Direkte MR-Arthrographie des Handgelenkes - Wertigkeit im Nachweis von Komplett- und Partialdefekten der intrinsischen Ligamente und des TFCC im Vergleich zur Arthroskopie

PURPOSE

To assess the value of two-compartment magnetic resonance (MR) wrist arthrography in comparison with diagnostic arthroscopy for the evaluation of defects of the triangular fibrocartilage complex (TFCC) and intrinsic ligaments in patients with refractory wrist pain. The direct MR arthrographies were evaluated following arthroscopic classification with consideration of complete and partial defects. The distinction between these types of lesions has clinical implications for treatment procedures such as cast immobilization, arthroscopic debridement, surgical repair or partial intercarpal arthrodesis.

MATERIALS AND METHODS

Seventy-five patients (25 female, 50 males, mean age 38.3 years) who suffered from refractory wrist pain without radiography evidence of carpal instability underwent two-compartment wrist MR arthrography. Under aseptic conditions a solution of gadopentate dimeglumine and iodinated contrast agent (concentration 2.5 mmol/l) was injected into the radiocarpal and midcarpal joints under fluoroscopy guidance. Using a scanner of 1.5 T field strength and a wrist-coil following sequences were acquired: coronary and sagittal T (1)-weighted spin-echo (SE) sequences (TR 500 ms, TE 25 ms, matrix 512 x 512.3 mm) and coronary fast low angle shot (FLASH) 3D sequences (TR 24 ms, TE 11 ms, matrix 256 x 256, 1.5 mm, flip angle 50 degrees). All patients underwent subsequent arthroscopy of the wrist. The direct MR arthrographies were evaluated retrospectively by two observers experienced in the diagnosis of wrist pathology. They were not aware of the clinicial, arthrographic and arthroscopic findings. Pathology of the scapholunate ligament was classified according to the guidelines of the German Society of Hand Surgery (DGH), lesions of the lunotriquetral ligament according to Hempfling and lesions of the TFCC according to Palmer.

RESULTS

Twenty-five complete and 47 partial defects were detected arthroscopically (TFCC: 21/20, scapholunate ligament: 3/18, lunotriquetral ligament: 1/9). The TFCC showed a higher prevalence for degenerative lesions (11 type 2C-lesions and 20 type 2A/B lesions) than for traumatic lesions (5 type 1A lesions, 5 type 1D lesions). For direct MR arthrography, the obtained sensitivities and specificities in assessing complete defects were 96 % and 99.6 % (T (1)-weighted SE) and 92 % and 100 % (FLASH 3D), respectively. For all partial defects, sensitivities and specificities were 68.1 % and 93.3 % (T (1)-weighted SE) and 63 % and 96.1 % (FLASH 3D), respectively. For depicting partial defects of the scapholunate ligament the T (1)-weighted SE sequence (83.3/95.5 %) was superior to the FLASH 3D sequence (64.7/96.6 %), p < 0.05. For the evaluation of the TFCC (T (1)-weighted SE: 65/94.4 %, FLASH 3D: 70/94.6 %) and the lunotriquetral ligament (T (1)-weighted SE: 44/89.4 %, FLASH 3D: 44 /96.7 %), direct MR arthrography showed an insufficient correlation with arthroscopy.

CONCLUSION

Direct MR arthrography proved to be of equal value compared with diagnostic arthroscopy in detecting complete defects of the intrinsic ligaments and the TFCC. The method has the potential of replacing diagnostic arthroscopy for the evaluation of the intrinsic ligaments and the TFCC. The T (1)-weighted SE sequence appeared to be superior to the FLASH 3D sequence in evaluating partial defects of the scapholunate ligament. Direct MR arthrography did not reliably detect partial defects of the TFCC and the lunotriquetral ligament.

[Too many heart catheter procedures in Germany ?]

BACKGROUND AND OBJECTIVE

Absolute numbers of cardiovascular procedures are higher in Germany as compared to other European countries. This fact is used as an argument for overuse. Therefore other indicators of an inappropriate use of these resources should be of interest.

PATIENTS AND METHODS

The relationship between diagnostic cardiac catheterisations and consequent revascularisation procedures were compared in 8 European countries. In addition the indication criteria for cardiac catheterisations were reviewed in a German registry of 205.581 consecutive inpatients.

RESULTS

Revascularisation procedures after diagnostic catheterisations in 8 countries range from 39,1 % to 57,9 %. Germany reaches 43,2 %. A relation between absolute numbers of diagnostic and percent subsequent revascularisation procedures does not exist. In a German registry the following indications for cardiac catheterisation could be identified: Acute Coronary Syndrome 22,9 %. Angina pectoris according to the Canadian Cardiac Society classification was present: CCS II/III in 80,3 %, CCS IV in 17,2 %. An exercise test was performed in 43 %. Final diagnoses were: significant coronary disease 69,5 %, exclusion of disease 9,4 %, lesions < 50 % 9 %, other cardiac disease 12,1 %.

CONCLUSION

Absolute numbers cannot be used as an indicator of overuse of cardiovascular procedures. Instead standards for data acquisition should be established on European, national and regional levels. In addition a validation procedure for criteria has to be developed in order to judge the appropriateness of indications for invasive cardiac procedures in different health care systems.

Small differences in non-fatal in-hospital reinfarctions complicating acute myocardial infarction as observed in current randomised controlled trials will not essentially influence long-term mortality

BACKGROUND

Recent randomized controlled trials (RCT) comparing different nonmechanical reperfusion strategies in patients with acute ST elevation myocardial infarction (AMI) (The GUSTO V, the ASSENT 3 and the HERO 2 trials) reported no differences in mortality, but lower nonfatal reinfarction rates in each best treatment arm during the hospital stay.

METHODS

We analyzed the prospective observational Maximal Individual The rapy in Acute Myocardial Infarction (MITRA) data base selecting AMI patients similar to the RCT patients, to determine whether the observed differences in reinfarction rates will have an influence on longterm mortality.

RESULTS

Out of 6737 patients included in MITRA between 1994 and 2000, 2109 (31%) fulfilled the selection criteria simulating the RCTs and were followed up for a median of 18 (quartiles: 16/22) months. Mortality at 1-year after discharge was 6.8% (95%CI: 2.3-11.3%) in patients with versus 4.4% (95%CI: 3.5-5.3%) in patients without a non-fatal reinfarction (absolute difference 2.4%, p = 0.04 by log rank test). Transferred to the results of the RCTs, this difference would require more than 1 million patients in each treatment arm of the RCTs to show significant differences in long-term mortality.

CONCLUSION

Non-fatal in-hospital reinfarctions were associated with a higher mortality during the 18 month follow-up in MITRA. However, because the observed differences in the rates of non-fatal in hospital reinfarctions between the treatment arms in the GUSTO V, the ASSENT 3 and the HERO 2 trials were very small, our data make it very improbable that they will result in lower 1-year mortality rates.

Two year follow-up in 643 patients with non-invasively unexplained syncope and therapy guided by electrophysiologic study

AIM

Although it has become standard practice to perform electrophysiologic studies in patients with unexplained syncope, limited information exists on prognosis after therapy guided by electrophysiologic studies.

METHODS AND RESULTS

Electrophysiologic studies were performed in 643 patients with unexplained syncope. Electrophysiologic studies revealed conduction abnormalities and tachyarrhythmias accounting for syncope in 35% of patients. An ejection fraction </= 40%, a PR-interval > 2 s and injury are helpful parameters in predicting a positive electrophysiologic study. There was no difference regarding cumulative 2-year survival rate after therapy guided by positive electrophysiologic study compared to patients with negative electrophysiologic study. The cumulative 2-year survival free-of-syncope rate was significantly higher after therapy guided by electrophysiologic study compared to patients with negative electrophysiologic findings-for patients with organic heart disease (71.3% vs 48.5%, p < 0.001) and patients without disease (91.3% vs. 65.2%, p < 0.001). Using a logistic regression model, a positive electrophysiologic study was associated with a favorable outcome; multiple syncopal events or organic heart disease were associated with an unfavorable outcome.

CONCLUSION

The cumulative overall 2-year surival free-of-syncope rate is significantly higher in patients after therapy guided by electrophysiologic study compared to patients with negative electrophysiologic findings.

Diagnosis, prescription, and prognosis of a bell-state filter by quantum process tomography

We apply the techniques of quantum process tomography to characterize errors and decoherence in a prototypical two-photon operation, a singlet-state filter. The quantum process tomography results indicate a large asymmetry in the process and also the required operation to correct for this asymmetry. We quantify residual errors and decoherence of the filtering operation after this modification.

Beneficial effects of human serum albumin on stability and functionality of alginate microcapsules fabricated in different ways

A key engineering challenge in designing microcapsules made from biocompatible alginate is maintaining adequate exchange of nutrients and oxygen between the entrapped cells and the environment, while simultaneously avoiding swelling and subsequent failure of the microcapsule. Approval for the use of alginate in pharmaceutical and/or biomedical applications also strictly requires that the components of the microcapsule material must meet the safety criteria of the ASTM and FDA. Incorporation of foetal calf serum (FCS) into the microcapsules for stabilization is not in accordance with the guidelines affirmed by these organizations. FCS should be substituted by microcapsule-stabilizing additives that are medically approved. In this communication, it is shown that 10% FCS can be replaced by 1% human serum albumin (i.e. by an agent for which medical approval is granted) without compromising effects on long-term in vitro stability. Furthermore, it is demonstrated that human serum albumin (HSA) significantly enhances cell survival and, particularly, insulin secretion of encapsulated rat islets over a time period of 3 weeks when incubated in culture medium. Thus, HSA-stabilized microcapsules made from UHV(Lam) alginate are apparently a promising system for immunoisolation of cells, particularly when alginate is cross-linked by injection of BaCl(2) crystals into the alginate droplets. Slight adjustments of the alginate concentration can tailor the microcapsule permeability to the released therapeutic factor.

Size of pancreatic islets of Langerhans: a key parameter for viability after cryopreservation

Large amounts and excellent viabilities of pancreatic islets are prerequisites for recent advances in islet transplantation. Cryopreservation has been shown to enlarge transplanted cell mass, but has been accompanied by reduced viability. In this study rat pancreatic islets were differentiated into small (<200 micro m), medium (200-400 micrometers) and large (>400 micrometers) categories and their susceptibilities to different freezing conditions were evaluated: concentration of cryoprotectant (0.7-3.1 M), equilibration (15 vs. 45 min, 22 degrees C vs. on ice) and post-thaw removal of cryoprotectant (15 vs. 30 min, stepwise vs. one-step). The most prominent finding was a negative correlation between islet size and viability observed in non-frozen islets to a minor degree (r=-0.44) and significantly enhanced after cryopreservation (r<-0.8). The concentration of cryoprotectant showed the most significant influence on viability affecting small, medium and large islets. Different techniques of equilibration with the cryoprotectant resulted in significant changes of islet viability of medium islets, whereas small and large islets were unaffected. For different techniques of removal of the cryoprotectant, no significant influence on viabilities was found. We conclude that large islets represented a highly susceptible population concerning damage due to cryopreservation.

Effectiveness of the glycoprotein IIb/IIIa antagonist abciximab during percutaneous coronary interventions (PCI) in clinical practice at a single high-volume center

OBJECTIVE

Randomized controlled trials (RCTs) showed that the glycoprotein (GP) IIb/IIIa antagonist abciximab is able to reduce ischemic complications during percutaneous transluminal coronary interventions (PCIs). Its effectiveness in daily clinical practice in unselected patients remains to be determined.

DESIGN, SETTING AND PATIENTS

From 7/1997 until 12/2000, 3310 PCIs were performed at the Heart Center Ludwigshafen. Out of them, 1076 (32.5%) patients were nonrandomly treated with a GP IIb/ IIa antagonist. Patients who were treated with abciximab were matched with patients not treated with abciximab. The matching procedure resulted in 590 pairs of patients.

RESULTS

Patients treated with abciximab were more likely to have a history of former PCI (13.7% versus 8.8%, p=0.008) or coronary artery bypass surgery (19.2% versus 12.8%, p=0.003). There were no differences in concomitant diseases, left ventricular function, number of vessels diseased or target vessel. However, patients treated with abciximab had a higher rate of more complex stenosis (> or =B2; 94.4% versus 80.7%, p<0.001) and a longer x-ray exposition (median 486 s versus 422 s, p<0.001). Treatment with abciximab was associated with a significantly lower incidence of the combined endpoint of death, reinfarction or stroke during the hospital stay (2.4% versus 4.4%, p=0.039). This was confirmed after adjustment for confounding parameters (p=0.034). There was no increase in the rate of severe bleeding in the abciximab group (p=0.347). After one year the rates for the combined endpoint were 8.5% in the control group and 6.2% in the abciximab group (univariate analysis, p=0.134; multivariate analysis, p=0.143).

CONCLUSION

Treatment with abciximab during PCI in daily clinical practice at a high volume center in patients with a high rate of acute coronary syndromes seems to be as effective as shown in RCTs.

Fabrication of homogeneously cross-linked, functional alginate microcapsules validated by NMR-, CLSM- and AFM-imaging

Cross-linked alginate microcapsules of sufficient mechanical strength can immunoisolate cells for the long-term treatment of hormone and other deficiency diseases in human beings. However, gelation of alginate by external Ba(2+) (or other divalent cations) produces non-homogeneous cross-linking of the polymeric mannuronic (M) and guluronic (G) acid chains. The stability of such microcapsules is rather limited. Here, we show that homogeneous cross-linking can be achieved by injecting BaCl(2) crystals into alginate droplets before they come into contact with external BaCl(2). The high effectiveness of this crystal gun method is demonstrated by confocal laser scanning microscopy and by advanced nuclear magnetic resonance imaging. Both techniques gave clear-cut evidence that homogeneous cross-linkage throughout the microcapsule is only obtained with simultaneous internal and external gelation. Atomic force microscopy showed a very smooth surface topography for microcapsules made by the crystal gun method, provided that excess Ba(2+) ions were removed immediately after gelation. In vitro experiments showed greatly suppressed swelling for crystal gun microcapsules. Even alginate extracted from Lessonia nigrescens (highly biocompatible) yielded microcapsules with long-term mechanical stability not hitherto possible. Encapsulation of rat islets, human monoclonal antibodies secreting hybridoma cells and murine mesenchymal stem cells transfected with cDNA encoding for bone morphogenetic protein (BMP-4) revealed that injection of BaCl(2) crystals has no adverse side effects on cell viability and function. However, the release of low-molecular weight factors (such as insulin) may be delayed when using alginate concentrations in the usual range.

[Reliability and general practice value of 2 rapid Streptococcus A tests]

Rapid streptococcal-A-antigen detection assays have good specificity (over 90 percent) but moderate sensitivity (between 80 and 90 percent), when the tests are compared with a standard throat culture. Contradictory results have been found for one of the more recent tests, the optical immune assay Strep A OIA MAX, while for 6 years, we have been using the immune assay Strep A Plus. Results of the optical immunoassay and the conventional immune assay Strep A Plus were compared in 65 patients with acute pharyngitis. A standard culture was used as reference and confirmed by enhanced broth culturing and nucleic acid hybridization assay (Gen-Probe) when the two detection assays produced contradictory results. While both assays were equally sensitive (78.3%), Strep A OIA MAX and Strep A Plus had a similar specificity of 95.2% and 100%, respectively. Four and nine steps were required for Strep A Plus and for Strep A OIA MAX test procedures, respectively with results being available in 4-5 min and in 9-10 min, respectively. We conclude that both rapid immunoassays have a similar reliability while the handling of the Strep A Plus is much simpler than the handling of the Strep A OIA MAX. Neither rapid immunoassays are sensitive enough to eliminate the need for backup cultures.

Influence of inhaled iloprost on transpulmonary gradient of big endothelin in patients with pulmonary hypertension

BACKGROUND

The pulmonary circulation is an important site for the production and clearance of endothelin (ET)-1, a potent vasoactive and mitogenic peptide. In healthy individuals, 40% to 50% of circulating ET-1 is removed on each passage through the lungs resulting in an arteriovenous ratio of <1, whereas many patients with pulmonary arterial hypertension (PAH) have ratios >1, indicating reduced clearance or increased release of endothelin. The influence of inhaled prostanoids on endothelin clearance is unknown.

METHODS AND RESULTS

In a prospective investigation, plasma concentrations of big endothelin-1 (big ET-1, Elisa) were measured in 15 patients with pulmonary hypertension undergoing right heart catheterization with iloprost inhalation (4 m, 11 f, aged 35 to 75 years, mean pulmonary arterial pressure (PAPm) 54+/-2.3 mm Hg, pulmonary vascular resistance (PVR) 1061+/-141 dyn x sec x cm(-5)). There was a significant transpulmonary gradient for big ET-1 with 31% +/-11% higher concentrations in the radial artery than in the pulmonary artery (P<0.001). After inhalation of iloprost a significant decrease in the AV-ratio from 1.31+/-0.11 to 0.92+/-0.06 (P<0.007) was observed. The pulmonary net release of 3.10+/-0.65 pmol/min big ET-1 at baseline decreased to -1.24+/-1.32 pmol/min (P=0.013) within 15 minutes indicating a restored balance. Patients under long-term treatment with iloprost (n=7) tended to have a lower net release and AV-ratio for big ET-1 than patients without pretreatment.

CONCLUSION

An increase in pulmonary clearance of big-ET could be a mechanism contributing to the beneficial effects of inhaled prostanoids in the treatment of PAH.

Usefulness of a non-invasive scoring system in predicting the outcome of electrophysiologic studies in non-invasively unexplained syncope

BACKGROUND

An electrophysiologic study is a useful method to clarify the cause of non-invasively unexplained syncope in 18-60% of patients. However, it is invasive with possible procedure-related complications. Therefore, it would be helpful to identify patients in whom an electrophysiologic study is useful for diagnosis of syncope.

METHODS

Patients with unexplained syncope were prospectively enrolled in a registry, if an electrophysiologic study was performed. The study group comprised of 643 consecutive patients.

RESULTS

The electrophysiologic study revealed conduction abnormalities and tachyarrhythmias accounting for syncope in 35% of patients. Using a logistic regression model, history of injury during syncope (p<0.001), ejection fraction < or =40% (p=0.03), and PR interval >0.2 s (p=0.001) were independent predictors of an abnormal electrophysiologic study. These three clinical and easily measurable variables were entered into a scoring system. The maximal score consisted of 3 points. A score of >1 predicts a positive electrophysiologic study result in more than 70% of patients with non-invasively unexplained syncope.

CONCLUSION

Electrophysiologic abnormalities were detected in 35% of patients with unexplained syncope. A history of injury, ejection fraction < or =40% and a PR interval >200 ms were independent predictors for a positive electrophysiologic study.

The short-term effects of fasting on the neuroendocrine system in patients with chronic pain syndromes

It is commonly reported that short term fasting leads to mood enhancement and emotional harmonisation. We investigated psychosocial well-being and the neuroendocrine response, assessed by nightly urinary excretion of cortisol and catecholamines, in 28 inpatients with chronic pain syndromes during and after a one-week modified fast. Twenty-two of the patients (51.4 +/- 2.7 years, BMI 26.8 +/- 1.0 kg/m2) participated in a 7-day fast with daily intake of 300 kcal/day, six control patients (47.5 +/- 4.0 years; BMI 22.9 +/- 1.1 kg/m2) received a vegetarian-based diet. With fasting significant increases of the urinary concentration of noradrenaline (17.8 +/- 3.0-27.8 +/- 3.8 microg/ml), adrenaline (1.5 +/- 0.2-3.4 +/- 0.7 microg/ml) and cortisol (26.1 +/- 3.7-40.7 +/- 6.1 microg/ml) were observed, whereas controls showed no significant endocrine changes. The neuroendocrine response to fasting was pronounced in younger subjects (age <50 years) and in the presence of a BMI >25 kg/m2, moreover the increase in cortisol excretion was significantly higher in subjects with lower baseline cortisol levels. Mood and well-being increased non-significantly in both groups. Fasting was well tolerated, and regarded as beneficial by most fasting patients. Our results show that short-term fasting leads to neuroendocrine activation and may suggest that the extent of this response is dependent on the individual metabolic and endocrine state at baseline.

Prognostic value of non-sustained ventricular tachycardias after acute myocardial infarction in the thrombolytic era: importance of combination with frequent ventricular premature beats

PURPOSE

of this study was to re-evaluate the association between ventricular arrhythmias and long-term mortality after acute myocardial infarction (AMI) in the thrombolytic era.

METHODS

MITRA (maximal individual therapy in patients with AMI) is a multicenter registry of 54 hospitals in Germany investigating patients with AMI.

RESULTS

2420 patients received Holter ECG. Positive Holter ECG was defined: > or =10 ventricular premature beats (VPB)/h, or > or =4 couplets/d, or > or =1 non-sustained ventricular tachycardia (nsusVT)/d, or their combination. Mortality rates (median 17 months) were 6.5% without ventricular arrhythmias, with > or =10 VPB/h 15.2% and with the combination of > or =10 VPB/h plus either > or =4 couplets/d or > or =1 nsusVT/d 23.4%. In multivariate analysis, none of the ventricular arrhythmias alone correlated with mortality. There was a significant association between mortality and the combination of > or =10 VPB/h plus > or =4 couplets/d (OR 2.3) or > or =10 VPB/h plus > or =1 nsusVT/d (OR 2.8).

CONCLUSION

Non-sustained VTs are only associated with poor prognosis if combined with frequent VPBs.

Practice parameter: treatment of the child with a first unprovoked seizure: Report of the Quality Standards Subcommittee of the American Academy of Neurology and the Practice Committee of the Child Neurology Society

The Quality Standards Subcommittee of the American Academy of Neurology and the Practice Committee of the Child Neurology Society develop practice parameters as strategies for patient management based on analysis of evidence regarding risks and benefits. This parameter reviews published literature relevant to the decision to begin treatment after a child or adolescent experiences a first unprovoked seizure and presents evidence-based practice recommendations. Reasons why treatment may be considered are discussed. Evidence is reviewed concerning risk of recurrence as well as effect of treatment on prevention of recurrence and development of chronic epilepsy. Studies of side effects of anticonvulsants commonly used to treat seizures in children are also reviewed. Relevant articles are classified according to the Quality Standards Subcommittee classification scheme. Treatment after a first unprovoked seizure appears to decrease the risk of a second seizure, but there are few data from studies involving only children. There appears to be no benefit of treatment with regard to the prognosis for long-term seizure remission. Antiepileptic drugs (AED) carry risks of side effects that are particularly important in children. The decision as to whether or not to treat children and adolescents who have experienced a first unprovoked seizure must be based on a risk-benefit assessment that weighs the risk of having another seizure against the risk of chronic AED therapy. The decision should be individualized and take into account both medical issues and patient and family preference.

A simulated annealing approach to define the genetic structure of populations

We present a new approach for defining groups of populations that are geographically homogeneous and maximally differentiated from each other. As a by-product, it also leads to the identification of genetic barriers between these groups. The method is based on a simulated annealing procedure that aims to maximize the proportion of total genetic variance due to differences between groups of populations (spatial analysis of molecular variance; samova). Monte Carlo simulations were used to study the performance of our approach and, for comparison, the behaviour of the Monmonier algorithm, a procedure commonly used to identify zones of sharp genetic changes in a geographical area. Simulations showed that the samova algorithm indeed finds maximally differentiated groups, which do not always correspond to the simulated group structure in the presence of isolation by distance, especially when data from a single locus are available. In this case, the Monmonier algorithm seems slightly better at finding predefined genetic barriers, but can often lead to the definition of groups of populations not differentiated genetically. The samova algorithm was then applied to a set of European roe deer populations examined for their mitochondrial DNA (mtDNA) HVRI diversity. The inferred genetic structure seemed to confirm the hypothesis that some Italian populations were recently reintroduced from a Balkanic stock, as well as the differentiation of groups of populations possibly due to the postglacial recolonization of Europe or the action of a specific barrier to gene flow.