Retrospective study on the pharyngeal airspace in the lateral cephalogram - A mathematical model to predict changes due to bimaxillary orthognathic surgery.

The aim of this study was the development of a statistical model for reliable prediction of Posterior Airway Space (PAS) changes in lateral cephalograms (LCR) of patients after bimaxillary orthognathic surgery. The LCRs of patients who underwent bimaxillary orthognathic surgery were retrospectively analyzed. The anteroposterior dimension of the PAS was measured at three levels in the pre-operative and postoperative LCR: On the nasopharyngeal (SPAS), oropharyngeal (MAS), and hypopharyngeal level (IAS). The data of 139 patients were collected. The following changes of the PAS were measured: in class II patients SPAS: 0.291 mm (SD = 2.570 mm); MAS: 2.444 mm (SD = 2.986 mm); IAS: 0.750 mm (SD = 3.017 mm); in class III patients SPAS: 1.377 mm (SD 3.212 mm); MAS: 0.962 (SD: = 3.135 mm); IAS: 0.370 mm (SD = 3.468 mm). Linear regression analysis showed for class II patients, a significant influence of mandibular movement on MAS (p = 0.049) and a significant effect of maxillary and mandibular movements on SPAS (p = 0.001) and MAS (p = 0.022) in class III patients. The other jaw displacements had no significant impact on the investigated PAS levels. While the presented method does not permit exact prediction of the dimension of the PAS, it is still an easily accessible method of orientation for the surgeon. The surgeon can initiate three-dimensional examinations to provide exact three-dimensional prediction based on this calculation.

A novel serum-free medium for the isolation, expansion and maintenance of stemness and tissue-specific markers of primary human periodontal ligament cells.

PURPOSE: Periodontal ligament (PDL) cell cultures are classically maintained in serum-containing media. However, unwanted side-effects of these conditions on cellular and molecular characteristics demand a serum-free alternative. Even though these limitations are well known and efforts for the development of adequate serum-free alternatives have been made, these approaches for replacement remained unsuccessful so far. This study aimed at developing a well-defined, serum-free formulation supporting both isolation from tissue samples and efficient expansion of PDL cells. Here, of particular focus was the perpetuation of tissue-characteristic markers detectable in primary tissues and of stemness features. BASIC PROCEDURES: Primary PDL cell cultures from generally healthy human donors (n = 3) were maintained in basal media N2B27 and E6 together with different concentrations of growth and attachment factors. Cell proliferation was recorded via microscopy and WST assay. Gene expression of RUNX2, Periostin, ALP, CD73, CD90, CD105, CD45, SOX10 and SOX2 was compared to primary PDL explants via qRT-PCR. Immunocytochemistry was performed for anti-CD105, SSEA-3, CD271, HNK1. Serum-containing sDMEM medium served as control. MAIN FINDINGS: N2B27 medium substituted with 25 ng/mL EGF, 25 ng/mL IGF1, 0.5 mg/mL Fetuin plus gelatine coating (designated N2B27-PDLsf) emerged as potent serum-free formulation ensuring adequate culture isolation and expansion. Here, PDL primary tissue signature markers RUNX2 and Periostin remained stable in N2B27-PDLsf compared to controls (229.0-fold ±101.0 and 83.2-fold ±9.6 increase). Additionally, stemness markers ALP and CD105 were significantly upregulated on transcriptional, and CD105 and SOX2 on protein level. PRINCIPAL CONCLUSIONS: This investigation identified a novel serum-free medium for the isolation, and expansion of primary human PDL cells with constantly high proliferation rates. Here, purity and stemness properties are maintained. Thus, N2B27-PDLsf represents a valid replacement for serum-containing media in PDL cultures.

The beneficial effect of cold atmospheric plasma on parameters of molecules and cell function involved in wound healing in human osteoblast-like cells in vitro.

The aim of this study was to analyse the effect of cold atmospheric plasma (CAP) on human osteoblast-like cells in vitro. Additionally, underlying intracellular mechanisms were to be studied. Human osteoblast-like (MG63) cells were exposed to CAP for 60 s. The effects of CAP on key molecules essential for the wound healing response were studied using real-time PCR, ELISA and immunocytochemistry. For studying intracellular signalling pathways, MAP kinase MEK 1/2 was blocked. Cell viability was analysed by an XTT assay and with an EVE automated cell counter. Cell migration was examined by an in vitro wound healing assay.CAP exposition on osteoblast-like cells caused a significant upregulation of interleukin (IL)-1ß, IL-6, IL-8, tumor necrosis factor (TNF)α, cyclooxygenase (COX)2, collagen (COL) 1α, matrix metalloproteinase (MMP)1, Ki67, proliferating-cell-nuclear-antigen (PCNA) and chemokine ligand (CCL)2 mRNA expression at 1 day. Interestingly, after blocking of MAP kinase, CAP-induced upregulation of Ki67 was inhibited by 57%. Moreover, CAP treatment improved significantly osteoblast-like cell viability as compared to untreated cells at 1 day. Beneficial effect of CAP treatment was shown by an in vitro wound healing assay, displaying a significant faster wound closure. Our findings provide evidence that CAP exposure effects gene and protein regulation in human osteoblast-like cells. Furthermore, CAP treatment has a positive impact on wound closure in an in vitro setting and might improve existing concepts of hard tissue regeneration in the future.

Influence of TGF-ß1 on tumor transition in oral cancer cell and BMSC co-cultures.

OBJECTIVES: TGF-ß1 signaling modulates epithelial mesenchymal transitions (EMT) of head and neck squamous cell carcinoma (HNSCC). Bone marrow mesenchymal stromal cells (BMSC) are able to exert a regulating influence on the expression of markers of EMT in HNSCC cells. It was thus the aim of this study to test the hypothesis that TGF-ß1 modulates the interactions of tumor transition between BMSCs and HNSCC, affecting the expression of E-cadherin, Vimentin, Snail, Twist, MMP14 and beta-catenin. Furthermore, we analyzed alterations in the AKT-signaling of tumor and stroma cells. MATERIALS AND METHODS: BMSCs were isolated from iliac bone marrow aspirates and co-cultured in trans-well permeable membrane wells with tumor cells of the established HNSCC cell line PCI-13. Following the induction with TGF-ß1 under serum free conditions the expression of Vimentin and E-Cadherin was assessed via immunofluorescence. A quantitative RT-PCR analysis of tumor transition markers E-cadherin, Vimentin, Snail, Twist, MMP14 and beta-catenin was performed. Changes in AKT-Signaling were identified via protein analysis. RESULTS: In non-induced co-cultures, BMSC were able to suppress Vimentin in PCI-13 as a marker of tumor transition. In TGF-ß1 induced co-cultures PCI-13 significantly increased the expression of Vimentin, Twist, Snail, MMP14, GSK3a, PRAS40, 4E-BP1, and AMPKa compared to monolayer controls. TGF-ß1 co-cultured BMSC demonstrated a significant increase of Snail, PRAS40, mTOR, GSK3a/b, Bad, PDK1 and 4E-BP1. CONCLUSIONS: TGF-ß1 was able to attenuate the modulating influence of BMSC in co-culture and drive the co-culture towards a progressive tumor transition, affecting the expression of markers of EMT, AKT-Signaling and proliferative checkpoints.

Can piezoelectric ultrasound osteotomies result in serious noise trauma?

The use of ultrasound to cut bone in oral and craniofacial surgery has increased. There is concern that the application of ultrasound to the craniofacial skeleton might represent a potential hazard to the inner ear because of sound transmission by bone conduction resulting in hearing trauma. Conventional and ultrasound osteotomies were performed on human specimens of temporal bone containing an intact middle and inner ear. The equivalent sound pressure was measured with a microphone at the round window, which had been calibrated with a bone conduction audiometer. Conventional osteotomy with a rose burr resulted in maximum sound pressures of 125dB(A) consisting of major frequency components at 2100, 7600, and 9300Hz. Ultrasound osteotomy resulted in maximum sound pressures of 122dB(A) and exhibited major frequency components at around 10kHz, 20kHz, and 26.5kHz. Ultrasound osteotomies have no acoustic advantage over conventional osteotomies. Both osteotomy techniques can produce noise-induced hearing trauma, especially when applied over longer durations of time. This appears to be more relevant for ultrasound osteotomies, because the bone cutting efficiency is usually poorer than in conventional osteotomies. Surgeons should consider the risk of noise-induced potential damage to the inner ear when selecting the method of osteotomy.

Interactions of human MSC with head and neck squamous cell carcinoma cell line PCI-13 reduce markers of epithelia-mesenchymal transition.

OBJECTIVES: Cancer progression is influenced by tumor microenvironment and communication of stromal cells and tumor cells. Interactions may enhance epithelial-mesenchymal transition (EMT) of tumor cells through signaling proteins such as Wnt/beta-catenin and matrix metalloproteinases (MMP), as well as loss of cellular integrity, which affects invasion, progression, and metastasis of head and neck squamous cell carcinoma (HNSCC). In this study, we are testing the hypothesis that interactions of human mesenchymal stromal cells (MSCs) with HNSCC might influence the expression of markers of EMT and tumor progression by co-culturing human MSC with the PCI-13 HNSCC line. MATERIALS AND METHODS: Pooled MSCs were derived from the iliac bone marrow of seven patients and co-cultured in transwell permeable membrane wells with tumor cells of the established HNSCC cell line PCI-13 (UICC: T3, N1, M0). MSCs were characterized through fluorescence-activated cell sorting (FACS) analysis. Expression of Wnt3, E-cadherin, beta-catenin, MMP14, cathepsin b, and ETS1 was assessed by quantitative RT-PCR. RESULTS: We were able to show that co-culture of MSCs and PCI-13 leads to a significantly reduced expression of Wnt3, MMP14, and beta-catenin compared to controls, whereas the expression of cathepsin b and ETS1 was not significantly different between co-cultures and controls. CONCLUSION: Our results suggest that the interaction between MSCs and PCI-13 may suppress EMT in cancer cells. CLINICAL RELEVANCE: The influence of MSCs can suppress the onset of EMT in HNSCC, affecting tumor progression and therapy.

UDP glucuronosyltransferase 1A expression levels determine the response of colorectal cancer cells to the heat shock protein 90 inhibitor ganetespib.

HSP90 inhibition represents a promising route to cancer therapy, taking advantage of cancer cell-inherent proteotoxic stress. The HSP90-inhibitor ganetespib showed benefit in advanced clinical trials. This raises the need to identify the molecular determinants of treatment response. We tested the efficacy of ganetespib on a series of colorectal cancer (CRC)-derived cell lines and correlated their sensitivities with comprehensive gene expression analysis. Notably, the drug concentration required for 50% growth inhibition (IC50) varied up to 70-fold (from 36 to 2500 nM) between different cell lines. Correlating cell line-specific IC50s with the corresponding gene expression patterns revealed a strong association between ganetespib resistance (IC50>500 nM) and high expression of the UDP glucuronosyltransferase 1A (UGT1A) gene cluster. Moreover, CRC tumor samples showed a comparable distribution of UGT1A expression levels. The members of the UGT1A gene family are known as drug-conjugating liver enzymes involved in drug excretion, but their function in tumor cells is hardly understood. Chemically unrelated HSP90 inhibitors, for example, 17-N-allylamino-17-demethoxygeldanamycin (17-AAG), did not show correlation of drug sensitivities with UGT1A levels, whereas the ganetespib-related compound NVP-AUY922 did. When the most ganetespib-resistant cell line, HT29, was treated with ganetespib, the levels of HSP90 clients were unaffected. However, HT29 cells became sensitized to the drug, and HSP90 client proteins were destabilized by ganetespib upon siRNA-mediated UGT1A knockdown. Conversely, the most ganetespib-sensitive cell lines HCT116 and SW480 became more tolerant toward ganetespib upon UGT1A overexpression. Mechanistically, ganetespib was rapidly glucuronidated and excreted in resistant but not in sensitive CRC lines. We conclude that CRC cell-expressed UGT1A inactivates ganetespib and other resorcinolic Hsp90 inhibitors by glucuronidation, which renders the drugs unable to inhibit Hsp90 and thereby abrogates their biological activity. UGT1A levels in tumor tissues may be a suitable predictive biomarker to stratify CRC patients for ganetespib treatment.

Nuclear LEF1/TCF4 correlate with poor prognosis but not with nuclear ß-catenin in cerebral metastasis of lung adenocarcinomas.

An essential function of the transcription factors LEF1/TCF4 in cerebral metastases of lung adenocarcinomas has been described in mouse models, suggesting a WNT/ß-catenin effect as potential mechanism. Their role in humans is still unclear, thus we analyzed LEF1, TCF4, ß-catenin, and early stage prognostic markers in 25 adenocarcinoma brain metastases using immunohistochemistry (IHC). IHC revealed nuclear TCF4 in all adenocarcinoma samples, whereas only 36 % depicted nuclear LEF1 and nuclear ß-catenin signals. Samples with nuclear LEF1 as well as high TCF4 (++++) expression were associated with a shorter survival (p = 0.01, HR = 6.68), while nuclear ß-catenin had no significant impact on prognosis and did not significantly correlate with nuclear LEF1. High proliferation index Ki67 was associated with shorter survival in late-stage disease (p = 0.03, HR 3.27). Additionally, we generated a LEF1/TCF4 as well as an AXIN2 signature, the latter as representative of WNT/ß-catenin activity, following a bioinformatics approach with a gene expression dataset of cerebral metastases in lung adenocarcinoma. To analyze the prognostic relevance in primary lung adenocarcinomas, we applied both signatures to a microarray dataset of 58 primary lung adenocarcinomas. Only the LEF1/TCF4 signature was able to separate clusters with impact on survival (p = 0.01, HR = 0.32). These clusters displayed diverging enrichment patterns of the cell cycle pathway. In conclusion, our data show that LEF1/TCF4, but not ß-catenin, have prognostic relevance in primary and cerebrally metastasized human lung adenocarcinomas. In contrast to the previous in vivo findings, these results indicate that LEF1/TCF4 act independently of ß-catenin in this setting.

Use of the Sentinel Lymph Node Technique Compared to Complete Inguino-femoral Lymph Node Removal in Patients with Invasive Vulvar Cancer in Germany.

In the current S2 guidelines, the standard surgical therapy for patients with vulvar cancer also includes inguino-femoral lymphadenectomy. However, in view of the severe side-effects associated with this approach such as problems with wound healing, lymphoceles and lymphoedema, the search is on for alternative treatments that could decrease treatment-associated morbidity and improve patients' quality of life, particularly for node-negative patients. The sentinel lymph node technique is currently the gold standard in the treatment of unifocal breast cancer (clinically negative axilla), and studies on the use of this technique in the treatment of vulvar cancer are promising. To date, the diagnostic accuracy of this method in vulvar cancer has only been evaluated in a single, one-arm, non-randomised, multicentre study. In preparation for a multicentre study, in 2010 we surveyed 41 German hospitals to investigate how often they used the sentinel lymph node technique compared to inguino-femoral lymphadenectomy. The hospitals were grouped according to hospital size and number of patients treated for vulvar cancer. The decision criteria to determine the type of procedure performed were also investigated. Finally, the hospitals were asked whether they would be willing to participate in a prospective clinical study to evaluate the sentinel lymph node technique in patients with vulvar cancer. The majority of surgeons questioned (73 %) already had some experience with this technique in patients with vulvar cancer. In our survey, 27 % of hospitals carried out inguino-femoral lymphadenectomy, 10 % used the sentinel lymph node technique, and 63 % used both methods. In 24 % of hospitals, the standard procedure consisted of the sentinel lymph node technique supplemented by inguino-femoral lymphadenectomy. Only 20 % of the institutions surveyed in our study carried out sentinel lymph node biopsy alone in accordance with the criteria of the consensus recommendations. The majority of the investigated institutions were willing to participate in a randomised prospective clinical study to evaluate the effectiveness of sentinel lymph node sampling in patients with vulvar cancer.

ß-catenin-independent WNT signaling in basal-like breast cancer and brain metastasis.

A role of WNT signaling for primary breast cancers of the basal-like subtype and as a predictor of brain metastasis has been described. However, a responsible WNT ligand has not been identified. To further clarify this question, we comparatively investigated 22 human breast cancer brain metastases as well as the highly invasive human breast cancer cell line MDA-MB-231 and the weakly motile MCF-7 as models for the basal-like and the luminal A subtype. WNT5A and B were found overexpressed in MDA-MB-231 cells as compared with MCF-7. This corresponded to reduction of MDA-MB-231 invasiveness by WNT inhibitors, whereas MCF-7 invasion was enhanced by recombinant WNT5B and abolished by WNT and Jun-N-terminal kinase antagonists. Expression and subcellular distribution of ß-catenin remained uninfluenced. Consistently, ß-catenin was not localized in the nuclei of brain metastases while there was strong nuclear c-Jun staining. Similar to MDA-MB-231, metastases showed expression of WNT5A/B and the alternative WNT receptors ROR1 and 2. These findings were validated using external gene expression datasets (Gene Expression Omnibus) of different breast cancer subtypes and brain metastases. Hierarchical cluster analysis yielded a close relation between basal-like cancers and brain metastases. Gene set enrichment analyses confirmed WNT pathway enrichment not only in basal-like primaries but also in cerebral metastases of all subtypes. In conclusion, WNT signaling seems highly relevant for basal-like and other subtypes of breast cancers metastasizing into the brain. ß-catenin-independent WNT signaling, presumably via ROR1-2, plays a major role in this context.

A double-blind, placebo-controlled test of 2 d of calorie deprivation: effects on cognition, activity, sleep, and interstitial glucose concentrations.

BACKGROUND: Anecdotal information and limited research suggest that short-term caloric deprivation adversely affects cognition. However, this issue has not been studied using double-blind, placebo-controlled procedures, because the formulation of a calorie-deficient feeding regimen identical to one with calories is impossible using ordinary foods. Therefore, test meals varying in caloric content, but indistinguishable in sensory characteristics, were formulated using hydrocolloid-based gels as the principal structural component. OBJECTIVE: The purpose of this study was to examine the effects of 2 d of near-total caloric deprivation on cognitive function, satiety, activity, sleep, and glucose concentrations in a controlled environment. DESIGN: A double-blind, placebo-controlled crossover study of caloric deprivation was conduced in a controlled environment for 48 h. Cognitive function in 27 healthy young subjects was assessed repeatedly with standardized tests of vigilance, reaction time, learning, memory, logical reasoning, mood, and satiety. Wrist-worn monitors were used to assess ambulatory vigilance, activity, and sleep. Interstitial glucose concentrations were assessed continuously with a minimally invasive monitor. RESULTS: When the subjects received the near calorie-free diets, mean calorie consumption totaled 1311 kJ (313 kcal) over the testing period. During the fully fed treatment sessions, the subjects consumed a mean of 9612 kJ/d (2294 kcal/d), which matched their individual, daily energy requirements. Satiety and interstitial glucose concentrations were lower during the calorie-deprived diet (P < 0.001) than during the fully fed diet. There were no detectable effects of calorie deprivation on any aspect of cognitive performance, ambulatory vigilance, activity, or sleep. The mood states assessed, including fatigue, were not affected by calorie deprivation. CONCLUSIONS: Cognitive performance, activity, sleep, and mood are not adversely affected in healthy humans by 2 d of calorie-deprivation when the subjects and investigators are unaware of the calorie content of the treatments.

An analysis of quality of life in 130 families having small children with cleft lip/palate using the impact on family scale.

Most parents are emotionally traumatized when confronted by the birth of a baby with an orofacial cleft (OFC). Affected families may have to compensate for increased financial, social and personal impacts before primary treatment is completed. This study was conducted to identify factors influencing the quality of life (QoL) of families having young children with OFC. A self-administered questionnaire containing the impact on family scale was applied in 130 consecutive families having children with OFC aged between 6 and 24 months. The results were related to the type of cleft and the time of initial diagnosis using non-parametric tests and multivariate correlation analysis (P<0.05). In families having children with isolated cleft lip, financial and social impacts were reduced, but problems in coping were increased when compared to families with children having cleft lip and palate or isolated cleft palate. Total impact was highest in families having children with isolated cleft palate, probably due to later surgery for reconstruction. Prenatal diagnosis of OFC did not reduce the general impact on affected families, but increased the social impact. The relation of certain impacts to distinct types of cleft might allow more tailored support of affected families and improve their QoL.

Intermittent administration of the circulating form of human parathyroid hormone (hPTH-1-37) prevents bone loss in ovariectomized rats.

The circulating hormonal form of human parathyroid hormone (hPTH-1-37) has been assessed in vitro as well as in vivo in the ovariectomized rat, a model for postmenopausal osteoporosis. In vitro, hPTH-1-37 induces a dose-dependent cAMP formation and increases vitality as well as alkaline phosphatase activity in UMR106 osteosarcoma cells. Differentiation and proliferation of osteoclasts in rat bone marrow-derived stem cell preparations are decreased. Daily hPTH-1-37 s.c. administration in ovariectomized rats for 60 days results in augmented formation of new bone, in amplified femural bone density, and in thickening of the calvaria.

Reconstruction of orbital wall defects with calcium phosphate cement: clinical and histological findings in a sheep model.

The aim of this pilot study was to investigate the potential of calcium phosphate cement in the treatment of orbital wall defect fractures in an adult sheep model, and to compare this alloplastic material to autologous calvaria split-bone grafts. Clinical, volumetric and histological examinations were carried out of both reconstruction materials. The use of cement made intraoperative corrections easier to perform, and increased the precision of reconstruction of the orbital volume. This material also proved to be osseoconductive. The two materials were used successfully in combination. Regions of most intensive remodelling were the anterior orbital floor and the adjacent orbital rim. The preliminary results of this study demonstrate the potential of calcium phosphate cement as a useful biomaterial in the reconstruction of the anterior orbital region. Further animal and clinical trials are necessary to investigate its ability as a carrier for mediators where bone healing requires influence or support.

Dental implants in patients with orofacial clefts: a long-term follow-up study.

Aim of this study was to determine the success of implants that were inserted in patients with cleft of the lip, alveolus and palate (CLAP) and to identify prognosis-relevant factors. In a prospective evaluation, 75 implants inserted in combination with bone grafting at cleft sites of 45 patients were examined. The observation period extended 5.5 years in average (minimum 1.5, maximum 11.3 years). Implant success was evaluated clinically and radiographically and was compared to age- and gender-matched control groups. Statistic assessment included Kaplan-Meier survival analysis, Log rank tests and Cox regression analysis. In total, 10 implants were lost in 8 patients, resulting in an implant survival rate of 82.2% at the end of the observation period. Patient-related parameters of age, gender or type of cleft had no significant influence. The length of an implant was significantly related to an improved survival rate (P<0.01). Implant survival was less in CLAP patients when compared to implant insertions in a non-cleft control group, but improved when compared to patients with bone grafting for other indications. It is concluded that implants combined with bone grafting can offer a reliable alternative in patients with CLAP.

Ultrasonic surgery--an alternative way in orthognathic surgery of the mandible. A pilot study.

The aim of this report is to present preliminary results and experiences using an ultrasonic bone-cutting device in bilateral sagittal split osteotomies of the mandible (BSSRO) with particular attention to possible damages to the inferior alveolar nerve (IAN). Seven patients with class II or class III malocclusion were treated by BSSRO with a conventional combined orthognathic and surgical approach. The osteotomy was carried out using an ultrasonic bone-cutting device. Subjective neurosensory deficits of the inferior alveolar nerve were assessed on 14 sides. Compared to the conventional techniques using saws, chisels and burs, the use of the ultrasonic device was more time-consuming, but the osteotomies were carried out at a high level of precision. In addition, this procedure offered the advantage of a blood-free surgical field and thus provided good control of the surgical procedure. Subjective neurosensory disturbances of the IAN showed a continuous decrease from 57.1% (eight sides) 2 months after the surgical procedure to 14.3% (2 sides) after 5 months and to 7.1% 7 months after BSSRO. Within the seven patients of this pilot study associated neurosensory disturbances were low. A possible advantage in terms of nerve protection is subject to a prospective study.

Effect of platelet-rich-plasma on cranial distraction osteogenesis in sheep: preliminary clinical and radiographic results.

The purpose of this study was to investigate the effect of platelet-rich-plasma (PRP) on cranial distraction osteogenesis. Standardized calvaria critical size defects (6 cm x 5 cm) were created in 16 adult female sheep. Bifocal cranial transport distraction osteogenesis with autogenous free calvaria bone grafts (2 cm x 4 cm) was performed at a rate of 1mm once daily to a total of 30 mm. The 16 sheep involved in the experiment were randomly divided into four groups, four animals in each: Group 1 (no PRP, latency 5 days); Group 2 (no PRP, latency 0 day), Group 3 (PRP, latency 5 days) and Group 4 (PRP, latency 0 day). After a consolidation phase of 6 weeks, the animals were sacrificed and specimens harvested for conventional radiological and 3D quantitative computer tomographic (3D-QCT) assessment. New bone was generated in the distraction zone in all groups. There were significantly (P < 0.05) higher densities in the proximal region of the distraction regenerate in Group 4 (PRP, latency 0 day) compared to Group 2. However, no significant differences in mean density of the total distraction regenerate were found, neither in volume of the bony regenerate between the experimental groups. This study showed that PRP only had an effect on bone regeneration if active distraction was started immediately after application of PRP in the distraction gap.

A comparison of two types of free bone grafts as transport discs in segmental distraction for reconstruction of calvarial bone defects: an experimental study.

INTRODUCTION: Several investigations over the past few years have shown that the importance of preserving the blood supply of the transport disc during segmental distraction has been overestimated. It was clearly demonstrated that distraction osteogenesis by local bone transportation could be achieved even with free bone grafts. So far, there have been no systematic investigations into how different types of free bone grafts vary in their function and suitability as transport discs in segmental craniofacial distraction. The aim of this study was to develop criteria to aid the clinician in selecting the most suitable free bone graft for distraction purposes. MATERIALS AND METHODS: Under general anesthesia, calvarial defects measuring 6 x 5 cm were created in 12 adult black head sheep in order to reconstruct them by segmental distraction using two different types of bone grafts as transport discs. Group 1 (n=6) received autotopical membranous bone of the calvarium as the transport segment, while group 2 (n=6) received heterotopical enchondral material from the iliac crest. Distraction was started postoperatively after 5 days at 0.6 mm/day and continued for 7 weeks. After a further 6 weeks of consolidation, the animals were killed and specimens examined macroscopically, radiographically and histologically. RESULTS: The significantly better quality of bone regenerates of group 1 was clearly influenced by the significantly better stability of the transport disc's connection to the distraction device, the calvaria grafts showing better volume stability and better mechanical resistance during transport than the iliac bone. The influence of both types of bone grafts on the macro- and microstructure of the newly formed bone was clearly evident. The mineralization density of group 2 regenerates was significantly lower than that of group 1 specimens. CONCLUSION: High mechanical stability of the bone graft is a very important point to consider when selecting a free graft for use as transport disc in local bone transport, especially if transport is necessary over long distances.

Ortho- and heterotopic bone grafts in bifocal transport osteogenesis for craniofacial reconstruction--an experimental study in sheep.

Bifocal transport osteogenesis (BTO) is a promising technique for the reconstruction of extended osseous craniofacial defects. Aim of this study was to determine the potential of this technique related to various donor sites of the transport segment. In 10 adult sheep critical size defects of the calvaria were treated by gradual movement of a transport segment consisting either of autogenous regional free calvarial bone grafts (n=5) or autogenous illiac free bone grafts (n=5). Latency period was 5 days; the rate of distraction was 1mm per day and extended approximately 40 days. The consolidation period was 28 days. After harvesting, specimens were investigated by conventional radiography, CT-scans, histologically and by fluorescence. In both groups transport osteogenesis resulted in a complete closure of the critical size defect. Membranous bone formation and remodeling occurred during the entire period of distraction and consolidation. The volumes and thickness of newly formed bone at the defect site were increased significantly when calvarial bone grafts were used (P<0.05). Iliac bone grafts became progrediently smaller during distraction, while the volume of calvarial grafts remained relatively constant (P<0.05). In conclusion, transport segments consisting of calvarial and iliac bone resulted in a reliable closure of craniofacial critical size defects in adult organisms; the application of calvarial bone grafts resulted in an increased extend of bone formation.

Oleate, not ligands of the receptor for advanced glycation end-products, promotes proliferation of human arterial smooth muscle cells.

AIMS/HYPOTHESIS: Diabetes accelerates cardiovascular disease caused by atherosclerosis. Accordingly, diabetes accelerates atherosclerotic lesion progression and increases arterial smooth muscle cell proliferation. We hypothesized that diabetes can exert growth-promoting effects on smooth muscle cells via increased advanced glycation end-products or by dyslipidaemia. METHODS: Primary human arterial smooth muscle cells were stimulated with advanced glycation end-products, other ligands of the receptor for advanced glycation end-products or fatty acids common in triglycerides. Cell proliferation was measured as DNA synthesis, cell cycle distribution and cell number. Effects of oleate on cellular phospholipids, diacylglycerol, triglycerides and cholesterol esters were analyzed by thin-layer chromatography, and oleate accumulation into diacylglycerol was confirmed by gas chromatography. RESULTS: Human arterial smooth muscle cells express the receptor for advanced glycation end-products, but its ligands N(epsilon)-(carboxymethyl)lysine-modified proteins, methylglyoxal-modified proteins, S100B polypeptide and amyloid-beta (1-40) peptide, exert no mitogenic action. Instead, oleate, one of the most common fatty acids in triglycerides, enhances platelet-derived growth factor-BB-mediated proliferation and oleate-containing 1,2-diacylglycerol formation in smooth muscle cells. This mitogenic effect of oleate depends on phospholipase D activity and is associated with an increased formation of oleate-enriched 1,2-diacylglycerol. CONCLUSION/INTERPRETATION: Oleate, not ligands of the receptor for advanced glycation end-products, acts as an enhancer of human smooth muscle cell proliferation. Thus, lipid abnormalities, rather than hyperglycaemia, could be a major factor promoting proliferation of smooth muscle cells in atherosclerotic lesions.