Comparative clinicoradiographical evaluation of effect of aminobisphosphonate (sodium alendronate) on peri-implant bone status: Controlled clinical trial

Aim:

The present study aims to compare the peri-implant bone status around immediately loaded dental implants treated with aminobisphosphonate solution and untreated control implants in terms of clinical and radiographical parameters.

Materials and Methods:

A total of 24 patients were randomly divided equally into two groups. This study was conducted in accordance to the Helsinki's declaration of 1975, revised in 2000, and with the approval of the institutional ethical committee. In the control group after preparation, osteotomy sites were irrigated with normal saline solution, whereas in the test group osteotomy sites were irrigated with modified bisphosphonate solution and then TRX-OP, Hi-Tec dental implants were inserted. Clinical parameters, such as modified plaque and gingival index, probing depth, mobility, and radiographic parameters were recorded at baseline (0), 3, 6, and 9 months. Data analysis was performed using the Statistical Package for the Social Sciences version 17 for windows, and the statistical techniques employed were repeated measures analysis of variance, independent sample t-test, and paired sample t-test.

Results:

Reduction in mean radiographic bone levels (height) was observed on the mesial and distal aspect of the control group in comparison to its baseline at all intervals. In the test group, there was reduction in mean radiographic bone levels on mesial and distal aspect of the implant site in comparison to its baseline till 6-month follow up, however, at 9 month, there was gain in bone level on both mesial and distal aspect of implant. This represents the effectiveness of sodium alendronate in enhancing the bone formation. On comparison, between both groups on mesial and distal aspect of implants, statistically significant differences were observed at 3 and 9 months on mesial and distal aspect, respectively, without any clinical evidence of mobility in the test group.

Conclusion:

Implant site treated with aminobisphosphonate solution represents greater efficacy in enhancing bone formation when used as an irrigant; thus, it is considered beneficial in implant dentistry.

Downregulation of CXCR4 Expression and Functionality After Zoledronate Exposure in Canine Osteosarcoma

Background

The establishment and progression of metastases remains the life‐limiting factor for dogs diagnosed with osteosarcoma (OS). The pattern of metastases is likely regulated through interactions between chemokine receptors and chemokines, and perturbations in these signaling cascades responsible for cytoskeletal organization and directional migration have the potential to alter metastatic cell trafficking behaviors.

Hypothesis

Zoledronate will impair directional migration of OS cells through downregulation of chemokine (C‐X‐C motif) receptor 4 (CXCR4) expression and functionality.

Samples

Nineteen archived tumor specimens and plasma from 20 dogs with OS.

Methods

Prospectively, the expressions of CXCR4 were studied in OS cell lines and spontaneous tumor samples. The effect of zoledronate on CXCR4 expression and functionality was investigated by characterizing responses in 3 OS cell lines. In 19 OS specimens and 20 dogs with OS, changes in CXCR4 expression and circulating CXCR4 concentrations were characterized in response to zoledronate therapy respectively.

Results

All canine OS cells express CXCR4, and zoledronate reduces CXCR4 expression and functionality by 27.7% (P < .0001), through augmented proteasome degradation and reduced prenylation of heterotrimeric G‐proteins in 33% of tumor cell lines evaluated. In OS‐bearing dogs, zoledronate reduces CXCR4 expressions by 40% within the primary tumor compared to untreated controls (P = .03) and also decreases the circulating concentrations of CXCR4 in 18 of 20 dogs with OS.

Conclusions and clinical importance

Zoledronate can alter CXCR4 expression and functionality in OS cells, and consequent perturbations in CXCR4 intracellular signaling cascades might influence patterns of metastases.

Stereotaxic administrations of allogeneic human Vγ9Vδ2 T cells efficiently control the development of human glioblastoma brain tumors

Glioblastoma multiforme (GBM) represents the most frequent and deadliest primary brain tumor. Aggressive treatment still fails to eliminate deep brain infiltrative and highly resistant tumor cells. Human Vγ9Vδ2 T cells, the major peripheral blood γδ T cell subset, react against a wide array of tumor cells and represent attractive immune effector T cells for the design of antitumor therapies. This study aims at providing a preclinical rationale for immunotherapies in GBM based on stereotaxic administration of allogeneic human Vγ9Vδ2 T cells. The feasibility and the antitumor efficacy of stereotaxic Vγ9Vδ2 T cell injections have been investigated in orthotopic GBM mice model using selected heterogeneous and invasive primary human GBM cells. Allogeneic human Vγ9Vδ2 T cells survive and patrol for several days within the brain parenchyma following adoptive transfer and can successfully eliminate infiltrative GBM primary cells. These striking observations pave the way for optimized stereotaxic antitumor immunotherapies targeting human allogeneic Vγ9Vδ2 T cells in GBM patients.