The chondrocyte channelome: A narrative review

Chondrocytes are the main cells in the extracellular matrix (ECM) of articular cartilage and possess a highly differentiated phenotype that is the hallmark of the unique physiological functions of this specialised load-bearing connective tissue. The plasma membrane of articular chondrocytes contains a rich and diverse complement of membrane proteins, known as the membranome, which defines the cell surface phenotype of the cells. The membranome is a key target of pharmacological agents and is important for chondrocyte function. It includes channels, transporters, enzymes, receptors, and anchors for intracellular, cytoskeletal and ECM proteins and other macromolecular complexes. The chondrocyte channelome is a sub-compartment of the membranome and includes a complete set of ion channels and porins expressed in these cells. Many of these are multi-functional proteins with “moonlighting” roles, serving as channels, receptors and signalling components of larger molecular assemblies. The aim of this review is to summarise our current knowledge of the fundamental aspects of the chondrocyte channelome, discuss its relevance to cartilage biology and highlight its possible role in the pathogenesis of osteoarthritis (OA). Excessive and inappropriate mechanical loads, an inflammatory micro-environment, alternative splicing of channel components or accumulation of basic calcium phosphate crystals can result in an altered chondrocyte channelome impairing its function. Alterations in Ca²⁺ signalling may lead to defective synthesis of ECM macromolecules and aggravated catabolic responses in chondrocytes, which is an important and relatively unexplored aspect of the complex and poorly understood mechanism of OA development.     

A new method for the termination of cervical pregnancy]

The authors described a 7 weeks old cervical pregnant case, whome was administered 250 mg methotrexate in infusion to eliminate the throphoblastic tissue. 3 days later the HCG was negative in the urine. After the dilatation of cervix by laminaria, the collapsed amniotic sac came from the cervix with minimal hemorrhage. They suggest the method is suitable to prevent the serious complications of cervical pregnancy.     

Risk factors for diabetic retinopathy in children and adolescents with type I diabetes mellitus

Based on repeated fluoroangiographic examinations in a group of 28 children with type I diabetes mellitus the authors observed progressing diabetic retinal changes. At the end of the three-year observation period they found progress in 32% of the children. They investigated influence of risk factors such as age, duration of the basic disease, its metabolic compensation, sex and HLA typing on the development of diabetic retinopathy.     

The use of endoprostheses (stents) in airway stenosis]

Six patients with obstruction of the trachea were treated with silicone rubber endothracheal stents implanted with flexible bronchoscope. In every case the stent caused significant clinical improvement of the ventilation. At the postintubation stenosis the stent can result a final recovery, at the malignant processes the implantation seems to be a new palliative method.     

Management of lung and bone metastases from thyroid cancers of differentiated structures

During a period of thirty years (1959-1989) 374 patients underwent surgery for differentiated thyroid carcinoma at the 1st Department of Surgery of the University Medical School in Debrecen. Distant metastases were found in the lungs or bones in 36 patients (9.6%). In 20 patients the first clinical sign of the primary disease was the distant metastasis. The aspects of surgical treatment depended on whether the metastases were solitary or multiple, capable or uncapable of radioiodine uptake. Whereas the majority of pulmonary metastases respond well to 131I-treatment the therapy of bone metastases is multidisciplinary. The 5-year survival rate was 47%, the 10-year one 19%.