Encapsulation of FRET-based glucose and maltose biosensors to develop functionalized silica nanoparticles.

Silicate nanoparticles with immobilized FRET-based biosensors were developed for the detection of glucose and maltose. Immobilization of the protein biosensor in the nanoparticle was achieved through specific interaction between the hexa-histidine tag of the protein and a calcium-silicate complex of the silica matrix. Encapsulation of the biosensors preserved the affinity for the respective sugar. Compared to the free biosensors, encapsulation had a stabilizing effect on the biosensor towards chemical and thermal denaturation. The demonstrated immobilization strategy for specific sensing proteins paves the way towards the development of protein-inorganic nanostructures for application in metabolite analyses.

Non-hazardous pesticide concentrations in surface waters: An integrated approach simulating application thresholds and resulting farm income effects.

Pesticide application rates are high and increasing in upland agricultural systems in Thailand producing vegetables, fruits and ornamental crops, leading to the pollution of stream water with pesticide residues. The objective of this study was to determine the maximum per hectare application rates of two widely used pesticides that would achieve non-hazardous pesticide concentrations in the stream water and to evaluate how farm household incomes would be affected if farmers complied with these restricted application rates. For this purpose we perform an integrated modeling approach of a hydrological solute transport model (the Soil and Water Assessment Tool, SWAT) and an agent-based farm decision model (Mathematical Programming-based Multi-Agent Systems, MPMAS). SWAT was used to simulate the pesticide fate and behavior. The model was calibrated to a 77 km(2) watershed in northern Thailand. The results show that to stay under a pre-defined eco-toxicological threshold, the current average application of chlorothalonil (0.80 kg/ha) and cypermethrin (0.53 kg/ha) would have to be reduced by 80% and 99%, respectively. The income effect of such reductions was simulated using MPMAS. The results suggest that if farm households complied with the application thresholds then their income would reduce by 17.3% in the case of chlorothalonil and by 38.3% in the case of cypermethrin. Less drastic income effects can be expected if methods of integrated pest management were more widely available. The novelty of this study is to combine two models from distinctive disciplines to evaluate pesticide reduction scenarios based on real-world data from a single study site.

Is spinal cord stimulation safe? A review of 13 years of implantations and complications.

OBJECTIVE: The aim of this review was to evaluate the complications of spinal cord stimulation (SCS) for chronic pain. METHODS: This was a retrospective case series of 212 patients treated with SCS for chronic lower-limb neuropathic pain between March 2002 and February 2015 in a Reims academic hospital. All patients received a surgically implanted paddle-type electrode. Complications with this technique are here described and analyzed, and other treatment and preventative methods proposed. RESULTS: The major indication was 'failed back surgery syndrome', and 74 (35%) patients experienced complications, of which 57% were benign, while 42% required invasive treatment. Most frequent complications (n=22, 10%) were hardware malfunctions. There were two cases (0.9%) of postoperative neurological deficit and nine (4.2%) with postoperative infections. All patients received the appropriate treatment for their complication. CONCLUSION: Despite the presence of complications, SCS is still a safe technique, although careful patient selection and proper surgical technique can help to avoid major complications.

Monitoring and risk assessment of pesticides in a tropical river of an agricultural watershed in northern Thailand.

The increasing application of pesticides in the uplands of northern Thailand has increased the transfer of pesticides to surface water. To assess the risk of pesticide use for stream water quality, we monitored the concentrations of seven pesticides (atrazine, dichlorvos, chlorpyrifos, dimethoate, chlorothalonil, (α-, ß-) endosulfan, cypermethrin) frequently used in the Mae Sa watershed (77 km(2)) in water and sediment samples over a period of one and a half years (2007-2008). All investigated pesticides were recorded in the river. Chlorpyrifos was detected most often in water samples (75% at the headwater station), while cypermethrin was most often found in riverbed (86%) and in all suspended sediment samples. The highest concentrations of the pesticides were detected during the rainy season. About 0.002 to 4.1% by mass of the applied pesticides was lost to surface water. The risk assessment was based on the risk characterization ratio (RCR). The RCRs of dichlorvos in water, (α-, ß-) endosulfan, and cypermethrin in water and sediments were higher than unity indicating that they are likely to pose a threat to aquatic ecosystem. Finally, we discuss the role of sampling design on ecotoxicological risk assessment. Our study shows that pesticide contamination of surface waters is an environmental issue in the Mae Sa watershed and that measures need to be undertaken to reduce the loss of pesticides from soil to surface waters.

Impact of discontinuation of antithrombotic therapy after surgery for chronic subdural hematoma.

INTRODUCTION: The management of antithrombotic therapy (AT) after surgery for chronic subdural hematoma (cSDH) requires taking account of the balance of risk between hemorrhage recurrence (HR) and the prophylactic thromboembolic effect (TE). The goal of the present study was to evaluate the prevalence of vascular events (VE: TE and/or HR) in the first 3 postoperative months after cSDH evacuation in patients previously treated by AT. The impact of AT resumption was also evaluated. PATIENTS AND METHODS: This observational prospective multicenter collaborative study (14 French neurosurgery centers) included patients with cSDH treated by AT and operated on between May 2017 and March 2018. Data collection used an e-CRF, and was principally based on an admission questionnaire and outcome/progression at 3 months. RESULTS: In this cohort of 211 patients, VE occurred in 58 patients (27.5%): HR in 47 (22.3%), TE in 17 (8%), with mixed event in 6 cases (2%). Median overall time to onset of complications 26 days±31.5, and specifically 43.5 days±29.25 for HR. Non-resumption of AT significantly increased the relative risk of VE [OR: 4.14; 95% CI: 2.08 - 8.56; P <0.001] and especially of TE [OR: 7.5; 95% CI: 1.2 - 42; P<0.001]. The relative risk of HR was significantly increased when AT was resumed at less than 30 days (P=0.015). CONCLUSION: The occurrence of VE in patients operated on for cSDH and previously treated by AT was statistically significant (27.5%). HR was the most common event (22.3%), whereas TE accounted for only the 8%, although with shorter time to onset. In order to prevent TE risk, AT should be restarted after 30 days, as HR risk is greatly decreased beyond this time.

Reconstruction of cranioplasty using medpor porouspolyethylene implant.

INTRODUCTION: We describe our experience of cranioplasty after a calvarial defect, following an external decompressive craniectomy, with the Medpor® (Stryker®) porous polyethylene implant for cosmetic cranioplasty and reconstruction. METHODS: A retrospective chart review was performed on 23 consecutive patients who underwent cranioplasty at a single institution between January 2013 and January 2016: 9 patients after head injury and 14 patients after vascular event (ruptured aneurysm, intraprenchymal haematoma, malignant cerebrovascular accident). All patients with cranioplasties after oncological resection or infection were excluded. These cranioplasties were performed using porous polyethylene sheet (Medpor®) and contoured with a burr or scissors in the sterile field, and fixed to the calvarial bone with screws. RESULTS: Porous polyethylene sheet (Medpor®) is a proven material used for cranial reconstruction in neurosurgery and maxillofacial surgery with a biocompatibility advantage. The implant can be directly used in an emergency context. The average operating time was 72minutes. An average delay of 527 days (1 year and 5months) with a median of 985 days (43; 4206) occurred between craniectomy and the cranioplasty. There was only one set back implant due to scalp necrosis with infection for a recovery-unit patient. CONCLUSION: Porous polyethylene is an excellent restorative material for the reconstruction of large sized cranial defects and can be also used safely in reconstruction of the cranium. The cosmetic results are good, easy to perform, with a low complication rate.

Simultaneous detection of pH value and glucose concentrations for wound monitoring applications.

Aging population and longer life expectancy are the main reasons for an increasing number of patients with wound problems. Although the interest in wound care increases continuously, wound management still remains a challenge mainly due to the higher occurrence of chronic wounds, which require intensive care and constant monitoring. Here, we demonstrate a fluorescent sensing system to monitor the wound status and to distinguish between an autonomously healing and a chronic wound at an early stage. The system allows monitoring two of the most relevant fluctuating wound parameters during the healing process which are pH and glucose concentration. A fluorescent pH indicator dye, carboxynaphthofluorescein, and a metabolite-sensing enzymatic system, based on glucose oxidase and horseradish peroxidase, were immobilized on a biocompatible polysaccharide matrix to develop a functional hydrogel coating for wound monitoring. The changes in metabolite and enzyme concentration in artificial wound extract were converted into a fluorescent signal.

Ectopic bone formation with joint impingement after posterior lumbar fusion with rhBMP-2.

Recombinant human bone morphogenetic protein-2 (rhBMP-2) was recently licensed for local administration during posterior lumbar fusion. In this indication, considerable uncertainty remains about the nature and mechanisms of the many adverse effects of rhBMP-2, such as ectopic bone formation. We report a case of ectopic bone formation with impingement on a facet joint and incapacitating low back pain after minimally invasive transforaminal L5-S1 interbody fusion with local application of rhBMP-2 (InductOs(®)). Revision surgery was eventually performed to alleviate the symptoms by removing the ectopic bone. Caution is in order regarding the use of rhBMP-2 during posterior lumbar fusion. Every effort should be made to minimise the risk of complications.

Spontaneous epidural hematoma due to cervico-thoracic angiolipoma.

Epidural angiolipomas are uncommon benign tumors of the spine. Their clinical presentation is usually a progressive spinal cord compression. We report the case of a 22-year-old patient who presented with an acute paraparesis and a spontaneous epidural hematoma, which revealed a epidural angiolipoma which extended from C7 to T3. The patient underwent a C7-T3 laminectomy, in emergency, with evacuation of the hematoma and extradural complete resection of a fibrous epidural tumor bleeding. The postoperative course was favorable with regression of neurological symptoms. Epidural angiolipomas can be revealed by spontaneous intratumoral hemorrhage without traumatism. The standard treatment is total removal by surgery.

Pesticide transport simulation in a tropical catchment by SWAT.

The application of agrochemicals in Southeast Asia is increasing in rate, variety and toxicity with alarming speed. Understanding the behavior of these different contaminants within the environment require comprehensive monitoring programs as well as accurate simulations with hydrological models. We used the SWAT hydrological model to simulate the fate of three different pesticides, one of each usage type (herbicide, fungicide and insecticide) in a mountainous catchment in Northern Thailand. Three key parameters were identified: the sorption coefficient, the decay coefficient and the coefficient controlling pesticide percolation. We yielded satisfactory results simulating pesticide load dynamics during the calibration period (NSE: 0.92-0.67); the results during the validation period were also acceptable (NSE: 0.61-0.28). The results of this study are an important step in understanding the modeling behavior of these pesticides in SWAT and will help to identify thresholds of worst-case scenarios in order to assess the risk for the environment.

Iron-loaded PLLA nanoparticles as highly efficient intracellular markers for visualization of mesenchymal stromal cells by MRI.

Monitoring of the fate of cells after injection appears paramount for the further development of cell therapies. In this context magnetic resonance imaging (MRI) is increasing in relevance owing to its unique tissue visualization properties. For assessment of cell trafficking and homing, the cells have to be labeled to become MR visible. The rather low sensitivity of MRI demands dedicated intracellular markers with high payloads of MR contrast agents for ensuring sensitive detection of local cell aggregations. In the presented work the application of custom-designed nanometer-sized iron oxide loaded poly-(l-lactide) (iPLLA) nanoparticles was investigated. The particles were synthesized by the mini-emulsion process and evaluated for labeling of mesenchymal stromal cells (MSCs). The efficient cellular uptake and long intracellular retention times of the particles as well as their nontoxicity are demonstrated. The average cellular iron content was 55 pg iron per cell. Further incorporation of, for example, fluorescent dye enables the generation of multireporter particles, providing the great potential for multimodal imaging. The efficiency of these nanoparticles as MRI contrast agent was evaluated in vitro using relaxation rate mapping, yielding relaxivities r2 = 273.3, r2 (*) = 545.1 mm(-1) s(-1) at 3 T and r2 = 415.7, r2 (*) = 872.3 mm(-1) s(-1) at 11.7 T. The high r2 (*) relaxivity of the iPLLA nanoparticles enabled visualization of a single labeled cell in vitro at 50-µm spatial resolution. In vivo evaluation in a rat injury model revealed the potential of the iPLLA particles to efficiently label MSCs for MRI monitoring of ~20 000-40 000 injected cells at 11.7 T. In conclusion the presented work demonstrates the applicability of iPLLA particles as efficient intracellular marker for MSC labeling for monitoring the fate of the cells by MRI.