Human papillomavirus and oral disease – emerging evidence: a review

Human papillomavirus (HPV) infections have received considerable attention in recent years. Of the 120 or so known types of the virus, some cause a variety of benign wart‐like lesions of the skin and genital and oral mucosae, whilst others are aetiologically associated with cervical and anogenital cancers. Recent epidemiologic evidence suggests that HPV may also be an independent risk factor for oropharyngeal cancer. In this context it has been suggested that HPV virus may modulate the process of carcinogenesis in some tobacco and alcohol induced oropharyngeal cancers and act as the primary oncogenic agent for inducing carcinogenesis among non‐smokers. Dental practitioners have a major role in detecting all lesions of the oral mucosa caused, or possibly caused, by HPV. This paper briefly reviews the current state of knowledge of molecular and clinical aspects of HPV infections of the oral mucosa.     

Effects of long-term water storage on the microtensile bond strength of five experimental self-etching adhesives based on surfactants rather than HEMA

Objectives

The purpose of this study is to evaluate the hypothesis that replacing 2-hydroxyethyl methacrylate (HEMA) for surfactant dimethacrylates (SD) does not affect the immediate and long-term microtensile bond strength (μTBS) of experimental two-step self-etch HEMA-free adhesive systems applied on dentin.

Materials and methods

Five experimental HEMA-free two-step self-etching systems containing different SD (ethoxylated bisphenol A diglycidyl dimethacrylate (Bis-EMA 10, B10), Bis-EMA 30 (B30), poly-ethyleneglycol (400) dimethacrylate (PEG 400, P400), PEG 1000 (P1000), and PEG 400 urethane dimethacrylate (UDMA) (UP400)) and a HEMA-containing system (control) (HA) were formulated. Specimens were subjected to the μTBS test after 24 h and 6 and 12 months of storage. Data (in megapascals) were analyzed by Kruskal–Wallis and Dunn tests (α?=?0.05).

Results

Medians of the μTBS data after 24 h of storage are: HA?=?57.2^A, B10?=?26.2^BC, B30?=?24.0^C, P400?=?32.6^BC, P1000?=?37.3^B, and UP400?=?57.9^A; after 6 months are: HA?=?47.9^A, B10?=?18.5^B, B30?=?7.8^C, P400?=?16.1^B, P1000?=?14.6^BC, and UP400?=?51.6^A; and after 12 months are: HA?=?31.2^A, B10?=?15.2^B, B30?=?9.0^B, P400?=?9.1^B, P1000?=?13.3^B, and UP400?=?35.7^A. Between the HEMA-free groups, the adhesive system formulated with PEG 400 UDMA produced similar μTBS to the HEMA-containing group. Also, the storage of specimens decreased the μTBS (p?<?0.05).

Conclusion

Replacing HEMA for PEG 400 UDMA in an adhesive system formulation generated a satisfactory μTBS to dentin.

Clinical relevance

Surfactant dimethacrylates have a potential use in the development of HEMA-free self-etching adhesive systems, which are more chemically stable.     

Comparision of blood loss between computer assisted and conventional total knee arthroplasty

Background:

Bleeding during total knee arthroplasty (TKA) can cause significant morbidity and mortality. One proposed benefit of computer assisted TKA is decreased bleeding as the femoral canal is not invaded. This study assessed blood loss between computer assisted surgery (CAS) and conventional TKA.

Materials and Methods:

73 consecutive patients (37 males, 36 females) underwent primary TKA between 2006 and 2009. Thirty eight patients underwent navigated TKA and 35 underwent conventional TKA for symptomatic osteoarthritis of the knee. These patients were matched for age, gender, and body mass index (BMI). Average age was 70.3 years (range 47-91 years). Mean BMI was 30 (range 17-49). Average preoperative hemoglobin was 13.26 g/dL (range 8.7-18.4 g/dL) in the navigated group and 13.47 g/dL (range 9.6-15.8 g/dL) in the conventional group (P = 0.9). Average tourniquet time was 110 min (range 90-150 min) in the navigated group and 96.7 min (range 60-145 min) in the conventional group (P = 0.77).

Results:

Average postoperative hemoglobin in the navigated group was 10.34 g/dL (range 7.5-14.8 g/dL) and in the conventional group was 10.03 g/dL (range 7.5-12.2 g/dL) (P = 0.17). Six patients in both groups required blood transfusions. The mean drain collection was 599 mL (range 150-1370 mL) in the navigated group and 562 mL (range 750-1000 mL) in the conventional group (P = 0.1724). These results suggest that there is no significant reduction in blood loss in CAS TKA.

Conclusion:

These results suggest that there is no significant difference in blood loss in CAS TKA and conventional TKA. This study also highlights the heterogeneity of methods used in studies related to CAS TKA. We believe that there is a need for a large multicenter prospective randomized controlled trial to be performed before a consensus can be reached on the influence of CAS techniques on blood loss during primary TKA.     

Tivozanib for the treatment of renal cell carcinoma

Introduction: Renal cell carcinoma (RCC) represents a heterogeneous group of cancers with distinct histological features, molecular alterations, prognosis, and response to therapy. Target agents directed against vascular endothelial growth factor and its receptor and mammalian target of rapamycin (mTOR) inhibitors have completely changed the landscape of RCC. However, the rate of complete response is still low, thus supporting the research of novel therapeutic agents.

Area covered: The authors describe the chemical features of tivozanib, its pharmacodynamic and pharmacokinetic properties, and the results obtained in human phase I–III clinical trials. Tivozanib received its first global approval in EU, Iceland, and Norway on 28 August 2017 for the first-line treatment of adult patients with advanced RCC and for adult patients who are VEGFR and mTOR inhibitor-naive following disease progression after one prior treatment with cytokines.

Expert opinion: The US Food and Drug Administration did not approve tivozanib due to the lack of a significant advantage in terms of survival compared to sorafenib. To date, the role of tivozanib in the pharmaceutical landscape of mRCC appears to be very limited. However, ongoing trials on the association between tivozanib and immunotherapy may represent a promising strategy to be assessed in future clinical trials.     

Activation of factor XI in plasma is dependent on factor XII [see comments]

The activation of factor XI initiates the intrinsic coagulation pathway. Until recently it was believed that the main activator of factor XI is factor XIIa in conjunction with the cofactor high molecular weight kininogen on a negatively charged surface. Two recent reports have presented evidence that in a purified system factor XI is activatable by thrombin together with the soluble polyanion dextran sulfate. To assess the physiological relevance of these findings we studied the activation of factor XI in normal and factor XII-deficient plasma. We used either kaolin/cephalin or dextran sulfate as a surface for the intrinsic coagulation pathway, tissue factor to generate thrombin via the extrinsic pathway, or the addition of alpha-thrombin directly. 125I-factor XI, added to factor XI-deficient plasma at physiologic concentrations (35 nmol/L), is rapidly cleaved on incubation with kaolin. The kinetics appear to be exponential with half the maximum cleavage at 5 minutes. Similar kinetics of factor XI cleavage are seen when 40 nmol/L factor XIIa (equal to 10% of factor XII activation) is added to factor XII-deficient plasma if an activating surface is provided. Tissue factor (1:500) added to plasma did not induce cleavage of factor XI during a 90-minute incubation, although fibrin formation within 30 seconds indicated that thrombin was generated via the extrinsic pathway. Adding 1 mumol/L alpha-thrombin (equivalent to 50% prothrombin activation) directly to factor XII deficient or normal plasma (with or without kaolin/cephalin/Ca2+ or dextran sulfate) led to instantaneous fibrinogen cleavage, but again no cleavage of factor XI was observable. We conclude that in plasma surroundings factor XI is not activated by thrombin, and that proposals of thrombin initiation of the intrinsic coagulation cascade are not supportable.     

The severe combined immunodeficient-human peripheral blood stem cell (SCID-huPBSC) mouse: a xenotransplant model for huPBSC-initiated hematopoiesis

Mononuclear cells (MNCs) containing peripheral blood stem cells (PBSCs) were obtained from solid-tumor patients undergoing mobilizing chemotherapy followed by granulocyte colony-stimulating factor for PBSC transplantation-supported dose-intensified anticancer chemotherapy and were transplanted into unconditioned "nonleaky" young severe combined immunodeficient mice. Multilineage engraftment was shown by flow cytometry and immunocytochemistry using monoclonal antibodies to various human cell surface antigens as well as identification of human immunoglobulin in murine sera. Within a dose range of MNCs suitable for transplantation (10 to 36 x 10(6) cells/graft) the number of CD34+ cells injected (optimal at > 0.7 x 10(6)/graft) determined the yield of human cells produced in recipient animals. Engraftment of hu PBSC preparations resulted in prolonged generation of physiologic levels of human cytokines including interleukin-3 (IL-3), IL-6, and granulocyte- macrophage colony-stimulating factor, which were detectable in the murine blood over a period of at least 4 months. In vivo survival of immature human progenitor cells was preserved even 9 months after transplantation. Because human IL-3 is known to stimulate early hematopoiesis, a rat fibroblast cell line was stably transfected with a retroviral vector carrying the human IL-3 gene and cotransplanted subcutaneously as additional source of growth factor. Cotransplants of this cell line producing sustained in vivo levels of circulating human IL-3 for at least 12 weeks significantly accelerated the process of engraftment of huPBSC and spurred the spread of mature human cells to the murine spleen, liver, thymus, and peripheral blood. Cotransplants of allogeneic human bone marrow stromal cells derived from long-term cultures resulted in a comparable--though less prominent--support of engraftment.