Preliminary evaluation of selected inflammatory cytokine gene expression in lymphocytes isolated from whole human blood infected with trans-anethole-treated Staphylococcus aureus Newman strain

In our previous study based on a whole-blood model of sepsis infected with trans-anethole (TA)-treated Staphylococcus aureus, we have found that innate immune response was more effective in comparison to non-treated cells. Due to the previous observation, in the current preliminary study, a primary adaptive immune response was analysed. This study was conducted to evaluate the expression of selected cytokine (IL1B, IL2, IL6, IL10, TNF, TGFB1, IFNG) and Toll-like receptor (TLR2) genes in lymphocytes isolated from whole human blood infected with S. aureus Newman strain treated with TA. The lymphocytes were isolated by density gradient centrifugation from blood samples infected with S. aureus, as well as from non-infected samples. Gene expression was measured using quantitative real-time PCR. The lymphocytes isolated from the blood infected with TA-treated staphylococcal cells demonstrated significantly greater IL10, IL1B, IL6, TNF and TLR2 expression. Hence, it is possible that the previously observed changes in the surface structure of TA-treated S. aureus Newman strain may significantly increase the relative expression of IL10, IL1B, IL6, TNF and TLR2 genes in lymphocytes; however, further studies are needed.

Effect of synthetic bone replacement material of different size on shear stress resistance within impacted native and thermodisinfected cancellous bone: an in vitro femoral impaction bone grafting model

Antibiotic carrier particles of variable size might influence mechanic properties within impacted thermodisinfected and native cancellous bone different. Herafill®G containing calciumsulfate and calciumcarbonate provides high local concentrations of gentamicin being important for revision surgery in infected joint replacements. Native and thermodisinfected cancellous bone derived from 6 to 7 months old piglets was used for in vitro impaction bone grafting and supplemented each with Herafill®G granules of two different sizes. Micromovement of implants related to shear force was measured in 29 specimens distributed in 6 groups. Thermodisinfected cancellous bone revealed a significant higher shear force resistance than native bone with a mean difference of 423.8 mdeg/Nm (p < 0.001) ranging within 95% confidence interval from 181.5 to 666.0 mdeg/Nm. Adding small granules to thermodisinfected bone did not reduce shear force resistance significantly since adding large granules to native bone improved it by 344.0 mdeg/Nm (p < 0.003). Shear force resistance was found higher at the distal region of the implant compared to a proximal point of measurement throughout all specimens. Less impaction impulses were necessary for thermodisinfected bone. Thermodisinfected cancellous bone might achieve a higher degree of impaction compared with native bone resulting in increased resistance against shear force since impaction was found increased distally. Supplementation of thermodisinfected bone with small granules of Herafill®G might be considered for application of local antibiotics. Large granules appeared more beneficial for supplementation of native bone. Heterogeneity of bone graft and technical aspects of the impaction procedure have to be considered regarding the reproducibility of femoral impaction bone grafting.

Influence of thermodisinfection on microstructure of human femoral heads: duration of heat exposition and compressive strength

Allogeneic bone derived from living donors being necessary to match demand for bone transplantation and thermodisinfection of femoral heads is an established sterilization method. During the thermodisinfection the peripheral bone is exposed to maximum 86 °C for 94 min providing 82.5 °C within the center of the femoral head for at least 15 min. This study examined the compression force of the central and representative peripheral regions of native and thermodisinfected human femoral heads to observe wether different duration and intensity of heat exposure might alter mechanic behaviour. Slices from the equatorial region of human femoral heads were taken from each 14 native and thermodisinfected human femoral heads. The central area revealed a significantly higher compression force for native (p ≤ 0.001) and for thermodisinfected bone (p = 0.002 and p = 0.005) compared with peripheral regions since no relevant differences were found between the peripheral and intermediate areas themselves. A small reduction of compression force for thermodisinfected bone was shown since this did not appear significant due to the small number of specimens. The heat exposure did not alter the pre-existing anatomical changes of the microarchitecture of the native femoral heads from the center towards the peripheral regions. The heterogeneity of microstructure of the femoral head might be of interest concerning clinical applications of bone grafts since the difference between native and thermodisinfected bone appears moderate as shown previously. The different quantity of heat exposure did not reveal any significant influence on compression force which might enable thermodisinfection of preformed bone pieces for surgical indications.

A Practical Concept for Preoperative Identification of Patients with Impaired Primary Hemostasis

The findings of a large prospective study designed to identify primary and/or secondary hemostatic disorders before surgical interventions are presented. A total of 5649 unselected adult patients were enrolled to identify impaired hemostasis before surgical interventions. Each patient was asked to answer a standardized questionnaire concerning bleeding history. Activated partial thromboplastin time (aPTT), prothrombin time (PT), and platelet counts (PC) including PFA-100 (platelet function analyzer): collagen-epinephrine (C/E), and collagen-ADP (C/ADP) were routinely done in all patients. Additional tests, bleeding time (BT), and von Willebrand factor (vWF: Ag) were performed only in patients with a positive bleeding history and/or evidence of impaired hemostasis; e.g., drug ingestion. The bleeding history was negative in 5021 patients (88.8%) but positive in the remaining 628 (11.2%). Impaired hemostasis could be verified only in 256 (40.8%) of these patients. The vast majority were identified with PFA-100: C/E (n=250; 97.7%). The other six patients with impaired hemostasis were identifiable solely based on the PT (n=2), PFA-100: C/ADP (n=2), and vWF: Ag (n=2). The PFA-100: C/ADP detected 199 patients (77.7%). The only abnormality found among patients with a negative bleeding history was a prolonged aPTT due to lupus anticoagulant in nine patients (0.2%). The sensitivity of the PFA-100: collagen-epinephrine was the highest (90.8%) in comparison to the other screening tests (BT, aPTT, PT, vWF: Ag). The positive predictive value of the PFA-100: collagen-epinephrine was high (81.8%), but the negative predictive value was higher (93.4%). The use of a standardized questionnaire and, if indicated, the PFA-100: C/E and/or other specific tests not only ensure the detection of impaired hemostasis in almost every case but also a significant reduction of the cost.

Effect of thermodisinfection on mechanic parameters of cancellous bone

Revision surgery of joint replacements is increasing and raises the demand for allograft bone since restoration of bone stock is crucial for longevity of implants. Proceedings of bone grafts influence the biological and mechanic properties differently. This study examines the effect of thermodisinfection on mechanic properties of cancellous bone. Bone cylinders from both femoral heads with length 45 mm were taken from twenty-three 6-8 months-old piglets, thermodisinfected at 82.5 °C according to bone bank guidelines and control remained native. The specimens were stored at -20 °C immediately and were put into 21 °C Ringer's solution for 3 h before testing. Shear and pressure modulus were tested since three point bending force was examined until destruction. Statistical analysis was done with non-parametric Wilcoxon, t test and SPSS since p < 0.05 was significant. Shear modulus was significantly reduced by thermodisinfection to 1.02 ± 0.31 GPa from 1.28 ± 0.68 GPa for unprocessed cancellous bone (p = 0.029) since thermodisinfection reduced pressure modulus not significantly from 6.30 ± 4.72 GPa for native specimens to 4.97 ± 2.23 GPa and maximum bending force was 270.03 ± 116.68 N for native and 228.80 ± 70.49 N for thermodisinfected cancellous bone. Shear and pressure modulus were reduced by thermodisinfection around 20 % and maximum bending force was impaired by about 15 % compared with native cancellous bone since only the reduction of shear modulus reached significance. The results suggest that thermodisinfection similarly affects different mechanic properties of cancellous bone and the reduction of mechanic properties should not relevantly impair clinical use of thermodisinfected cancellous bone.

Platelet-Rich Plasma Preparation Types Show Impact on Chondrogenic Differentiation, Migration, and Proliferation of Human Subchondral Mesenchymal Progenitor Cells

PURPOSE

To evaluate the chondrogenic potential of platelet concentrates on human subchondral mesenchymal progenitor cells (MPCs) as assessed by histomorphometric analysis of proteoglycans and type II collagen. Furthermore, the migratory and proliferative effect of platelet concentrates were assessed.

METHODS

Platelet-rich plasma (PRP) was prepared using preparation kits (Autologous Conditioned Plasma [ACP] Kit [Arthrex, Naples, FL]; Regen ACR-C Kit [Regen Lab, Le Mont-Sur-Lausanne, Switzerland]; and Dr.PRP Kit [Rmedica, Seoul, Republic of Korea]) by apheresis (PRP-A) and by centrifugation (PRP-C). In contrast to clinical application, freeze-and-thaw cycles were subsequently performed to activate platelets and to prevent medium coagulation by residual fibrinogen in vitro. MPCs were harvested from the cortico-spongious bone of femoral heads. Chondrogenic differentiation of MPCs was induced in high-density pellet cultures and evaluated by histochemical staining of typical cartilage matrix components. Migration of MPCs was assessed using a chemotaxis assay, and proliferation activity was measured by DNA content.

RESULTS

MPCs cultured in the presence of 5% ACP, Regen, or Dr.PRP formed fibrous tissue, whereas MPCs stimulated with 5% PRP-A or PRP-C developed compact and dense cartilaginous tissue rich in type II collagen and proteoglycans. All platelet concentrates significantly (ACP, P = .00041; Regen, P = .00029; Dr.PRP, P = .00051; PRP-A, P < .0001; and PRP-C, P < .0001) stimulated migration of MPCs. All platelet concentrates but one (Dr.PRP, P = .63) showed a proliferative effect on MPCs, as shown by significant increases (ACP, P = .027; Regen, P = .0029; PRP-A, P = .00021; and PRP-C, P = .00069) in DNA content.

CONCLUSIONS

Platelet concentrates obtained by different preparation methods exhibit different potentials to stimulate chondrogenic differentiation, migration, and proliferation of MPCs. Platelet concentrates obtained by commercially available preparation kits failed to induce chondrogenic differentiation of MPCs, whereas highly standardized PRP preparations did induce such differentiation. These findings suggest differing outcomes with PRP treatment in stem cell-based cartilage repair.

CLINICAL RELEVANCE

Our findings may help to explain the variability of results in studies examining the use of PRP clinically.

Influence of thermodisinfection and duration of cryopreservation at different temperatures on pull out strength of cancellous bone

Thermodisinfection of human femoral heads from living donors harvested during hip joint replacement is an established processing procedure. This study was designed to examine the influence of heat sterilization on pull out strength of cancellous bone and storage at different temperatures up to 2 years since we had previously studied the storage of unprocessed cancellous bone. Porcine cancellous bone resembling human bone structure was obtained from 140 proximal humerus of 6-8 months old piglets. Pull out strength of screws after thermodisinfection was compared with unprocessed cancellous bone and tested immediately and after 6, 12 and 24 months of storage at -20 and -80 °C. A three-way ANOVA was performed and significance level was 5 %. The thermodisinfected bone showed a pull out force of 2729 N (1657-3568 N). The reduction of pull out strength compared with unprocessed bone over all periods of storage was 276 N on average with 95 % confidence interval ranging from 166 N to 389 N (p < 0.0001). Different freezing temperatures did not influence this mechanic property within 24 months storage and showed no difference compared with fresh frozen bone. Thermodisinfection of cancellous bone preserves tensile strength necessary for clinical purposes. The storage at -20 °C for at least 2 years did not show relevant decrease of pull out strength compared with -80 °C without difference between thermodisinfected and fresh frozen bone. The increase of the storage temperature to -20 °C for at least 2 years should be considered.

Validation of Serological Testing for Anti-Treponema pallidum from Postmortem Blood on the Siemens-BEP(®)-III Automatic System

BACKGROUND

Infectious disease marker testing is obligatory for the release of human tissue for transplantation. Most CE-marked tests are not validated for postmortem blood. In a previous study we have validated the testing for anti-HIV-1/2, anti-HCV, HBsAg, and anti-HBc. Here, we present the validation of testing for antibodies against T. pallidum, which is the last marker obligatory for tissue release for transplantation.

METHODS

17 samples of postmortem sera and 10 samples of both pre-und postmortem sera were obtained from cornea donors and tested for anti-T. pallidum on the Siemens-BEP-III-System. These sera were spiked with anti-T. pallidum-positive standard sera in concentrations which give low- and high-positive results at the respective dilution.

RESULTS

Two of the unspiked postmortem sera were false-positive most likely due to intense hemolysis (free hemoglobin > 50 mg/dl). Of the 25 negative postmortem sera, none of the spiked samples was false-negative after 0, 24 and 60 h.

CONCLUSION

There is no indication that postmortem samples give false-negative or false-positive results with the test system and test kits used in cases of low hemolysis. The procedure described might serve as a model for validating other test kits on postmortem samples.

Six years of clinical follow-up with endothelial cell-seeded small-diameter vascular grafts during coronary bypass surgery

This clinical study was performed to investigate the patency rate of endothelial cell–seeded small-diameter expanded polytetrafluoroethylene grafts during coronary artery bypass surgery. Between September 1995 and December 1998, 14 patients (median age: 71 years, range: 61–79 years) received 21 endothelial cell–seeded small-diameter grafts. In all, 43% of the performed implantations were reoperations. Endothelial cells were harvested from a forearm vein, cultured and characterized in the laboratory until a sufficient number was available. After in vitro seeding, the grafts were allowed to mature for another 10 days, prior to implantation. Graft patency was investigated with angiography, angioscopy, and intravascular ultrasonography during follow-up. Cumulative data represented 58 patients’ years and was 100% complete. The seeded autologous vascular endothelial cell density was 1.05 × 10⁵ ± 0.12 × 10⁵ cells/cm² with a cell viability of 95.5 ± 1.5%. Operative mortality was 7.1% (one patient). Patency rate at discharge was 95.2%, and at a mean follow-up of 27 months was 90.5%. The proven patency rate at up to 72 months was at least 50.0%, as five patients refused angiographic evaluation. None of these five patients suffered from angina pectoris and so the best scenario would have shown a patency rate of 85.7%. Angioscopy and intravascular ultrasonography showed absence of atheroma or stenosis in the investigated patent grafts. Autologous vascular endothelial cell seeding improves patency rate of small-caliber expanded polytetrafluoroethylene grafts in patients without suitable autologous graft material.

Comparison of in situ Corneoscleral Disc Excision versus Whole Globe Enucleation in Cornea Donors Regarding Microbial Contamination in Organ Culture Medium - a Prospective Monocentric Study over 9 Years

BACKGROUND

CORNEAS NEEDED FOR KERATOPLASTY CAN BE HARVESTED USING TWO TECHNIQUES: whole globe enucleation and in situ excision of the corneoscleral disc. This study evaluates the rate of microbial contamination of the donor cornea organ culture medium according to the method of retrieval.

METHODS

All donor corneas of our cornea bank received between January 1, 2001 and December 31, 2009 put into organ culture and microbio-logically tested were prospectively analyzed for microbial contamination of the organ culture medium.

RESULTS

2,805 donor corneas could be included in this study in total. 975 of them were retrieved by whole globe enucleation (group 1) and 1,830 by in situ corneoscleral disc excision (group 2). 15 corneas of group 1 (1.5%) and 46 corneas of group 2 (2.5%) showed a contamination of the organ culture medium. The difference was shown not to be statistically significant (p = 0.082).

CONCLUSION

The rate of microbial contamination in organ-cultured donor corneas does not seem to be dependent on the method of their retrieval.

Validation of the Microbiological Testing of Tissue Preparations Using the BACTEC™ Blood Culture System

BACKGROUND

Since blood culture bottles are validated by the manufacturer for blood only, an additional validation for the use with fluids of tissue preparations is necessary.

METHODS

Two 10-ml samples of cornea culture medium, histidine-tryptophan-ketoglutarate (HTK) solution, or Ringer solution at the end of femur head thermo-disinfection were given into blood culture bottles (BD BACTEC™ Plus Aerobic/F, Anaerobic/F for cornea culture medium and BD BACTEC™ Standard Aerobic/Anaerobic for HTK and Ringer solution) and subsequently spiked with 10-100 colony forming units (CFU) of bacteria or fungi (aerobic bacteria: Staphylococcus aureus, Bacillus subtilis, Pseudomonas aeruginosa; anaerobic bacteria: Clostridium sporogenes; fungi: Candida albicans, Aspergillus brasiliensis) according to the European Pharmacopoeia Chapter 2.6.1.

RESULTS

All tested bacteria and fungi could be detected in all solutions. All positive and negative controls were tested correctly. Compared to the positive controls, the microbial growth was delayed in the antibiotic-containing cornea culture medium, and negative in two cases of B. subtilis spiking.

CONCLUSION

The use of BACTEC™ blood culture bottles seems to be a suitable method for microbiological testing of HTK solution, Ringer solution, and, with limitations, also for testing of the antibiotic-containing cornea culture medium.

Virus NAT for HIV, HBV, and HCV in Post-Mortal Blood Specimens over 48 h after Death of Infected Patients - First Results

OBJECTIVE

According to EU regulations (EU directive 2006/17/EC), blood specimens for virologic testing in the context of post-mortal tissue donation must be taken not later than 24 h post mortem.

METHODS

To verify validity of NAT in blood specimens collected later, viral nucleic acid concentrations were monitored in blood samples of deceased persons infected with HIV (n = 7), HBV (n = 5), and HCV (n = 17) taken upon admission and at 12 h, 24 h, 36 h and 48 h post mortem. HIV and HCV RNA were quantified using Cobas TaqMan (Roche), HBV DNA was measured by in-house PCR.

RESULTS

A more than 10-fold decrease of viral load in samples taken 36 h or 48 h post mortem was seen in one HIV-infected patient only. For all other patients tested the decrease of viral load in 36-hour or 48-hour post-mortal samples was less pronounced. Specimens of 3 HIV- and 2 HBV-infected patients taken 24 h post mortem or later were even found to have increased concentrations (>10-fold), possibly due to post-mortem liberation of virus from particular cells or tissues.

CONCLUSION

Our preliminary data indicate that the time point of blood collection for HIV, HBV and HCV testing by PCR may be extended to 36 h or even 48 h post mortem and thus improve availability of tissue donations.

Coding of tissue preparations with eurocode in Germany

SUMMARY

A safe look back of products requires their unique identification. Blood products are encoded in Germany with Eurocode since 1987. EU Directives 2004/23/EC und 2006/86/EC demanded unique identification and safe look back procedure also for tissues and cells. Eurocode IBLS e.V. and the DGTI working parties 'Tissue Preparations' and 'Automation and Data Processing' supplemented the already available Eurocode nomenclature for blood products with further data structures for tissue preparations and deliberated the federal authorities during the EU hearings. In result all EU member states can administer the coding system oneself, but have to take care about the 'key code' structure as defined and the common part at the begin of the ID number of the preparations. Eurocode today offers an EU-conform coding system considering various aspects of blood, tissue and cell preparations in an ISO-standardized form.

Comparative infectious serology testing of pre- and post-mortem blood samples from cornea donors

Defined serological blood tests of deceased cornea donors are required to minimize the risk of viral infections of a transplant recipient as much as possible. Haemolysis, autolysis and bacterial contamination, may produce significant changes of post-mortem blood samples, which may lead to false serological test results. Pre- and post-mortem findings from the same cornea donors of the University Tissue Bank of the Charité in the years 2004-2009 (n = 487) were retrospectively analyzed and compared. The test results from pre-mortem blood samples were defined as the reference for the post-mortem blood test. Of 487 cornea donors, there were a total of 21 cases (4.3%) with discrepancies between serological test results from pre- and post-mortem blood samples. Of these, 7 values referred to the HBsAg-testing, 3 to the anti-HBs-, 1 to the anti-HBcIgG + IgM-, 1 to the anti-HCV-, 4 to the anti-HIV 1/2- and 5 to the TPLA-findings. False negative results within post-mortem serology occurred in 4 of 487 cases (0.8%). False positive results within the post-mortem blood samples occurred at a much more frequent rate, with 17 of 487 cases (3.5%). Discrepancies between serological pre- and post-mortem blood tests occur mainly due to the use of non-validated test systems. Therefore, it seems reasonable to test pre- and post-mortem blood samples serologically, whenever possible, at the same time, regardless of the sample age. Positive results, regardless of the sample type, should always be retested with validated confirmation tests (e.g. NAT), in order to differentiate between false and true positive results.

Human platelet-rich plasma stimulates migration and chondrogenic differentiation of human subchondral progenitor cells

In cartilage repair, platelet-rich plasma (PRP) is used in one-step approaches utilizing microfracture and matrix-induced chondrogenesis procedures, bone marrow-derived cell transplantation, or intra-articular injection. The aim of our study was to evaluate the effect of human PRP on the migration and chondrogenic differentiation of human subchondral progenitors. Human progenitors were derived from subchondral cortico-spongious bone (CSP), were analyzed for their migration capacity upon PRP treatment in 96-well chemotaxis assays and cultured in high-density pellet cultures under serum-free conditions in the presence of 5% PRP. Chemotaxis assays showed that 0.1-100% PRP significantly (p < 0.05) stimulate the migration of CSP compared to untreated controls. Histological staining of proteoglycan and immuno-staining of type II collagen indicated that progenitors stimulated with PRP show significantly increased cartilage matrix formation compared to untreated progenitors. Real-time gene expression analysis of typical chondrocyte marker genes as well as osteogenic and adipogenic markers like osteocalcin and fatty acid binding protein showed that PRP induces the chondrogenic differentiation sequence of human progenitors in high-density pellet cultures, while osteogenic or adipogenic differentiation was not evident. These results suggest that human PRP may enhance the migration and stimulate the chondrogenic differentiation of human subchondral progenitor cells known from microfracture.

Sterilization with electron beam irradiation influences the biomechanical properties and the early remodeling of tendon allografts for reconstruction of the anterior cruciate ligament (ACL)

Although allografts for anterior cruciate ligament (ACL) replacement have shown advantages compared to autografts, their use is limited due to the risk of disease transmission and the limitations of available sterilization methods. Gamma sterilization has shown detrimental effects on graft properties at the high doses required for sufficient pathogen inactivation. In our previous in vitro study on human patellar tendon allografts, Electron beam (Ebeam) irradiation showed less detrimental effects compared to gamma sterilization (Hoburg et al. in Am J Sports Med 38(6):1134-1140, 2010). To investigate the biological healing and restoration of the mechanical properties of a 34 kGy Ebeam treated tendon allograft twenty-four sheep underwent ACL replacement with either a 34 kGy Ebeam treated allograft or a non-sterilized fresh frozen allograft. Biomechanical testing of stiffness, ultimate failure load and AP-laxity as well as histological analysis to investigate cell, vessel and myofibroblast-density were performed after 6 and 12 weeks. Native sheep ACL and hamstring tendons (HAT, each n = 9) served as controls. The results of a previous study analyzing the remodeling of fresh frozen allografts (n = 12) and autografts (Auto, n = 18) with the same study design were also included in the analysis. Statistics were performed using Mann-Whitney U test followed by Bonferroni-Holm correction. Results showed significantly decreased biomechanical properties during the early remodeling period in Ebeam treated grafts and this was accompanied with an increased remodeling activity. There was no recovery of biomechanical function from 6 to 12 weeks in this group in contrast to the results observed in fresh frozen allografts and autografts. Therefore, high dose Ebeam irradiation investigated in this paper cannot be recommended for soft tissue allograft sterilization.

Inactivation Effect of Standard and Fractionated Electron Beam Irradiation on Enveloped and Non-Enveloped Viruses in a Tendon Transplant Model

BACKGROUND: For increasing allograft tendon safety in reconstructive surgery, an effective sterilization method achieving sterility assurance including viruses without impairing the grafts properties is needed. Fractionated Electron Beam (Ebeam) has shown promising in vitro results. The proof of sufficient virus inactivation is a central part of the process validation. METHODS: The Ebeam irradiation of the investigated viruses was performed in an optimized manner (oxygen content < 0.1%, -78 °C). Using principles of a tendon model the virus inactivation kinetics for HIV-2, HAV, pseudorabies virus (PRV) and porcine parvovirus (PPV) were calculated as TCID(50)/ml and D(10) value (kGy) for the fractionated (10 × 3.4 kGy) and the standard (1 × 34 kGy) Ebeam irradiation. RESULTS: All viruses showed comparable D(10) values for both Ebeam treatments. For sufficient virus titer reduction of 4 log(10) TCID(50)/ml, a dose of 34 kGy of the fractionated Ebeam irradiation was necessary in case of HIV-2, which was the most resistant virus investigated in this study. CONCLUSION: The fractionated and the standard Ebeam irradiation procedure revealed comparable and sufficient virus inactivation capacities. In combination with the known good biomechanical properties of fractionated Ebeam irradiated tendons, this method could be a safe and effective option for the terminal sterilization of soft tissue allografts.

Characteristic Markers of the WNT Signaling Pathways Are Differentially Expressed in Osteoarthritic Cartilage

OBJECTIVE

It is well known that expression of markers for WNT signaling is dysregulated in osteoarthritic (OA) bone. However, it is still not fully known if the expression of these markers also is affected in OA cartilage. The aim of this study was therefore to examine this issue.

METHODS

Human cartilage biopsies from OA and control donors were subjected to genome-wide oligonucleotide microarrays. Genes involved in WNT signaling were selected using the BioRetis database, KEGG pathway analysis was searched using DAVID software tools, and cluster analysis was performed using Genesis software. Results from the microarray analysis were verified using quantitative real-time PCR and immunohistochemistry. In order to study the impact of cytokines for the dysregulated WNT signaling, OA and control chondrocytes were stimulated with interleukin-1 and analyzed with real-time PCR for their expression of WNT-related genes.

RESULTS

Several WNT markers displayed a significantly altered expression in OA compared to normal cartilage. Interestingly, inhibitors of the canonical and planar cell polarity WNT signaling pathways displayed significantly increased expression in OA cartilage, while the Ca(2+)/WNT signaling pathway was activated. Both real-time PCR and immunohistochemistry verified the microarray results. Real-time PCR analysis demonstrated that interleukin-1 upregulated expression of important WNT markers.

CONCLUSIONS

WNT signaling is significantly affected in OA cartilage. The result suggests that both the canonical and planar cell polarity WNT signaling pathways were partly inhibited while the Ca(2+)/WNT pathway was activated in OA cartilage.

Ten years of clinical results with a tissue-engineered pulmonary valve

BACKGROUND

This study was performed to collect prospective safety and effectiveness data from a tissue-engineered heart valve implanted for reconstruction of the right ventricular outflow tract during the Ross operation.

METHODS

From May 2000 until June 2002, 11 consecutive patients, mean age 39.6 ± 10.3 years, received a tissue-engineered heart valve (additive and logistic European System for Cardiac Operative Risk Evaluation, respectively, 3.3 ± 1.3 and 2.8% ± 1.4%). Two to four weeks prior to the Ross operation a piece of forearm vein or saphenous vein was harvested to isolate, characterize, and expand endothelial cells. A cryopreserved pulmonary allograft was decellularized, coated, and seeded with autologous vascular endothelial cells, using a specially developed bioreactor. Cell seeding density was 1.1 × 10(5) ± 0.5 × 10(5) cells/cm(2) with a viability of 93.2% ± 2.1%.

RESULTS

All patients survived surgery. Postoperatively no fever of unknown origin was evident. Currently all patients are in New York Heart Association class I. Evaluation of the tissue-engineered heart valve by transthoracic echocardiography showed a mean pressure gradient of 5.4 ± 2.0 mm Hg at 10 years. Multislice computed tomography showed no calcification up to 10 years.

CONCLUSIONS

Tissue-engineered heart valves showed excellent hemodynamic performance and may prevent degeneration during long-term follow-up.

Validation of the Serological Testing for Anti-HIV-1/2, Anti-HCV, HBsAg, and Anti-HBc from Post-mortem Blood on the Siemens-BEP-III Automatic System

BACKGROUND: Some properties of blood are modified post mortem. These modifications might give false-negative or false-positive results in infectious disease testing. Most CE-marked test equipment for infectious serology testing is not validated for testing post-mortal blood. Validation, however, is obligatory, if the results are used for the release of tissues for transplantation. MATHODS: Samples of pre- and post-mortem sera were obtained from 20 cornea donors, and the results were compared for anti-HIV-1/2, anti-HCV, HBsAg, and anti-HBc on the Siemens-BEP-III Automatic System. Negative post-mortem sera were spiked with standard sera (PEI anti-HCV IgG, PEI HBsAg ad 1000 standard, anti-HBc IgG (WHO) NIBSC 95/522, PEI anti-HIV-IV) in concentrations which give low- and high-positive results for the respective marker. RESULTS: All pre-mortem sera were negative for all markers. None of the post-mortem samples was false-positive. None of the spiked postmortem samples was false-negative. Technical errors occurred during the validation process but could be detected and eliminated. Serum samples should be centrifuged immediately after collection, and it must be taken into account that post-mortem serum could rarely lead to blockage of pipetting systems due to clotting phenomena. CONCLUSION: There is no indication that post-mortem samples give false-negative or false-positve results with the test system and test kits used. The procedure described might serve as a model for validating other test kits on post-mortem samples.

Tissue donation and virus safety: more nucleic acid amplification testing is needed

In tissue and organ transplantation, it is of great importance to avoid the transmission of blood-borne viruses to the recipient. While serologic testing for anti-human immunodeficiency virus (HIV)-1 and -2, anti-hepatitis C virus (HCV), hepatitis B surface antigen (HBsAg), anti-hepatitis B core antigen (HBc), and Treponema pallidum infection is mandatory, there is until now in most countries no explicit demand for nucleic acid amplification testing (NAT) to detect HIV, hepatitis B virus (HBV), and HCV infection. After a review of reports in the literature on viral transmission events, tissue-specific issues, and manufacturing and inactivation procedures, we evaluated the significance of HIV, HCV, and HBV detection using NAT  in  donors of various types of tissues and compared our results with the experiences of blood banking organizations. There is a significant risk of HIV, HCV, and HBV transmission by musculoskeletal tissues because of their high blood content and the high donor-recipient ratio. If no effective virus inactivation procedure for musculoskeletal tissue is applied, donors should be screened using NAT  for  HIV, HCV, and HBV. Serologically screened cardiovascular tissue carries a very low risk of HIV, HCV, or HBV transmission. Nevertheless, because effective virus inactivation is impossible (retention of tissue morphology) and the donor-recipient ratio may be as high as 1:10, we concluded that NAT  should be performed for HIV, HCV, and HBV as an additional safety measure. Although cornea allografts carry the lowest risk of transmitting HIV, HCV, and HBV  owing to corneal physiology, morphology, and the epidemiology of corneal diseases, NAT  for  HCV should still be performed. If the NAT  screening of a donor for HIV, HCV, and HBV is negative, quarantine storage of the donor tissue seems dispensable. In view of numerous synergistic effects with transfusion medicine, it would be advantageous for tissue banks to cooperate with blood bank laboratories in performing virological tests.

Tissue-engineered cartilage of porcine and human origin as in vitro test system in arthritis research

The increasing prevalence of cartilage destruction during arthritis has entailed an intensified amount for in vitro cartilage models to analyze pathophysiological processes and to screen for antirheumatic drugs. Tissue engineering offers the opportunity to establish highly organized 3D cell cultures facilitating the formation of in vitro models that reflect the human situation. We report the comparison of porcine chondrocyte pellet and alginate bead cultures as model systems for human cartilage and the further development into a human system that was applied in an arthritis model. In porcine pellet and alginate cultures, formation of cartilage matrix similar to human matrix was verified by histology and PCR. As alginate beads could be cultivated batch-wise in one well of a multiwell plate, we further developed this setting into a human system. In contrast, each pellet had to be cultivated individually in one well of a multiwell plate, which is time consuming. Following stimulation of human chondrocyte alginate cultures with conditioned media from human synovial fibroblasts derived from arthritis patients, microarray analysis verified the induction of genes related to cartilage destruction (like MMP10, -12) and inflammation (like IL6, -8 and chemokines). Several genes are coding for proteins that are members of inflammatory and catabolic pathways. Belonging to the most affected pathways, we identified the focal adhesion, cytokine-cytokine receptor interaction, ECM-receptor signalling, Jak-STAT signalling, and toll-like receptor signalling pathways, all relevant in arthritis. Therefore, we demonstrate that engineered cartilage of porcine and human origin represents a powerful in vitro model for cartilage in vivo.

Molecular signatures and new candidates to target the pathogenesis of rheumatoid arthritis

Rheumatoid arthritis (RA) is a chronic, inflammatory joint disease of unknown etiology and pronounced interpatient heterogeneity. To characterize RA at the molecular level and to uncover pathomechanisms, we performed genome-wide gene expression analysis. We identified a set of 1,054 genes significantly deregulated in pair-wise comparisons between RA and osteoarthritis (OA) patients, RA and normal donors (ND), or OA and ND. Correlation analysis revealed gene sets regulated identically in all three groups. As a prominent example secreted phosphoprotein 1 (SPP1) was identified to be significantly upregulated in RA compared with both OA and ND. SPP1 expression was found to correlate with genes expressed during an inflammatory response, T-cell activation and apoptosis, suggesting common underlying regulatory networks. A subclassification of RA patients was achieved on the basis of proteoglycan 4 (PRG4) expression, distinguishing PRG4 high and low expressors and reflecting the heterogeneity of the disease. In addition, we found that low PRG4 expression was associated with a more aggressive disease stage, which is in accordance with PRG4 loss-of-function mutations causing camptodactyly-arthropathy-coxa vara-pericarditis syndrome. Altogether we provide evidence for molecular signatures of RA and RA subclasses, sets of new candidate genes as well as for candidate gene networks, which extend our understanding of disease mechanisms and may lead to an improved diagnosis.

Gene expression profiling of primary human articular chondrocytes in high-density micromasses reveals patterns of recovery, maintenance, re- and dedifferentiation

The high-density micromass culture has been widely applied to study chondrocyte cell physiology and pathophysiological mechanisms. Since an integrated image has not been established so far, we analyzed the phenotypic alterations of human articular chondrocytes in this model on the broad molecular level. Freshly isolated chondrocytes were assembled as micromasses and maintained up to 6 weeks in medium containing human serum. Formation of cartilaginous extracellular matrix (ECM) was evaluated by histological and immunohistochemical staining. At 0, 3 and 6 weeks, chondrocyte micromasses were subjected to gene expression analysis using oligonucleotide microarrays and real-time RT-PCR. Micromasses developed a cartilaginous ECM rich in proteoglycans and type II collagen. On gene expression level, time-dependent expression patterns was observed. The induction of genes associated with cartilage-specific ECM (COL2A1 and COL11A1) and developmental signaling (GDF5, GDF10, ID1, ID4 and FGFR1-3) indicated redifferentiation within the first 3 weeks. The repression of genes related to stress response (HSPA1A and HSPA4), apoptotic events (HYOU1, NFKBIA and TRAF1), and degradation (MMP1, MMP10 and MMP12) suggested a recovery of chondrocytes. Constant expression of other chondrogenic (ACAN, FN1 and MGP) and hypertrophic markers (COL10A1, ALPL, PTHR1 and PTHR2) indicated a pattern of phenotypic maintenance. Simultaneously, the expression of chondrogenic growth (BMP6, TGFA, FGF1 and FGF2) and transcription factors (SOX9, EGR1, HES1 and TGIF1), and other cartilage ECM-related genes (COMP and PRG4) was consistently repressed and expression of collagens related to dedifferentiation (COL1A1 and COL3A1) was steadily induced indicating a progressing loss of cartilage phenotype. Likewise, a steady increase of genes associated with proliferation (GAS6, SERPINF1, VEGFB and VEGFC) and apoptosis (DRAM, DPAK1, HSPB, GPX1, NGFRAP1 and TIA1) was observed. Sequence and interplay of identified expression patterns suggest that chondrocyte micromass cultures maintain a differentiated phenotype up to 3 weeks in vitro and might be useful for studying chondrocyte biology, pathophysiology and differentiation. Cultivation longer than 6 weeks leads to progressing dedifferentiation of chondrocytes that should be considered on long-term evaluations.

Lyophilised plasma: evaluation of clotting factor activity over 6 days after reconstitution for transfusion

Aims

Little is known about long-term stability of clotting factors in dissolved human lyophilised plasma. This study evaluated clotting factor and inhibitor activity in reconstituted lyophilised plasma after storage for up to 6 days at 4°C.

Methods

Five samples from different lots of pooled lyophilised plasma (LyoPlas; German Red Cross Blood Transfusion Service West) were reconstituted. The activity of fibrinogen, factor II (FII), FV, FVII, FVIII, FIX, FX, FXI, FXII, FXIII, antithrombin, plasmin inhibitor, von Willebrand factor antigen, free protein S and protein C were determined immediately and at 2, 4, 6, 24, 48, 72, 96, 120 and 144 h after reconstitution. Tests for bacterial contamination were performed after 12, 72 and 144 h from each plasma bottle.

Results

Storage at 4°C for 6 h led to a decrease in the activity of FVIII (Δ −14.9%), FIX (Δ −6.9%) and FXI (Δ −6.3%), and an increase in the activity of plasmin inhibitor (Δ +10.2%). Storage for up to 6 days resulted in a further decrease in activity of FVIII (Δ −24.3%), FIX (Δ −13.4%) and FXI (Δ −22.9%), and, additionally, a decrease in the activity of FV (Δ −15.0%), fibrinogen (Δ −6.9%) and plasmin inhibitor (Δ −17.5%). Other factors and inhibitors, with exception of protein C (Δ +8.2%), remained almost unchanged over time. Blood cultures were sterile and showed no bacterial growth.

Conclusions

The activity of all measured coagulation factors and inhibitors in a time course of up to 6 days met required quality standards. Further in vivo testing is required to demonstrate safety and efficacy of extended clinical use of refrigerated reconstituted lyophilised plasma.

"Eurocode International Blood Labeling System" enables unique identification of all biological products from human origin in accordance with the European Directive 2004/23/EC

Due to their limited availability and compatibility, biological products must be exchanged between medical institutions. In addition to a number of national systems and agreements which strive to implement a unique identification and classification of blood products, the ISBT 128 was developed in 1994, followed by the Eurocode in 1998. In contrast to other coding systems, these both make use of primary identifiers as stipulated by the document ISO/IEC 15418 of the International Organization for Standardization (ISO), and thus provide a unique international code. Due to their flexible data structures, which make use of secondary identifiers, both systems are able to integrate additional biological products and their producers. Tissue and cells also constitute a comparable risk to the recipient as that of blood products in terms of false labeling and the danger of infection. However, in contrast to blood products, the exchange of tissue and cells is much more intensively pursued at the international level. This fact is recognised by Directives 2004/23/EC and 2006/86/EC of the European Union (EU), which demand a standardized coding system for cells and tissue throughout the EU. The 2008 workshop agreement of the European Committee for Standardization (CEN) was unique identification by means of a Key Code consisting of country code corresponding to ISO 3166-1, as well as competent authority and tissue establishment. As agreed at the meeting of the Working Group on the European Coding System for Human Tissues and Cells of the Health and Consumers Directorate-General of the European Commission (DG SANCO) held on 19 May 2010 in Brussels, this Key Code could also be used with existing coding systems to provide unique identification and allow EU traceability of all materials from one donation event. Today Eurocode already uses country codes according to ISO 3166-1, and thus the proposed Key Code can be integrated into the current Eurocode data structure and does not need to be introduced separately. The Eurocode product classification for all products is based on its own unique coding system, which can be accessed over the internet by all users who are not themselves members of Eurocode. In summary, it can be said that the standardized single coding system for tissues and cells requires only unique sections in the data structure such the Key Code to fulfil the requirements of the EU Directive. Thus, various systems currently in place in different EU member states can continue to operate if the Key Code as suggested by the EU is integrated into them. The classification and description of each product characteristic is currently being discussed by the DG SANCO Working Group on the European Coding System for Human Tissues and Cells. Following intensive scrutiny in light of the stipulations laid out in EU Directives 2004/23/EC and 2006/86/EC as well as the CEN/ISSS workshop agreements, the Germany Federal Ministry for Health and organisations representing German tissue establishments under the responsibility of the German Society of Transfusion Medicine and Immunohematology, Working Party "Tissue preparations" proposed in 2009 that Eurocode be adopted for the donor identification and product coding of tissue and cells in Germany. The technical details for implementation have already been completed and are presented in the current article.

Effect of electron beam irradiation on biomechanical properties of patellar tendon allografts in anterior cruciate ligament reconstruction

BACKGROUND

Sterilization of anterior cruciate ligament (ACL) allografts is an important prerequisite to prevent disease transmission. However, mechanical tissue properties are compromised by most current sterilization procedures, so that uncompromised sterilization of allografts is difficult to achieve. Hypothesis/

PURPOSE

The aim of this study was to evaluate the effect of the novel electron beam sterilization procedure on the biomechanical properties of human patellar tendon allografts at various irradiation dosages. Electron beam sterilization may be an appropriate alternative to gamma sterilization.

STUDY DESIGN

Controlled laboratory study.

METHODS

Thirty-two human 10-mm wide bone-patellar tendon-bone grafts were randomized into 4 groups of sterilization with 15, 25, or 34 kGy of electron beam irradiation, respectively. The grafts' biomechanical properties were evaluated at time zero. Unsterilized grafts functioned as controls. Biomechanical properties were analyzed during cyclic and load-to-failure testing.

RESULTS

Strain and cyclic elongation response showed no significant differences between the groups. Electron beam irradiation had no significant effect on stiffness and failure load with the exception of 34 kGy, which resulted in a significant decrease in failure load (1300.6 +/- 229.2 N) compared with unsterilized grafts (1630.5 +/- 331.1 N).

CONCLUSION

This study showed that electron beam might be an appropriate alternative in sterilization of patellar tendon allografts with minimal effect on mechanical properties of tendon grafts in vitro. Future studies will have to evaluate the effect of the process on the biological properties of allografts in vitro and in vivo.

CLINICAL RELEVANCE

Terminal sterilization of patellar tendon allografts with electron beam irradiation can ensure higher safety of transplanted grafts and hence improve patient safety and acceptance.

Current concepts for quality assured long-distance transport of temperature-sensitive red blood cell concentrates

BACKGROUND AND OBJECTIVES

The German Armed Forces Blood Service in Koblenz supplies red blood cell concentrates (RBCs) to military and civilian institutions at home and to field hospitals during peacekeeping operations abroad. During long-distance transport, blood products can be exposed to extreme environmental conditions or inappropriate handling, which may compromise product quality.

MATERIALS AND METHODS

Different active and passive cooling systems, cooling elements, packaging material and data loggers were examined in a climate chamber. A number of techniques for measuring temperature were investigated in order to preserve the blood products' quality during transport, including some field tests with multiparametric data recording.

RESULTS

Any kind of active cooling systems, conventional cooling elements and customary packaging material, as well as temperature-sensitive labels, minimum-maximum thermometers and intra-product measurement were found to be unsuitable for military requirement. The best results were obtained when the passively cooling RCB 25 transport box (Dometic) was used together with latent heat/cold storage elements (deltaT) and Junior data loggers (Escort).

CONCLUSION

The elaborated protocol allows temperatures to be maintained between 2 and 6 degrees C as required by European guidelines for at least 36 h each and between 1 and 10 degrees C as required by German guidelines for at least 48 or 64 h at ambient temperatures between -10 and 40 degrees C. Preliminary results indicate that care must be taken concerning additional factors such as air pressure variation or vibration.

Validation of a hospital-laboratory workstation for immunohematologic methods

BACKGROUND

The FREELYS Nano system (Diagast) is a manual workstation for ABO/D grouping, Rh phenotyping, K typing, and antibody screening (ABS) for immunoglobulin G (IgG) antibodies only and works with the erythrocyte-magnetized technology (EMT). The principle of EMT is based on magnetization of red blood cells and avoids centrifugation and washing steps.

STUDY DESIGN AND METHODS

A total of 304 samples were tested with our routine blood bank methods, 100 samples for ABO/D grouping, 196 samples (100 at first evaluation, 96 at second evaluation) for Rh phenotyping and K typing (PK7200, Olympus), and 108 samples for ABS (DiaMed). All samples were tested in parallel with the FREELYS Nano.

RESULTS

We found a 100% concordance between the observed (FREELYS Nano) and the expected (Olympus PK7200) results for ABO/D grouping in all 100 samples. For Rh phenotyping and K tests, in 24 of 100 samples false-positive reactions were observed in the first evaluation by the FREELYS Nano. After changing the test kit batch for Rh phenotyping by the manufacturer, a complete concordance in Rh phenotyping and K tests was observed in a second evaluation. For ABS, the FREELYS Nano showed in 4 of 108 samples (3.7%) false-negative reactions for IgG antibodies (two anti-K, one anti-E, one anti-C(w)), and one (0.9%) false-positive reaction.

CONCLUSIONS

The FREELYS Nano is reliably suited to ABO/D grouping, Rh phenotyping, and K testing. The rate of false-negative reactions for IgG antibodies should be reduced.

[Procedural guidelines. Good tissue practice for cornea banks]

A cornea bank must have an organizational structure in which responsibility and authority to issue directives are clearly defined. It must also use a documented quality management system on the basis of good practice procedures which is maintained to the current standards. The personnel of a cornea bank must be present in sufficient numbers and be suitably qualified. A cornea bank must be in possession of appropriate facilities which are suitable for the main purpose of conservation of donor corneas. All equipment must be designed and maintained corresponding to the intended purpose. Deviations from the stipulated quality and safety standards must give rise to documented investigations which include decisions on options for correctional and preventive measures. Acquisition of donors and tissue sampling must be strictly controlled and documented. This also applies to entry of donor tissue in the cornea bank. During conservation a microscopic examination of the endothelial cell layer must be carried out at least once. Measures must be taken to keep the risk of contamination as low as possible. Donor corneal tissue can only be released if defined criteria are fulfilled. Any suspicion of severe undesired reactions and events for the recipient of a corneal transplant must be registered with the authorities. The activities of a cornea bank must maintain and adapt the state-of-the-art with respect to scientific progress.

Specific magnetic bead-based capture of free fetal DNA from maternal plasma

An automated magnetic capture hybridization (MCH) method for the extraction and enrichment of fetal RHD specific DNA fragments from maternal plasma was developed using plasma from 1000 D-negative pregnant women. A real time PCR protocol for RHD exon 7 was applied. MCH was compared with the QIAamp DSP Virus Kit (QIAamp) as a reference. Compared with the QIAamp method, the percentage of fetal DNA increased from 2.86% to 4.83% (p<0.05, n=8). The 95% detection limit of MCH was determined at 286 pg/ml (43 geg/ml) compared with 138 pg/ml (21 geq/ml) for the QIAamp DSP Virus Kit.

Allogenic versus autologous cancellous bone in lumbar segmental spondylodesis: a randomized prospective study

The current gold standard in lumbar fusion consists of transpedicular fixation in combination with an interbody interponate of autologous bone from iliac crest. Because of the limited availability of autologous bone as well as the still relevant donor site morbidity after iliac crest grafting the need exists for alternative grafts with a comparable outcome. Forty patients with degenerative spinal disease were treated with a monosegmental spondylodesis (ventrally, 1 PEEK-cage; dorsally, a screw and rod system), and randomly placed in two groups. In group 1, autogenous iliac crest cancellous bone was used as a cage filling. In group 2 the cages were filled with an allogenic cancellous bone graft. Following 3, 6, 9 and 12 months, the clinical outcome was determined on the basis of: the Oswestry Low Back Pain Disability Questionnaire; patient satisfaction; patient willingness to undergo the operation again; and a visual analog scale for pain. The radiological outcome was based on both fusion rate (radiographs, computed tomography), and on the bone mineral density of the grafts. After 6 months, the X-rays of the patients in group 2 had a significantly lower rate of fusion. Aside from this, there were no further significant differences. After 12 months, radiological results showed a similar fusion rate in both groups. Donor site complications consisted of five patients with hematoma, and three patients with persistent pain in group 1. No implant complications were observed. If a bone bank is available for support and accepting the low risk of possible transmission of infectious diseases, freeze-dried allogenic cancellous bone can be used for monosegmental spondylodeses. The results demonstrated an equivalent clinical outcome, as well as similar fusion rates following a 12-month period. This is in despite of a delayed consolidation process.

Influence of blood donation on levels of water-soluble vitamins

Iron depletion is a well-known side effect of blood donation. Research evidence also suggests an increasing prevalence of vitamin deficiency in apparently healthy subjects, but there is little information regarding the relationship between blood donation and vitamin status. A total of 217 volunteers (80 first-time and 137 repeat blood donors) were consecutively enrolled in the study. All subjects completed self-administered medical history and food intake forms, which included questions regarding alcohol consumption and smoking as well as on vitamin supplement, iron and contraceptive use (females). Vitamin B6, folic acid, vitamin B12 and biotin levels were measured using standard techniques. The mean vitamin levels of first-time and repeat blood donors did not significantly differ. Vitamin deficiencies occurred in both first-time and repeat blood donors but not on vitamin supplements. Vitamin status was affected by alcohol, nicotine and contraceptives. Blood donation does not decrease the level of water-soluble vitamins. Vitamin deficiencies occur in apparently healthy first-time as well as in repeat blood donors and can be prevented by vitamin supplementation.

[Modified acetabuloplasty using bioresorbable screws and lyophilised allogenic bone]

AIM

Various pericapsular procedures are available to surgically improve the acetabular coverage of the femoral head prior to closure of the triradiate cartilage. In this study the acetabuloplasty with the modification according to Westin (Pember-Sal) was applied. Indications for surgery were congenital hip dysplasia or luxation as well as Perthes' disease. To date, the standard procedures for acetabuloplasty include the transplantation of an autologous iliac crest bone graft and the fixation with K-wires. The aim of this study was to investigate if a modification of the operative procedure with the use of resorbable screws and allogenic bone transplants can minimise the operative trauma, avoid a second procedure, and permit MRI follow-ups without increasing the risk of the operation.

METHOD

15 patients with a mean age of 6.7 years were included in this case series and treated with a modified acetabuloplasty for the indication hip dysplasia or Perthes' disease. The modification of the standard procedure included the transplantation of allogenic bone wedges customised from lyophilised femoral grafts. The fixation was performed with bioresorbable polylactide screws. Clinical and radiographical follow-ups were conducted.

RESULTS

Procedure-related complications occurred neither in the intra- nor the postoperative period. The allogenic bone graft was remodelled successively as seen on radiographic controls. Dislocations of the bone wedges were not detectable. Subsiding of the allograft did not occur to a noticeable extent as the acetabular index showed no increase during follow-up.

CONCLUSION

This study presents a gentle method of acetabuloplasty which avoids iliac crest bone harvesting with its known complications as well as a second procedure under anaesthesia for the removal of implants.

Remodeling of ACL allografts is inhibited by peracetic acid sterilization

Sterilization of allografts for anterior cruciate ligament (ACL) reconstruction has become an important prerequisite to prevent disease transmission. However, current sterilization techniques impair the biological or mechanical properties of such treated grafts. Peracetic acid (PAA) has been successfully used to sterilize bone allografts without these disadvantages and does not impair the mechanical properties of soft tissue grafts in vitro. We asked whether PAA sterilization would influence recellularization, restoration of crimp length and pattern, and revascularization of ACL grafts during early healing. We used an in vivo sheep model for open ACL reconstruction. We also correlated the histologic findings with the restoration of anteroposterior stability and structural properties during load-to-failure testing. PAA slowed remodeling activity at 6 and 12 weeks compared to nonsterilized allografts and autografts. The mechanical properties of PAA grafts were also reduced compared to these control groups at both time points. We conclude PAA sterilization currently should not be used to sterilize soft tissue grafts typically used in ACL reconstruction.

Association between alloantibody specificity and autoantibodies to red blood cells

BACKGROUND

Alloantibodies (ALLOs) to red blood cells (RBCs) are frequently associated with autoantibodies (AABs). An association between ALLO specificity and AABs has not yet been described.

STUDY DESIGN AND METHODS

All patients and healthy blood donors screened for RBC antibodies between 2000 and 2006 were included. The odds ratio (OR) for ALLOs in patients with AABs compared to those without AABs was correlated with the OR of general ALLO prevalence in patients with AABs (normalized OR).

RESULTS

ALLOs were found in 4,626 of 204,330 patients and healthy blood donors (2.3%). The ALLOs were associated with AABs in 413 cases (8.9%). Among the specificities, anti-S with a normalized OR of 2.9 was overrepresented. This was most evident in pregnant women who showed a normalized OR of 15.1 for anti-S and AABs. The normalized OR revealed an additional association between Rh antibodies and AABs. No association was found between ALLOs to the Kell glycoprotein, Duffy protein, Lewis, or glycophorin A (M/N) and AABs.

CONCLUSION

The majority of associated ALLOs and AABs are directed against neighboring antigens of the Rh complex and glycophorin B.

No influence of collagenous proteins of Achilles tendon, skin and cartilage on the virus-inactivating efficacy of peracetic acid–ethanol

The risk of transmitting human pathogenic viruses via allogeneic musculoskeletal tissue transplants is a problem requiring effective inactivation procedures. Virus safety of bone transplants was achieved using peracetic acid (PAA)-ethanol sterilisation. Proteins are known to have an adverse effect on the virus-inactivating capacity of PAA. Therefore we investigated virus inactivation by PAA in collagenous tissues. Achilles tendon, skin and cartilage were cut into small pieces, lyophilised and contaminated with pseudorabies virus (PRV) or porcine parvovirus (PPV). The inactivating capacity of PAA-ethanol was investigated by determining virus titres in the supernatant or the tissue pellet at different time-points. In all virus-contaminated tissue samples treatment for 10 min with PAA-ethanol resulted in titre reductions by a factor of >10(3). PRV was rapidly inactivated below the detection limit (< or =2.8 x 10(1) TCID(50)/ml). After 240 min a reduction by a factor of >10(4) was obtained for PPV in all samples, but a residual infectivity remained. Collagenous proteins of Achilles tendon, skin and cartilage had no adverse effect on the virus-inactivating capacity of PAA. PAA-ethanol used in the production process at the Charité tissue bank can therefore be recommended for treatment of non-osseous musculoskeletal tissues.