682 research outputs found

    Repair of critical size defects in the rat cranium using ceramic-reinforced PLA scaffolds obtained by supercritical gas foaming

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    Bioresorbable scaffolds made Of poly(L-lactic acid) (PLA) obtained by supercritical gas foaming were recently described as suitable for tissue engineering, portraying biocompatibility with primary osteoblasts in vitro and interesting mechanical properties when reinforced with ceramics. The behavior of such constructs remained to be evaluated in vivo and therefore the present study was undertaken to compare different PLA/ceramic composite scaffolds obtained by supercritical gas foaming in a critical size defect craniotomy model in Sprague-Dawley rats. The host-tissue reaction to the implants was evaluated semiquantitatively and similar tendencies were noted for all graft substitutes: initially highly reactive but decreasing with time implanted. Complete bone-bridging was observed IS weeks after implantation with PLA/ 5 wt % beta-TCP (PLA/TCP) and PLA/5 wt % HA (PLA/HA) scaffolds as assessed by histology and radiography. We show here for the first time that this solvent-free technique provides a promising approach in tissue engineering demonstrating both the biocompatibility and osteoconcluctivity of the processed structures in vivo

    Early Toxicities After High Dose Rate Proton Therapy in Cancer Treatments

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    Background: The conventional dose rate of radiation therapy is 0.01-0.05 Gy per second. According to preclinical studies, an increased dose rate may offer similar anti-tumoral effect while dramatically improving normal tissue protection. This study aims at evaluating the early toxicities for patients irradiated with high dose rate pulsed proton therapy (PT). Materials and methods: A single institution retrospective chart review was performed for patients treated with high dose rate (10 Gy per second) pulsed proton therapy, from September 2016 to April 2020. This included both benign and malignant tumors with ≥3 months follow-up, evaluated for acute (≤2 months) and subacute (>2 months) toxicity after the completion of PT. Results: There were 127 patients identified, with a median follow up of 14.8 months (3-42.9 months). The median age was 55 years (1.6-89). The cohort most commonly consisted of benign disease (55.1%), cranial targets (95.1%), and were treated with surgery prior to PT (56.7%). There was a median total PT dose of 56 Gy (30-74 Gy), dose per fraction of 2 Gy (1-3 Gy), and CTV size of 47.6 ml (5.6-2,106.1 ml). Maximum acute grade ≥2 toxicity were observed in 49 (38.6%) patients, of which 8 (6.3%) experienced grade 3 toxicity. No acute grade 4 or 5 toxicity was observed. Maximum subacute grade 2, 3, and 4 toxicity were discovered in 25 (19.7%), 12 (9.4%), and 1 (0.8%) patient(s), respectively. Conclusion: In this cohort, utilizing high dose rate proton therapy (10 Gy per second) did not result in a major decrease in acute and subacute toxicity. Longer follow-up and comparative studies with conventional dose rate are required to evaluate whether this approach offers a toxicity benefit

    A two-stage ultrafiltration process for separating multiple components of Tetraselmis suecica after cell disruption

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    A two-stage ultrafiltration process was applied to the aqueous phase of Tetraselmis suecica after breaking its cell wall by high-pressure homogenization. Microscopic observation revealed that the cells were completely disrupted from 600 bar and cell fragmentation of the cells was also noticeable after 800 bar. In addition, the highest concentration of all the molecules of interest in the aqueous phase was observed at 1,000 bar and a temperature of 46 °C while preserving the integrity of the molecules of interest in the downstream process. After centrifugation, the aqueous phase was submitted to ultrafiltration through two consecutive membranes of different molecular weight cutoffs. Complete retention of starch was possible with a 100-kDa membrane and separation of sugars from proteins with a 10-kDa membrane on the remaining mixture. After testing the process with model solutions, the transmembrane pressure selected was 2.07 bar, which succeeded in retaining starch and pigments during the first part of the process, and proteins during the second part. A linear correlation between the permeate flux rate and the pressure was observed in both parts of the process

    Pharmacokinetics of intramuscular maropitant in pigs (Sus scrofa domesticus)

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    Pigs are at risk of vomiting from medical conditions as well as the emetic side effects of drugs administered for peri-operative manipulations, but there is a lack of pharmacokinetic data for potential anti-emetic therapies, such as maropitant, in this species. The main objective of this study was to estimate plasma pharmacokinetic parameters for maropitant in pigs after a single intramuscular (IM) administration dosed at 1.0 mg/ kg. A secondary objective was to estimate pilot pharmacokinetic parameters in pigs after oral (PO) administration at 2.0 mg/kg. Maropitant was administered to six commercial pigs at a dose of 1.0 mg/kg IM. Plasma samples were collected over 72 h. After a 7-day washout period, two pigs were administered maropitant at a dose of 2.0 mg/ kg PO. Maropitant concentrations were measured via liquid chromatography/mass spectrometry (LC–MS/ MS). A non-compartmental analysis was used to derive pharmacokinetics parameters. No adverse events were noted in any of the study pigs after administration. Following single IM administration, maximum plasma concentration was estimated at 412.7 ± 132.0 ng/mL and time to maximum concentration ranged from 0.083 to 1.0 h. Elimination half-life was estimated at 6.7 ± 1.28 h, and mean residence time was 6.1 ± 1.2 h. Volume of distribution after IM administration was 15.9 L/ kg. Area under the curve was 1336 ± 132.0 h*ng/mL. The relative bioavailability of PO administration was noted to be 15.5% and 27.2% in the two pilot pigs. The maximum systemic concentration observed in the study pigs after IM administration was higher than what was observed after subcutaneous administration in dogs, cats, or rabbits. The achieved maximum concentration exceeded the concentrations for anti-emetic purposes in dogs and cats; however, a specific anti-emetic concentration is currently not known for pigs. Further research is needed into the pharmacodynam

    Prospective exploratory muscle biopsy, imaging, and functional assessment in patients with late-onset Pompe disease treated with alglucosidase alfa: The EMBASSY Study

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    Background Late-onset Pompe disease is characterized by progressive skeletal myopathy followed by respiratory muscle weakness, typically leading to loss of ambulation and respiratory failure. In this population, enzyme replacement therapy (ERT) with alglucosidase alfa has been shown to stabilize respiratory function and improve mobility and muscle strength. Muscle pathology and glycogen clearance from skeletal muscle in treatment-naïve adults after ERT have not been extensively examined. Methods This exploratory, open-label, multicenter study evaluated glycogen clearance in muscle tissue samples collected pre- and post- alglucosidase alfa treatment in treatment-naïve adults with late-onset Pompe disease. The primary endpoint was the quantitative reduction in percent tissue area occupied by glycogen in muscle biopsies from baseline to 6 months. Secondary endpoints included qualitative histologic assessment of tissue glycogen distribution, secondary pathology changes, assessment of magnetic resonance images (MRIs) for intact muscle and fatty replacement, and functional assessments. Results Sixteen patients completed the study. After 6 months of ERT, the percent tissue area occupied by glycogen in quadriceps and deltoid muscles decreased in 10 and 8 patients, respectively. No changes were detected on MRI from baseline to 6 months. A majority of patients showed improvements on functional assessments after 6 months of treatment. All treatment-related adverse events were mild or moderate. Conclusions This exploratory study provides novel insights into the histopathologic effects of ERT in late-onset Pompe disease patients. Ultrastructural examination of muscle biopsies demonstrated reduced lysosomal glycogen after ERT. Findings are consistent with stabilization of disease by ERT in treatment-naïve patients with late-onset Pompe disease

    Lower-limb lengths and angles in children older than six years: Reliability and reference values by EOS® stereoradiography

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    Lower-limb alignment in children is classically assessed clinically or based on conventional radiography, which is associated with projection bias. Low-dose biplanar radiography was described recently as an alternative to conventional imaging. The primary objective of this study was to assess the reliability of length and angle values inferred from 3D reconstructions in children seen in everyday practice. The secondary objective was to obtain reference values for goniometry parameters in children. The paediatric reliability study was done in 18 volunteers who were divided into three groups based on whether they were typically developing (TD) children, had skeletal development abnormalities, or had cerebral palsy. The reference data were obtained in 129 TD children. Each study participant underwent biplanar radiography with 3D reconstruction performed by experts and radiology technicians. Goniometry parameters were computed automatically. Reproducibility was assessed based on the intra-class coefficient (ICC) and the ISO 5725 standard (standard deviation of reproducibility, SDR). For length parameters, the ICCs ranged from 0.94 to 1.00 and the SDR from 2.1 to 3.5 mm. For angle parameters, the ICC and SDR ranges were 0.60–0.95 and 0.9°–4.6°, respectively. No significant differences were found across experts or radiology technicians. Age-specific reference data are reported. These findings confirm the reliability of low-dose biplanar radiography for assessing lower-limb parameters in children seen in clinical practice. In addition, the study provides reference data for commonly measured parameters

    Gender-dependent differences in plasma matrix metalloproteinase-8 elevated in pulmonary tuberculosis.

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    Tuberculosis (TB) remains a global health pandemic and greater understanding of underlying pathogenesis is required to develop novel therapeutic and diagnostic approaches. Matrix metalloproteinases (MMPs) are emerging as key effectors of tissue destruction in TB but have not been comprehensively studied in plasma, nor have gender differences been investigated. We measured the plasma concentrations of MMPs in a carefully characterised, prospectively recruited clinical cohort of 380 individuals. The collagenases, MMP-1 and MMP-8, were elevated in plasma of patients with pulmonary TB relative to healthy controls, and MMP-7 (matrilysin) and MMP-9 (gelatinase B) were also increased. MMP-8 was TB-specific (p<0.001), not being elevated in symptomatic controls (symptoms suspicious of TB but active disease excluded). Plasma MMP-8 concentrations inversely correlated with body mass index. Plasma MMP-8 concentration was 1.51-fold higher in males than females with TB (p<0.05) and this difference was not due to greater disease severity in men. Gender-specific analysis of MMPs demonstrated consistent increase in MMP-1 and -8 in TB, but MMP-8 was a better discriminator for TB in men. Plasma collagenases are elevated in pulmonary TB and differ between men and women. Gender must be considered in investigation of TB immunopathology and development of novel diagnostic markers

    The Economic Consequences of Social-Network Structure

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    We survey the literature on the economic consequences of the structure of social networks. We develop a taxonomy of "macro" and "micro" characteristics of social-interaction networks and discuss both the theoretical and empirical findings concerning the role of those characteristics in determining learning, diffusion, decisions, and resulting behaviors. We also discuss the challenges of accounting for the endogeneity of networks in assessing the relationship between the patterns of interactions and behaviors
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