RANKL, OPG, and RUNX2 expression and epigenetic modifications in giant cell tumour of bone in 32 patients.

Aims: The present study investigated receptor activator of nuclear factor kappa-Β ligand (RANKL), osteoprotegerin (OPG), and Runt-related transcription factor 2 (RUNX2) gene expressions in giant cell tumour of bone (GCTB) patients in relationship with tumour recurrence. We also aimed to investigate the influence of CpG methylation on the transcriptional levels of RANKL and OPG. Methods: A total of 32 GCTB tissue samples were analyzed, and the expression of RANKL, OPG, and RUNX2 was evaluated by quantitative polymerase chain reaction (qPCR). The methylation status of RANKL and OPG was also evaluated by quantitative methylation-specific polymerase chain reaction (qMSP). Results: We found that RANKL and RUNX2 gene expression was upregulated more in recurrent than in non-recurrent GCTB tissues, while OPG gene expression was downregulated more in recurrent than in non-recurrent GCTB tissues. Additionally, we proved that changes in DNA methylation contribute to upregulating the expression of RANKL and downregulating the expression of OPG, which are critical for bone homeostasis and GCTB development. Conclusion: Our results suggest that the overexpression of RANKL/RUNX2 and the lower expression of OPG are associated with recurrence in GCTB patients.

Impact of Needle Size on the Onset and the Progression of Disc Degeneration in Rats.

BACKGROUND: Numerous animal models of intervertebral disc (IVD) degeneration have been proposed in the literature. The rat caudal disc has been used in disc degeneration studies because of its low cost and simplicity. However, no consensus on the size of the needle to be used during this process has been reached, yet. OBJECTIVES: This study aims to select an optimal needle size to establish a reproducible IVD degeneration model. STUDY DESIGN: This is a randomized, experimental trial. SETTING: Cell therapy and experimental surgery of musculoskeletal system LR18SP1 Lab, The Faculty of Medicine of Sfax, Tunisia. METHODS: The validity was verified by magnetic resonance imaging (MRI), histological, and immunohistochemical examinations. RESULTS: The MRI, histological, and immunohistochemical examinations showed that a disc that is perforated with a 21G needle degenerated acutely one week after the surgery, while a 29G needle puncture failed to develop disc degeneration. A 25G needle induced progressive degeneration in the IVD. LIMITATIONS: This study was not very long (6 weeks). CONCLUSIONS: We conclude that the size of the needle affects the onset and the progression of disc degeneration; a larger needle size leads to a more extended histological and radiographic degeneration within the IVD and in a relatively short time. Therefore, a 21G needle is an optimal choice to induce rapid degeneration in rats' caudal discs. However, the use of a 29G needle failed to establish a degenerative IVD model, which makes it ideal for IVD injection of drugs, plasmids, and growth factors. A 25G needle may be used to induce gradual degeneration.

The effectiveness of platelet-rich plasma gel on full-thickness cartilage defect repair in a rabbit model.

AIMS: The present study investigates the effectiveness of platelet-rich plasma (PRP) gel without adjunct to induce cartilage regeneration in large osteochondral defects in a rabbit model. METHODS: A bilateral osteochondral defect was created in the femoral trochlear groove of 14 New Zealand white rabbits. The right knees were filled with PRP gel and the contralateral knees remained untreated and served as control sides. Some animals were killed at week 3 and others at week 12 postoperatively. The joints were harvested and assessed by Magnetic Resonance Observation of Cartilage Repair Tissue (MOCART) MRI scoring system, and examined using the International Cartilage Repair Society (ICRS) macroscopic and ICRS histological scoring systems. Additionally, the collagen type II content was evaluated by the immunohistochemical staining. RESULTS: After 12 weeks post-surgery, the defects of the PRP group were repaired by hyaline cartilage-like tissue. However, incomplete cartilage regeneration was observed in the PRP group for three weeks. The control groups showed fibrocartilaginous or fibrous tissue, respectively, at each timepoint. CONCLUSION: Our study proved that the use of PRP gel without any adjuncts could successfully produce a good healing response and resurface the osteochondral defect with a better quality of cartilage in a rabbit model. Cite this article: Bone Joint Res 2021;10(3):192-202.

Cutaneous manifestations of COVID-19: report of three cases.

Coronavirus disease 2019 (COVID-19) shows rapid spread around the world. Its classic presentation is a respiratory illness. However, cutaneous manifestations have rarely been described as the first clinical manifestation in patients with this infection. The aim of this article is to describe cutaneous manifestations in patients with COVID-19 through three case reports.

Humeral artery aneurysm revealing a rare association between tuberculosis and behçet's disease.

The association of pulmonary tuberculosis and Behçet's disease revealed by an aneurysm of the humeral artery is exceptional with a complicated management. We report a case in which the two conditions occurred concomitantly with the vascular complication, apart from any use of immunosuppressive therapy, something that has never been reported in the literature. We report an extremely rare case of a spontaneous rupture of an aneurysm of the humeral artery of a 29-year-old woman with no history. The patient underwent axillo-humeral bypass. Investigations concluded the diagnosis of Behçet's disease associated with pulmonary and lymph node tuberculosis. Antituberculous chemotherapy followed by corticosteroids, immunosuppressants, and colchicine has been administrated. Based on this observation, we insist on the necessity of searching the symptoms of Behçet's disease in the presence of arterial involvement when having a young patient. Therapeutic management must include medical treatment to control inflammation and limit the risk of recurrence. Endovascular or surgical treatment is necessary if the arterial involvement is threatening. The association with tuberculosis complicates management and requires close monitoring.

Bilateral tuberculous dacryoadenitis.

Tuberculosis is a real public health problem in developing countries. The ophthalmic form is a rare clinical entity. Dacryoadenitis presents an exceptional manifestation. We report the case of a 45-year-old female who presented with a 1-month history of painless bilateral dacryoadenitis with a normal initial work-up. Anatomopathological examination of the lacrimal glandular tissue showed a gigantic epithelioid granuloma with caseous necrosis confirming the diagnosis of tuberculosis. The search for a primary focus was negative. Evolution was good under anti-tuberculosis chemotherapy. The objective of this work is to think of the tuberculous etiology when having dacryoadenitis in an endemic country.