Long term effect of dietary lipid saturation on eggshell quality and bone characteristics of laying hens.

This study investigated the long-term effect of dietary fatty acid saturation on eggshell quality and bone characteristics of laying hens at end of lay. Five isoenergetic (3,011.5 kcal AME/kg DM) and isonitrogenous (169 g CP/kg DM) diets were formulated using different lipid sources at a constant 30 g/kg inclusion level. The control, polyunsaturated omega-3 (PUFA n-3), polyunsaturated omega-6 (PUFA n-6), monounsaturated omega-9 (MUFA n-9), and saturated fatty acid (SFA) diets consisted of linseed- and fish oil (50:50 blend), fish oil, sunflower oil, high oleic acid sunflower oil, and tallow, respectively. A total of 200 individually caged Hy-Line Silver-Brown hens (20 wk of age) were randomly allocated to the 5 treatments (n = 40 replicates/treatment) and received the experimental diets for 54 wk. During weeks 58, 62, 66, 70, and 74 of age (end-of-lay period), 20 eggs/treatment per day (n = 140 eggs/treatment per week) were selected for determining eggshell quality traits. At 74 wk of age, 10 birds per treatment (n = 10 birds/treatment) were randomly selected for the determination of bone quality characteristics. Data were statistically analyzed (P < 0.05) using a fully randomized 1-way ANOVA. Dietary treatment had no effect (P > 0.05) on eggshell quality traits. The MUFA n-9 treatment with the highest unsaturated to SFA ratio (UFA: SFA) resulted in a higher (P < 0.05) femur weight (10.34 g) as well as femur- (52.99%) and tibia ash (51.07%) content than the SFA treatment. Also, the PUFA n-3 diet resulted in a higher (P < 0.05) femur weight (10.21 g), femur ash (51.82%), and percentage femur (0.57%) compared to the SFA diet. Results suggested that prolonged feeding of diets varying in FA profile had no negative effect on eggshell quality, whereas UFA: SFA and long-chain n-3 PUFA affected the bone quality (especially the femur) of hens at the end of lay.

Clinical and Wear Analyses of 9 Large Metal-on-Metal Total Hip Prostheses.

BACKGROUND: Metal-on-Metal (MoM) total hip arthroplasties (THA) are associated with pseudotumor formation and high revision rates. This prospective study analysed the clinical and wear analyses of 9 large Metal-on-Metal (MoM) total hip arthroplasties (THA) to understand the underlying mechanisms of failure. The MoM bearings were revised for multiple reasons; the main reason was pseudotumor formation. MATERIALS AND METHODS: From 2006 till 2010 the Reinier de Graaf Hospital implanted 160 large head M2a-Magnum™ (Biomet Inc. Warsaw, Indiana, USA) THAs in 150 patients. The first year, 9 bearings were revised and analysed at the Biomechanics Section, Hamburg University of Technology, Germany. We performed clinical (Harris Hip Score, radiographic analysis, blood cobalt and chromium) and wear analysis (implant, tissue and fluid) of the 9 bearings. Since this study did not fall under the scope of the Medical Research Involving Human Subjects Act in The Netherlands, no ethical approval was necessary. In this prospective study all patient details were anonymized by the corresponding author, all other authors were blinded during the research and wear analyses. Patients with bilateral MoM implants were excluded. RESULTS: The 9 bearings had a median (IQR) survival of 41.0 (25) months in situ. From these bearings, three showed no noticeable wear. The median (IQR) head wear volume was 3.2 (3.6) mm3 and maximum wear depth 0.02 (0.02) mm. For the cup the median (IQR) wear volume was 0.23 (0.3) mm3 with a maximum wear depth of 0.03 (0.05) mm. CONCLUSION: An early identification of parameters related to failure of the MoM THA, such as pain, decreased range of motion, radiographic changes and high levels of blood cobalt and chromium is of great importance for patient's quality of life. Especially now patients and surgeons face the long term effects of all these bearings still in situ. This study reports the clinical and wear analyses of 9 MoM THA. In the majority of this group the reason for revision was pseudotumor formation. Most bearings showed signs of wear, however with a great diversity in clinical analysis, in inclination angle, serum cobalt and chromium levels as well as wear analysis. For a better understanding of the underlying mechanisms related with failure, more wear analyses of revised MoM bearings are necessary as well as a frequent follow-up of the patients with a MoM bearing.

Severe Wear and Pseudotumor Formation Due to Taper Mismatch in a Total Hip Arthroplasty: A Case Report.

CASE: We describe the case of a seventy-six-year-old woman who had undergone bilateral total hip arthroplasty with Zweymüller-Metasul prostheses in 1996. After a fall sixteen years after the index procedures, radiographs suggested a taper fracture of the left total hip arthroplasty. However, revision surgery showed pseudotumor formation, with no evidence of taper fracture. Analysis of the prosthesis showed massive wear of the male stem taper caused by a mismatch between the stem taper and the head taper. CONCLUSION: This case vividly demonstrates how taper size mismatch can cause dramatic metal wear and increased release of metal ions, resulting in pseudotumor formation.

The relation between titanium taper corrosion and cobalt-chromium bearing wear in large-head metal-on-metal total hip prostheses: a retrieval study.

BACKGROUND: Revision of hip implants due to adverse tissue reactions to metal debris has been associated with wear and corrosion of the metal-on-metal bearing articulation and the modular taper interface. Bearing articulation wear is increased in conditions of poor lubrication, which can also lead to high friction moments that may cause corrosion at the taper interface. This suggests that wear of the bearing and increased corrosion of the taper interface should occur simultaneously, which was investigated in this study. METHODS: Forty-three large-diameter cobalt-chromium bearings of the same design, implanted with a titanium stem using a titanium adapter, were retrieved at revision at a single center. Retrievals were grouped according to visual inspection of the female taper surface of the adapter into slight and severe corrosion groups. Volume change of bearing and taper surfaces was assessed using a coordinate measurement machine. Serum ion concentrations were determined for forty-three patients, whereas tissue metal concentration was measured for twelve patients. RESULTS: Severe taper corrosion was observed in 30% of the retrievals. Corrosion was observed either as material deposition or wear. The overall bearing wear rate was significantly higher in the group with severe taper corrosion than in the group with slight corrosion (7.2 ± 9.0 mm(3)/yr versus 3.1 ± 6.8 mm(3)/yr, respectively; p = 0.023) as were the serum cobalt (40.5 ± 44.9 µg/L versus 15.2 ± 23.9 µg/L, respectively; p = 0.024) and chromium ion concentrations (32.7 ± 32.7 µg/L versus 12.0 ± 15.1 µg/L, respectively; p = 0.019). Serum metal ion concentrations were more consistent indicators of wear than tissue metal concentrations. CONCLUSIONS: The increased bearing articulation wear and serum metal ion concentrations in cases with taper interface corrosion support the hypothesis that increased friction in the joint articulation is one of the factors responsible for simultaneous articulation and taper damage. However, independent taper or bearing damage was also observed, suggesting that other factors are involved in the process.

[Report on notifications according to section 8d of the German Transplantation Act (TPG) for the years 2009-2011]. / Bericht zur Meldung nach § 8d Transplantationsgesetz (TPG) für die Jahre 2009 bis 2011.

In Germany, the Tissue Act came into effect on 1 August 2007. Since then, every tissue establishment is legally obligated to keep a record of its activities according to section 8d subsection 3 of the Transplantation Act (TPG). An annual report must be submitted to the Paul Ehrlich Institute once a year up to 1 March of the subsequent year. The report should include the types and quantities of tissues procured, conditioned, processed, stored, distributed or otherwise disposed of, imported, and exported. The report should be made on a TPG-based notification form published on the Internet by the Paul Ehrlich Institute. The present report according to section 8d subsection 3 of the TPG is based on data of the reporting years 2009-2011. Six years after implementation of the TPG's reporting obligation for tissue establishments, the number of tissue establishments known by the Paul Ehrlich Institute has increased from 349 in 2007 to 949 in 2011. In the course of continuous optimization of the notification forms, including tissue-specific glossaries, the reported data of most of the tissues and tissue preparations have become more conclusive.

The spatio-temporal arrangement of different tissues during bone healing as a result of simple mechanobiological rules.

During secondary bone healing, different tissue types are formed within the fracture callus depending on the local mechanical and biological environment. Our aim was to understand the temporal succession of these tissue patterns for a normal bone healing progression by means of a basic mechanobiological model. The experimental data stemmed from an extensive, previously published animal experiment on sheep with a 3 mm tibial osteotomy. Using recent experimental data, the development of the hard callus was modelled as a porous material with increasing stiffness and decreasing porosity. A basic phenomenological model was employed with a small number of simulation parameters, which allowed comprehensive parameter studies. The model distinguished between the formation of new bone via endochondral and intramembranous ossification. To evaluate the outcome of the computer simulations, the tissue images of the simulations were compared with experimentally derived tissue images for a normal healing progression in sheep. Parameter studies of the threshold values for the regulation of tissue formation were performed, and the source of the biological stimulation (comprising e.g. stem cells) was varied. It was found that the formation of the hard callus could be reproduced in silico for a wide range of threshold values. However, the bridging of the fracture gap by cartilage on the periosteal side was observed only (i) for a rather specific choice of the threshold values for tissue differentiation and (ii) when assuming a strong source of biological stimulation at the periosteum.

Hospital centers of excellence defy geographic trends.

A study of "centers of excellence" of hospitals finds that dominant hospitals of excellence-those with citations in many specialties-are in relatively smaller metropolitan areas.

The mechanical heterogeneity of the hard callus influences local tissue strains during bone healing: a finite element study based on sheep experiments.

During secondary fracture healing, various tissue types including new bone are formed. The local mechanical strains play an important role in tissue proliferation and differentiation. To further our mechanobiological understanding of fracture healing, a precise assessment of local strains is mandatory. Until now, static analyses using Finite Elements (FE) have assumed homogenous material properties. With the recent quantification of both the spatial tissue patterns (Vetter et al., 2010) and the development of elastic modulus of newly formed bone during healing (Manjubala et al., 2009), it is now possible to incorporate this heterogeneity. Therefore, the aim of this study is to investigate the effect of this heterogeneity on the strain patterns at six successive healing stages. The input data of the present work stemmed from a comprehensive cross-sectional study of sheep with a tibial osteotomy (Epari et al., 2006). In our FE model, each element containing bone was described by a bulk elastic modulus, which depended on both the local area fraction and the local elastic modulus of the bone material. The obtained strains were compared with the results of hypothetical FE models assuming homogeneous material properties. The differences in the spatial distributions of the strains between the heterogeneous and homogeneous FE models were interpreted using a current mechanobiological theory (Isakson et al., 2006). This interpretation showed that considering the heterogeneity of the hard callus is most important at the intermediate stages of healing, when cartilage transforms to bone via endochondral ossification.

Prostate-specific antigen (PSA) in the monitoring of prostate cancer after radical prostatectomy and external beam radiation.

BACKGROUND: During the last few years, prostate-specific antigen (PSA) has been established as the most important tumor marker for prostate cancer. The aim of our study was to evaluate the response of PSA after surgery and radiotherapy of prostate cancer. PATIENTS AND METHODS: From 1/1995 to 9/1997, 32 patients were treated by radical prostatectomy and subsequent radiotherapy. Radiation therapy was carried out using a linear accelerator to the prostate bed, a total dose of 60 Gy was given. PSA values were measured immediately before irradiation, weekly during radiation therapy and every three months thereafter in the usual follow-up pattern. RESULTS: 21 of 32 patients had no measurable PSA after surgery. In the remaining 11 patients the median PSA half-life was reached 3 months after irradiation, the nadir after 15 months. 5 patients with increasing PSA levels suffered from a relapse (15.6%). CONCLUSIONS: We found that PSA monitoring is a useful marker for treatment outcome and that adjuvant radiotherapy after surgery improves local control as well as biochemical failure rate. If PSA is still detectable after surgery the risk for biochemical failure is significantly higher (45.5%).

Apparatus for sectioning diffusion specimens in liquid nitrogen.

Details are given on the design and operation of an apparatus which enables sectioning of samples in a liquid nitrogen bath. The sectioning of samples, in which a radioactive tracer has been diffused, is made by abrasion.