Attachment of hybridizable oligonucleotides to a silica support and its application for selective extraction of unmodified and antisense oligonucleotides from serum samples

The main aim of the present study was the synthesis of an oligonucleotide-based material with high chemical stability, repeatability and specificity to complementary oligonucleotides. The oligonucleotides were attached to a silica gel surface modified with amino acids during one-step synthesis. The amount of the oligonucleotides immobilized on the support surface had an impact on adsorption effectiveness, due to steric interference. The adsorption capacity corresponds to 4.7 μg of complementary oligonucleotide per 1 mg of material, which reflects 50% of immobilized oligonucleotides. The presented results contain comprehensive studies on hybridization and release of fully complementary, partially complementary, non-complementary and antisense oligonucleotides from the newly synthesized adsorbent. The salt concentration and time period were the most influential parameters in the case of adsorption, while high temperature and low salt content were indispensable for effective desorption. Selectivity studies revealed that the adsorption percentage increases with the decreasing number of base mismatches. Consequently, the desorption of low complementarity oligonucleotides was always greater in comparison with the fully complementary sequence. Furthermore, it was shown that oligonucleotide-based materials may be successfully used for the extraction of antisense oligonucleotides and their metabolites from serum samples with recoveries ranging between 65 and 73%.

The main aim of the present study was the synthesis of an oligonucleotide-based material with high chemical stability, repeatability and specificity to complementary oligonucleotides.     

Bone graft incorporation after revision hip arthroplasty in patients with rheumatoid arthritis, seventy eight revisions using bone allografts with or without metal reinforcements

Purpose

The aim of the study was to assess bone graft incorporation after revision hip arthroplasty in patients with rheumatoid arthritis (RA).

Methods

We report an acetabular reconstruction using impacted, morselized, frozen, radiation sterilized bone allografts in 71 patients suffering from RA. There were sixty-six women and five men at a mean age of 57.5 years. Reconstruction was performed in 78 revision total hip arthroplasties (THAs) for aseptic loosening of acetabular component. The mean follow-up was five years and four months. In 38 cases, a revision was done with use of reinforcement devices.

Results

In four revised hips (10 %) without reinforcement implants, resorption of the allografts was noticed. All Mueller rings and 50 % of unscrews cages (Link, Howmedica) were revised because of aseptic loosening and bone graft resorption. In all of 17 hips with the Burch-Schneider cage, no measurable migration or bone allografts resorption occurred. There were no major general complications.

Conclusions

Acetabular reconstruction with use of morselized, frozen, radiation sterilized bone allografts and the Burch-Schneider cage can be highly successful in managing massive deficiency of acetabular bone stock in revision hip arthroplasty in RA patients.     

Efficacy of concomitant and adjuvant temozolomide in glioblastoma treatment. A multicentre randomized study

Background and purposeThe common treatment in patients with newly diagnosed glioblastoma multiforme is the ultimately radical surgical removal of the tumour combined with radiotherapy. This study compared safety and efficacy of radiotherapy alone with radiotherapy combined with temozolomide (TMZ) given before, during, and after radiotherapy.Material and methodsThe patients operated on for glioblastoma multiforme during the first 21 postoperative days were randomly assigned to the group treated with radiotherapy alone (involved-field radiotherapy in 2 Gy fractions daily five times a week up to the total of 60 Gy over 6 weeks of treatment) or to the group treated with radiotherapy and TMZ, initially in the dose of 200 mg/m² during 5 postoperative days and after 23 days followed by 75 mg/m² of body surface area daily, 7 days a week (from the first to the last day of radiotherapy). On completion of radiotherapy, five complementary courses of TMZ were introduced (150–200 mg/m² for 5 days, repeated every 28 days). The primary outcome measure was overall survival.ResultsFifty-eight patients from 3 centres were included in the study. The mean age of patients was 55 years and all the patients underwent a surgical procedure of glioblastoma removal. The mean overall survival in the group treated with TMZ was 16.0 months, whereas in the group with radiotherapy alone the overall survival reached 12.5 months. 24-month survival reached 23% in patients treated with TMZ and 6.7% in those who received radiotherapy only. Haematological complications of third or fourth degree were present in 10% of patients treated with radiotherapy and TMZ.ConclusionsThe introduction of TMZ before, during and after radiotherapy for newly diagnosed glioblastoma multiforme gives clinically and statistically significant improvement of survival with unremarkably increased toxicity of the treatment.     

Magnetically responsive polycaprolactone nanocarriers for application in the biomedical field: magnetic hyperthermia,magnetic resonance imaging,and magnetic drug delivery

There are huge demands on multifunctional nanocarriers to be used in nanomedicine. Herein, we present a simple and efficient method for the preparation of multifunctional magnetically responsive polymeric-based nanocarriers optimized for biomedical applications. The hybrid delivery system is composed of drug-loaded polymer nanoparticles (poly(caprolactone), PCL) coated with a multilayer shell of polyglutamic acid (PGA) and superparamagnetic iron oxide nanoparticles (SPIONs), which are known as bio-acceptable components. The PCL nanocarriers with a model anticancer drug (Paclitaxel, PTX) were formed by the spontaneous emulsification solvent evaporation (SESE) method, while the magnetically responsive multilayer shell was formed via the layer-by-layer (LbL) method. As a result, we obtained magnetically responsive polycaprolactone nanocarriers (MN-PCL NCs) with an average size of about 120 nm. Using the 9.4 T preclinical magnetic resonance imaging (MRI) scanner we confirmed, that obtained MN-PCL NCs can be successfully used as a MRI-detectable drug delivery system. The magnetic hyperthermia effect of the MN-PCL NCs was demonstrated by applying a 25 mT radio-frequency (f = 429 kHz) alternating magnetic field. We found a Specific Absorption Rate (SAR) of 55 W g⁻¹. The conducted research fulfills the first step of investigation for biomedical application, which is mandatory for the planning of any in vitro and in vivo studies.

There are huge demands on multifunctional nanocarriers to be used in nanomedicine.     

Balloon Dilatation for Removal of an Irretrievable Permanent Hemodialysis Catheter: The Safest Approach

Long‐term hemodialysis catheter dwell time in the central vein predisposes to fibrin sheath development, which subsequently causes catheter malfunction or occlusion. In very rare cases, the catheter can be overgrown with fibrin and rigidly connected with the vein or heart structures. This makes its removal almost impossible and dangerous because of the possibility of serious complications, namely vein and heart wall perforation, bleeding, or catheter abruption in deep tissues. We describe two cases in which standard retrieval of long‐term catheters was not possible. Balloon dilatation of catheter lumens was successfully used to increase the catheter diameter with simultaneous tearing of the fibrin sheath surrounding it. This allowed the catheter to be set free safely. Based on this experience, we present recent literature and our point of view.     

Reliability of measurements performed on two dimensional and three dimensional computed tomography in glenoid assessment for instability

Purpose

The main purpose of this study is to establish which of two methods is more reliable in glenoid assessment for instability in pre-operative planning. Accordingly, we have studied the intra- and inter-observer reliability of glenoid parameters with the use of two-dimensional (2D) and three-dimensional (3D) reconstructed computed tomography (CT) images.

Methods

One hundred glenoids were measured with the use of 2D-CT and 3D-CT (in 3D orientation) by two independent observers (one experienced and one inexperienced). Measurements were repeated after one week for 30 randomly selected glenoids.

Results

The intra-class correlation coefficient (ICC) for inter-observer reliability was significantly greater for 3D-CT (0.811 to 0.915) than for 2D-CT (0.523 to 0.925). All intra-observer reliability values for 3D-CT were near perfect (0.835 to 0.997), while those for 2D-CT were less reliable (0.704 to 0.960). A dependent t-test showed that, for both observers, almost all glenoid parameters (except R and d) differed significantly (p?<?0.05) between 2D and 3D measurement methods.

Conclusions

Therefore, it can be concluded that 3D glenoid reconstructions are more reliable for glenoid bone loss assessment than 2D-CT. The results suggest that quantifying a glenoid defect with the use of 2D image only—even if performed by an experienced orthopaedic surgeon—is prone to errors. Differences in measurements between and within observers can be explained by plane setting and identifying glenoid rim in 2D-CT. Accordingly, we recommend that glenoid measurements should be performed in 3D orientation using 3D reconstruction obtained from CT images for pre-operative assessments, which are crucial for surgical planning.

     

Arthrogryposis: an update on clinical aspects,etiology, and treatment strategies

Arthrogryposes – multiple joint contractures – are a clinically and etiologically heterogeneous class of diseases, where accurate diagnosis, recognition of the underlying pathology and classification are of key importance for the prognosis as well as for selection of appropriate management. This treatment remains challenging and optimally in arthrogrypotic patients should be carried out by a team of specialists familiar with all aspects of arthrogryposis pathology and treatment modalities: rehabilitation, orthotics and surgery. In this comprehensive review article, based on literature and clinical experience, the authors present an update on current knowledge on etiology, classifications and treatment options for skeletal deformations possible in arthrogryposis.