Strategic Ambiguity: The Pragmatic Utopianism of Daniel Callahan's "Bioethics as a Discipline"

This article highlights the continuing relevance of a classic bioethical text, "Bioethics as a Discipline," published by the Hastings Center's cofounder Daniel Callahan in 1973. Connecting the text's programmatic recommendations with later reflections and interventions Callahan wrote about the development of bioethics illuminates how the vision Callahan established and the reality this vision helped create were interrelated-just not in the way Callahan had hoped for. Although this portrait relies on an individual perception of the development of bioethics, it might nevertheless, through its unique linkage of different bioethical temporalities, contribute to a broader reassessment of what bioethics became and why.

Ethicizing history. Bioethical representations of Nazi medicine

The article presents and analyzes different approaches of U.S. bioethicists in comprehending the Nazi medical crimes after 1945. The account is divided into two sections: one dealing with discussions on research ethics and the Nuremberg Code up until the 1970s and the other ranging from the 1970s to the present and highlighting bioethics' engagement with Nazi analogies. The portrayal of different bioethical scholars, institutions, and documents-most notably Henry K. Beecher, Jay Katz, the Belmont Report, the Hastings Center, Arthur L. Caplan, and Robert M. Veatch-provides a nuanced interpretation of the motives that bioethicists held and the strategies that they applied to establish an understanding of the Nazi medical crimes and their relation to contemporary bioethical issues. In this, the different approaches shared a common goal: To integrate the Nazi medical crimes into an ethical framework by means of selective acknowledgments and representation of their history.

Kompetenzorientierte Ethik-Lehre im Medizinstudium

Die anstehenden Reformen des Medizinstudiums nach den Vorgaben des Masterplans 2020 sehen eine kompetenzorientierte Neustrukturierung des Medizinstudiums vor. Dieser Artikel zielt darauf ab, Perspektiven aufzuzeigen, wie der Ethik-Unterricht im Medizinstudium noch stärker kompetenzorientiert ausgerichtet werden kann. Er verfolgt damit das Ziel, den Kompetenzbegriff für die Medizinethik greifbarer und für die Gestaltung der Medizinethik-Lehre nutzbar zu machen. Kompetenzen verstehen wir als Handlungsdispositionen, die zur Problemlösung befähigen. Durch Übertragung des Konzepts der moralischen Intelligenz auf das moralische Handeln von Ärzt:innen in der Patient:innenversorgung spezifizieren wir fünf ethisch-moralische Kompetenzen, die für moralisch angemessenes, ethisch reflektiertes professionelles Handeln angehender Ärzt:innen angelegt sein müssen: 1.) die Fähigkeit zur Ausgestaltung eines professionellen moralischen Kompasses, 2.) die Ausrichtungsbereitschaft an professionsethischen Normen und Werten, 3.) die Fähigkeit zur Wahrnehmung moralischer Dimensionen ärztlichen Handelns, 4.) die Fähigkeit zum moralischen Urteilen anhand ethischer Überlegungen über das richtige Handeln und 5.) die Realisierungsbereitschaft ethisch begründeten Handelns. Wir illustrieren ihre Bedeutung für die Medizinethik-Lehre am Beispiel des Unterrichts zur Ethik der Patient:innenversorgung (u. a. Klinische Ethik) im Medizinstudium. Unsere Konzeptualisierung ethisch-moralischer Kompetenzen kann dazu verwendet werden, konkrete Lehrangebote kompetenzorientiert auszugestalten. Unser Vorgehen kann analog auf andere Bereiche der Lehre von Ethik im Gesundheitswesen übertragen werden.

After Pettenkofer. Munich's Institute of Hygiene and the long shadow of National Socialism, 1894-1974

The year 2019 marked the 140th anniversary of the inauguration of the first Institute of Hygiene, which was established for Max von Pettenkofer at the university of Munich. After Pettenkofer, his successors tried to advance the science of hygiene each in their own specific way, highlighting different aspects and trying to relate them to Pettenkofer's legacy: Max von Gruber promoted an understanding of hygiene which was more and more tied to constitutional and racial factors, Karl Kisskalt tried to revise a perceived bacteriological paradigm, and Hermann Eyer focused on preventive public health measures. All of those influences had a more or less explicit and distinct connection to the general development of German medicine in the first half of the 20th century and its culmination in National Socialist crimes. The history of Munich's Institute of Hygiene after Pettenkofer illustrates the differing scientific and ideological paths this development pursued by the examples of its three long-term protagonists and their relationship to National Socialism.

Heterogeneous Clusters of Phthalocyanine and Water Prepared and Probed in Superfluid Helium Nanodroplets

Superfluid helium nanodroplets comprised of thousands to millions of helium atoms can serve as a reactor for the synthesis of heterogeneous molecular clusters at cryogenic conditions. The cluster synthesis occurs via consecutive pick-up of the cluster building blocks by the helium droplet and their subsequent coalescence within the droplet. The effective collision cross section of the building blocks is determined by the helium droplet size and thus exceeds by orders of magnitude that of a reactive collision in the gas phase. Moreover, the cryogenic helium environment (at 0.38 K) as a host promotes the formation of metastable cluster configurations. The question arises as to the extent of the actual involvement of the helium environment in the cluster formation. The present study deals with clusters of single phthalocyanine (Pc) molecules with single water molecules. A large fluorophore such as Pc offers several sites where the water molecule can attach. The resulting isomeric variants of the Pc-H₂O complex can be selectively identified by electronic spectroscopy. We compare the experimental electronic spectra of the Pc-H₂O complex generated in superfluid helium nanodroplets with the results of quantum-chemical calculations on the same cluster but under gas-phase conditions. The number of isomeric variants observed in the helium droplet experiment comes out the same as that obtained from our gas-phase calculations.

Soil net nitrogen mineralisation across global grasslands

Soil nitrogen mineralisation (Nmin), the conversion of organic into inorganic N, is important for productivity and nutrient cycling. The balance between mineralisation and immobilisation (net Nmin) varies with soil properties and climate. However, because most global-scale assessments of net Nmin are laboratory-based, its regulation under field-conditions and implications for real-world soil functioning remain uncertain. Here, we explore the drivers of realised (field) and potential (laboratory) soil net Nmin across 30 grasslands worldwide. We find that realised Nmin is largely explained by temperature of the wettest quarter, microbial biomass, clay content and bulk density. Potential Nmin only weakly correlates with realised Nmin, but contributes to explain realised net Nmin when combined with soil and climatic variables. We provide novel insights of global realised soil net Nmin and show that potential soil net Nmin data available in the literature could be parameterised with soil and climate data to better predict realised Nmin.

[Blockade of the distal sciatic nerve in the supine position with a newly developed ultrasound probe holder]

Sonographically controlled blockade of the distal sciatic nerve is usually performed by placing the ultrasound probe on the dorsal side of the thigh. This requires positioning maneuvers (prone or side positioning) of the patient as well as additional assistance. In order to avoid these positioning maneuvers, a positioning aid with integrated ultrasound probe holder has been developed and its practicability was examined on patients with lower limb surgery. The sonographically controlled block of the sciatic nerve was performed with the patient under general anesthesia and in a supine position with the help of the new positioning aid with an integrated ultrasound probe holder. A total of >100 patients were treated, who underwent elective lower leg, ankle or foot surgery with a continuous blockade of the distal sciatic nerve using catheters for postoperative analgesia. The advantages are easy performance, hands-free needle movement and catheter placement. The disadvantages might be the need for in-plane catheter placement and a fixed ultrasound angle.

[Minimally invasive proximal hamstring insertion repair]

OBJECTIVE

Minimally invasive endoscopic reconstruction of avulsion injuries of the proximal hamstring insertion to prevent persistent weakness and pain.

INDICATIONS

Fresh retracted 2‑ and 3‑tendon avulsion injuries of the proximal hamstring insertion. Unsuccessful conservative therapy of less retracted injuries. Painful chronic partial lesions of the proximal hamstring insertion.

CONTRAINDICATIONS

Major comorbidities with an increased surgical risk, older patients with low functional demands. Chronic injuries without functional deficits.

SURGICAL TECHNIQUE

Endoscopic refixation using suture anchors after freshening the footprint on the tuber ischiadicum. Visualization of the sciatic nerve to ensure its protection.

POSTOPERATIVE MANAGEMENT

Partial loading with a knee brace for strict prevention of combined knee extension and hip flexion for 4-6 weeks. Start of active exercise and stretching 8 weeks postoperatively.

RESULTS

From 2014-2016, 12 patients were treated with an endoscopic reconstruction of the proximal hamstring insertion. After a mean follow-up of 25 months (range 16-34 months), an average visual analog scale (VAS) of 0 (range 0-2) and an average subjective assessment of function (Subjective Hip Value) of 94% (range 80-100%) were found. No neurovascular complications were seen in our collective, in particular no evidence of hypesthesia in the area of the posterior femoral cutaneous nerve. All patients were able to return to their original level of activity (Tegner Activity Scale 5.2 preoperatively vs. 5.2 postoperatively), while the average time until return to sport was 6.5 months (range 3-12 months). All patients were able to return to their original occupation.

[Double standards : The Medical Student Kurt Gerstein and the History of Anatomical Body Procurement in Germany]

This article presents a hitherto unknown memorandum authored by Kurt Gerstein, the Confessing Church's resistance fighter and witness to the Holocaust. In this memorandum, submitted to the Reich Ministry of the Interior in April 1938, Gerstein deals extensively with the contemporary system of anatomical body procurement, its roots and predicaments. Putting the memorandum into the wider context of his discordant life allows a gap to be closed in Gerstein's biography, whereby his relationship with medicine presented a means of moral reorientation between a Christian requirement and the National Socialist reality. Moreover, the positions Gerstein explicates in the memorandum, his criticism of the system of anatomical body procurement and his proposals for reform, make it possible to retrace the history of anatomy in Germany. In particular, the memorandum's inconsistency, which on the one hand, calls for a comprehensive respect for the dead, but on the other hand, excludes a certain group - executed prisoners - from this deference, reveals the basic conflict of how anatomy deals with the human body. It also illustrates Gerstein's inner conflict with regard to his moral positioning under National Socialist conditions.

Munich anatomy and the distribution of bodies from the Stadelheim execution site during National Socialism

During the reign of National Socialism (NS) anatomical institutes regularly received bodies of executed prisoners in steadily increasing numbers. After 1939, the execution site at Stadelheim prison in Munich supplied not only Munich anatomy but also the institutes in Erlangen, Innsbruck and Würzburg. Due to the disappearance of the Munich body journals, the exact dimension and procedure of body procurement from Stadelheim remained unknown for 70 years. After consultation of a wide range of sources, including rediscovered fragments of the body journals, it is now possible to give an almost comprehensive account of the developments. This article deals with the attempts at recovering information on body procurement from Stadelheim prison during the NS period, which already indicated the significance of Munich anatomy in organizing the distribution of bodies. Thereafter, it addresses the number and distinct groups of Stadelheim prisoners, executed and delivered to the four anatomical institutes, the differences in the handling of their bodies, and the extent to which in particular Munich anatomy profited from the massive increase in executions. Finally, it unveils the role of the Munich Anatomical Institute in distributing those bodies among the anatomies during the Second World War, making it not only the main beneficiary but also the interim center of this process.

Tissue engineering and regenerative approaches to improving the healing of large bone defects

Despite the high innate regenerative capacity of bone, large osseous defects fail to heal and remain a clinical challenge. Healing such defects requires the formation of large amounts of bone in an environment often rendered hostile to osteogenesis by damage to the surrounding soft tissues and vasculature. In recent years, there have been intensive research efforts directed towards tissue engineering and regenerative approaches designed to overcome this multifaceted challenge. In this paper, we describe and critically evaluate the state-of-the-art approaches to address the various components of this intricate problem. The discussion includes (i) the properties of synthetic and natural scaffolds, their use in conjunction with cell and growth factor delivery, (ii) their vascularisation, (iii) the potential of gene therapies and (iv) the role of the mechanical environment. In particular, we present a critical analysis of where the field stands, and how it can move forward in a coordinated fashion.

[Sarcoma of the spleen with MDM2 expression]

Primary sarcomas and sarcoma metastases are a rarity in the spleen. We report on the case of a 69-year-old male patient presenting with unclear abdominal symptoms and computed tomography (CT) revealed a tumor mass in the spleen. Histologically the tumor mass predominantly showed features of a spindle cell sarcoma with lymphoid infiltrates. The expression and amplification of MDM2 could be demonstrated by means of immunohistochemistry and fluorescence in situ hybridization (FISH). Furthermore, staging examinations did not reveal indications of any other primary tumors. These preliminary findings were suggestive of a dedifferentiated liposarcoma; however, in the further diagnostic work-up the tumor showed strong expression of CD21 and CD23 and was ultimately diagnosed as a follicular dendritic cell sarcoma (FDCS). The case emphasizes that MDM2 expression represents a possible pitfall in the diagnosis of spindle cell tumors. The differential diagnostic distinction between FDCS and a dedifferentiated liposarcoma is discussed.

Gemcitabine plus sorafenib versus gemcitabine alone in advanced biliary tract cancer: a double-blind placebo-controlled multicentre phase II AIO study with biomarker and serum programme

BACKGROUND

Since sorafenib has shown activity in different tumour types and gemcitabine regimens improved the outcome for biliary tract cancer (BTC) patients, we evaluated first-line gemcitabine plus sorafenib in a double-blind phase II study.

PATIENTS AND METHODS

102 unresectable or metastatic BTC patients with histologically proven adenocarcinoma of gallbladder or intrahepatic bile ducts, Eastern Cooperative Oncology Group (ECOG) 0-2 were randomised to gemcitabine (1000 mg/m2 once weekly, first 7-weeks+1-week rest followed by once 3-weeks+1-week rest) plus sorafenib (400 mg twice daily) or placebo. Treatment continued until progression or unacceptable toxicity. Tumour samples were prospectively stained for sorafenib targets and potential biomarkers. Serum samples (first two cycles) were measured for vascular endothelial growth factors (VEGFs), vascular endothelial growth factor receptor 2 (VEGFR-2) and stromal cell-derived factor 1 (SDF1)α by enzyme-linked immunosorbent assay (ELISA).

RESULTS

Gemcitabine plus sorafenib was generally well tolerated. Four and three patients achieved partial responses in the sorafenib and placebo groups, respectively. There was no difference in the primary end-point, median progression-free survival (PFS) for gemcitabine plus sorafenib versus gemcitabine plus placebo (3.0 versus 4.9 months, P=0.859), and no difference for median overall survival (OS) (8.4 versus 11.2 months, P=0.775). Patients with liver metastasis after resection of primary BTC survived longer with sorafenib (P=0.019) compared to placebo. Patients who developed hand-foot syndrome (HFS) showed longer PFS and OS than patients without HFS. Two sorafenib targets, VEGFR-2 and c-kit, were not expressed in BTC samples. VEGFR-3 and Hif1α were associated with lymph node metastases and T stage. Absence of PDGFRβ expression correlated with longer PFS.

CONCLUSION

The addition of sorafenib to gemcitabine did not demonstrate improved efficacy in advanced BTC patients. Biomarker subgroup analysis suggested that some patients might benefit from combined treatment.

[History of anatomy - academy history. On the development of scientific academies in the Third Reich exemplified by anatomy]

Research on the history of National Socialism has for decades ignored the German academies of sciences as well as the subject of anatomy. This was due to the rather minor roles the societies played in the scientific policy of the Third Reich and role anatomy played in medicine during this period of time. Recent investigations in both subjects were able to show how worthwhile the dealing with seemingly minor aspects of National Socialist policies is: Those aspects can especially help to sharpen the historical judgment of scientific and political actions. On the basis of recent archival research this article tries to present and analyze the subject of anatomy and the academies of sciences regarding their reciprocal relationship between 1933 and 1945. Besides the Leopoldina, the Prussian and the Bavarian Academies of Sciences will be focused on: By the examples of the anatomists represented in these societies it can be shown how anatomy as well as the societies developed under National Socialism and which general tendencies, entanglements and differences are relevant for the matter. The insight in this relationship focuses on the one hand on the anatomists represented in the societies. On the other hand it deals with the presence of anatomical research in the society, their meetings and publications, and especially with ideology and crimes reflected in this research.

Mixed integer evolution strategies for parameter optimization

Evolution strategies (ESs) are powerful probabilistic search and optimization algorithms gleaned from biological evolution theory. They have been successfully applied to a wide range of real world applications. The modern ESs are mainly designed for solving continuous parameter optimization problems. Their ability to adapt the parameters of the multivariate normal distribution used for mutation during the optimization run makes them well suited for this domain. In this article we describe and study mixed integer evolution strategies (MIES), which are natural extensions of ES for mixed integer optimization problems. MIES can deal with parameter vectors consisting not only of continuous variables but also with nominal discrete and integer variables. Following the design principles of the canonical evolution strategies, they use specialized mutation operators tailored for the aforementioned mixed parameter classes. For each type of variable, the choice of mutation operators is governed by a natural metric for this variable type, maximal entropy, and symmetry considerations. All distributions used for mutation can be controlled in their shape by means of scaling parameters, allowing self-adaptation to be implemented. After introducing and motivating the conceptual design of the MIES, we study the optimality of the self-adaptation of step sizes and mutation rates on a generalized (weighted) sphere model. Moreover, we prove global convergence of the MIES on a very general class of problems. The remainder of the article is devoted to performance studies on artificial landscapes (barrier functions and mixed integer NK landscapes), and a case study in the optimization of medical image analysis systems. In addition, we show that with proper constraint handling techniques, MIES can also be applied to classical mixed integer nonlinear programming problems.

[Diagnostic and therapeutic consequences of abnormal ultrasound findings]

BACKGROUND AND OBJECTIVE

The aim of this study was to evaluate the diagnostic and therapeutic consequences arising from abnormal ultrasound findings in a multidisciplinary setting in the University of Regensburg Clinical Centre.

PATIENTS AND METHODS

The results of 1162 randomly selected ultrasound examinations (on 671 males and 491 females) from a total of 14,301 at an interdisciplinary ultrasound unit were analysed. The investigators recorded the findings in a routinely used standardized manner. The records and discharge reports of each patient were then evaluated with regard to the diagnostic and therapeutic consequences of the findings.

RESULTS

There were 1843 abnormal findings in 901 patients. In 114 patients (6.2 %) no adequate diagnostic measures had been undertaken or recommended at discharge, but the reasons for the decisions taken could not be judged (value 4). 72.1 % of all patients were recruited from departments of internal medicine. However, the highest percentage of findings without adequate consequences were found to be in patients of the departments of oral and maxillofacial surgery, dermatology and nuclear medicine.

CONCLUSION

The number of ultrasound examinations that had been done without adequate consequences was comparatively low at 6.2 %. But perhaps this number can be further reduced by improved wording of the examination reports.

Reduced-exposure cyclosporine is safe and efficacious in de novo renal transplant recipients treated with enteric-coated mycophenolic acid and basiliximab

BACKGROUND

The lower limit of exposure to calcineurin inhibitors has not yet been established in de novo renal transplant patients receiving mycophenolic acid therapy with basiliximab.

METHODS

A 12-month, multicenter, randomized, open-label trial was carried out in which de novo renal transplant patients received enteric-coated mycophenolate sodium, cyclosporine microemulsion, steroids and basiliximab. Patients were randomized to receive standard-exposure (n = 45) or reduced-exposure (n = 44) cyclosporine, based on differing C2 target ranges, after the first month post-transplant.

RESULTS

Cyclosporine exposure gradually increased over the first month and was lower than previously recommended. Mean calculated creatinine clearance (primary end-point) was similar in the standard-exposure and reduced-exposure groups at month 6 (55.3+/-3.2 ml/min and 61.5+/-3.7 ml/min respectively, n.s.). There were 4 deaths but no death-censored graft losses, resulting in 95.5% patient and graft survival at one year in both groups. At 6 and 12 months, the incidence of biopsy-proven acute rejection was 17.8% and 17.8% in the standard-exposure group, and 13.6% and 15.9% in the reduced-exposure group. Adverse events were similar between treatment groups. Exploratory analyses could not identify a lower limit for the optimal CsA exposure range, but results suggested that high exposure at one year was associated with deteriorating renal function.

CONCLUSIONS

These results indicate that enteric-coated mycophenolate sodium with reduced-exposure cyclosporine, steroids and basiliximab induction has an excellent therapeutic effect and is safe in de novo kidney transplant recipients. Lower C2 targets than previously recommended, particularly early post-transplant, do not appear to be associated with compromised efficacy.

Myocardial perfusion in patients with typical chest pain and normal angiogram

BACKGROUND

Approximately 10-30% of patients with typical chest pain present normal epicardial coronaries. In a proportion of these patients, angina is attributed to microvascular dysfunction. Previous studies investigating whether angina is the result of abnormal resting or stress perfusion are controversial but limited by varying inclusion criteria. Therefore, we investigated whether microvascular dysfunction in these patients is associated with perfusion abnormalities at rest or at stress.

PATIENTS AND METHODS

In 58 patients (39 female, 19 male, mean age 58+/-10 years) with angina and normal angiogram as well as 10 control patients with atypical chest pain and normal coronaries (six female, four male, mean age 53+/-11 years) myocardial blood flow (MBF) was measured at rest and under dipyridamole using 13N-ammonia PET. Resting MBF and coronary flow reserve (CFR) as the ratio of hyperaemic to resting MBF were corrected for rate-pressure-product (RPP): normalized resting MBF (MBFn)=MBFx10,000/RPP and CFRn=CFRxRPP/10,000.

RESULTS

Sixteen/58 patients had a normal CFRn (=2.5; group I; CFRn: 3.1+/-0.88); the same as the controls (CFRn: 3.3+/-0.74). Forty-two/58 patients presented a reduced CFRn (group II; CFRn: 1.78+/-0.57). Group II had both a higher MBFn (group II: 1.30+/-0.33 vs. Group I: 1.03+/-0.26; P<0.05 and vs. controls: 1.07+/-0.19; P<0.01) and a lower hyperaemic MBF (group II: 2.25+/-0.76 mL g-1 min-1 vs. Group I: 3.07+/-0.78 mL g-1 min-1; P<0.001 and vs. controls: 3.41+/-0.94 mL g-1 min-1; P<0.0001).

CONCLUSION

Impaired CFRn in patients with typical angina and normal angiogram is owing to both an increased resting and reduced hyperaemic MBF. Therefore, PET represents a prerequisite for further studies to optimize treatment in individuals with anginal pain and normal coronary angiogram.

Stabilisation of periprosthetic fractures with angular stable internal fixation: a report of 13 cases

INTRODUCTION

Periprosthetic fractures of the femur present a challenging surgical problem. The aim of this study was to retrospectively evaluate the outcome of periprosthetic fractures stabilised with an angular stable, less invasive stabilisation system (LISS).

PATIENTS AND METHODS

Thirteen patients (ten total hip-, two total knee-, one total hip- and knee-arthroplasty) with periprosthetic fractures were treated with the LISS internal fixator (in ten cases minimal invasive). Six patients had previous operations due to periprosthetic fractures. The average follow-up period was 20 months, follow-up rate 85%.

RESULTS

All fractures showed radiographic fracture healing without implant loosening. Except one patient, all patients had returned to their pre-operative activity level. No early post-operative complications were seen. There was one implant failure after 4 months and two cases of malunion.

CONCLUSION

The cases showed the internal fixator to be effective for the stabilisation of periprosthetic fractures, even in cases of poor bone quality with good functional outcomes. The internal fixator, with the option of minimal invasive application, is the preferred method of osteosynthesis in periprosthetic fractures.

Dexamethasone stimulation of retinoic Acid-induced sodium iodide symporter expression and cytotoxicity of 131-I in breast cancer cells

CONTEXT

The sodium iodide symporter (NIS) mediates the active iodide uptake in the thyroid gland as well as lactating breast tissue. Recently induction of functional NIS expression was reported in the estrogen receptor-positive human breast cancer cell line MCF-7 by all-trans retinoic acid (atRA) treatment in vitro and in vivo, which might offer the potential to treat breast cancer with radioiodine.

OBJECTIVE

In the current study, we examined the effect of dexamethasone (Dex) on atRA-induced NIS expression and therapeutic efficacy of 131-I in MCF-7 cells.

DESIGN

For this purpose, NIS mRNA and protein expression levels in MCF-7 cells were examined by Northern and Western blot analysis after incubation with Dex (10(-9) to 10(-7) m) in the presence of atRA (10(-6) m) as well as immunostaining using a mouse monoclonal human NIS-specific antibody. In addition, NIS functional activity was measured by iodide uptake and efflux assay, and in vitro cytotoxicity of 131-I was examined by in vitro clonogenic assay.

RESULTS

After incubation with Dex in the presence of atRA, NIS mRNA levels in MCF-7 cells were stimulated up to 11-fold in a concentration-dependent manner, whereas NIS protein levels increased up to 16-fold and iodide accumulation was stimulated up to 3- to 4-fold. Furthermore, iodide efflux was modestly decreased after stimulation with Dex in the presence of atRA. Furthermore, in the in vitro clonogenic assay, selective cytotoxicity of 131-I was significantly increased from approximately 17% in MCF-7 cells treated with atRA alone to 80% in MCF-7 cells treated with Dex in the presence of atRA.

CONCLUSION

Treatment with Dex in the presence of atRA significantly increases functional NIS expression levels in addition to inhibiting iodide efflux, resulting in an enhanced selective killing effect of 131-I in MCF-7 breast cancer cells.

[Combined simulation training: a new concept and workshop is useful for crisis management in gastrointestinal endoscopy]

INTRODUCTION

Crisis management as well as realistic emergency situations can be trained in the new developed simulation workshop "Gastrointestinal Endoscopy and Crisis Resource Management" by combining a full-scale simulator and the Erlanger Endoscopy Trainer. The aim of the current study was to evaluate the efficiency of the newly developed simulation workshop.

METHODS

Endoscopists with more than 12 months experience can train their endoscopic skills and crisis resource management with the help of different simulators. In addition, two different scenarios (GI bleeding with significant blood loss and sedation overdoses) embedded in a realistic surrounding (emergency room) have to be managed by the participants. Vital parameters, endoscopic skills, as well as personal interactions were recorded and graded.

RESULTS

100 participants took part in the newly developed workshop (between June and December 2003). The participants showed a significantly better endoscopic performance and a significantly better crisis management after the standardized training program.

CONCLUSIONS

Simulation training plays an essential role in aviation and minimizes the risk for human errors. In the current study it is clearly shown that simulation training is also useful in gastrointestinal endoscopy. The newly developed workshop may thus be of crucial importance to improve personal crisis management. Simulation also leads to an improvement of endoscopic and emergency skills. Accordingly, simulation training should be recommended or offered as an education option in gastrointestinal endoscopy.

Angle stable locking reduces interfragmentary movements and promotes healing after unreamed nailing. Study of a displaced osteotomy model in sheep tibiae

BACKGROUND

Large interfragmentary movements may delay bone-healing. The hypothesis of the present study was that a reduction of interfragmentary movements, especially of torsional rotation and bending angles, would support the healing process and lead to improved healing following unreamed tibial nailing. The objective of this study was to investigate healing of an unstable tibial osteotomy site following stabilization with unreamed nailing with a modified tibial device that had angle stable holes for the locking bolts. We compared those findings with healing after stabilization of such sites with standard unreamed tibial nailing. The duration of the study period was nine weeks.

METHODS

The site of a standardized displaced osteotomy (3-mm gap) in twelve ovine tibiae was stabilized with unreamed tibial nailing: six animals were treated with a modified nail that had angle stable holes for the locking bolts, and six were treated with standard unreamed tibial nailing. In vivo gait analysis with optical measurements of interfragmentary movements and simultaneous measurements of ground reaction parameters were performed three days after the operation and once weekly afterward. After the animals were killed at nine weeks, the treated and contralateral tibiae were explanted, the implants were removed, and radiographs were made and evaluated for bridged cortices. Each pair of tibiae was also mechanically tested until torsional failure, after which the whole callus region was subjected to histological and histomorphometric analysis.

RESULTS

Throughout the examination period, the interfragmentary movements in all directions were significantly smaller in the group treated with the angle stable tibial nail than they were in the group treated with standard unreamed tibial nailing. The limbs treated with the angle stable tibial nails returned to almost full weight-bearing during the period of the investigation, whereas those treated with standard nailing did not. Histomorphometric analysis, radiographic data, and mechanical testing showed superior bone-healing following treatment with the angle stable tibial nail.

CONCLUSIONS

Use of an angle stable tibial nail may help to reduce interfragmentary movements in vivo and thus lead to superior bone-healing compared with that following standard unreamed tibial nailing.

[New osteosynthesis techniques for the treatment of distal femoral fractures]

The treatment of distal femoral fractures was for a long-time associated with high complication rates. Although implants and surgical techniques were improved, plate osteosynthesis and intramedullary nailing suffered from considerable rates of infection, non-union und malalignment. Attention to the soft tissue envelope by "biological" osteosynthesis and minimally invasive approaches resulted in decreased complication rates. Out of this movement grew the concept of minimal invasive plating with an internal fixator -- the LISS-DF (Less Invasive Stabilization System -- Distal Femur) -- and the retrograde nailing concept. This article should give a review about these two new techniques for the treatment of distal femoral fractures. Indications, the clinical use and the aftercare will be discussed.

Local-MP2 electron correlation method for nonconducting crystals

Rigorous methods for the post-HF (HF-Hartree-Fock) determination of correlation corrections for crystalline solids are currently being developed following different strategies. The CRYSTAL program developed in Torino and Daresbury provides accurate HF solutions for periodic systems in a basis set of Gaussian type functions; for insulators, the occupied HF manifold can be represented as an antisymmetrized product of well localized Wannier functions. This makes possible the extension to nonconducting crystals of local correlation linear scaling On techniques as successfully and efficiently implemented in Stuttgart's MOLPRO program. These methods exploit the fact that dynamic electron correlation effects between remote parts of a molecule (manifesting as dispersive interactions in intermolecular perturbation theory) decay as an inverse sixth power of the distance R between these fragments, that is, much more quickly than the Coulomb interactions that are treated already at the HF level. Translational symmetry then permits the crystalline problem to be reduced to one concerning a cluster around the reference zero cell. A periodic local correlation program (CRYSCOR) has been prepared along these lines, limited for the moment to the solution of second-order Moller-Plesset equations. Exploitation of point group symmetry is shown to be more important and useful than in the molecular case. The computational strategy adopted and preliminary results concerning five semiconductors with tetrahedral structure (C, Si, SiC, BN, and BeS) are presented and discussed.

Density-functional theory-symmetry-adapted intermolecular perturbation theory with density fitting: A new efficient method to study intermolecular interaction energies

The previously developed DFT-SAPT approach, which combines symmetry-adapted intermolecular perturbation theory (SAPT) with a density-functional theory (DFT) representation of the monomers, has been implemented by using density fitting of two-electron objects. This approach, termed DF-DFT-SAPT, scales with the fifth power of the molecular size and with the third power upon increase of the basis set size for a given dimer, thus drastically reducing the cost of the conventional DFT-SAPT method. The accuracy of the density fitting approximation has been tested for the ethyne dimer. It has been found that the errors in the interaction energies due to density fitting are below 10(-3) kcal/mol with suitable auxiliary basis sets and thus one or two orders of magnitude smaller than the errors due to the use of a limited atomic orbital basis set. An investigation of three prominent structures of the benzene dimer, namely, the T shaped, parallel displaced, and sandwich geometries, employing basis sets of up to augmented quadruple-zeta quality shows that DF-DFT-SAPT outperforms second-order Moller-Plesset theory (MP2) and gives total interaction energies which are close to the best estimates inferred from combining the results of MP2 and coupled-cluster theory with single, double, and perturbative triple excitations.

Locked internal fixator: sensitivity of screw/plate stability to the correct insertion angle of the screw

OBJECTIVE

Internal fixators with angular stability have been developed to provide high stability without compression of the plate on to the bone. Angular and axial stability of a plate-screw construct can be achieved using a conically threaded screw head undersurface and a corresponding conically threaded plate hole. Furthermore, the insertion angle of the screw must correspond precisely to the axis of the screw hole. This is not always achieved in clinical practice and may result in screw loosening. The objective of this study was to examine the relationship between the stability of the locked screw-plate on the insertion angle of the screw.

METHODS

Locking screws were inserted in an isolated (Point Contact Fixator, PC-Fix) or combined (Locking Compression Plate, LCP 4.5) locking hole with the use of an aiming device. The optimal insertion angle for these plates is perpendicular to the plate surface. The screws were inserted with an axis deviation of 0 degrees (optimal condition), 5 degrees , and 10 degrees respective to the optimal angle (variance +/- 1 degrees ). The samples were tested under shear or axial (push out) loading conditions until failure occurred. An Instron materials testing machine was used.

RESULTS

Locking screws inserted in the isolated locking hole (PC-Fix) showed a significant decrease of failure load if inserted at 5 degrees and 10 degrees angle. Using an optimal insertion angle (0 degrees ), failure load was 1480 +/- 390 N, with 5 degrees axis deviation 780 +/- 160 N, P = 0.0001, and with 10 degrees axis deviation 550 +/- 110 N, P = 0.0001. Screws inserted in the combined locking hole (LCP) also showed a significant decrease of push-out force of 77% (4960 +/- 1000 N versus 1120 +/- 400 N) with 10 degrees axis deviation. Compared to optimal insertion angle (0 degrees ), bending load to failure did decrease up to 69% (1240 +/- 210 N vs. 390 +/- 100 N) with 10 degrees axis deviation.

CONCLUSION

A locking head screw exhibits high stability with a moderate axis deviation in the angle of insertion of up to 5 degrees . However, there is a significant decrease in stability with increasing axis deviation (>5 degrees ). An aiming device is recommended to provide optimal fixation with angular stability.

Pharmacodynamics of FTY720, the first member of a new class of immune-modulating therapeutics in transplantation medicine

FTY is a novel immunomodulator currently undergoing clinical investigation and has the potential of improving immunosuppressive therapy after organ transplantation. Previous experimental studies in animals have shown that FTY has a unique mechanism of action. We have studied the pharmacodynamic effects of FTY in stable renal allograft recipients taking part in a phase I clinical trial. As in various animal models including non-human primates, a single oral dose of FTY (0.25 - 3.5 mg) significantly reduced peripheral lymphocyte count by 30 - 70%. The peripheral lymphocyte count returned to baseline within 24 hours. Only in those patients treated with the highest dose of FTY (3.5 mg), did peripheral lymphopenia persist for more than 96 hours. FTY reduced all lymphocyte subsets, T cells more than B cells and CD4+ cells more than CD8+ cells. The reduction in CD3+CD62L+ cell counts was more pronounced, whereas CD3+CCR5+ cell counts were less affected in comparison to the total number of CD3+ lymphocytes. We found only slightly increased apoptosis rates (< 5%) in peripheral lymphocytes, and this change does not explain the marked reduction in lymphocyte count. In cultured human lymphocytes only suprapharmacological doses of 10 microM FTY induced apoptosis (20.6 +/- 2.8%) after a 4-h incubation. More important, clinically relevant doses of 0.1 microM FTY increased lymphocyte mobility 2-fold. No effect of FTY on anti-CD3mAb-stimulated lymphocyte proliferation was detected and there was no change in phagocytosis rates in whole-blood cultures incubated with FTY. Further studies are necessary to investigate the mechanism of action of FTY in detail.

Stabilization of proximal tibial fractures with the LIS-System: early clinical experience in Berlin

The Proximal Tibia Less Invasive Stabilization System (LISS PLT) is an internal fixator for the treatment of proximal tibial fractures according to the principles of "Minimally invasive surgery". From July 1998 to August 2000 22 fractures were treated in our clinic with the new Proximal Tibia LISS and the prospective course of healing was documented. The period of follow-up was 12 months. The inclusion criteria were defined as proximal tibial shaft fractures and intraarticular proximal tibial fractures of all degrees of severity. A total of 15 proximal medial and lateral tibial plateau fractures (AO 41) and 7 metaphyseal fractures were treated (AO 42), seven of these fractures presented with open soft tissue damage. The average age of the patients treated was 42 years. With a follow-up rate of 91% (2 patients lost to follow-up), definite consolidation of the fracture was seen in 19/20 cases. In one patient, the fracture had only been partially bridged and secondary bone grafting was performed. Radiologically, there was one case of a varus malalignment of 6 degrees, in two further cases there were valgus malalignments of 5 degrees and 7 degrees at the time of surgery. The other cases all healed in correct alignment. In one case, the implant became loose on the distal shaft and was stabilized again using bicortical screws. In a case with type IIIB soft tissue damage, a soft tissue infection became manifest, but healed uneventfully after a revision operation with the implant in situ.

[Mechanical borderline indications in the treatment of unreamed tibial nailing]

The extended usage of unreamed tibial nailing resulted in reports of an increased rate of complications, especially for the distal portion of the tibia. The goal was to gain a thorough understanding of the load-sharing mechanism between unreamed nail and bone in a fractured tibia, and to identify borderline indications due to biomechanical factors. In finite element analyses of a human tibia, horizontal defects were modeled using unreamed nailing for five different fracture locations, including proximal and distal borderline indications for this treatment method. The findings of this study show that with all muscle and joint contact forces included, nailing leads to considerable unloading of the interlocked bone segments. Unreamed nailing of the distal defect results in an extremely low axial and high shear strain between the fragments. Apart from biological reasons, clinical problems reported for distal fractures may be due to the less favorable mechanical conditions in unreamed nailing. From a biomechanical perspective, the treatment of distal tibial shaft fractures with unreamed nailing without additional fragment contact or without stabilizing the fibula should be carefully reconsidered.

Less invasive stabilization system (LISS) in the treatment of distal femoral fractures

The treatment of distal femoral fractures has been associated with a high rate of complications for a long time. Although implants and surgical techniques have improved, plate osteosynthesis and intramedullary nailing have been accompanied by a high occurrence of infection, non-union and malalignment. The treatment of soft tissue envelopes using "biological" osteosynthesis and minimally invasive approaches has resulted in a decrease in complication rates and ultimately led to the concept of the less invasive stabilization system (LISS). This is an extramedullary-applied, internal fixator shaped according to the implantation site anatomy, with minimal invasiveness. The purpose of this study was to present this new surgical technique and draw attention to its advantages and importance. Although this is not a scientific paper, we hope to provide enough evidence of the LISS usefulness. The main LISS components include multiple-fixed angle screws and an insertion handle for submuscular sliding of a fixator and placement of percutaneous, self-drilling, unicortical screws for fixation of the diaphyseal fracture fragments. The LISS has been designed to preserve periosteal perfusion and to facilitate a minimally invasive application. Since the first implantation of the LISS, only a few studies have been published on its use in treatment of distal femoral fractures. The rate of infection has been low, ranging from 0 to 4%. The rate of delayed union has been between 2.4 and 6.1%, but delayed unions do not necessarily lead to secondary bone grafting or repeat osteosynthesis as the LISS has a high and lasting stability. When the LISS is used, bone grafting is rarely necessary (0 to 1.6% in primary and 0 to 5% in secondary grafting). Also implant failure differs from the failure of plate osteosynthesis because, with the use of LISS, no screw loosening or secondary malalignment occurs. Implant failures (up to 7.4%) were recorded particularly at the time of LISS introduction in surgical practice and were attributed to the technique of implantation rather than to the implant itself. Good treatment outcomes have been reported. The average knee flexion has been 103 degrees and 107 degrees. In 72.5% of the patients, flexion has been more than 90 degrees and an extension lag of > or = 10 degrees has been found in only 7.5% of all cases. The average Neer score has ranged from 73.9 to 77.2 points. In conclusion, the LISS is a useful implant for treatment of distal femoral fractures, especially when bone quality is poor. Infection, delayed union and non-union rates are low, as shown by yet unpublished data from our clinic. Primary bone grafting, which is rarely necessary with this system, is carried out only when there is a great bone loss. Implant failure, such as screw loosening or secondary malalignment, is not seen.

Functional relevance of soluble TNF-alpha, transmembrane TNF-alpha and TNF-signal transduction in gastrointestinal diseases with special reference to inflammatory bowel diseases

As a result of extensive clinical and basic research, the pivotal role of tumour necrosis factor (TNF) in the pathogenesis of chronic inflammatory diseases such as inflammatory bowel disease (IBD) has now generally been acknowledged. This has led to promising clinically effective anti-TNF-strategies. Of note, there is more and more evidence that TNF seems to play a key role in other gastrointestinal diseases including Helicobacter pylori infection, pancreatitis, viral hepatitis and toxic liver damage, too. The action of TNF at the cellular level is mediated by two cell surface receptors, TNF-R1 (p60) and TNF-R2 (p80). The function of these receptors and the downstream intracellular signal transduction pathway have been extensively studied in vitro and it can be expected, that there are critically important steps in TNF-signal transduction that might be dysregulated in these disease states. Their elucidation could lead to a better understanding of the pathogenesis of these diseases, in particular IBD and potentially reveal new, more specific therapeutic targets. Objective of this review is to give an overview about the current knowledge on TNF signal transduction in relationship to selected examples of important gastrointestinal disorders with special focus on IBD. Finally, the implications for future research efforts will be discussed.

Die winkelstabile palmare Plattenosteosynthese bei der dorsal dislozierten distalen Radiusfraktur - Anwendung und erste klinische Erfahrungen

Injuries and irritation of extensor tendons are common problems in the treatment of fractures of the distal radius when plating is used via a dorsal approach. By the development of locking compression plates the possibility of palmar plating for dorsally displaced fractures of the distal radius is available. In this study our first clinical experiences using the 3.5 mm radius locking compression plate (LCP) are reported. Between February 2002 and September 2002 24 patients with dorsally displaced fractures of the distal radius were treated using a palmar approach with the LCP and included in a prospective study. The mean age of the patients was 52 years (28-87 years). Six weeks and six months after surgery a clinical assessment was done, the range of motion of the injured wrist was measured, and an X-ray control of the injured joint was performed. The preliminary results demonstrate the option of early functional treatment using the locking compression plate. Most of the patients had a good to excellent range of motion of the injured wrist which resulted in an early return to former activity. There were few intra- and postoperative complications. No irritation of the median nerve, no infection was observed. In one case a screw which was placed intraarticularly was removed prematurely. The palmar locking compression plate has been proven as a safe and effective implant for the treatment of dorsally displaced fractures of the distal radius.