Osteonecrosis of the jaw in patients transitioning from bisphosphonates to denosumab treatment for osteoporosis.

Antiresorptive-related osteonecrosis of the jaw (ARONJ) is a rare but severe side effect of antiresorptive treatment with bisphosphonates or RANKL-antibody denosumab in patients with malignant diseases or osteoporosis. Whilst osteonecrosis of the jaw (ONJ) related to the administration of bisphosphonates (BPs) has been investigated for more than 1 decade now, only few data are available on denosumab-related ONJ, especially in patients with osteoporosis. From 2008 to 2016, 52 osteoporosis patients were treated with ARONJ in the Department of Oral and Maxillofacial Surgery, University Medical Center Freiburg, Germany. In all patients, a surgical regimen consisting of complete removal of necrotic bone, primary wound closure and perioperative i.v. antibiotic therapy was applied. Of the 52 patients, 38 developed ARONJ after BP monotherapy; in 11 patients, antiresorptive therapy had been transitioned from BPs to denosumab and 3 patients had received denosumab monotherapy. From July 2013, when the first patient with ONJ and transitioning therapy from BPs to denosumab presented to our department, to October 2016, we found recurrences in 17.6% of the patients with BP monotherapy and in 45.5% of the patients with transitioning therapy from BPs to denosumab. Transitioning antiresorptive therapy from BPs to denosumab may be an additional risk factor for developing ARONJ. In these patients, treatment of ARONJ-lesions seems to provoke more complications. An additional dental screening before transitioning should be initiated. Further studies are needed to evaluate if a first-line treatment with denosumab decreases the incidence of ARONJ in patients with osteoporosis and simplifies its treatment.

Update MRONJ and perspectives of its treatment.

Antiresorptive agents are widely used in catabolic bone diseases. Not only bisphosphonates but also new drugs like Denosumab may induce osteonecrosis of the jaw as a side effect. The present review describes the current effect mechanisms of commonly used antiresorptives, pathogenetic theories for the development of antiresorptive-related osteonecrosis of the jaw (ARONJ), and potential risk factors. Furthermore, diagnostic modalities and treatment options as well as new and innovative strategies are discussed. The major key factor to avoid the occurrence of ARONJ still remains the implementation of throughout preventive measures.

A prospective study of factors influencing morbidity after iliac crest harvesting for oral onlay grafting.

OBJECTIVE: The present study evaluates the morbidity after iliac crest harvesting from the anterior iliac rim for oral onlay grafting and identifies influential factors. MATERIAL AND METHODS: Twenty partially edentulous or edentulous patients (15 females and 5 males) with a mean age of 54.25 years (range 20-78 years, SD 13.86 years, remaining bone height <5 mm of the alveolar ridge) underwent iliac onlay bone grafting. The postoperative clinical morbidity was classified in minor and major complications and was evaluated with respect to body mass index (BMI). RESULTS: The grafting procedure was successfully performed in all patients with a mean BMI of 23.34 (range 18-29, SD 3.36). A significant difference between BMI and walking aid necessity (p = 0.018) was demonstrated, but no difference between BMI and hip pain, duration of disturbance, gait disturbance, complication rate, and sensory loss was identified (p > 0.05). Between hip pain and scar length, age and hip/jaw pain did not demonstrate a significant difference (p > 0.05). Postoperative complications were minor and consisted of hematoma, seroma, and transient sensory disturbance. CONCLUSION: Patients undergoing bone harvest from the anterior superior iliac crest with oral grafting show a low minor complication rate and a high overall satisfaction of 95%.

Long-term retrospective evaluation of the peri-implant bone level in onlay grafted patients with iliac bone from the anterior superior iliac crest.

OBJECTIVE: The purpose of the present study was to evaluate crestal bone level changes around dental implants after iliac bone augmentation in the long term. MATERIAL AND METHODS: A total of 32 partially edentulous/edentulous patients (mean age, 52 years; range, 22-70 years) and a remaining bone volume of less than 5 mm of the alveolar ridge underwent maxillary or mandibular iliac bone graft augmentation. All patients received spaced standardized radiological examination for evaluation of peri-implant crestal bone loss. RESULTS: The grafting procedure was successfully performed in all patients. A total of 150 implants were placed. The mean observation period was 69 months (range, 12-165 months; success rate for maxilla, 96%; success rate for mandible, 92%). The mean amount of crestal bone loss after 10 years was 1.8 mm. A significant difference between gender and crestal bone loss was shown, but no influence was found regarding the implant system, diameter of implant, and age of the patients. CONCLUSION: In patients with atrophic jaws, a sufficient long-term reconstruction can be achieved with the combination of iliac onlay grafting and dental implants. The results demonstrate high success rates and a stable peri-implant bone level in the long term.

Rehabilitation of irradiated patients with chemically modified and conventional SLA implants: five-year follow-up.

The aim of this study is to evaluate the clinical and radiological parameters of standard SLA surface implants compared to chemically modified hydrophilic SLActive implants in irradiated patients after the initial 12-month loading period up to 5 years. Twenty patients with a mean age of 61·1 years were treated with dental implants after ablative surgery and radio-chemotherapy of oral cancer. All patients were non-smokers. The placement of 102 implants (50 SLA, 52 SLActive) was performed bilaterally according to a split-mouth design. Mean crestal bone changes were evaluated using standardised orthopantomographies and clinical parameters. Data were analysed using a Kaplan-Meier curve, Mann-Whitney U-test and two-factorial non-parametric analysis. The average observation period was 60 months. The amount of bone loss at the implant shoulder of SLA implants was mesial and distal 0·7 mm. The SLActive implants displayed a bone loss of mesial 0·6 mm as well as distal 0·7 mm after 5 years. Two SLA implants were lost before loading. One patient lost five implants due to recurrence of a tumour. The overall cumulative 12-month, 3-year and 5-year survival rate of SLA implants was 92%, 80% and 75·8% and of SLActive implants 94·2%, 78·8% and 74·4%, respectively. Eighteen implants were considered lost because the patients had died. Sandblasted acid-etched implants with or without a chemically modified surface can be used in irradiated patients with a high predictability of success. Lower implant survival rates in patients with irradiated oral cancer may be associated with systemic effects rather than peri-implantitis.

Monitoring the variations of the oxygen transfer rate in a full scale membrane bioreactor using daily mass balances.

Oxygen transfer in biological wastewater treatment processes with high sludge concentration, such as membrane bioreactor (MBR), is an important issue. The variation of alpha-factor versus mixed liquor suspended solids (MLSS) concentration was investigated in a full scale MBR plant under process conditions, using mass balances. Exhaustive data from the Supervisory Control And Data Acquisition (SCADA) and from additional online sensors (COD, DO, MLSS) were used to calculate the daily oxygen consumption (OC) using a non-steady state mass balance for COD and total N on a 24-h basis. To close the oxygen balance, OC has to match the total oxygen transfer rate (OTRtot) of the system, which is provided by fine bubble (FB) diffusers in the aeration tank and coarse bubbles (CB) in separate membrane tanks. First assessing OTR(CB) then closing the balance OC = OTRtot allowed to calculate OTR(FB) and to fit an exponential relationship between OTR(FB) and MLSS. A comparison of the alpha-factor obtained by this balance method and by direct measurements with the off-gas method on the same plant is presented and discussed.

Management of recurrence from a retroperitoneal xanthogranuloma: case report.

Xanthogranulomas from the retroperitoneal space are rare. To our knowledge only a few cases have been reported in the literature in the retroperitoneal space. In this report, the authors present the case of a 24-year-old woman with a recurrence of this rare tumor. Two years after resection, the mass showed rapid local recurrence. Attention should be paid to the possibility of the transformation into a fibroxanthosarcoma, which could have an aggressive clinical course.

Modelling a full scale membrane bioreactor using Activated Sludge Model No.1: challenges and solutions.

A full-scale membrane bioreactor (1,600 m(3) d(-1)) was monitored for modelling purposes during the summer of 2006. A complete calibration of the ASM1 model is presented, in which the key points were the wastewater characterisation, the oxygen transfer and the biomass kinetics. Total BOD tests were not able to correctly estimate the biodegradable fraction of the wastewater. Therefore the wastewater fractionation was identified by adjusting the simulated sludge production rate to the measured value. MLVSS and MLSS were accurately predicted during both calibration and validation periods (20 and 30 days). Because the membranes were immerged in the aeration tank, the coarse bubble and fine bubble diffusion systems coexisted in the same tank. This allowed five different aeration combinations, depending whether the 2 systems were operating separately or simultaneously, and at low speed or high speed. The aeration control maintained low DO concentrations, allowing simultaneous nitrification and denitrification. This made it difficult to calibrate the oxygen transfer. The nitrogen removal kinetics were determined using maximum nitrification rate tests and an 8-hour intensive sampling campaign. Despite the challenges encountered, a calibrated set of parameters was identified for ASM1 that gave very satisfactory results for the calibration period. Matching simulated and measured data became more difficult during the validation period, mainly because the dominant aeration configuration had changed. However, the merit of this study is to be the first effort to simulate a full-scale MBR plant.

Development of a Scorpion probe-based real-time PCR for the sensitive quantification of Bacteroides sp. ribosomal DNA from human and cattle origin and evaluation in spring water matrices.

Spring water from alpine catchments are important water resources but they can be vulnerable against faecal contamination. Potential faecal contamination sources are wildlife populations, pasturing activities, or alpine tourism. Unfortunately, no faecal source tracking method is available to date which is sensitive enough for appropriate spring water monitoring and source allocation. Our purpose was to develop a Duplex Scorpion real-time PCR approach for the specific and sensitive quantification of Bacteroides sp. 16S rDNA fragments from human and cattle origin. By the developed approach, detection of plasmids, carrying the respective biomarker sequence, was possible over a range of more than seven orders of magnitudes down to six copy numbers per PCR assay. Furthermore, the Duplex Scorpion real-time PCR allowed the specific quantification down to 50 targets in plasmid spiked spring water matrices. Results indicate that microbial source tracking appears feasible in spring water habitats by probe-based real-time PCR technologies. However, preliminary testing of the established approach on faecal samples collected from a representative alpine habitat did not allow unambiguous source allocation in all cases. In the future, the available sequence database has thus to be widened to allow reliable source tracking in alpine spring watersheds and even expand this approach to other potential faecal sources.

Hindered and compression settling: parameter measurement and modelling.

The Vesilind settling velocity function forms the basis of flux theory used both in state point analysis (for design and capacity rating) and one-dimensional dynamic models (for dynamic process modelling). This paper proposes new methods to address known shortcomings of these methods, based on an extensive set of batch settling tests conducted at different scales. The experimental method to determine the Vesilind parameters from a series of bench scale settling tests is reviewed. It is confirmed that settling cylinders must be slowly stirred in order to represent settling performance of full scale plants for the whole range of solids concentrations. Two new methods to extract the Vesilind parameters from settling test series are proposed and tested against the traditional manual method. Finally, the same data set is used to propose an extension to one-dimensional (1-D) dynamic settler models to account for compression settling. Using the modified empirical function, the model is able to describe the batch settling interface independently of the number of layers.

ASM1 dynamic calibration and long-term validation for an intermittently aerated WWTP.

Activated sludge models, and ASM1 in particular, are well recognised and useful mathematical representations of the macroscopic processes involved in the biological degradation of the pollution carried by wastewater. Nevertheless, the use of these models through simulation software requires a careful methodology for their calibration (determination of the model parameters' values) and the validation step (verification with an independent data set). This paper presents the methodology and the results of dynamic calibration and validation tasks as a prior work to a modelling project for defining a reference guideline destined to French designers and operators. To reach these goals, a biological nutrient removal (BNR) wastewater treatment plant (WWTP) with intermittent aeration was selected and monitored for 2 years. Two sets of calibrated parameters are given and discussed. The results of the long-term validation task are presented through a 2-month simulation with lots of operation changes. Finally, it is concluded that, even if calibrating ASM1 with a high degree of confidence with a single set of parameters was not possible, the results of the calibration are sufficient to obtain satisfactory results over long-term dynamic simulation. However, simulating long periods reveals specific calibration issues such as the variation of the nitrification capacity due to external events.

Application of Activated Sludge Model No. 1 to biological treatment of pure winery effluents: case studies.

The practical applicability of computer simulation of aerobic biological treatment systems for winery effluents was investigated to enhance traditional on-site evaluation of new processes. As there is no existing modelling tool for pure winery effluent, a model widely used for municipal activated sludge (ASM1) was used. The calibration and validation steps were performed on extended on-site data. The global soluble COD, DO and OUR were properly reproduced. Possible causes for the remaining discrepancies between measured and simulated data were identified and suggestions for improvement directions were made to adapt ASM1 to winery effluents. The calibrated model was then used to simulate scenarios to evaluate the plant behaviour for different operation or design. In combination with on-site observations, it allowed us to establish useful and justified improvement suggestions for aeration tank and aeration device design as well as feed, draw and aeration operation.

Biodegradable osteosynthesis material for stabilization of midface fractures: experimental investigation in sheep.

The most frequently tested biodegradable osteosynthesis materials have up to now largely consisted of poly-L-lactide (PLLA). The PLLA polymers appear to have sufficient mechanical strength for fracture treatment in the midface, but their degradation does not seem to be uniform enough to allow their clinical use. During the degradation process the disintegration products elicit a foreign body reaction due to non-uniform degradation rates. The foreign body reaction is sometimes combined with a fluctuant swelling at the implantation site. Implants injection-moulded from 90:10 PLLA/PGA (polyglycolic acid) have a more uniform degradation rate and seem to lead to a milder foreign body reaction. We bridged Le Fort I osteotomies in sheep using a system of injection-moulded PLLA/PGA 90:10 plates and screws and compared it with 2 mm AO miniplates and mini-screws made from titanium. Light microscopy evaluation showed that the PLLA/PGA copolymer system experienced its highest mechanical stress at the transition from screw head to screw shaft. Nevertheless, the fragments fixed with the copolymers were on the whole only slightly less stable than those fixed with the titanium system. The foreign body reaction solely due to co-polymer degradation was not severe, considering the fibrous tissue response that was found associated with the titanium components. The study does show that the copolymer investigated is adequate for clinical use as a biodegradable osteosynthesis material, at least in low stress bearing areas.

Experimental gluing of lung parenchyma in rats.

Gelatin-resorcinol-dialdehyde adhesive has been developed from a gelatin-resorcinol-formaldehyde adhesive by replacing the formaldehyde with two less histotoxic dialdehydes, ethandial and pentandial. The aim of the present study was to evaluate the usefulness of this modified composition in gluing defects in lung parenchyma. In 40 male Wistar rats a standardized lung incision 1.0 cm in length and 0.8 cm in depth were closed by application of gelatin-resorcinol-dialdehyde adhesive. For macroscopic and microscopic examination 4 animals were sacrificed on each of postoperative days 2, 7, and 14 and 14 animals on each of postoperative days 28 and 120. Macroscopic examination revealed a tight closure of the parenchymal defects in all postoperative stages. Initially by an adhesive layer and later on by granulation tissue and scar tissue respectively. On microscopic examination an inflammatory tissue response with polymorphonuclear neutrophils and macrophages predominating was found 2 days postoperatively. After 7 days multinucleated giant cells appeared. On postoperative day 14 the tissue response presented a distinct granulomatous character with multinucleated giant cells persisting. After 28 days remnants of adhesive surrounded by granulation tissue were detectable. On postoperative day 120 the adhesive had been completely resorbed and the parenchymal defect was replaced by fibrous scar tissue. The gelatin-resorcinol-adhesive proved effective in tight closure of lung parenchyma in rats. The adhesive is resorbed completely and does not interfere with parenchymal healing.

Microdialysis in the estimation of interstitial myocardial neuropeptide Y release.

The purpose of this study was to investigate the feasibility of cardiac microdialysis for the in vivo estimation of cardiac interstitial peptide concentrations, and, to determine the changes in neuropeptide Y release in myocardial tissue during experimental brain death in pigs. Using a specifically designed concentric flexible probe, perfused with Ringer solution containing 0.5% of bovine serum albumin at a flow rate of 2 microliters/min, allowed us to obtain a 23 +/- 2% relative recovery rate in vitro. Based on these in vitro recovery data, a regional study of the kinetics of interstitial NPY levels following brain death was obtained by monitoring the changes in NPY dialysate levels recorded from dialysis probes implanted into the right and left ventricular walls of the beating heart in vivo. Basal dialysate NPY levels determined by radioimmunoassay were of 95.2 +/- 7.0 and 93.2 +/- 9.1 pmol/l in left and right ventricle, respectively. Brain death was followed by a sustained 2 h increase in NPY dialysate levels in both ventricles (peak levels: 173.2 +/- 30.9 pmol/l in left ventricle, and 149.7 +/- 23.9 pmol/l in right ventricle), which then returned to control levels. We conclude that cardiac microdialysis is a simple and promising new tool for evaluating the role of peptides in cardiovascular regulation.

Incorporating nursing assistive personnel into a nursing professional practice model.

A pilot project evaluated the effect of incorporating nursing assistive personnel (NAP) into the existing nursing professional practice model at a tertiary care university medical center. A plan to use permanent, unit-based NAP was developed, implemented, and evaluated. Among the findings were a redistribution of selected nursing activities and conditions enhancing the integration of NAP to fulfill nonprofessional tasks and thus support the work of the registered nurse.