Alendronate reduces periosteal microperfusion in vivo.

Objectives: Bisphosphonates are known to induce a severe adverse effect known as medication-related osteonecrosis of the jaw (MRONJ). Previous studies have proven the impact of bisphosphonates on microperfusion; therefore, this study aimed to investigate alendronate-induced microcirculatory reactions in the calvarial periosteum of rats.

Study Design: Bone chambers were implanted into 48 Lewis rats.

Reporter gene assays and chromatin-level assays define substantially non-overlapping sets of enhancer sequences.

Background: Transcriptional enhancers are essential for gene regulation, but how these regulatory elements are best defined remains a significant unresolved question. Traditional definitions rely on activity-based criteria such as reporter gene assays, while more recently, biochemical assays based on chromatin-level phenomena such as chromatin accessibility, histone modifications, and localized RNA transcription have gained prominence.

Results: We examine here whether these two types of definitions, activity-based and chromatin-based, effectively identify the same sets of sequences.

Antimicrobial peptide gene expression in medication-related osteonecrosis of the jaw.

Bisphosphonates and denosumab are commonly used antiresorptive therapies in patients with bone metastasis and osteoporosis. Medication-related osteonecrosis of the jaw (MRONJ) is a serious side effect of these drugs, and infection has been recognized as a contributing factor. Current therapeutic options for MRONJ show limited effectiveness, therefore necessitating novel treatment strategies.

Decelerated vascularization in tissue-engineered constructs in association with diabetes mellitus in vivo.

Aims: Rapid blood vessel ingrowth in transplanted tissue engineering constructs is the key factor for successful incorporation, but many potential patients who may use engineered tissues suffer from widespread diseases that limit the capacity of neovascularization (e.g. diabetes).

Patient specific implants (PSI) in reconstruction of orbital floor and wall fractures.

Fractures of the orbital wall and floor can be challenging due to the demanding three-dimensional anatomy and limited intraoperative overview. Misfitting implants and inaccurate surgical technique may lead to visual disturbance and unaesthetic results. A new approach using individually manufactured titanium implants (KLS Martin, Group, Germany) for daily routine is presented in the current paper.

Nonradiological method for 3-dimensional implant position assessment using an intraoral scan: new method for postoperative implant control.

Introduction: This study presents a method to verify the position of dental implants after insertion without the repeated x-ray exposure.

Material And Methods: An implant was inserted into the natural gap between the canines and premolars of 8 domestic pigs and 1 human patient. A scanbody was then connected to the implants and a digital intraoral impression of the jaw segment was acquired using a handheld scanner.

Optic nerve monitoring.

Orbital and anterior skull base surgery is generally performed close to the prechiasmatic visual pathway, and clear strategies for detecting and handling visual pathway damage are essential. To overcome the common problem of a missed clinical examination because of an uncooperative or unresponsive patient, flash visual evoked potentials and electroretinograms should be used. These electrophysiologic examination techniques can provide evidence of intact, pathologic, or absent conductivity of the visual pathway when clinical assessment is not feasible.

Additive effect of mesenchymal stem cells and VEGF to vascularization of PLGA scaffolds.

Bone marrow derived mesenchymal stem cells (bmMSCs) are widely used for the generation of tissue engineering constructs, since they can differentiate into different cell types occurring in bone tissues. Until now their use for the generation of tissue engineering constructs is limited. All cells inside a tissue engineering construct die within a short period of time after implantation of the construct because vascularization and establishment of connections to the recipient circulatory system is a time consuming process.

Non-radiological method for three-dimensional implant position evaluation using an intraoral scan method.

Introduction: This technical innovation presents a method that reproduces the position of a dental implant after insertion without the reuse of X-ray radiation.

Material And Methods: An implant was inserted into the natural gap between the canines and premolars of three domestic pigs. A Straumann Scanbody was then screwed to the implant, and a digital impression of the jaw segment was made.

Accelerating the early angiogenesis of tissue engineering constructs in vivo by the use of stem cells cultured in matrigel.

In tissue engineering research, generating constructs with an adequate extent of clinical applications remains a major challenge. In this context, rapid blood vessel ingrowth in the transplanted tissue engineering constructs is the key factor for successful incorporation. To accelerate the microvascular development in engineered tissues, we preincubated osteoblast-like cells as well as mesenchymal stem cells or a combination of both cell types in Matrigel-filled PLGA scaffolds before transplantation into the dorsal skinfold chambers of balb/c mice.

Perspectives on resorbable osteosynthesis materials in craniomaxillofacial surgery.

Since introduction to the clinics in the 1990s, resorbable osteosynthesis systems have undergone extensive improvements in order to establish their use as a standard treatment, especially in craniomaxillofacial surgery. However, the development of osteosynthesis systems made of poly(α-hydroxy acid) polymers has been hindered by the lack of information on the mechanical properties and biocompatibility of these materials. Moreover, magnesium-based degredable osteosynthesis materials have not yet been integrated into clinical practice owing to biocompatibility problems.

Increase in periosteal angiogenesis through heat shock conditioning.

Objective: It is widely known that stress conditioning can protect microcirculation and induce the release of vasoactive factors for a period of several hours. Little, however, is known about the long-term effects of stress conditioning on microcirculation, especially on the microcirculation of the periosteum of the calvaria. For this reason, we used intravital fluorescence microscopy to investigate the effects of heat shock priming on the microcirculation of the periosteum over a period of several days.

Virtual 3D tumor marking-exact intraoperative coordinate mapping improve post-operative radiotherapy.

The quality of the interdisciplinary interface in oncological treatment between surgery, pathology and radiotherapy is mainly dependent on reliable anatomical three-dimensional (3D) allocation of specimen and their context sensitive interpretation which defines further treatment protocols. Computer-assisted preoperative planning (CAPP) allows for outlining macroscopical tumor size and margins. A new technique facilitates the 3D virtual marking and mapping of frozen sections and resection margins or important surgical intraoperative information.

A novel approach for studying microcirculation in bone defects by intravital fluorescence microscopy.

Angiogenic and inflammatory responses to biodegradable scaffolds were previously studied using the dorsal skinfold chamber for testing different scaffold materials. In this model, the angiogenic response originates from the soft tissue of the skin. Herein, we introduce a new model that allows the study of developing microcirculation of bone defects for testing tissue-engineered constructs.

The Hannover experience: surgical treatment of tongue cancer--a clinical retrospective evaluation over a 30 years period.

Objectives: In this retrospective study, we present a clinical review of our experience with tongue cancer in order to obtain valid criteria for therapeutic decision-making.

Materials And Methods: Between 1980 and 2009, a total of 341 patients with squamous cell carcinoma of the tongue were treated at our Department. The average follow-up was 5.

Comparably accelerated vascularization by preincorporation of aortic fragments and mesenchymal stem cells in implanted tissue engineering constructs.

The demanding need for tissue replacement resulted in manifold approaches for the construction of different tissues. One common problem which hampers the clinical usage of tissue engineering constructs is a limited vascularization. In an attempt to accelerate the vascularization of tissue engineering constructs we compared the usage of bone marrow mesenchymal stem cells (bmMSCs) and fragments derived from the aorta in vivo.

Prolongated survival of osteoblast-like cells on biodegradable scaffolds by heat shock preconditioning.

The implantation of tissue-engineered constructs leads to hypoxic and physical stress to the seeded cells until they were reached by a functional microvascular system. Preconditioning of cells with heat shock induced heat shock proteins, which can support the cells to survive a subsequent episode of stress that would otherwise be lethal. Preconditioning of tissue-engineered constructs resulted in significantly higher number of surviving osteoblast-like cells (OLC).

Effects of VEGF loading on scaffold-confined vascularization.

Adequate vascularization of tissue-engineered constructs remains a major challenge in bone grafting. In view of this, we loaded ß-tricalcium-phosphate (ß-TCP) and porous poly(L-lactide-co-glycolide) (PLGA) scaffolds via collagen coating with vascular endothelial growth factor (VEGF) and studied whether the VEGF loading improves scaffold angiogenesis and vascularization. Dorsal skinfold chambers were implanted into 48 balb/c mice, which were assigned to 6 groups (n = 8 each).

Accelerated angiogenic host tissue response to poly(L-lactide-co-glycolide) scaffolds by vitalization with osteoblast-like cells.

Background: Bone substitutes should ideally promote rapid vascularization, which could be accelerated if these substitutes were vitalized by autologous cells. Although adequate engraftment of porous poly(L-lactide-co-glycolide) (PLGA) scaffolds has been demonstrated in the past, it has not yet been investigated how vascularization is influenced by vitalization or, more precisely, by seeding PLGA scaffolds with osteoblast-like cells (OLCs). For this reason, we conducted an in vivo study to assess host angiogenic and inflammatory responses after the implantation of PLGA scaffolds vitalized with isogeneic OLCs.

Consequences of seeded cell type on vascularization of tissue engineering constructs in vivo.

Implantation of tissue engineering constructs is a promising technique to reconstruct injured tissue. However, after implantation the nutrition of the constructs is predominantly restricted to vascularization. Since cells possess distinct angiogenic potency, we herein assessed whether scaffold vitalization with different cell types improves scaffold vascularization.

Different curcuminoids inhibit T-lymphocyte proliferation independently of their radical scavenging activities.

Purpose: We investigated the inhibitory effects of curcumin, curcumin derivatives and degradation products on OKT3-induced human peripheral blood mononuclear cell (PBMC) proliferation and the role of their radical scavenging activity.

Methods: OKT3-induced human PBMC proliferation was determined by measuring 3H-thymidine incorporation. Radical scavenging activity was evaluated by using an in vitro DPPH assay.