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Biomedical subjects

F Schreiber

Publications and source records attributed to F Schreiber.

At least 19 recordsLinked to original sources
PubMed2006

Use of sedation for routine diagnostic upper gastrointestinal endoscopy: a European Society of Gastrointestinal Endoscopy Survey of National Endoscopy Society Members.

BACKGROUND/AIMS: Sedation rates may vary among countries, depending on patients' and endoscopists' preferences. The aim of this survey was to investigate the rate of using premedication for routine diagnostic upper gastrointestinal (UGI) endoscopy in endoscopy societies, members of the European Society of Gastrointestinal Endoscopy (ESGE). METHODS: We evaluated a multiple-choice questionnaire which was e-mailed to representatives of national endoscopy societies, which are members of the ESGE. The questionnaire had 14 items referring to endoscopy practices in each country and the representatives' endoscopy units. RESULTS: The response rate was 76% (34/45). In 47% of the countries, less than 25% of patients undergo routine diagnostic UGI endoscopy with conscious sedation. In 62% of the responders' endoscopy units, patients are not asked their preference for sedation and do not sign a consent form (59%). Common sedatives in use are midazolam (82%), diazepam (38%) or propofol (47%). Monitoring equipment is not available 'in most of the endoscopy units' in 46% (13/28) of the countries. Though they were available in 91% of the national representatives' endoscopy units, they are rarely (21%) used to monitor unsedated routine diagnostic UGI endoscopy. CONCLUSIONS: In about 50% of ESGE-related countries, less than 25% of patients are sedated for routine diagnostic UGI endoscopy. Major issues to improve include availability of monitoring equipment and the use of a consent form.

Procedural Sedation↗
PubMed2006

Real-time observation of structural and orientational transitions during growth of organic thin films.

We study kinetically controlled orientational and structural transitions of molecular thin films during growth in situ and in real time, using diindenoperylene (DIP) as an example. By time-resolved surface-sensitive x-ray scattering (out of plane and in plane), we follow the organic molecular beam deposition of DIP on silicon oxide, on stepped sapphire, and on rubrene as an organic model surface. We identify transitions for the few-monolayer (ML) regime, as well as for thick (several 10's of ML) films. We show that the differences in the interaction of DIP with the substrate change the thickness as well as temperature range of the transitions, which include (transient) strain, subtle changes of the orientation, as well as complete reorientation. These effects should be considered rather general features of the growth of organics, which, with its orientational degrees of freedom, is qualitatively different from growth of inorganics.

Journal Article↗
PubMed2006

Anomalous roughness evolution of rubrene thin films observed in real time during growth.

We study the growth and structure of thin films of the organic semiconductor rubrene during organic molecular beam deposition (OMBD) on silicon oxide in situ and in real time using X-ray scattering. Using in situ grazing incidence diffraction (GID) we find a small degree of local order but an otherwise largely disordered structure, consistent with out of plane scans. Monitoring the surface morphology in real time during growth, we find relatively smooth films (surface roughness sigma below approximately 15 A for thicknesses up to at least 600 A) and a significant delay before the onset of roughening. This anomalous roughening in the beginning and crossover to normal roughening later during growth may be related to conformational changes of rubrene in the early stages of growth.

Naphthacenes↗
PubMed2005

Mucosal vaccination delays or prevents prion infection via an oral route.

In recent years major outbreaks of prion disease linked to oral exposure of the prion agent have occurred in animal and human populations. These disorders are associated with a conformational change of a normal protein, PrP(C) (prion protein cellular), to a toxic and infectious form, PrP(Sc) (prion protein scrapie). None of the prionoses currently have an effective treatment. A limited number of active immunization approaches have been shown to slightly prolong the incubation period of prion infection. Active immunization in wild-type animals is hampered by auto-tolerance to PrP and potential toxicity. Here we report that mucosal vaccination with an attenuated Salmonella vaccine strain expressing the mouse PrP, is effective at overcoming tolerance to PrP and leads to a significant delay or prevention of prion disease in mice later exposed orally to the 139A scrapie strain. This mucosal vaccine induced gut anti-PrP immunoglobulin (Ig)A and systemic anti-PrP IgG. No toxicity was evident with this vaccination approach. This promising finding suggests that mucosal vaccination may be a useful method for overcoming tolerance to PrP and preventing prion infection among animal and potentially human populations at risk.

Administration, Oral↗
PubMed2003

Rapid roughening in thin film growth of an organic semiconductor (diindenoperylene).

The scaling exponents alpha, beta, and 1/z in thin films of the organic molecule diindenoperylene deposited on SiO2 under UHV conditions are determined. Atomic-force microscopy, x-ray reflectivity, and diffuse x-ray scattering were employed. The surface width displays power law scaling over more than 2 orders of magnitude in film thickness. We obtained alpha = 0.684+/-0.06, beta = 0.748+/-0.05, and 1/zeta = 0.92+/-0.20. The derived exponents point to an unusually rapid growth of vertical roughness and lateral correlations. We suggest that they could be related to lateral inhomogeneities arising from the formation of grain boundaries between tilt domains in the early stages of growth.

Journal Article↗
PubMed2003

Optimized preparation of cross-sectional TEM specimens of organic thin films.

We present a route for the preparation of cross-sectional TEM specimens of crystalline organic thin films which minimizes the mechanical, chemical and thermal load of the organic film during preparation and allows to take TEM images with molecular resolution. A typical example of a thin film of diindenoperylene capped with a thin layer of gold is shown to demonstrate the application of the technique for the investigation of metal-organic interfaces.

Journal Article↗
PubMed1999

Bone scintigraphy and magnetic resonance imaging in adult-onset Still's disease.

Adult-onset Still's disease (AOSD) is an acute systemic inflammatory disorder of unknown origin. We report a patient whose AOSD presented with the commonly accepted diagnostic clinical signs and laboratory parameters. The painful joints distinctly demonstrated increased uptake of 99mTc-methylene diphosphonate in scintigraphy and areas of increased gadolinium-enhanced signal in MRI. Biopsies indicated bone marrow edema. AOSD in association with bone marrow edema had not been previously demonstrated. AOSD is often diagnosed after a considerable delay, bone scintigraphy, and magnetic resonance imaging may offer new imaging techniques for early diagnosis and successful therapy in follow-up examinations.

Adult↗
PubMed1997

Haemoglobin O Padova and falsely low haemoglobin A1c in a patient with type I diabetes.

Glycated haemoglobin (HbA1c) measured by high performance liquid chromatography (HPLC) in a 20 year old female with insulin dependent diabetes mellitus was consistently within the normal range although her daily blood glucose values were > 11.1 mmol/l. HbA1c measured by immunoagglutination and fructosamine was elevated and correlated with the patient's blood glucose values. The HPLC chromatogram showed an additional peak at HbA0. Electrophoresis of haemoglobin on citrate agar gel revealed an abnormal haemoglobin anodal of HbS. Cellulose acetate electrophoresis and isoelectric focusing demonstrated an additional haemoglobin migrating close to HbA2. Amino acid analysis and DNA sequencing revealed an alpha 30 (B11) Glu-->Lys replacement, that is, haemoglobin O Padova. Investigations of two family members without diabetes revealed the same rare haemoglobin variant. This case showed that this silent haemoglobin mutation caused an additional peak and falsely low HbA1c values when measured by HPLC, the gold standard for this evaluation.

Adult↗
PubMed1996

Sonographically-guided extracorporeal shockwave lithotripsy for pancreatic stones in patients with chronic pancreatitis.

Over a 2 year period, 10 patients with pancreatic stones due to alcohol induced chronic pancreatitis (proven by endoscopic retrograde pancreatography) underwent extracorporeal shockwave lithotripsy. Prior to shockwave therapy, all patients underwent endoscopic sphincterotomy. Targeting of shockwave lithotripsy was exclusively performed under sonographic control. All patients were treated with a second generation electrohydraulic spark gap lithotriptor and fragmentation of concrements could be achieved in all cases. Complete duct clearance was confirmed in seven patients by endoscopic retrograde pancreatography in one session, with endoscopic fragment extraction by basket and/or balloon catheter. In three patients, balloon dilation of concomitant strictures located in the head of the pancreas was performed prior to fragment extraction. All stone-free patients showed no further symptoms over the follow-up period of 12 months. Three patients in whom complete extraction of fragments was not successful experienced minor symptoms over the 12 month follow-up period.

Adult↗
PubMed1995

Endoscopic intracorporeal laser lithotripsy of difficult common bile duct stones with a stone-recognition pulsed dye laser system.

BACKGROUND: Endoscopic retrograde intracorporeal lithotripsy with a stone recognition laser system seems to be a promising alternative in patients with difficult bile duct stones. METHOD: Sixteen patients with bile duct stones not suitable for endoscopic standard procedures underwent intracorporeal laser lithotripsy during a 3-month period. An average of 6800 (120 to 25000) discharges were applied with a power setting of 100 mJ. Inserting the laser fiber into a radiopaque marked catheter or into a balloon catheter guaranteed a successful location on the stone surface in 70% of all discharges. The automatic feedback/cut-off at the fiber is not in contact with the stone surface. RESULTS: Fragmentation was achieved in all cases. Complete bile duct clearance was reached in 14/16 cases. In two cases, remaining fragments passed spontaneously through the papilla as controlled by ERCP. Minor complications were noted in two patients (hemobilia, cholangitis). Complete recovery was achieved in both patients with conservative management. CONCLUSIONS: For a selected group of patients with difficult common bile duct stones, intracorporeal laser lithotripsy with a stone recognition laser system was found to be a highly effective and safe technique.

Aged↗