| 1. |
- Kwon, David H., et al.
(författare)
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Bone tissue response following local drug delivery of bisphosphonate through titanium oxide nanotube implants in a rabbit model
- 2017
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Ingår i: Journal of Clinical Periodontology. - : Wiley. - 0303-6979. ; 44:9, s. 941-949
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Tidskriftsartikel (refereegranskat)abstract
- Objectives: The objective of this study was to evaluate whether surface chemistry-controlled TiO2 nanotube structures may serve as a local drug delivery system for zoledronic acid improving implant-bone support. Methods: Twenty-four screw-shaped Ti implants with surface chemistry-controlled TiO2 nanotube structures were prepared and divided into a zoledronic acid-formatted test and a native control group. The implants were inserted into contra-lateral femoral condyles in 12 New Zealand White rabbits. Bone support was evaluated using resonance frequency analysis (RFA) and removal torque (RTQ), as well as histometric analysis following a 3-weeks healing interval. Results: Zoledronic acid-formatted TiO2 nanotube test implants showed significantly improved implant stability and osseointegration measured using RFA and RTQ compared with control (p<0.05), and showed significantly enhanced new bone formation within the root of the threads compared with control (p<0.05). Conclusions: TiO2 nanotube implants may prove to be a significant delivery system for drugs or biologic agents aimed at supporting local bone formation. Additional study of candidate drugs/agents, optimized dosage and release kinetics is needed prior to evaluation in clinical settings. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd
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| 2. |
- Lundberg, J., et al.
(författare)
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Access to the brain parenchyma using endovascular techniques and a micro-working channel
- 2017
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Ingår i: Journal of Neurosurgery. - : Journal of Neurosurgery Publishing Group (JNSPG). - 0022-3085 .- 1933-0693. ; 126:2, s. 511-517
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVE Several older studies report a low risk for parenchymal access to the CNS by surgical techniques. In more recent studies, including those with post-puncture CT scans, there are indications that the risk of bleeding might approach 8%. New therapies, such as those that use viral vectors, modified mRNA, or cell transplantation, will probably warrant more parenchymal access to the CNS. Other minimally invasive routes might then be tempting to explore. This study was designed in 2 parts to address the possibility of using the endovascular route. The first aim was to test the ability to create a parenchymal micro-working channel to the CNS in macaque monkeys through the vessel wall. Second, the biocompatibility of a device-associated, detached, distal securing plug that was made of nitinol was investigated in swine for 1 year. METHODS Trans-vessel wall intervention in the middle cerebral artery and associated cerebral parenchyma was performed in 4 rhesus macaque monkeys using a full clinical angiography suite. A contrast agent and methylene blue were injected to test the working channel and then detached at the distal end to act as a securing plug through the vessel wall. One-year follow-ups were also performed using angiography and histological analysis in 10 swine with 24 implants that were distributed in the external carotid artery tree. RESULTS The cerebral interventions were performed without acute bleeding. Both the contrast agent and methylene blue were infused into the brain parenchyma and subarachnoidal space via the endovascular micro-working channel (7 injections in 4 animals). In the 1-year follow-up period, the implant that was left in the external carotid vessel wall in the swine was covered by the endothelium, which was followed by dislodgement just outside the blood vessel with thin capsule formation. No stenosis in the artery was detected on 1-year angiography. The animals showed normal behavior and blood sample results during the follow-up period. This is the first histological demonstration of nitinol biocompatibility when the implant is positioned through an arterial wall and indicates that the trans-vessel wall technique is not comparable with stent placement and its ability to induce intimal hyperplasia and restenosis. CONCLUSIONS This study demonstrates that the trans-vessel wall technique is applicable to brain intervention in macaque monkeys, providing a micro-working channel for delivery or sampling. The long-term follow-up study of the detached device in swine showed no clinical or biochemical complications and a normal angiography appearance.
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| 3. |
- Barkarmo, Sargon, et al.
(författare)
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Biofilm formation on polyetheretherketone and titanium surfaces
- 2019
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Ingår i: Clinical and Experimental Dental Research. - : Wiley. - 2057-4347. ; 5:4, s. 427-437
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Tidskriftsartikel (refereegranskat)abstract
- Objective: Polyetheretherketone (PEEK) is a polymer used in devices in orthopedic and dental rehabilitation. The aim of this in vitro study was to compare biofilm formation by a range of important oral bacterial species on PEEK, blasted PEEK, commercially pure titanium (cp-Ti), and titanium-6 aluminium-4 vanadium (Ti6Al4V). Material and methods: Coin-shaped samples were manufactured, and the surfaces were characterized using optical interferometry, scanning electron microscopy, energy-dispersive X-ray spectroscopy, and contact angle measurements. Bacterial species of Streptococcus sanguinis, Streptococcus oralis, Enterococcus faecalis, and Streptococcus gordonii were cultured on the four material surfaces for varying amounts of time. Biofilms were quantified following staining with crystal violet. Results: Roughness and contact angle results showed blasted PEEK>PEEK>cp-Ti=Ti6Al4V. There was increased biofilm formation on blasted PEEK by S. sanguinis, S. oralis, and S. gordonii, whereas the bacterial adhesion was similar on PEEK, cp-Ti, and Ti6Al4V. The bacterial growth of E. faecalis was significantly higher on cp-Ti compared with the other three groups. Conclusion: The results, taking into consideration the biofilm formation, suggest that PEEK should perform as well as cp-Ti or TiAl6V4 when used as a dental restorative material. © 2019 The Authors. Clinical and Experimental Dental Research published by John Wiley & Sons Ltd.
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| 4. |
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| 5. |
- Bratt, Anna S., 1969-, et al.
(författare)
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An internet-based compassion course for healthcare professionals : Rationale and protocol for a randomised controlled trial
- 2022
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Ingår i: Internet Interventions. - : Elsevier BV. - 2214-7829. ; 28
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Tidskriftsartikel (refereegranskat)abstract
- Background: Severe stress is one of the most common causes of sick leave in Sweden. Previous research has shown that compassion interventions for healthcare professionals can decrease work-related stress through the introduction of self-care, self-awareness, and emotion regulation abilities when experiencing difficult situations. Internet-based stress management interventions have hitherto shown promising results in reducing stress. However, further research is needed to examine the effectiveness of internet-based compassion interventions for healthcare professionals. Objective: In the present study protocol, a randomised controlled trial is described, aiming to examine the effects of an internet-based compassion course for healthcare professionals on work-related stress and stress of conscience. Method: Healthcare professionals will be offered an internet-based stress management course of five modules across a period of five weeks. The design is a randomised controlled study consisting of three groups enrolled in one of the following: a compassion course (n = 120), a cognitive behavioural stress management course (n = 120), or placed on a waitlist followed by either the compassion course or the cognitive behavioural stress management course (n = 36). We hypothesise that the internet-based compassion course would reduce the participants' stress of conscience to a greater degree compared to the other two groups. The secondary hypothesis is that the compassion course would increase the participants' professional quality of life (i.e., higher job satisfaction and lower empathy fatigue) and self-compassion. In addition, the internet-based compassion course is expected to reduce the participants' work-related stress and sick leave rates to the same degree (non-inferiority) as the cognitive behavioural stress management course and to a higher degree when compared to the waitlist condition. The primary outcome measure is the Stress of Conscience Questionnaire (SCQ) and the secondary outcome measures are the Professional Quality of Life Scale (PROQOL), the Work-related Stress Copenhagen Psychosocial Questionnaire (COPSOQ), and the Self-compassion Scale (SCS). Assessments will be performed at baseline, four weekly assessments during treatment, post-treatment (5 weeks), and follow-ups at 10 weeks, 15 weeks, and 6 months. The repeated measures data will be analysed using a generalised estimating equation for repeated measurements to examine whether changes over time differ between the groups and whether the improvements persist over time. Discussion: The clinical trial is expected to provide novel data on the effects of compassion interventions and add to the existing knowledge of internet-based interventions for stress management in healthcare professionals.
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| 6. |
- Crescitelli, Rossella, 1985, et al.
(författare)
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Subpopulations of extracellular vesicles from human metastatic melanoma tissue identified by quantitative proteomics after optimized isolation
- 2020
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Ingår i: Journal of Extracellular Vesicles. - : Wiley. - 2001-3078. ; 9:1
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Tidskriftsartikel (refereegranskat)abstract
- The majority of extracellular vesicle (EV) studies conducted to date have been performed on cell lines with little knowledge on how well these represent the characteristics of EVs in vivo. The aim of this study was to establish a method to isolate and categorize subpopulations of EVs isolated directly from tumour tissue. First we established an isolation protocol for subpopulations of EVs from metastatic melanoma tissue, which included enzymatic treatment (collagenase D and DNase). Small and large EVs were isolated with differential ultracentrifugation, and these were further separated into high and low-density (HD and LD) fractions. All EV subpopulations were then analysed in depth using electron microscopy, Bioanalyzer (R), nanoparticle tracking analysis, and quantitative mass spectrometry analysis. Subpopulations of EVs with distinct size, morphology, and RNA and protein cargo could be isolated from the metastatic melanoma tissue. LD EVs showed an RNA profile with the presence of 18S and 28S ribosomal subunits. In contrast, HD EVs had RNA profiles with small or no peaks for ribosomal RNA subunits. Quantitative proteomics showed that several proteins such as flotillin-1 were enriched in both large and small LD EVs, while ADAM10 were exclusively enriched in small LD EVs. In contrast, mitofilin was enriched only in the large EVs. We conclude that enzymatic treatments improve EV isolation from dense fibrotic tissue without any apparent effect on molecular or morphological characteristics. By providing a detailed categorization of several subpopulations of EVs isolated directly from tumour tissues, we might better understand the function of EVs in tumour biology and their possible use in biomarker discovery.
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| 7. |
- Franke-Stenport, Victoria, et al.
(författare)
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Titanium implants and BMP-7 in bone : an experimental model in the rabbit
- 2003
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Ingår i: Journal of materials science. Materials in medicine. - 0957-4530 .- 1573-4838. ; 14:3, s. 247-254
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Tidskriftsartikel (refereegranskat)abstract
- This study evaluates the effect of rhBMP-7/OP-1 on the osseointegration of commercially pure titanium implants in an experimental implant model in rabbits. Threaded titanium implants with two transverse parallel canals were inserted in the femur and tibia of rabbits. The canals were filled with, 10 microg of BMP-7/collagen carrier, pure collagen carrier or were left empty as a control. The stiffness of the implant fixation was evaluated by Resonance Frequency Analysis (RFA) at baseline and four weeks postoperatively. Percentage of bone ingrowth in the canals was measured on microradiographs. Histomorphometry along the threaded part of the implants was performed on 15 microm thin sections. The results from the RFA demonstrated a higher mean value for the BMP-7 treated implants in the tibia than the carrier treated implants but not compared to the control implants. The control implants in the tibia demonstrated more bone ingrowth in the upper canal than to the carrier or the BMP-7 treated implants. Apart from these differences there were no significant effects of BMP. In this study BMP-7 did not contribute to any substantially improved bone anchorage of titanium implants.
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| 8. |
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| 9. |
- Jansson, Saga, et al.
(författare)
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Incidence of acute myocardial injury and its association with left and right ventricular systolic dysfunction in critically ill COVID-19 patients
- 2022
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Ingår i: Annals of Intensive Care. - Heidelberg, Germany : Springer. - 2110-5820. ; 12:1
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Tidskriftsartikel (refereegranskat)abstract
- Background: Previous studies have found an increase in cardiac troponins (cTns) and echocardiographic abnormalities in patients with COVID-19 and reported their association with poor clinical outcomes. Whether acute injury occurs during the course of critical care and if it is associated with cardiac function is unknown.The purpose of this study was to document the incidence of acute myocardial injury (AMInj) and echocardiographically defined left ventricular (LV) and right ventricular (RV) systolic dysfunction in consecutive patients admitted to an intensive care unit (ICU) for COVID-19. The relationship between AMInj and echocardiographic abnormalities during the first 14 days of ICU admission was studied. Finally, the association between echocardiographic findings, AMInj and clinical outcome was evaluated.Methods: Seventy-four consecutive patients (≥18 years) admitted to the ICU at Linköping University Hospital between 19 Mar 2020 and 31 Dec 2020 for COVID-19 were included. High-sensitivity troponin-T (hsTnT) was measured daily for up to 14 days. Transthoracic echocardiography was conducted within 72 h of ICU admission. Acute myocardial injury was defined as an increased hsTnT > 14ng/l and a > 20% absolute change with or without ischaemic symptoms. LV and RV systolic dysfunction was defined as at least 2 abnormal indicators of systolic function specified by consensus guidelines.Results: Increased hsTnT was observed in 59% of patients at ICU admission, and 82% developed AMInj with peak levels at 8 (3–13) days after ICU admission. AMInj was not statistically significantly associated with 30-day mortality but was associated with an increased duration of invasive mechanical ventilation (10 (3–13) vs. 5 days (0–9), p=0.001) as well as ICU length of stay (LOS) (19.5 (11–28) vs. 7 days (5–13), p=0.015). After adjustment for SAPS-3 and admission SOFA score, the effect of AMInj was significant only for the duration of mechanical ventilation (p=0.030).The incidence of LV and RV dysfunction was 28% and 22%, respectively. Only indices of LV and RV longitudinal contractility (mitral and tricuspid annular plane systolic excursion) were associated with AMInj. Echocardiographic parameters were not associated with clinical outcome.Conclusions: Myocardial injury is common in critically ill patients with COVID-19, with AMInj developing in more than 80% after ICU admission. In contrast, LV and RV dysfunction occurred in approximately one-quarter of patients. AMInj was associated with an increased need for mechanical ventilation and ICU LOS but neither AMInj nor ventricular dysfunction was significantly associated with mortality.
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