17 research outputs found
Osteolytic lesion in the greater trochanter mimicking tumor
Two patients with an osteolytic lesion of the greater trochanter suggesting a malignant bone tumor are presented. Biopsy, microbiological and histological examination suggested a diagnosis of trochanteric tuberculosis. Treatment consisted of multiple surgical debridements and antituberculous chemotherapy. The incidence of similar cases is expected to increase with the rising incidence of tuberculosi
Cotton-induced pseudotumor of the femur
Twenty-five years prior to presentation a 41-year-old man had a femoral fracture stabilized with a 4.5 mm AO/ASIF steel plate. The femur healed uneventfully and the patient was asymptomatic for the following 20 years. He then noticed a slow-growing swelling of the left thigh associated with a degree of weakness. Radiographs of the femur 25 years after fracture stabilization showed a massive expansive osteolytic process surrounded by a rim of bone. Magnetic resonance imaging (MRI) confirmed the presence of a large tumor. Since malignancy could not be excluded the patient underwent incisional biopsy. The histologic findings were nonspecific. Because of persistent symptoms the lesion was marginally excised. Intraoperatively a folded cotton sponge was found adjacent to the femur. Histopathologic investigation confirmed a foreign body reaction probably related to the retained cotton sponge. Reactive, foreign-body-induced change may mimic bone and or soft tissue malignancie
Progressive melorheostosis in the peripheral and axial skeleton with associated vascular malformations: imaging findings over three decades
A 28-year old woman presented with Leri's disease (melorheostosis) and the rare combination of complex vascular malformations and lymphatic anomalies. Multifocal melorheostosis was segmental and unilateral, located in the left axial and peripheral skeleton, fifth thoracic vertebral body, fifth rib. left upper limb and lumbosacral spine (third lumbar body to first sacral segment). Sacral involvement was associated with spinal canal stenosis. Additionally the patient had multiple nevi and had suffered from left hemiplegia since birth. Lymphangiectasia of the mesentery and thorax led to chylothorax resistant to therapy for which the patient underwent a pleuropericardiectomy. Death ensued due to respiratory failur
Doppler tomography of the circumstellar disk of
Aims. The work is aimed at studying the circumstellar disk of the bright
classical binary Be star π Aqr.
Methods. We analysed variations of a double-peaked profile of the
Hα emission line in the spectrum of π Aqr
that was observed in many phases during ~40 orbital cycles in 2004−2013. We applied the
discrete Fourier transform (DFT) method to search for periodicity in the peak intensity
ratio (V/R). Doppler tomography was used to study the structure of the disk around the
primary.
Results. The dominant frequency in the power spectrum of the
Hα V/R ratio is 0.011873 day-1, which
corresponds to a period of 84.2(2) days and agrees with the earlier determined orbital
period of the system, Porb = 84.1 days. The V/R shows a
sinusoidal variation that is phase-locked with the orbital period. Doppler maps of all our
spectra show a non-uniform structure of the disk around the primary: a ring with the inner
and outer radii at Vin ≈ 450 km s-1 and
Vout ≈ 200 km s-1, respectively, along with an
extended stable region (spot) at Vx ≈ 225
km s-1 and Vy ≈ 100
km s-1. The disk radius of ≈65 R⊙ = 0.33 AU was
estimated by assuming Keplerian motion of a particle on a circular orbit at the disk’s
outer edge
Neurogenic Potential of Engineered Mesenchymal Stem Cells Overexpressing VEGF
Numerous signaling molecules are altered following nerve injury, serving as a blueprint for drug delivery approaches that promote nerve repair. However, challenges with achieving the appropriate temporal duration of recombinant protein delivery have limited the therapeutic success of this approach. Genetic engineering of mesenchymal stem cells (MSCs) to enhance the secretion of proangiogenic molecules such as vascular endothelial growth factor (VEGF) may provide an alternative. We hypothesized that the administration of VEGF-expressing human MSCs would stimulate neurite outgrowth and proliferation of cell-types involved in neural repair. When cultured with dorsal root ganglion (DRG) explants in vitro, control and VEGF-expressing MSCs (VEGF-MSCs) increased neurite extension and proliferation of Schwann cells (SCs) and endothelial cells, while VEGF-MSCs stimulated significantly greater proliferation of endothelial cells. When embedded within a 3D fibrin matrix, VEGF-MSCs maintained overexpression and expressed detectable levels over 21 days. After transplantation into a murine sciatic nerve injury model, VEGF-MSCs maintained high VEGF levels for 2 weeks. This study provides new insight into the role of VEGF on peripheral nerve injury and the viability of transplanted genetically engineered MSCs. The study aims to provide a framework for future studies with the ultimate goal of developing an improved therapy for nerve repair