Endocultivation: the influence of delayed vs. simultaneous application of BMP-2 onto individually formed hydroxyapatite matrices for heterotopic bone induction.

When bone morphogenetic protein (BMP) is delivered to matrices in vivo may affect tissue engineered bone constructs for jaw reconstruction after cancer surgery. This study compared the effects of BMP application at different times after matrix implantation for heterotopic bone induction in a rat model. Hydroxyapatite blocks were implanted unilaterally onto the surface of the latissimus dorsi muscle. A second block was implanted onto the contralateral muscle after 1, 2 or 4 weeks and 200 µg rhBMP-2 was injected into the blocks on both sides. Bone formation and density inside the blocks was analysed by CT and histology. 8 weeks after BMP application increases in bone density within the scaffolds were most pronounced in the simultaneous application group (179 HU). Less pronounced increases were observed for the 1 (65 HU), 2 (58 HU) and 4 (31 HU; p<0.0001) week delay group. Homogeneous bone induction started from the central channel of the blocks. Capillaries and larger vessels were seen in all constructs, samples receiving delayed BMP treatment demonstrated significantly greater neovascularization. Delayed application of BMP was less effective for heterotopic bone formation than simultaneous application. A central channel allows homogeneous bone induction directly from the centre of the blocks.

Mirror, mirror on the wall : self-perception of facial beauty versus judgement by others.

In 1878, Margaret Wolfe Hungerford published a simple but insightful phrase in her novel 'Molly Bawn' that was to be quoted so often it has almost become cliché: "Beauty is in the eye of the beholder". While many questions regarding the perception and neural processing of facial attractiveness have been resolved, it became obvious to us that study designs have been principally based on either facial self-perception or perception by others. The relationship between these however, remains both crucial and unknown. Standardized images were taken of 141 subjects. These 141 subjects were asked to complete the adjective mood scale (AMS) and to rank specific issues related to their looks on a visual analogue scale. The images were then shown to independent judges to rank specific issues related to their looks on a visual analogue scale. Our results show proof for a strikingly simple observation: that individuals perceive their own beauty to be greater than that expressed in the opinions of others (p < 0.001). This observation provides insight into our basic behavioural patterns and suggests that there are strong psychological mechanisms in humans supporting self-identification and thereby encouraging the self-confidence and resilience necessary to maintain one's social standing. While the psychological basis of self-confidence is multifactorial, our finding provides critical objective insight. We prove here for the first time that nothing more than the beauty of the beholder is in the eyes of the latter.

Learning by doing virtually.

Selective reduction of bone without collateral damage (nerves, teeth) is essential in apicectomy. To test whether skills acquired on a virtual apicectomy simulator (VOXEL-MAN system with integrated force-feedback) are transferable from virtual to physical reality, two groups of trainees were compared. Group 1 received computer-based virtual surgical training before performing an apicectomy in a pig cadaver model. The probability of preserving vital neighboring structures was improved significantly, i.e. six-fold, after virtual surgical training (P<0.001). The average volume of the bony defects created by the trainees of Group 2 (mean: 0.47 ml) was significantly (P<0.001) larger than by the trainees of Group 1 (mean: 0.25 ml). Most importantly, the ability to objectively self-assess performance was significantly improved after virtual training. Training with a virtual apicectomy simulator appears to be effective, and the skills acquired are transferable to physical reality.

Inhibition of nitric oxide and reactive oxygen species production improves the ability of a sunscreen to protect from sunburn, immunosuppression and photocarcinogenesis.

BACKGROUND: More effective strategies are required for the prevention of skin cancer, which is caused by ultraviolet (UV) radiation in sunlight. Sunscreens containing UV filters or reflectors offer some protection from sunlight. Pharmacologically active compounds that reduce UV damage offer considerable potential for improving sunscreen formulations. However, few studies have investigated whether the addition of such biological modifiers are an improvement. OBJECTIVES: In this study we supplemented a 2-ethyl hexyl methoxycinnamate-based sunscreen with the nitric oxide (NO) inhibitor NG-monomethyl-L-arginine acetate, the iron chelator 2,2'-dipyridyl, which reduces reactive oxygen species (ROS) production, or both. This was to determine whether inhibition of NO, ROS, or both could improve photoprotection by a sunscreen. METHODS: These sunscreens were compared for photoprotection from sunburn, immunosuppression and skin carcinogenesis in mice. To observe additional photoprotection by the NO and ROS inhibitors, UV doses were used that exceeded the protective capacity of the sunscreen. RESULTS: The combined inhibition of both NO and ROS production, but neither alone, increased sunscreen protection from sunburn and immunosuppression. Similarly, inhibition of both NO and ROS but neither alone reduced tumour multiplicity and incidence, therefore improving sunscreen protection from photocarcinogenesis. CONCLUSIONS: Whether NO and ROS inhibition were independently improving sunscreen photoprotection, with both being required for an observable effect, or whether inhibition of an interaction between NO and ROS was responsible for improved photoprotection by the sunscreen is unknown. These studies show that supplementation of a sunscreen with inhibitors of NO and ROS production improves the ability of the sunscreen to protect from sunburn, immunosuppression and photocarcinogenesis. Such an approach may be useful for reducing skin cancer incidence in humans.

Antibacterial essential oils in malodorous cancer patients: clinical observations in 30 patients.

Malodorous necrotic ulcers in cancer patients are of major concern as it leads to social isolation and poor quality of life. Current medications and topical therapies have proven inadequate in their ability to reduce foul smell to acceptable levels. We report the positive experience we have had in using antibacterial essential oils in patients with incurable head and neck cancer and associated malodorous necrotic ulcers. All patients received a standard course of therapy with oral or systemic antibiosis. In addition, we rinsed the ulcers with an antibacterial essential oil mix (mainly based on Eucalyptus oil) twice a day. All patients experienced complete resolution of the foul smell by only the third or fourth day of therapy. As a secondary effect we saw that besides smell reduction the oils had anti-inflammatory effects on neoplastic ulcers. In some patients ulcers started to heal and achieved complete re-epithiliazation. The patients experienced great personal relief upon resolution of their malodorous conditions. Quality of life improved significantly with the resulting reintroduction of social contact with friends and relatives.

Intraoral lesions associated with sebaceous nevus syndrome.

The sebaceous nevus syndrome describes the rare association of a sebaceous nevus with systemic features such as mental retardation, seizures and colobomas (among others). It is thought to be a cutaneous mosaic inherited as a paradominant trait. Three cases are provided illustrating the intraoral manifestations of the syndrome. The first histological comparison of contiguous mucosal and cutaneous lesions is provided. We also describe the possible association of SFM syndrome with a benign fibrous histiocytic lesion of the mandible. This and other mandibular tumors associated with the sebaceous nevus syndrome may have significant implications for patients. Awareness of the potential presence or development of significant intraoral lesions in association with the sebaceous nevus syndrome is important for those involved in the care of patients with this syndrome.

Innate immunity in human bone.

Bone has exceptional regenerative properties. Oral bone appears to be particularly resistant to infection despite exposure to oral flora, even in circumstances such as oral surgery where the thin mucosal layer covering the bone is disrupted. The goal of this study was to determine whether the innate immune system of antimicrobial peptides exists inside bone. Biopsies of non-infected and chronically infected mandibular bone were harvested from patients during maxillofacial surgical procedures. Bone biopsies from the iliac crest and fibula served as controls. Immunohistochemical staining was performed, directed against the human beta-defensin antimicrobial peptides (hBD) -1, -2 and -3. In addition, cultures of osteoblast-like cells were examined for the presence of each of the three beta-defensins and their mRNA transcripts. All three human beta-defensins were detected within the mineralized bone matrix of chronically infected mandibular bone in the vicinity of the endosteum and osteocytes. hBD-1, -2 and -3 were also found in the cytoplasm of osteocytes. Expression of all three beta-defensins was detected in each of the non-infected bone types including the controls, however, to a lesser degree than that found in the chronically infected mandibular bone. This may reflect upregulation of antimicrobial peptide expression in the presence of chronic infection. Cultures of non-infected osteoblast-like cells were found to express mRNA for each of hBD-1, -2 and -3. Immunohistochemical staining of the cultures was positive for hBD-1 and -2, but not for hBD-3. We provide the first evidence of a previously unrecognized innate immunological function of bone through the demonstration of the presence of the human beta-defensins hBD-1, -2 and -3 in bone.

Growth and transplantation of a custom vascularised bone graft in a man.

BACKGROUND: A major goal of research in bone transplantation is the ability to avoid creation of secondary bone defects. We aimed to repair an extended mandibular discontinuity defect by growth of a custom bone transplant inside the latissimus dorsi muscle of an adult male patient. METHODS: Three-dimensional computed tomography (CT) scanning and computer-aided design techniques were used to produce an ideal virtual replacement for the mandibular defect. These data were used to create a titanium mesh cage that was filled with bone mineral blocks and infiltrated with 7 mg recombinant human bone morphogenetic protein 7 and 20 mL of the patient's bone marrow. Thus prepared, the transplant was implanted into the latissimus dorsi muscle and 7 weeks later transplanted as a free bone-muscle flap to repair the mandibular defect. FINDINGS: In-vivo skeletal scintigraphy showed bone remodelling and mineralisation inside the mandibular transplant both before and after transplantation. CT provided radiological evidence of new bone formation. Postoperatively, the patient had an improved degree of mastication and was satisfied with the aesthetic outcome of the procedure. INTERPRETATION: Heterotopic bone induction to form a mandibular replacement inside the latissimus dorsi muscle in a human being is possible. This technique allows for a lower operative burden compared with conventional techniques by avoiding creation of a secondary bone defect. It also provides a good three-dimensional outcome.