2-Butoxyethanol model of haemolysis and disseminated thrombosis in female rats: a preliminary study of the vascular mechanism of osteoarthritis in the temporomandibular joint

Athrocentesis: What, When, and Why?

The introduction of temporomandibular joint (TMJ) arthroscopy by Onishi in 1970 (results published in 1975 and 1980) opened a new modality for TMJ treatment. The efficiency of arthroscopic lavage and lysis led in the 1990s to its simplification: TMJ arthrocentesis. Always associated with load control, physiotherapy, and elimination of any occlusal hazards, arthrocentesis, a simple procedure, entails less expensive and more available tools and is performed under local anesthesia. Although lacking direct visual inspection of the joint structures, it has become quite popular. Arthrocentesis is most efficient in localized joint pain and limited joint movements such as closed lock, anchored disc phenomenon, osteoarthritis, and various inflammatory diseases. In clicking joint, the results are somewhat controversial. The efficiency of arthrocentesis elicited many enquiries that led to the study and a better understanding of joint function and dysfunction and the actual role of disc location. The release of closed lock without disc repositioning was quite surprising; it improved our understanding of the pathogenesis of closed lock and led to the discovery of the anchored disc phenomenon. This was followed by the awareness of the joint-lubrication system and, in turn, alternative suggestions for the pathogenesis of TMJ disc displacement with and without reduction, open lock, and osteoarthritis, and ultimately by the development of an effective bio-lubricant. Awareness of the role of joint overloading led to the development of an interocclusal appliance that reduces intraarticular pressure; it has become a "must" support for arthrocentesis and any surgical intervention. In our view, arthrocentesis is the definitive indication of the need for surgical intervention and, therefore, should be the first in the cascade of interventions in TMJ disorders.

Early Morphological and Functional Reorganization of the Articular Cartilage in Rats with Experimental Osteoarthrosis of Different Genesis

Peculiarities of the morphology of some phenotypes of experimental osteoarthrosis was studied in experiments on rats. Reorganization of the knee articular cartilage of Wistar rats during aging (age-associated phenotype), obesity (metabolic phenotype), circulatory disturbances (e.g., chronic heart failure), and their combinations (polymorbidity) was studied by hematoxylin and eosin staining, immunohistochemical staining for collagen II and caspase 3, and morphometry. High sensitivity of the cartilage to non-traumatic influence of different anthropomorphic factors was demonstrated; morphological changes in osteoarthrosis of different genesis. The most pronounced pathological changes were observed in polymorbid animals, which allowed developing a new pathogenetically substantiated model of nontraumatic osteoarthrosis.

Rapid conditional targeted ablation model for hemolytic anemia in the rat

Effective methods for cell ablation are important tools for examining the anatomical, functional, and behavioral consequences of selective loss of specific cell types in animal models. We have developed an ablation system based on creating genetically modified animals that express human CD59 (hCD59), a membrane receptor, and administering intermedilysin (ILY), a toxin produced by Streptococcus intermedius, which binds specifically to hCD59 to induce cell lysis. As proof-of-concept in the rat, we generated an anemia model, SD-Tg(CD59-HBA1)Bryd, which expresses hCD59 on erythrocytes. Hemolysis is a common complication of inherited or acquired blood disorders, which can result in cardiovascular compromise and death. A rat model that can replicate hemolysis through specific ablation of erythrocytes would allow further study of disease and novel treatments. In vitro, complete lysis of erythrocytes expressing hCD59 was observed at and above 250 pM ILY, while no lysis was observed in wild-type erythrocytes at any ILY concentration (8-1,000 pM). In vivo, ILY intravenous injection (100 ng/g body wt) dramatically reduced the hematocrit within 10 min, with a mean hematocrit reduction of 43% compared with 1.4% in the saline control group. Rats injected with ILY at 500 ng/g intraperitoneally developed gross signs of anemia. Histopathology confirmed anemia and revealed hepatic necrosis, with microthrombi present. These studies validate the hCD59-ILY cell ablation technology in the rat and provide the scientific community with a new rapid conditional targeted ablation model for hemolytic anemia and hemolysis-associated sequelae.

Metabolic stress-induced joint inflammation and osteoarthritis

Osteoarthritis (OA) is a heterogeneous disorder with several risk factors. Among them, obesity has a major impact on both loading and non-loading joints. Mechanical overload and activity of systemic inflammatory mediators derived from adipose tissue (adipokines, free fatty acids (FFA), reactive oxygen species (ROS)) provide clues to the increased incidence and prevalence of OA in obesity. Recently, research found greater OA prevalence and incidence in obese patients with cardiometabolic disturbances than "healthy" obese patients, which led to the description of a new OA phenotype - metabolic syndrome (MetS)-associated OA. Indeed, individual metabolic factors (diabetes, dyslipidemia, and hypertension) may increase the risk of obesity-induced OA. This review discusses hypotheses based on pathways specific to a metabolic factor in MetS-associated OA, such as the role of advanced glycation end products (AGEs) and glucose toxicity. A better understanding of these phenotypes based on risk factors will be critical for designing trials of this specific subset of OA.

Full length articles published in BJOMS during 2010-11--an analysis by sub-specialty and study type

Full length articles such as prospective and retrospective studies, case series, laboratory-based research and reviews form the majority of papers published in the British Journal of Oral and Maxillofacial Surgery (BJOMS). We were interested to evaluate the breakdown of these types of articles both by sub-specialty and the type of study as well as the proportion that are written by UK colleagues compared to overseas authors over a 2 year period (2010-11). A total of 191 full length articles across all sub-specialties of our discipline were published, with 107 papers (56%) coming from UK authors. There were proportionately more oncology papers arising from the UK than overseas (60 and 30% of total respectively) while the opposite was found for cleft/deformity studies (10% and 22%). There was only one laboratory-based study published from the UK compared with 27 papers from overseas. The number of quality papers being submitted to the Journal continues to increase, and the type of article being published between UK and overseas probably reflects different practices and case-loads amongst colleagues. The relatively few UK laboratory based studies published in BJOMS compared to overseas authors are most likely due to authors seeking the most prestigious journals possible for their work.