamate requires a simple and rapid procedure. The conditions for such a procedure were also elaborated using non-radioactive substances.

Estradiols are able to form two monosulphamates and one disulphamate. In the present work all the sulphamates of 17α-estradiol, 17β-estradiol and 16α-fluoroestradiol were synthesized and characterized. For characterization NMR spectroscopy was used first of all. Because of its high sulphatase inhibitory efficiency 16α-fluoroestradiol-3,17β-disulphamate found a special interest among the new sulphamates. Just the binding between sulphamate and sulphatase favoured 16α-[18F]fluorestradiol-3,17β-disulphamate to a new radio-pharmaceutical which should be appropriate to image the active sites of sulphatase by positron emission tomography. The preparation of 16α-[18F]fluoro-estradiol-3,17β-disulphamate requires a simple and rapid procedure. The conditions for such a procedure were also elaborated using non-radioactive substances.

A method for the correction of both vertical and lateral drifts of in situ atomic force microscopy (AFM) images is presented. The surface of a copper plate is marked with microstructured carbonaceous reference points by electron-beam-induced deposition (EBD or EBID) in the chamber of a scanning electron microscope (SEM). Image alignment to these points using a numerical procedure facilitates the comparison of images recorded over periods of several hours where usually a shift due to thermal drift is observed. The applicability of the method is demonstrated in a corrosion experiment. Absolute changes in height can be determined with reference to the carbon markings which are not affected by the etching solution.

For preparing 16 alpha-[F-18]fluoroestradiol, a new one-pot procedure reported in the literature was elaborated in detail. The experimental conditions for synthesizing the required precursor and for converting it into 16 alpha-fluoroestradiol or 16 alpha-[F-18]fluoroestradiol are given. The synthesis consists of the fluoridation reaction and hydrolysis reactions. For rapid hydrolysis of the fluorosteroid formed in the fluoridation reaction two methods are presented. The synthesis time does not exceed 1 h. Pure 16 alpha-[F-18]fluoroestradiol can be obtained in a 70% overall radiochemical yield.