Erwiderung

Ohne Zusammenfassung     

Postmortem degradation of porcine articular cartilage

Postmortem decompositional changes to articular cartilage were analysed to help establish a new methodology in determining the postmortem interval. The cartilage was collected from porcine trotters buried in simulated shallow graves for different time periods. The trotters were dissected to expose the cartilage located at the metatarsal joint. Numerous macroscopic changes including a colour change, gradual degradation of cartilage and adjacent soft tissues and a loss of cartilage covering articular facets were observed. Further analysis was conducted using light microscopy (LM) and scanning electron microscopy (SEM) to assess microstructural changes. Both LM and SEM showed gradual morphological and structural changes to the tissue over time, along with loss of nuclear material. Tissue surface analysis with SEM highlighted orthorhombic shaped crystals that appear at approximately three weeks postmortem and persist until six weeks postmortem. Both microscopic and macroscopic characteristics followed a recognisable succession over the burial times observed. These results indicate that postmortem degradation of articular cartilage may be useful for estimating a presumptive postmortem interval.     

Targeting the palm: a leap forward toward treatment of keratin disorders

Any rational therapy benefits from an understanding of basic biology and the simplicity of its strategy. Among keratinopathies, epidermolytic palmoplantar keratoderma stands out by virtue of hotspot mutations in the KRT9 gene, exclusively expressed in the palmoplantar epidermis. In this issue, Leslie Pedrioli et al. report on the successful application of KRT9-specific siRNAs in cultured cells and in a mouse model. The study beautifully illustrates the potency of a thorough experimental approach and the challenges that remain, especially in its delivery.     

BRCA1 und BRCA2: Mutationen und andere genetische Ver?nderungen – praktische Relevanz

Bei 5–10 % aller an Mammacarcinom erkrankten Frauen ist die Erkrankung auf eine genetische Disposition zurückzuführen. Innerhalb der letzten 10 Jahre sind die wichtigsten disponierenden Gene für Mammacarcinom, BRCA1 und BRCA2, identifiziert worden. Beide Gene sind Tumorsuppressorgene, deren Funktion bislang noch nicht vollst?ndig aufgekl?rt ist. Die Gendiagnostik von BRCA1 und BRCA2 bildet die Grundlage, das Erkrankungsrisiko für Frauen aus Risikofamilien mit Mammacarcinom zu bestimmen und wird wichtige Informationen zur Pr?vention und Behandlung von erblichem Mammacarcinom geben.     

Phototransformation of Sensitisers: 3. Implications for Clinical Dosimetry

Spectroscopic studies of aqueous solutions of haematoporphyrin-type sensitisers reveal that photobleaching during eposure to light is followed by the formation of stable red-absorbing photoproducts. Experiments in model systems (sensitisers bound to human serum albumin or in a suspension of resealed erythrocyte ‘ghosts’) and in tumour tissue show that similar photomodification takes place in all investigated environments. Loss of total absorption and emission intensities is accompanied by an increase of absorption in the red spectral region (630–650 nm) which is used for the treatment of tumours because of the deeper penetration of light into tissues. This should be taken into account when the duration of illumination is chosen to reach an appropriate photodynamic dose using Hp-type sensitisers in the photodynamic treatment of tumours. Received for publication 4 November 1996; accepted in revised form 17 March 1998     

An Initial Experience with Hip Resurfacing Versus Cementless Total Hip Arthroplasty

Background

Hip resurfacing is an alternative to total hip arthroplasty.

Questions/Purpose

We aimed to compare an experienced hip surgeon’s initial clinical results of hip resurfacing with a new cementless total hip arthroplasty (THA).

Methods

The first 55 consecutive hip resurfacing arthroplasties were compared to 100 consecutive cementless THAs using a cylindrical tapered femoral stem. The learning curve between the two procedures was compared utilizing the incidence of reoperation, complications, Harris Hip Scores (HHS), and implant survivorship.

Results

The reoperation rate was significantly higher (p = 0.019) for hip resurfacing (14.5%) versus THA (4%). The overall complication rate between the two groups was not significantly different (p = 0.398). Preoperative HHS were similar between the two groups (p = 0.2). The final mean HHS was similar in both the resurfacing and THA groups (96 vs. 98.3, respectively, p < 0.65). Kaplan–Meier survival analysis with an endpoint of reoperation suggests complications occurred earlier in the resurfacing group versus the THA group (log-rank test, p = 0.007).

Conclusions

In comparison to our initial experience with a cementless THA stem, operative complications occur earlier and more often after hip resurfacing during the learning period. The clinical outcomes in both groups however are similar at 5 year follow-up.

Electronic supplementary material

The online version of this article (doi:10.1007/s11420-013-9333-0) contains supplementary material, which is available to authorized users.     

Classification and management of the unstable total hip arthroplasty

Seventy-five total hip arthroplasty revisions for instability were classified into 6 primary etiologies: I, acetabular component malposition; II, femoral component malposition; III, abductor deficiency; IV, impingement; V, late wear; or VI, unresolved etiology. The most common etiologies were cup malposition (type I; 33%) and abductor deficiency (type III; 36%). At a mean of 35.3 months, 11 redislocations occurred (14.6%). Acetabular revisions were protective against redislocation (P < .015). The number of previous operations (P = .0379) and previously failed constrained liners (P < .02) were risk factors for failure. Tripolar constrained liners demonstrated improved survivorship vs locking ring types (P < .02); cemented constrained liners failed more often than modular constrained liners (P < .0018). The highest risk of failure was in patients with abductor insufficiency with revisions for other etiologies having a success rate of 90%.     

Analysis of progenitor cell involvement in B-CLL by simultaneous immunophenotypic and genotypic analysis at the single cell level

B-cell chronic lymphocytic leukaemia (B-CLL) results from the clonal expansion of mature B lymphocytes. The detection of leukaemia-associated genetic markers in CD34-positive progenitor cells in a subset of B-CLL patients suggests that malignant transformation in B-CLL occurs in an immature progenitor cell compartment. To further quantify the percentage of B-CLL patients with genetically aberrant progenitor cells we have investigated CD34+ bone marrow cells in 11 B-CLL patients at the single cell level by simultaneous genetic and immunophenotypic analysis (FICTION). In five patients with trisomy 12, CD34+ haemopoietic progenitor cells were detectable on bone marrow smears. In one patient with trisomy 12, CD34+ progenitor cells were isolated by FACS sorting. In all six patients trisomy 12 was not found in the CD34+ cells. Progenitor cells were also analysed in three patients with Rb-deletion and in two patients with deletion of p53. In all patients the genetic marker was not detected in the CD34+ cells. In conclusion, we did not find genetically aberrant progenitor cells in this group of B-CLL patients. These results suggest that the subset of B-CLL patients with genetically aberrant CD34+ cells may be very small. This is of significance for our understanding of B-CLL biology and for future strategies using autologous stem cell transplantation.