Immunoporosis: A New Role for Invariant Natural Killer T (NKT) Cells Through Overexpression of Nuclear Factor-κB Ligand (RANKL).

BACKGROUND Osteoporosis affects millions of postmenopausal women worldwide. Invariant natural killer T cells (iNKT) are important cells for bone homeostasis. The sim of this study was to investigate the contribution of invariant natural killer T cells (iNKT) in the increased receptor activator of the nuclear factor-kappaB ligand (RANKL) pool and bone resorption, a characteristic of patients with osteoporosis. MATERIAL AND METHODS Whole blood was collected from 79 female patients. The dual energy x-absorptiometry scan was performed in all patients, and the T-score was calculated in order to classify our patients according to the World Human Organization (WHO) criteria for diagnosis and classification of osteoporosis. Eleven patients had a T-score -2.5 and were included in the osteoporosis group. We performed alpha-galactosylceramide activation of iNKT cells in vitro. Surface RANKL expression was detected by multicolor flow cytometry in naive and activated lymphocytes. Beta-Crosslaps (ß-CTx) levels were measured in whole blood plasma by ELISA (enzyme-linked immunosorbent assay). RESULTS Although iNKT cells were not clonally expanded in patients with osteoporosis, iNKT cells from osteoporotic patients overexpressed RANKL compared to ND and osteopenic patients. This is a distinctive feature of iNKT cells and is not seen in conventional T-lymphocytes. RANKL expression in iNKT cells was not related to ß-CTx levels in the blood. Finally, iNKT cell activation by the prototypal glycolipid ligand alpha-galactosylceramide increased by 8 times their RANKL expression. CONCLUSIONS In patients with osteoporosis, iNKT cells specifically overexpress RANKL, a cytokine that regulates osteoclast activity. It seems that iNKT cells have a long-standing effect of on the bone physiology, which plays an important role in the bone loss of patients with osteoporosis.

The effect of drugs on implant osseointegration- A narrative review.

OBJECTIVE: This narrative review aims to investigate the effects of drugs on implant osseointegration, analyzing their potential positive or negative impact on the direct structural and functional connection between bone and load-carrying implants. BACKGROUND: The review seeks to provide a comprehensive understanding of osseointegration, which refers to the successful integration of an implant with living bone, resulting in no progressive relative movement between them. Exploring the effects of drugs on implant osseointegration is crucial for optimizing outcomes and enhancing patient care in orthopedic implant procedures. METHODS: Relevant studies on the effects of drugs on implant osseointegration were identified through a literature search. Electronic databases, including PubMed, Embase, and Google Scholar, were utilized, employing appropriate keywords and MeSH terms related to osseointegration, implants, and drug interventions. The search was limited to English studies. DISCUSSION: This overview presents a detailed analysis of the effects of drugs on implant osseointegration. It explores drugs such as bisphosphonates, teriparatide, statins, angiotensin-converting enzyme inhibitors, beta-blockers, nitrites, and thiazide diuretics as promoters of osseointegration. Conversely, loop diuretics, non-steroidal anti-inflammatory drugs, corticosteroids, cyclosporine A, cisplatin, methotrexate, antibiotics, proton pump inhibitors (PPIs), antiepileptics, selective serotonin reuptake inhibitors (SSRIs), and anticoagulants are discussed as inhibitors of the process. The role of vitamin D3 remains uncertain. The complex relationship between drugs and the biology of implant osseointegration is emphasized, underscoring the need for further in vitro and in vivo studies to validate their effects CONCLUSION: This narrative review contributes to the literature by providing an overview of the effects of drugs on implant osseointegration. It highlights the complexity of the subject and emphasizes the necessity for more extensive and sophisticated studies in the future. Based on the synthesis of the reviewed literature, certain drugs, such as bisphosphonates and teriparatide, show potential for promoting implant osseointegration, while others, including loop diuretics and certain antibiotics, may impede the process. However, additional research is required to solidify these conclusions and effectively inform clinical practice.

Participation in athletic activities may be associated with later development of hip and knee osteoarthritis.

Participation in physical activity and recreational sports is critical for maintaining overall health; athletic activities and reduction in the incidence of several "lifestyle" diseases seem to have a dose-dependent relationship. Also, quality of life is enhanced in people who are active and regularly participate in sports. However, sports-related joint loading and strenuous occupational loading have been shown to increase the risk of osteoarthritis (OA), which seems to have a multifactorial etiology. This article reviews the literature on known connections between participation in sports and athletic activities and development of secondary OA in the joints of the major upper and lower limbs (ie, knee, hip, elbow, and shoulder) in athletes without injury. Most studies examining the connection between participation in sports and later development of OA usually provide low-level evidence and have many methodological weaknesses. Based on the literature reviewed in this article, it may be concluded that the connection between participation in athletic activities and development of OA has not been proven; however, the condition is highly likely to occur in the hip and knee joints. Definite conclusions regarding the connection between development of glenohumeral and/or elbow OA and participation in athletic activities cannot be drawn.

The effect of a new oral anticoagulant (Rivaroxaban) on implants pull-out strength. An experimental study in rats.

OBJECTIVES: Thromboprophylaxis reduces the risk of surgery related deep venous thrombosis and pulmonary embolism. The classical anticoagulants (heparin and LWMH) were associated with systemic osteoporosis, poor bone healing and materials' osseointegration. There is a lack of data concerning the effect of the new orally administered anticoagulants on osseointegration. The aim of this study is to investigate the possible effect of rivaroxaban, a direct anti-Xa factor, on osseointegration. METHODS: Twenty eight white, male, Wistar rats were divided into two groups: Group A, study group (n=14) and group B, control group (n=14). In all animals under general anesthesia one screw was inserted on the right tibia. For twenty eight days the animals of group A received intraperitoneal rivaroxaban injections 5mgr/kgr every day. The animals of group B received intraperitoneal equal amount of normal saline injections. At the end of the four weeks all animals were sacrificed and their right tibias were excised and underwent the pull-out test. RESULTS: The mean values of pull-out test were 92,10±19,12N for the control group and 95,46±21,02N for the study group. The statistical analysis using t-test showed no significant difference (p=0,665) for the pull-out test. CONCLUSIONS: These results indicate that Rivaroxaban hasn't got any deleterious effect on the osseointegration of implants on rats.