Implementation of a uniform nationwide medical licensing examination in general practice. A feasibility study

Objective: A competency-based training of medical students that is adapted to the realities of care is required internationally and is being intended in Germany with the Master Plan for Medical Studies 2020. In order to test these competencies, the German National Institute for state examinations in Medicine, Pharmacy and Psychotherapy (IMPP) has developed a concept for the redesign of the final part of the medical licensing examination in Germany. It focuses on general and interprofessional healthcare in the examination with outpatients. The aim of this work is to assess the feasibility of the new final examination on the basis of pilot examinations in family practices and to derive further steps for the national implementation. Methods: Fourteen medical students in their internship year completed a full examination with patients aged 42 to 84 years. Examiners evaluated the examination performance using standardised evaluation forms. Feasibility was qualitatively assessed in terms of compliance with content and time limits, examination results, patient reflections, and implementation in the practice. Results: Students were able to complete all tasks within the given time frame. Based on the evaluation forms, the examiners assessed the performance of the students. Patients appreciated the structured course of the examination in the familiar location of their family practice. For the nationwide implementation of the examination, 2,500 examination practices are required for about 10,000 examinees per year. Four students can then be examined on two days per year in each practice. Conclusions: Oral-practical examinations with outpatients in general medical practices can be carried out successfully throughout the nation. An implementation of the examinations throughout Germany requires that medical studies are restructured and that this new curriculum is implemented as intended by the Master Plan for Medical Studies 2020. Furthermore, training and remuneration of examiners together with a legal framework for the new examination must be established.

N-acetylcysteine modulates effect of the iron isomaltoside on peritoneal mesothelial cells

Intravenous (i.v.) iron supplementation is used in patients on chronic peritoneal dialysis (pd). Iron induced intraperitoneal inflammation observed in our previous studies with iron sucrose may deteriorate the function of the peritoneum as the dialysis membrane. We evaluated effect iron compound, iron-isomaltoside-100 (IIS) on the peritoneal mesothelial cells (MC). We studied the effect of iv treatment with IIS ± N-acetylcysteine (NAC) on the dialysate parameters and function of MC. In 7 uremic pd patients IIS 200 mg was infused i.v. ± NAC 600 mg. Afterward, a 4 hours exchange was performed with Dianeal 1.5%. As a control dialysate exchange preceding IIS treatment was used. Inflammatory parameters of the drained dialysates as well as the dialysates and IIS effects on MC were evaluated in ex vivo experiments. Intravenous infusion of IIS resulted in an increase of the dialysate Fe (+147%, P < 0.01). Concentrations of the dialysates inflammatory mediators were increased: interleukin-6 (IL-6) +39%, P < 0.02, monocyte chemoattractant protein-1(MCP1) +50%, P < 0.02, and hyaluronan (HA) +64%, P < 0.02. Simultaneous i.v. infusion of NAC prevented increase of the dialysate inflammatory mediators. Dialysates collected after IIS treatment induced oxidative stress in MC (+29%, P < 0.05) and stimulated IL-6 synthesis (+64%, P < 0.05) in MC; no such effect was seen in dialysates obtained after simultaneous IIS and NAC i.v. treatment. IIS used as the additive to culture medium stimulated synthesis in MC of IL6 (+76%, P < 0.001) and plasminogen activator inhibitor-1 (PAI-1) (28%, P < 0.001) whereas synthesis of tissue plasminogen activator (t-PA) was reduced (-16%, P < 0.001). These changes were prevented in the presence of NAC 1 mmol/L. Intravenous administration of IIS results in the mild stimulation of intraperitoneal inflammation. IIS changes MC phenotype to the inflammatory one with reduced fibrinolytic activity. These effects are prevented by NAC.

Positron Emission Tomography Imaging Evaluation of a Novel 18F-Labeled Sigma-1 Receptor Radioligand in Cynomolgus Monkeys

We report a convenient radiosynthesis and the first positron emission tomography (PET) imaging evaluation of [18F]FBFP as a potent sigma-1 (σ1) receptor radioligand with advantageous characteristics. [18F]FBFP was synthesized in one step from an iodonium ylide precursor. In cynomolgus monkeys, [18F]FBFP displayed high brain uptake and suitable tissue kinetics for quantitative analysis. It exhibited heterogeneous distribution with higher regional volume of distribution (VT) values in the amygdala, hippocampus, insula, and frontal cortex. Pretreatment with the σ1 receptor agonist SA4503 (0.5 mg/kg) significantly reduced radioligand uptake in the monkey brain (>95%), indicating high binding specificity of [18F]FBFP in vivo. Compared with (S)-[18F]fluspidine, [18F]FBFP possessed higher regional nondisplaceable binding potential (BPND) values across the brain regions. These findings demonstrate that [18F]FBFP is a highly promising PET radioligand for imaging and quantification of σ1 receptors in humans.

Sulodexide modulates the dialysate effect on the peritoneal mesothelium

Peritoneal membrane damage during chronic peritoneal dialysis is the main cause of that treatment failure. Preservation of the mesothelial cells (MC) is important for the survival of the peritoneum. Evaluation of dialysates effect on the function of MC and potential modification of that effect by sulodexide (heparin 80% and dermatan sulfate 20%). Dialysate effluents, after the overnight exchange with dianeal 1.5% dextrose, were collected from 7 continuous ambulatory peritoneal dialysis (CAPD) patients, and their effect ± sulodexide 0.5 LRU/mL on genes expression, secretory activity and protein synthesis in MC was studied. Exposure of MC to the studied dialysates caused intracellular oxidative stress and significantly increased expression of the genes regulating the synthesis of interleukin-6 (IL-6), monocyte chemoattractant protein-1 (MCP-1), transforming growth factor-beta (TGF-β), vascular cell adhesion molecule 1 (VCAM-1) and vascular endothelial growth factor (VEGF). Secretion of the studied molecules from MC treated with dialysates was increased: by 96% for IL-6 (P < 0.01), 34% for MCP-1(P < 0.01), 24% for TGF-β (P < 0.01), 27% for VCAM-1 (P < 0.01), and by 15% for VEGF (P < 0.01). Sulodexide reduced the stimulatory effect of the dialysates on the intracellular generation of free radicals, genes expression and secretory activity of MC. These cells exposed to the dialysates showed increased synthesis of total protein (by 216%, P < 0.005) and collagen (by 264%, P < 0.005), as compared to standard culture medium. Supplementation of the dialysates with sulodexide resulted in weaker stimulation of collagen synthesis (-21% versus dialysate). We concluded that peritoneal dialysate changes the genes expression and phenotype of MC to a proinflammatory, profibrotic and proangiogenic one. Sulodexide reduces these negative effects of the dialysate.

Synthesis and Preclinical Evaluation of an 18F-Labeled Synaptic Vesicle Glycoprotein 2A PET Imaging Probe: [18F]SynVesT-2

Synaptic vesicle glycoprotein 2A (SV2A) is a 12-pass transmembrane glycoprotein ubiquitously expressed in presynaptic vesicles. In vivo imaging of SV2A using PET has potential applications in the diagnosis and prognosis of a variety of neuropsychiatric diseases, e.g., Alzheimer's disease, Parkinson's disease, schizophrenia, multiple sclerosis, autism, epilepsy, stroke, traumatic brain injury, post-traumatic stress disorder, depression, etc. Herein, we report the synthesis and evaluation of a new ¹⁸F-labeled SV2A PET imaging probe, [¹⁸F]SynVesT-2, which possesses fast in vivo binding kinetics and high specific binding signals in non-human primate brain.

A Novel 18F-Labeled Radioligand for Positron Emission Tomography Imaging of 11β-Hydroxysteroid Dehydrogenase (11β-HSD1): Synthesis and Preliminary Evaluation in Nonhuman Primates

11β-Hydroxysteroid dehydrogenase type 1 (11β-HSD1) catalyzes the conversion of cortisone to cortisol and controls a key pathway in the regulation of stress. Studies have implicated 11β-HSD1 in metabolic diseases including type 2 diabetes and obesity, as well as stress-related disorders and neurodegenerative diseases, such as depression and Alzheimer's disease (AD). We have previously developed [¹¹C]AS2471907 as a PET radiotracer to image 11β-HSD1 in the brain of nonhuman primates and humans. However, the radiosynthesis of [¹¹C]AS2471907 was unreliable and low-yielding. Here, we report the development of the ¹⁸F-labeled version [¹⁸F]AS2471907, including the synthesis of two iodonium ylide precursors and the optimization of ¹⁸F-radiosynthesis. Preliminary PET experiments, composed of a baseline scan of [¹⁸F]AS2471907 and a blocking scan with the reversible 11β-HSD1 inhibitor ASP3662 (0.3 mg/kg), was also conducted in a rhesus monkey to verify the pharmacokinetics of [¹⁸F]AS2471907 and its specific binding in the brain. The iodonium ylide precursors were prepared in a seven-step synthetic route with an optimized overall yield of ∼2%. [¹⁸F]AS2471907 was synthesized in good radiochemical purity, with the ortho regioisomer of iodonium ylide providing greater radiochemical yield as compared with the para regioisomer. In monkey brain, [¹⁸F]AS2471907 displayed high uptake and heterogeneous distribution, while administration of the 11β-HSD1 inhibitor ASP3662 significantly reduced radiotracer uptake, thus demonstrating the binding specificity of [¹⁸F]AS2471907. Given the longer half-life of F-18 and feasibility for central production and distribution, [¹⁸F]AS2471907 holds great promise to be a valuable PET radiotracer to image 11β-HSD1 in the brain.

DVO Leitlinie 2017 zur Prophylaxe, Diagnostik und Therapie der Osteoporose bei postmenopausalen Frauen und Männern

Diese DVO Leitlinien, die in erster Linie für Allgemeinmediziner und Spezialisten für Knochenerkrankungen bestimmt sind, sollten von allen im klinischen und ambulanten Bereich tätigen medizinischen Fachkräften angewendet werden. Ziel der Leitlinie ist die Verbesserung der Diagnose, Prävention und Behandlung von Osteoporose und der Folgen der Erkrankung auf der Grundlage evidenzbasierter Medizin.

Klare Empfehlungen, welche Patienten zu diagnostizieren und behandeln sind (basierend auf Risikofaktoren [einschließlich sekundärer Osteoporose]) sowie Primär-, Sekundär- oder Tertiärprävention werden dargestellt, mit dem Schwerpunkt auf der postmenopausalen Osteoporose und der Osteoporose bei Männern.

Die Identifizierung von Patienten mit einem hohen Risiko für Frakturen wird hervorgehoben, und spezifische Schwellenwerte für die Intervention sind definiert (20 % Hüftfrakturrisiko innerhalb von 10 Jahren diagnostischer Schwellenwert, 30 % Hüftfrakturrisiko innerhalb von 10 Jahren therapeutische Schwelle). Die Diagnose von Osteoporose basiert auf der Anamnese des Patienten, der körperlichen Untersuchung, dem Funktionstest (z. B. Timed Up and Go Test), konventionellen Röntgenaufnahmen der Brust- und Lendenwirbelsäule und der Bestimmung der Knochenmineraldichte (BMD) durch das DXA Verfahren.

Die Anamnese ist entscheidend für die Abschätzung des Frakturrisikos auf der Grundlage von 40 wissenschaftlich überprüften Risikofaktoren, die das Frakturrisiko mindestens verdoppeln (z. B. Begleiterkrankungen, Hüftfrakturen in der Familie, prävalente Frakturen an jedem Ort, Lebensstil, Anwendung von Medikamenten, körperliche Aktivität und Stürze). Röntgenaufnahmen der Brust- und Lendenwirbelsäule sind wichtig, um prävalente Wirbelkörperfrakturen zu erkennen. Beim Fehlen eines großen Traumas kann jede Fraktur bei Erwachsenen über dem Alter von 50 Jahren eine Diagnose von Osteoporose nahelegen, mit dem höchsten Risiko für eine nachfolgende Fraktur innerhalb einer kurzen Zeit nach der ersten Fraktur. BMD-Messungen mit DXA sind wichtig, um das individuelle Frakturrisiko besser abschätzen zu können. Eine grundlegende Laboruntersuchung ist obligatorisch, um verschiedene Formen der sekundären Osteoporose ausschließen zu können.

Der DVO-Patientenfindungs-Algorithmus basiert auf dem Geschlecht, Alter, Knochenmineraldichte und vorbestehenden Frakturen als wichtigste Informationen. Die Indikation für eine aktive anti-osteoporotische Therapie kann durch multiple Risikofaktoren modifiziert und verfeinert werden. Dieser Algorithmus wurde seit dem Richtlinien-Update 2006 verwendet und wurde entsprechend der internationalen Literatur zu Risikofaktoren für Osteoporose und osteoporotische Frakturen aktualisiert und angepasst.

Die Behandlung der Osteoporose enthält viele Therapiepfeiler. Zusammen mit Empfehlungen für Bewegung, Physiotherapie und Sturzprävention sowie Ernährung (z. B. Calcium, Vit. D), werden pharmakologische Behandlungen basierend auf evidenzbasierter Medizin empfohlen. Die aktiven Anti-Osteoporose-Medikamente müssen für die Indikation postmenopausale Osteoporose und männliche Osteoporose in Deutschland, Österreich und der Schweiz zugelassen sein. Das Management und die Vorbeugung von häufigen oder seltenen Nebenwirkungen aufgrund von Anti-Osteoporose-Behandlungen, die in der klinischen Praxis angewendet werden, werden ebenfalls detailliert behandelt.

Imaging synaptic density in the living human brain

Chemical synapses are the predominant neuron-to-neuron contact in the central nervous system. Presynaptic boutons of neurons contain hundreds of vesicles filled with neurotransmitters, the diffusible signaling chemicals. Changes in the number of synapses are associated with numerous brain disorders, including Alzheimer's disease and epilepsy. However, all current approaches for measuring synaptic density in humans require brain tissue from autopsy or surgical resection. We report the use of the synaptic vesicle glycoprotein 2A (SV2A) radioligand [(11)C]UCB-J combined with positron emission tomography (PET) to quantify synaptic density in the living human brain. Validation studies in a baboon confirmed that SV2A is an alternative synaptic density marker to synaptophysin. First-in-human PET studies demonstrated that [(11)C]UCB-J had excellent imaging properties. Finally, we confirmed that PET imaging of SV2A was sensitive to synaptic loss in patients with temporal lobe epilepsy. Thus, [(11)C]UCB-J PET imaging is a promising approach for in vivo quantification of synaptic density with several potential applications in diagnosis and therapeutic monitoring of neurological and psychiatric disorders.

PET Imaging Evaluation of Four σ1 Radiotracers in Nonhuman Primates

The σ1 receptors (S1Rs) are implicated in a variety of diseases including Alzheimer disease and cancer. Previous PET S1R radiotracers are characterized by slow kinetics or off-target binding that impedes their use in humans. Here, we report the first PET imaging evaluation in rhesus monkeys of 4 18F-labeled spirocyclic piperidine-based PET radiotracers (18F-1 to 18F-4). Methods: Baseline scans for the 4 radiotracers were obtained on an adult male rhesus monkey. Blocking scans were obtained with the S1R-selective agonist SA4503 to assess binding specificity of 18F-2 and 18F-4 Arterial input functions were measured, and binding parameters were determined with kinetic modeling analysis. Results: In the rhesus brain, all 4 radiotracers showed high and fast uptake. Tissue activity washout was rapid for 18F-2 and 18F-4, and much slower for 18F-1 and 18F-3, in line with their respective in vitro S1R-binding affinities. Both the 1-tissue-compartment and multilinear analysis-1 kinetic models provided good fits of time-activity curves and reliable estimates of distribution volume. Regional distribution volume values were highest in the cingulate cortex and lowest in the thalamus for all radiotracers. 18F-4 showed greater differential uptake across brain regions and 3-fold-higher binding potential than 18F-2 SA4503 at the dose of 0.5 mg/kg blocked approximately 85% (18F-2) and 95% (18F-4) of radiotracer binding. Conclusion: Tracers 18F-2 and 18F-4 displayed high brain uptake and fast tissue kinetics, with 18F-4 having higher specific binding signals than 18F-2 in the same monkey. Taken together, these data indicate that both 18F-2 and 18F-4 possess the requisite kinetic and imaging properties as viable PET tracers for imaging S1R in the human brain.

Sulodexide suppresses inflammation in patients with chronic venous insufficiency

AIM

According to previously performed studies, inflammation plays a crucial role in vein wall and leg tissue injury related to chronic venous insufficiency (CVI) development. Sulodexide (SUL) is a balanced mix of glycosaminoglycans with potential anticoagulant and profibrinolytic activity, also protecting endothelial cells and suppressing inflammatory reactions in various vascular disease-related conditions. The goal of the present study was to evaluate the anti-inflammatory action of SUL in patients with CVI.

METHODS

The study was performed on a group of 11 patients with chronic venous disease (stage C5 according to CEAP classification). The mean age of the patients was 58.4±7.7 years, and none of them were diabetic. The patients were treated for 8 weeks with orally-administered SUL (2 x 500 LSU/day). Blood samples were collected at the start and at the end of the study for measurement of MMP-9, IL-6 and monocyte chemoattractant protein-1 (MCP-1). Additionally, the effect of the obtained serum samples on the function of human venous endothelial cells (HVEC) in in-vitro culture was evaluated.

RESULTS

After treatment with SUL, the serum concentration of MMP-9 (ng/mL) decreased from 6.50±3.48 to 5.41±1.36, P<0.05, and the concentration of IL-6 (pg/mL) decreased from 11.5±3.4 to 10.1±2.3, P<0.005. There was also a trend of decreased serum MCP-1 (pg/mL) from 31.3±23.0 before treatment to 27.1±10.7 at the end. Intracellular generation of oxygen-derived free radicals in HVEC maintained in in-vitro culture was lower in the serum samples collected after treatment with SUL: 3.09±0.35 abs/μg protein vs. 3.63±0.32 abs/μg protein, at the start, P<0.05. Synthesis of IL-6 was lower in HVEC exposed in vitro to serum collected at the end of SUL treatment: 1.02±0.31 ng/μg cell protein vs. 1.32±0.41 ng/μg cell protein before SUL treatment. The proliferation rate of HVEC was similar in serum collected at the beginning and at the end of SUL treatment.

CONCLUSION

We conclude that treatment with SUL in patients with CVI reduces intravascular inflammation and is protective for the endothelial cells and for the extracellular matrix changes related to metalloproteinase expression.

N-Acetylglucosamine modulates function of the skin fibroblasts

BACKGROUND

Fibroblasts are an important component of the skin determining its properties. N-Acetylglucosamine (NAG) is the substrate for hyaluronan synthesis, and it also has anti-inflammatory and anti-senescent activity in mesothelial cells.

METHODS

We tested in in vitro-cultured human skin fibroblasts how supplementation of culture medium with NAG 10 mmol L(-1) changes properties of these cells.

RESULTS

Fibroblasts cultured in presence of NAG produced more proteins and that was mainly due to increased synthesis of collagen (+33% vs. control, P < 0.05). Hyaluronan synthesis was increased (+107% vs. control, P < 0.001), but interleukin-6 synthesis was reduced (-22% vs. control, P < 0.05). Fibroblasts cultured in medium with NAG 10 mmol L(-1) demonstrated improved ability to heal the injured layer of cells (+34% vs. control, P < 0.05). Additionally senescence of fibroblasts undergoing replicative ageing in the presence of NAG was less pronounced, as reflected by smaller increase in the population doubling time (-70% vs. control, P < 0.05).

CONCLUSION

We conclude that NAG induced changes in the skin fibroblasts' properties maybe important for prevention of the age-dependent changes in its structure and function.

High-speed phosphor thermometry

Phosphor thermometry is a semi-invasive surface temperature measurement technique utilising the luminescence properties of doped ceramic materials. Typically, these phosphor materials are coated onto the object of interest and are excited by a short UV laser pulse. Up to now, primarily Q-switched laser systems with repetition rates of 10 Hz were employed for excitation. Accordingly, this diagnostic tool was not applicable to resolve correlated temperature transients at time scales shorter than 100 ms. This contribution reports on the first realisation of a high-speed phosphor thermometry system employing a highly repetitive laser in the kHz regime and a fast decaying phosphor. A suitable material was characterised regarding its temperature lifetime characteristic and its measurement precision. Additionally, the influence of laser power on the phosphor coating was investigated in terms of heating effects. A demonstration of this high-speed technique has been conducted inside the thermally highly transient system of an optically accessible internal combustion engine. Temperatures have been measured with a repetition rate of 6 kHz corresponding to one sample per crank angle degree at 1000 rpm.