Local bone metabolism during the consolidation process of spinal interbody fusion.

Introduction: Although computed tomography (CT) can identify the presence of eventual bony bridges following lumbar interbody fusion (LIF) surgery, it does not provide information on the ongoing formation process of new bony structures. F sodium fluoride (F-NaF) positron emission tomography (PET) could be used as complementary modality to add information on the bone metabolism at the fusion site. However, it remains unknown how bone metabolism in the operated segment changes early after surgery in uncompromised situations.

Early bone ingrowth and segmental stability of a trussed titanium cage versus a polyether ether ketone cage in an ovine lumbar interbody fusion model.

Background Context: Lumbar interbody fusion is an effective treatment for unstable spinal segments. However, the time needed to establish a solid bony interbody fusion between the two vertebrae may be longer than twelve months after surgery. During this time window, the instrumented spinal segment is assumed to be at increased risk for instability related complications such as cage migration or subsidence.

In vitro and in vivo study on the osseointegration of BCP-coated versus uncoated nondegradable thermoplastic polyurethane focal knee resurfacing implants.

Focal knee resurfacing implants (FKRIs) are intended to treat cartilage defects in middle-aged patients. Most FKRIs are metal-based, which hampers follow-up of the joint using magnetic resonance imaging and potentially leads to damage of the opposing cartilage. The purpose of this study was to develop a nondegradable thermoplastic polyurethane (TPU) FKRI and investigate its osseointegration.

Signatures of knee osteoarthritis in women in the temporal and fractal dynamics of human gait.

Background: Osteoarthritis of the knee is characterized by progressive cartilage deterioration causing pain and function loss. Symptoms develop late with limited disease-modifying opportunities. Osteoarthritis is a major cause of immobility, with a higher prevalence above 60 years.

Quantitative Profiling of Platelet-Rich Plasma Indole Markers by Direct-Matrix Derivatization Combined with LC-MS/MS in Patients with Neuroendocrine Tumors.

Background: Currently, several indole markers are measured separately to support diagnosis and follow-up of patients with neuroendocrine tumors (NETs). We have developed a sensitive mass spectrometry method that simultaneously quantifies all relevant tryptophan-related indoles (tryptophan, 5-hydroxytryptophan, serotonin, 5-hydroxyindoleacetic acid) in platelet-rich plasma. Direct-matrix derivatization was used to make the chemical properties of the indoles uniform and to improve the analytical sensitivity and specificity of the assay.

Serotonin and Dopamine Receptor Expression in Solid Tumours Including Rare Cancers.

In preclinical studies serotonin stimulates and dopamine inhibits tumour growth and angiogenesis. Information regarding serotonin and dopamine receptor (5-HTR and DRD) expression in human cancers is limited. Therefore, we screened a large tumour set for receptor mRNA overexpression using functional genomic mRNA (FGmRNA) profiling, and we analysed protein expression and location of 5-HTR1B, 5-HTR2B, DRD1, and DRD2 with immunohistochemistry in different tumour types.

Melatonin is not stored in platelets.

Background: Melatonin is one of numerous biologically active compounds reported to be stored in platelets. As melatonin is increasingly linked to several diseases, we wanted to confirm the storage of melatonin in platelets using sensitive liquid chromatography in combination with isotope dilution tandem mass spectrometry (LC-MS/MS). The difference between melatonin levels analyzed in platelet-rich plasma (PRP) and platelet-poor plasma (PPP) served as proxy for platelet levels of melatonin.

The diagnostic accuracy of imaging modalities to detect pseudarthrosis after spinal fusion-a systematic review and meta-analysis of the literature.

Objective: The aim of the study was to determine the diagnostic accuracy of imaging modalities to detect pseudarthrosis after thoracolumbar spinal fusion, with surgical exploration as reference standard.

Materials And Methods: A systematic literature search for original studies was performed on the diagnostic accuracy of imaging as index test compared to surgical exploration as reference standard to diagnose pseudarthrosis after thoracolumbar spinal fusion. Diagnostic accuracy values were extracted and methodologic quality of studies was evaluated by the Quality Assessment of Diagnostic Accuracy Studies 2 (QUADAS-2) tool.

Biomechanical Alterations during Sit-to-Stand Transfer Are Caused by a Synergy between Knee Osteoarthritis and Obesity.

Osteoarthritis is one of the major causes of immobility and its current prevalence in elderly (>60 years) is 18% in women and 9.6% in men. Patients with osteoarthritis display altered movement patterns to avoid pain and overcome movement limitations in activities of daily life, such as sit-to-stand transfers.

Dopamine concentration in blood platelets is elevated in patients with head and neck paragangliomas.

Background: Plasma 3-methoxytyramine (3-MT), a metabolite of dopamine, is elevated in up to 28% of patients with head and neck paragangliomas (HNPGLs). As free dopamine is incorporated in circulating platelets, we determined dopamine concentration in platelets in patients with a HNPGL.

Methods: A single center cohort study was performed between 2012 and 2014.

Pseudarthrosis after lumbar spinal fusion: the role of ¹⁸F-fluoride PET/CT.

Purpose: Painful pseudarthrosis is one of the most important indications for (revision) surgery after spinal fusion procedures. If pseudarthrosis is the source of recurrent pain it may require revision surgery. It is therefore of great clinical importance to ascertain if it is the source of such pain.

Evaluation of a short dynamic 18F-fluoride PET/CT scanning method to assess bone metabolic activity in spinal orthopedics.

Objective: A complication after spinal fusion surgery is pseudarthrosis, but its radiological diagnosis is of limited value. (18)F-fluoride PET with its ability to assess bone metabolism activity could be of value. The goal of this study was to assess the clinical feasibility of calculating the static standardized uptake value (SUV) from a short dynamic scan without the use of blood sampling, thereby obtaining all dynamic and static parameters in a scan of only 30 min.

Dopamine and serotonin regulate tumor behavior by affecting angiogenesis.

The biogenic amines dopamine and serotonin are neurotransmitters and hormones, which are mainly produced in the central nervous system and in the gastro-intestinal tract. They execute local and systemic functions such as intestinal motility and tissue repair. Dopamine and serotonin are primarily stored in and transported by platelets.

Assessment of bone graft incorporation by 18 F-fluoride positron-emission tomography/computed tomography in patients with persisting symptoms after posterior lumbar interbody fusion.

Background: Posterior lumbar interbody fusion (PLIF) is a method that allows decompression of the spinal canal and nerve roots by laminectomy combined with fusion by means of intervertebral cages filled with bone graft and pedicle screw fixation. Conventional imaging techniques, such as plain radiography and computed tomography (CT), have limitations to assess bony fusion dynamics.

Methods: In 16 PLIFs of 15 patients with persisting symptoms, positron-emission tomography (PET)/CT scans were made 60 min after intravenous administration of 156 to 263 MBq of 18 F-fluoride, including 1-mm sliced, high-dose, non-contrast-enhanced CT scanning.