Synthesis and evaluation of (S)-2-(2-[18F]fluoroethoxy)-4-([3-methyl-1-(2-piperidin-1-yl-phenyl)-butyl-carbamoyl]-methyl)-benzoic acid ([18F]repaglinide): a promising radioligand for quantification of pancreatic beta-cell mass with positron emission tomography (PET)

18F-labeled non-sulfonylurea hypoglycemic agent (S)-2-(2-[(18)F]fluoroethoxy)-4-((3-methyl-1-(2-piperidin-1-yl-phenyl)-butylcarbamoyl)-methyl)-benzoic acid ([(18)F]repaglinide), a derivative of the sulfonylurea-receptor (SUR) ligand repaglinide, was synthesized as a potential tracer for the non-invasive investigation of the sulfonylurea 1 receptor status of pancreatic beta-cells by positron emission tomography (PET) in the context of type 1 and type 2 diabetes. [(18)F]Repaglinide could be obtained in an overall radiochemical yield (RCY) of 20% after 135 min with a radiochemical purity higher than 98% applying the secondary labeling precursor 2-[(18)F]fluoroethyltosylate. Specific activity was in the range of 50-60 GBq/micromol. Labeling was conducted by exchanging the ethoxy-moiety into a 2-[(18)F]fluoroethoxy group. To characterize the properties of fluorinated repaglinide, the affinity of the analogous non-radioactive (19)F-compound for binding to the human SUR1 isoform was assessed. [(19)F]Repaglinide induced a complete monophasic inhibition curve with a Hill coefficient close to 1 (1.03) yielding a dissociation constant (K(D)) of 134 nM. Biological activity was proven via insulin secretion experiments on isolated rat islets and was comparable to that of repaglinide. Finally, biodistribution of [(18)F]repaglinide was investigated in rats by measuring the concentration of the compound in different organs after i.v. injection. Pancreatic tissue displayed a stable accumulation of approximately 0.12% of the injected dose from 10 min to 30 min p.i. 50% of the radioactive tracer could be displaced by additional injection of unlabeled repaglinide, indicating that [(18)F]repaglinide might be suitable for in vivo investigation with PET.

A mycotic aneurysm of the ascending aorta and aortic arch induced by salmonella enteritidis

In very rare cases, salmonella infection may be associated with extra-intestinal manifestations. Of these, a mycotic aneurysm represents a life-threatening complication that is characterised by a high mortality rate. Prompt treatment with a combination of antibiotic therapy and surgical intervention is urgently required. We report on the case of a 60-year-old woman who presented with salmonella bacteraemia and the rare complication of an infected aneurysm of the ascending aorta and aortic arch.

Klinische Ergebnisse nach Sauv�-Kapandji-Operation in Abh�ngigkeit der Erkrankung

We present the results of a retrospective study on 56 patients who underwent the Sauve-Kapandji procedure for chronic disorders of the distal radioulnar joint (DRUJ). Outcome was assessed with special regard to the diagnosis. The average follow-up was 5.9 years (1-12 years). Patients were assessed for pain, range of motion of wrist and forearm, and radiological features. The DASH score and Mayo wrist score were used. The diagnosis had an influence on the outcome. Patients with primary arthrosis of the DRUJ demonstrated better results than patients with traumatic disorders. Patients with growth deficiency-related complaint of the DRUJ showed slightly inferior results after the Sauve-Kapandji procedure compared to all patients. Patients were free of pain or had pain only during heavy labor in 81% of cases; 95% of the patients rated the outcome as excellent or improved, but only 50% were free of symptoms on the operated side during heavy manual labor. Symptoms of ulnar impingement were found in 11%. Improvement in range of motion of wrist and forearm was significant. The postoperative DASH score was 24.2+/-22.5 and the Mayo wrist score was 76.1+/-17.6. Our results confirm the Sauve-Kapandji procedure to be a reliable salvage procedure resulting in high patient satisfaction and reliable improvement in range of motion. However, decreased grip strength on the affected side must be accepted to some extent. The diagnosis of a DRUJ disorder influences the outcome.

Feasibility of using the TOSCA telescreening procedures for diabetic retinopathy

AIMS

The TOSCA project was set up to establish a tele-ophthalmology service to screen for diabetic retinopathy (DR) in Europe. The aim of this study was to determine the feasibility of establishing telemedicine-based digital screening for detecting DR and to evaluate the satisfaction of both patients and healthcare professionals with the screening procedures used within the TOSCA project.

METHODS

The study was a non-randomized, multicentre study carried out in four different countries over a period of 3 months. Patients (n = 390) with diabetes aged > 12 years were included. Two digital retinal images per eye (macular and nasal) were taken and exported to a central server. Patients were asked to complete a questionnaire to assess satisfaction. Accredited graders carried out grading remotely and the results were reported back to the referring centre. Previously graded patient data chosen randomly to represent examples of both DR and no DR were also sent anonymously to the grading centre at a frequency of approximately every 10 patients.

RESULTS

Most (99%) of the images were assessable enabling a retinopathy grade to be assigned to the patient. Patients found the retinal photography procedures acceptable; only 6% in one centre would not recommend the procedure. Healthcare professionals (photographers and graders) were also satisfied with the overall procedures. The average time taken to grade each patient was approximately 5 min.

CONCLUSIONS

This study demonstrated that it is feasible to electronically transmit and grade retinal images remotely using the TOSCA process. Built-in quality assurance procedures proved acceptable.

Binding N2, N2H2, N2H4, and NH3 to transition-metal sulfur sites: modeling potential intermediates of biological N2 fixation

In the quest for low-molecular-weight metal sulfur complexes that bind nitrogenase-relevant small molecules and can serve as model complexes for nitrogenase, compounds with the [Ru(PiPr(3))('N(2)Me(2)S(2)')] fragment were found ('N(2)Me(2)S(2)'(2-)=1,2-ethanediamine-N,N'-dimethyl-N,N'-bis(2-benzenethiolate)(2-)). This fragment enabled the synthesis of a first series of chiral metal sulfur complexes, [Ru(L)(PiPr(3))('N(2)Me(2)S(2)')] with L=N(2), N(2)H(2), N(2)H(4), and NH(3), that meet the biological constraint of forming under mild conditions. The reaction of [Ru(NCCH(3))(PiPr(3))('N(2)Me(2)S(2)')] (1) with NH(3) gave the ammonia complex [Ru(NH(3))(PiPr(3))('N(2)Me(2)S(2)')] (4), which readily exchanged NH(3) for N(2) to yield the mononuclear dinitrogen complex [Ru(N(2))(PiPr(3))('N(2)Me(2)S(2)')] (2) in almost quantitative yield. Complex 2, obtained by this new efficient synthesis, was the starting material for the synthesis of dinuclear (R,R)- and (S,S)-[micro-N(2)[Ru(PiPr(3))('N(2)Me(2)S(2)')](2)] ((R,R)-/(S,S)-3). (Both 2 and 3 have been reported previously.) The as-yet inexplicable behavior of complex 3 to form also the R,S isomer in solution has been revealed by DFT calculations and (2)D NMR spectroscopy studies. The reaction of 1 or 2 with anhydrous hydrazine yielded the hydrazine complex [Ru(N(2)H(4))(PiPr(3))('N(2)Me(2)S(2)')] (6), which is a highly reactive intermediate. Disproportionation of 6 resulted in the formation of mononuclear diazene complexes, the ammonia complex 4, and finally the dinuclear diazene complex [micro-N(2)H(2)[Ru(PiPr(3))('N(2)Me(2)S(2)')](2)] (5). Dinuclear complex 5 could also be obtained directly in an independent synthesis from 1 and N(2)H(2), which was generated in situ by acidolysis of K(2)N(2)(CO(2))(2). Treatment of 6 with CH(2)Cl(2), however, formed a chloromethylated diazene species [[Ru(PiPr(3))('N(2)Me(2)S(2)')]-micro-N(2)H(2)[Ru(Cl)('N(2)Me(2)S(2)CH(2)Cl')]] (9) ('N(2)Me(2)S(2)CH(2)Cl'(2-) =1,2-ethanediamine-N,N'-dimethyl-N-(2-benzenethiolate)(1-)-N'-(2-benzenechloromethylthioether)(1-)]. The molecular structures of 4, 5, and 9 were determined by X-ray crystal structure analysis, and the labile N(2)H(4) complex 6 was characterized by NMR spectroscopy.

[Pro- and supination impairments due to torsional deformities of the radial diaphysis before and after ulna osteotomy]

The aim of this experimental study was to measure the exact influence of torsional deformities at the middle third of the radial shaft before and after osteotomy of the ulnar shaft on the rotation of the forearm. Intact and fresh cadaver specimens were fixed in a newly developed apparatus that allowed free pronation and supination. A ring fixator was applied to the radial shaft with K wires that allowed torsional deformities to be stabilized in steps of 10 degrees. The middle of the radial shaft was osteotomized via a small soft tissue window leaving the other soft tissues including the interosseous membrane intact. Supination and pronation were measured using a goniometer in a standardized fashion. The mean supination value before osteotomy of the radius was 71.6 degrees [standard deviation (SD)15.2 degrees], the mean pronation value was 64.5 degrees (SD 12.4 degrees). Radial osteotomy caused no significant difference in the range of motion prior to creation of torsional deformities. Supination torsional deformities greater than 30 degrees showed a significant loss of pronation and pronation torsional deformities greater than 30 degrees resulted in a significant loss of supination in 14 fresh cadavers, respectively. The amount of mean rotational loss was approximately the same in the respective pronation and supination torsional deformities. In the next step the influence of an ulna osteotomy on the range of motion was evaluated in different torsional deformities. In the four cadavers measured, there was an increase of the range of motion in the direction of the torsional deformity. These values were not significant when compared to values before ulna osteotomy, but there were significant changes to the non deformity (p=0.004 for pronation, p=0.003 for supination). Impairment of range of motion in the opposite direction of the deformity showed a similar appearance as values before ulna osteotomy. Again, there were significant changes to the non deformity (p=0.003 for pronation, p=0.005 for supination).

?Real life? use of sirolimus-eluting coronary stents in Germany

BACKGROUND

Drugeluting stents (DES) are currently judged to be a "break-through" technology for the prevention of restenosis after percutaneous coronary interventions (PCI). However, experience is limited to randomised controlled clinical trials (RCT) in selected lesions and the currently available DES are more expensive compared to conventional "bare" stents. Therefore, actual clinical practice may be very different to RCT.

METHODS

We analysed the data of the German Cypher trade mark Registry, a nationwide registry which was initiated in parallel to the launch of the first DES, the Cypher trade mark sirolimus-eluting coronary stent, in April 2002.

RESULTS

From April 2002 until March 2003, 1638 procedures at 88 hospitals were included in the German Cypher trade mark Registry. The mean inclusion rate per centre and month remained low (<3 procedures/month and participating hospital) during the whole inclusion period. Most patients presented with stable angina pectoris (45.8%); however, 6.4% of patients were treated for a non-ST elevation myocardial infarction, 10.3% of patients for ST elevation myocardial infarction and 1.7% in cardiogenic shock. In patients without ST elevation myocardial infarction, a de novo stenosis was treated in 68.4% of cases, a restenosis in 4.1%, and an in-stent restenosis in 25.5% of cases. Chronic total occlusions were treated in 6.1% of patients. Predilatation was performed in 68.3% of patients and 1.05 +/- 0.35 Cypher trade mark stents were implanted per patient with a median (quartiles) stent length of 18 (13-21) mm. PCI-related death occurred in 0.1% of patients and a Q-wave myocardial infarction in 1.1%. Urgent re-PCI before hospital discharge was performed in 1.3% and urgent bypass surgery in 0.1% of cases.

CONCLUSIONS

The use of the sirolimus-eluting coronary stents in this "real life" registry was found to be safe concerning acute complications. In about one half of the registry patients, the DES was implanted in lesions that were excluded from RCTs.

Establishing an international reference image database for research and development in medical image processing

INTRODUCTION

The lack of comparability of evaluation results is one of the major obstacles of research and development in Medical Image Processing (MIP). The main reason for that is the usage of different image datasets with different quality, size and Gold standard.

OBJECTIVES

Therefore, one of the goals of the Working Group on Medical Image Processing of the European Federation for Medical Informatics (EFMI WG MIP) is to develop first parts of a Reference Image Database.

METHODS

Kernel of the concept is to identify highly relevant medical problems with significant potential for improvement by MIP, and then to provide respective reference datasets. The EFMI WG MIP has primarily the role of a specifying group and an information broker, while the provider user relationships are defined by bilateral co-operation or license agreements.

RESULTS

An explorative database prototype has been implemented using the MySQL database software on the Web. Templates for provider user agreements have been worked out and already applied for own 'pre-RID-MIP' co-operations of the authors.

DISCUSSION AND CONCLUSION

First steps towards a comprehensive reference image database have been done. Issues like funding, motivation, management, provision of Gold standards and evaluation guidelines are to be solved. Due to the interest from research groups and industry the efforts will be continued.

Intensive treatment of coronary artery disease in diabetic patients in clinical practice: results of the MITRA study

Patients with diabetes are at high risk for the development of coronary artery disease and have a significantly impaired prognosis after ST-elevation myocardial infarction (STEMI) as compared with non-diabetic patients. The beneficial effect of pharmaceutical treatment for secondary prevention after STEMI is proven also for diabetics, but little is known about its use in clinical practice. Between June 1994 and December 2000, consecutive patients with STEMI, admitted to hospital within 24 h of symptoms onset, were enrolled into the multicenter MITRA registry in 61 hospitals in Germany. We examined whether there were differences in the frequencies of pharmaceutical secondary prevention after STEMI and in long-term outcomes between diabetics and nondiabetics in 8206 patients who had been discharged alive and followed for a mean period of 17 months. The prevalence of diabetes in 8206 patients discharged alive after acute STEMI was 18%. Diabetics were older and more often female, and more often already had prior myocardial infarction (MI) and stroke than non-diabetics. As chronic discharge medication, diabetics received aspirin and betablockers less often, but more often ACE inhibitors than non-diabetics. The mortality rate 17 months after STEMI was nearly twice as high in diabetics than in non-diabetics (19.1% vs. 10.4%, p<0.01 at univariate analysis; OR=1.50 and 95% CI 1.27-1.77 at multivariate analysis). The combined endpoint of death, MI and stroke occurred in 25.8% of diabetics, but only in 15.8% of non-diabetics ( p<0.01). Long-term treatment with aspirin, betablockers and ACE inhibitors in diabetics was associated with a significant reduction of mortality. Diabetics received intensive pharmaceutical therapy for secondary prevention significantly less often than non-diabetics, although the beneficial effects of this treatment were similar or even more pronounced as compared with non-diabetics. Diabetes was an independent predictor of increased mortality in follow-up after acute STEMI. Intensifying secondary prevention by a more frequent use of established pharmaceutical regimes might improve the prognosis of diabetics after STEMI and prevent cardiovascular and cerebrovascular events.

Comparison of different cardiac markers in monitoring percutaneous coronary interventions with frequent use of stents and gpIIbIIIa-antagonists

Studies from the early 1990s found elevations of creatine kinase (CK) and its isoform CK-MB in 5-30% of patients after PCI, indicating minor myocardial damage. Less is known about the influence of modern improved PCI-techniques on the frequency of elevated cardiac markers and the correlation between different commonly used markers, especially cardiac troponins. From 1997 to 2001, 1486 patients undergoing PCI during the regular working hours were included in the prospective "Ludwigshafen Infarctlet Registry". Myocardial infarction in the past 48 hours was an exclusion criterion. Clinical and procedural data were documented. Follow-up data were obtained from discharge up to one year. PCI-related elevations of troponin T were found in 18%, of total-CK in 11%, of CK-MB in 33% and of myoglobin in 23% of cases. The correlation between the different markers was poor. Compared with troponin T, other markers showed low sensitivity (total-CK 58%, CK-MB 27%, myoglobin 22%) and, especially total-CK, low specificity. Stenting, side branch occlusion or major dissection, complex lesion morphology, gpIIbIIIa-antagonist application, proximal stenosis and unstable angina were independent predictors of an elevated troponin T in multivariate analysis. Due to this weak correlation between more specific and sensitive troponins and the other markers, troponins are preferred in monitoring after PCI. In addition to lesion characteristics, particularly stenting is associated with an increased rate of elevated troponin.