Indikation, OP-Technik und Ergebnisse des endoskopischen Releases der Plantarfaszie (ERPF)

Zusammenfassung Fragestellung Ziel der vorliegenden Untersuchung ist es, die Indikation, OP-Technik sowie die Ergebnisse des endoskopischen Releases der Plantarfaszie darzustellen. Material und Methode An 5 nicht fixierten Präparaten wurde eine biportale Technik zum endoskopischen Release der Plantarfaszie erprobt. Ziel war es hierbei zum einen, die Relation zwischen Plantarfaszie und plantarem Fersensporn zu evaluieren; zum anderen wurde eine Technik erprobt, bei welcher nur 50–70% der medialen Plantarfaszie vom Kalkaneus abgelöst wurde.Über einen Zeitraum von 5 Jahren wurde diese Technik bei 10 männlichen und 7 weiblichen Patienten mit dem klinischen Bild einer Plantarfasziitis durchgeführt. Das mittlere Alter der Patienten betrug 35 Jahre (24–56 Jahre). Alle Patienten durchliefen zunächst konservative Therapieversuche von zumindest 6 Monaten. Ergebnisse Bei den ersten 5 Patienten wurde der Eingriff unter Bildwandlerkontrolle durchgeführt; bei den weiteren Patienten erfolgte die Resektion ohne intraoperative BV-Kontrolle. Bei allen Patienten konnte der Eingriff wie geplant durchgeführt werden. Die endoskopischen Portale heilten ohne Probleme. Die OP-Zeit ist im Rahmen der Lernkurve mit Zeiten zwischen 21 und 74 Minuten (MW: 41 Minuten) noch länger als in der offenen Technik. Der Nachuntersuchungszeitraum betrug zwischen 4 und 48 Monate (MW: 18,5 Monate). Bei 13 der 17 Patienten kam es zu einer klinischen Verbesserung und sie würden den Eingriff erneut durchführen lassen. 7 Patienten zeigten ein gutes und 6 ein sehr gutes Ergebnis im Ogilvie-Harris-Score. Bei 2 Patienten war das initiale Ergebnis nicht zufriedenstellend. Die Ursache hier lag in einer ossären Übermüdungsreaktion des Kalkaneus. Diese Komplikation wurde durch Entlastung über 6 Wochen symptomastisch behandelt. Bei zwei weiteren Patienten stellten sich sekundäre Überlastungen am lateralen Fußrand ein. Im Rahmen der frühen Rehabilitationsphase war es wichtig, trotz des minimalinvasiven Vorgehens, eine vorsichtige Belastungssteigerung durchzuführen. Schlussfolgerung Die Technik des endoskopischen Releases der Plantarfaszie (ERPF) ist standardisiert und reproduzierbar durchführbar. Sie führt zu guten mittelfristigen Ergebnissen. Ein Stabilitätsverlust der plantaren Verspannung sollte jedoch unbedingt vermieden werden.     

Assessment of the human epidermis model SkinEthic RHE for in vitro skin corrosion testing of chemicals according to new OECD TG 431.

Based on two successfully completed ECVAM validation studies for in vitro skin corrosion testing of chemicals, the National Co-ordinators of OECD Test Guideline Programme endorsed in 2002 two new test guidelines: TG 430 'Transcutaneous Electrical Resistance assay' and TG 431 'Human Skin Model Test'. To allow all suitable in vitro human reconstructed (dermal or epidermal) models to be used for skin corrosion testing, the OECD TG 431 defines general and functional conditions that the model must meet before it will be routinely used for skin corrosion testing. In addition, the guideline requires correct prediction of 12 reference chemicals and assessment of intra- and inter-laboratory variability. To show that the OECD TG 431 concept works, in 2003 ZEBET tested several chemicals from the ECVAM validation trials on the SkinEthic reconstituted human epidermal (RHE) model. Based on knowledge that reconstructed human skin models perform similarly in toxicological studies, it was decided to adopt the validated EpiDerm skin corrosion test protocol and prediction model to the SkinEthic model. After minor technical changes, classifications were obtained in concordance with those reported for the validated human skin models EPISKIN and EpiDerm. To allow adequate determination of inter-laboratory reproducibility, a blind trial was conducted in three laboratories -- ZEBET (D), Safepharm (UK) and BASF (D), in which the 12 endorsed reference chemicals were tested. Results obtained with the SkinEthic epidermal model were reproducible, both within and between laboratories, and over time. Concordance between the in vitro predictions of skin corrosivity potential obtained with the SkinEthic model and the predictions obtained with the accepted tests of OECD TG 430 and TG 431 was very good. The new test was able to distinguish between corrosive and non-corrosive reference chemicals with an accuracy of 93%.     

Effects of light fractionation and different fluence rates on photodynamic therapy with 5-aminolaevulinic acid in vivo

To improve efficacy of photodynamic therapy (PDT) with intravenously administered 5-aminolaevulinic acid (ALA) fractionating the light dose or reducing the light intensity may be a possibility. Therefore, Syrian Golden hamsters were fitted with dorsal skinfold chambers containing an amelanotic melanoma (n=26). PDT was performed (100 mW cm(-2), 100 J cm(-2), continuously or fractionated, and 25 mW cm(-2), 100 J cm(-2); continuously or fractionated) using an incoherent light source following i.v. application of ALA. Following fractionated irradiation, the light was paused after 20 J cm(-2) for 15 min. Prior to and up to 24 h after PDT tissue, pO(2) was measured using luminescence lifetime imaging. The efficacy was evaluated by measuring the tumour volume of amelanotic melanoma cells grown subcutaneously in the back of Syrian Golden hamsters (n=36). Only high-dose PDT resulted in a significant decrease of pO(2). Irrespective of the mode of irradiation only high-dose PDT induced complete remission of all tumours (13 out of 13). It could be shown that low-dose PDT failed to induce a significant decrease of pO(2). No significant effect of fractionated irradiation was shown regarding the therapeutic efficacy 28 days after PDT. Thus performing a fractionated PDT with ALA or reducing the light intensity seems not to be successful in clinical PDT according to the present data.     

Developmental toxicity testing in the 21st century: the sword of Damocles shattered by embryonic stem cell assays?

Modern society faces an inherent dilemma. In our globalized society, we are spoilt for choice by an ever-increasing number of products, many of which are made of new materials and compound mixtures. At the same time, as consumers we got accustomed to the idea of a life minimized for risk, including our own exposure to chemicals from the environment or to compounds present in and released from everyday products. Chemical safety testing bridges these obviously diverging interests, and the corresponding legislation has hence been tremendously extended (e.g., introduction of the European legislation REACH in 2007). However, the underlying regulatory toxicology still relies mainly on animal testing, which is relatively slow, expensive, and ethically arguable. Meanwhile, recent years have seen a surge in efforts to develop alternative testing systems and strategies. Expectations are particularly high for the applicability of stem cells as test systems especially for developmental toxicity testing in vitro. For the first time in history, test systems can be based on differentiating cells and tissue progenitors in culture, thus bringing the ‘vision of toxicity testing in the 21st century’ a step closer.     

A new concept in the electrophysiological evaluation of syringomyelia

OBJECT: The current neurophysiological assessment of syringomyelia is inadequate. Early-stage syringomyelia is anatomically predisposed to affect decussating spinothalamic fibers that convey pain and sensation primarily. Silent periods have been proven to be a sensitive tool for detecting alterations in this pathway. METHODS: Thirty-seven patients with syringomyelia were included in this prospective study. Routine electrophysiological measurements were applied including somatosensory evoked potential (SSEP) and motor evoked potential (MEP) recordings for all extremities. The silent periods were recorded from the pollicis brevis muscle, and electrical stimuli were applied to the ipsilateral digiti II. To establish baseline values, the authors had 28 healthy controls undergo monitoring. Sensitivity and specificity values were statistically evaluated according to the main clinical symptoms (paresis, dissociative syndrome, and pain). RESULTS: All control individuals had normal silent periods in voluntarily activated muscle. In syringomyelia patients, the affected limb showed pathological silent periods with all symptoms (sensitivity 30-50%). Pain was the most specific symptom (90%), despite SSEP and MEP values that were within the normal range. CONCLUSIONS: Silent period testing is a sensitive neurophysiological technique and an invaluable tool for preoperative assessment of syringomyelia. Silent periods are associated with early dysfunction of thin myelinated spinothalamic tract fibers, even when routine electrophysiological measurements still reveal normal values. Conduction abnormalities that selectively abolish the silent periods can distinguish between hydromyelia (a physiologically dilated central canal) and space-occupying syringomyelia.     

Serotonin-Konzentrationsbestimmung im Plasma nach in-vitro-Stimulation postmortal gewonnener Thrombozyten

Platelets from corpse blood samples (n = 77) taken during the first 9 h post mortem (repeated collections in 1 or 2 h intervals) were stimulated in vitro with collagen, arachidonic acid, ADP, epinephrine or by agitation. Activatable platelets released endogenically stored serotonin upon adequate stimulation. The plasma serotonine concentration was measured by means of an immunoassay and is a direct measure of functional platelet status. Results: The platelets in corpse blood can initially (up to 3 h post mortem) be activated differentially depending on the type and concentration of the agonists. By the 6th hour post mortem, platelets lose their capacity to react adequately with a release reaction. Later, the secretive capacity of the platelets disappears completely.     

Base of skull chordomas in children and adolescents: a clinicopathologic study of 73 cases

Chordomas in children and adolescents comprise <5% of all chordomas and most frequently develop in the skull base. These tumors are believed to behave more aggressively than chordomas in adults and may have unusual morphology. This study examines a large series of pediatric skull base chordomas treated with a standardized protocol to characterize the behavior and morphology of these tumors. There were 31 males and 42 females ranging from 1 to 18 (mean 9.7) years. Forty-two cases (58%) were conventional chordomas, some of which had unusual histopathologic features. Chondroid chordomas comprised 23% of cases. Fourteen tumors (19%) were highly cellular and had a solid growth pattern with no myxoid matrix or lobular architecture. Eight of these had cytologic features of conventional chordoma cells including physaliferous cells (cellular chordoma). The remaining cellular tumors were composed of poorly differentiated epithelioid cells set in a fibrous stroma and lacked physaliferous cells (poorly differentiated chordoma). All variants studied by immunohistochemistry showed positive staining for cytokeratin, epithelial membrane antigen, S100 protein, and vimentin. Mitoses and necrosis were seen in all variants. Follow-up data were available for all patients and ranged from 1 to 21 (mean 7.25) years. The survival rate was 81%. All but 1 patient with poorly differentiated chordoma died of disease. Overall, base of skull chordomas in children and adolescents treated with proton beam radiation have better survival than chordomas in adults. However, poorly differentiated chordomas are highly aggressive tumors.