Abstract
Bioceramic bone substitutes with programmed architecture were manufactured at room temperature in this study using a novel 3D printing process that combined 3D powder printing with calcium ...phosphate cement chemistry. During printing, biphasic α/β‐tricalcium phosphate (Ca
3
(PO
4
)
2
, TCP) powder reacted with a liquid component consisting of phosphoric acid solution to form a matrix of dicalcium phosphate dihydrate (CaHPO
4
·H
2
O, DCPD, brushite) and unreacted TCP. Printed samples showed compressive strengths between 0.9–8.7 MPa after printing depending on the acid concentration. A further strength improvement to a maximum of 22 MPa could be obtained by additional hardening of the samples in phosphoric acid for three one minute washes. After this treatment, the samples mainly consisted of brushite with minor phases of unreacted TCP and a lesser amount of dicalcium phosphate anhydrate (CaHPO
4
, DCPA, monetite). Hydrothermal conversion of brushite to DCPA resulted in an increase of porosity of approximately 13 % and a decrease of strength to 15 MPa, however the resorption rate in vivo was increased as demonstrated after intramuscular implantation over 56 weeks. Major advantages compared with commonly used sintering techniques are the low processing temperature, which enables the fabrication of thermally instable and degradable matrices of secondary calcium phosphates.
This study investigated the cytocompatibility of low-temperature direct 3-D printed calcium phosphate scaffolds in vitro. The fabrication of the scaffolds was performed with a commercial 3-D powder ...printing system. Diluted phosphoric acid was printed into tricalcium phosphate powder, leading to the formation of dicalcium phosphate dihydrate (brushite). Hydrothermal conversion of the brushite matrices led to the formation of dicalcium phosphate anhydrous (monetite). The biocompatibility was investigated using the osteoblastic cell line MC3T3-E1. Cell viability and the expression of alkaline phosphatase served as parameters. The culture medium was analyzed for pH value, concentration of free calcium and phosphate ions and osteocalcin. Both types of scaffolds showed a considerable increase of cell proliferation and viability; the monetite matrices were a little inferior compared with the brushite ones. The activity of alkaline phosphatase showed a similar pattern. Optical and electron microscopy revealed an obvious cell growth on the surface of both materials. Analysis of the culture medium showed minor alterations of pH value within the physiological range. The concentrations of free calcium and phosphate ions were obviously different among brushite and monetite cultures, due to their different solubility. The content of osteocalcin of the culture medium was reduced by the printed scaffolds due to adsorption. We conclude that the powder printed brushite and monetite matrices have a suitable biocompatibility for their use as cell culture scaffolds. Both materials enable osteoblastic cells in vitro to proliferate and differentiate due to the expression of typical osteoblastic markers.
Zusammenfassung
Schwere genetisch determinierte Fehlbildungen des Mittelgesichts, wie sie bei kraniofazialen Fehlbildungen anzutreffen sind, führen zu verschiedenen funktionellen Beeinträchtigungen. ...Diese schließen meist skeletal bedingte Okklusionsstörungen und Kieferfehlstellungen mit ein. Die Behandlung der Dysgnathien stellt für die Patienten und Behandler eine große Herausforderung dar. Die Komplexität der Erkrankung erfordert ein interdisziplinäres Team und sollte im Idealfall in einem Zentrum erfolgen. Nur dadurch kann den verschiedenen Teilaspekten der Erkrankung und den Patientenwünschen ausreichend Rechnung getragen werden. Die Ziele der Behandlung beinhalten nicht nur die funktionelle Verbesserung, sondern auch eine Harmonisierung des Gesichtsprofils. Im vorliegenden Beitrag wird auf die kieferorthopädischen Aspekte, Indikationen und Risiken MKG- und neurochirurgischer Maßnahmen eingegangen und die notwendige supportive Therapie erläutert. Danach werden Möglichkeiten zur Korrektur des Mittelgesichts und der Kieferfehlstellung auch anhand von Fallbeispielen dargestellt.
Zusammenfassung
Die Verfahren zur Ruhigstellung und Stabilisierung verlagerter Kieferabschnitte sind essenzielle Bestandteile der orthognathen Chirurgie, die, neben einer Reihe weiterer Aspekte, von ...jeher den Umfang und Schweregrad der operativen Intervention wie auch das Ausmaß der Verlagerung limitiert haben. Wichtige Meilensteine der orthognathen Chirurgie waren die sagittale Spaltung des Unterkiefers, die simultane bimaxilläre Umstellungsosteotomie und die Down-Fracture-Technik. Deren breite und sichere klinische Anwendung war immer auch an die Weiterentwicklung der verfügbaren Osteosyntheseverfahren geknüpft. Die Verbesserung dieser Verfahren wurde einerseits durch zunehmende Kenntnisse über Knochenphysiologie und Frakturheilung begünstigt, andererseits beruhte sie auf materialseitigen Verbesserungen und verfahrenstechnischen Innovationen. Im vorliegenden Beitrag wird zunächst ein kurzer Überblick über die historische Entwicklung der relevanten Osteosyntheseverfahren gegeben. Anschließend werden die derzeit in der orthognathen Chirurgie gängigen Methoden und Materialien dargestellt.
OBJECTIVES
To examine the effects of the antimuscarinic agent solifenacin on urinary urgency, using a range of novel and established outcome measures, as urgency is the principal symptom of the ...overactive bladder syndrome (OAB).
PATIENTS AND METHODS
The study (SUNRISE, solifenacin in the treatment of urgency symptoms of OAB in a rising dose, randomized, placebo‐controlled, double‐blind, efficacy trial) was a randomized, double‐blind, 16‐week, placebo‐controlled, multicentre study of solifenacin 5/10 mg in 863 patients with symptoms of OAB for ≥3 months. The primary efficacy variable was the change from baseline to endpoint in the number of episodes of severe urgency with or without urgency incontinence per 24 h, as measured using the Patient Perception of Intensity of Urgency Scale, grade 3 + 4. Secondary efficacy variables included patient‐reported outcomes for bladder condition, urgency bother and treatment satisfaction. A 3‐day voiding diary was used to record micturition frequency and episodes of urgency and incontinence. A 7‐day diary was used to assess speed of onset of effect.
RESULTS
Solifenacin 5/10 mg was significantly more effective than placebo in reducing the mean number of episodes of severe urgency with or without incontinence per 24 h from baseline to endpoint (−2.6 vs −1.8, P < 0.001). There were also statistically significant differences in favour of solifenacin 5/10 mg over placebo for all secondary variables measured at endpoint, including patient‐reported outcomes. There was a significant improvement in urgency as early as day 3 of treatment. Treatment‐emergent adverse events with solifenacin 5/10 mg were mainly mild or moderate in severity, and only led to discontinuation in 3.6% of patients.
CONCLUSION
Solifenacin significantly reduced the number of urgency episodes and the extent of urgency bother, and was well tolerated; it was effective as early as day 3 of treatment.
Monoclonal antibodies (mAbs) specific for cytokeratins are potent probes for the identification of disseminated individual epithelial tumour cells in mesenchymal organs such as bone marrow. We have ...used a monoclonal antibody (mAB) against cytokeratin 18 (CK18) for the detection of individual metastatic tumour cells in bone marrow aspirates from 84 patients with carcinoma of the prostate. CK18+ cells were detected in a sensitivity of 1 per 8 x 10(5) marrow cells using the alkaline phosphatase anti-alkaline phosphatase (APAAP) system for staining. We were able to detect CK18+ tumour cells in the marrow of 33% of patients with stage N0M0 prostate cancers. The incidence of CK18+ cells showed a significant correlation with established risk factors, such as local tumour extent, distant metastases and tumour differentiation. For further characterization of such cells in patients with prostate cancer, we developed an immunocytochemical procedure for simultaneous labelling of cytokeratin component no. 18 (CK18) and prostate-specific antigen (PSA). In a first step, cells were incubated with a murine mAb against PSA, followed by gold-conjugated goat anti-mouse antibodies. In a second step, a biotinylated mAb to CK18 was applied as primary antibody and subsequently incubated with complexes of streptavidin-conjugated alkaline phosphatase, which were developed with Newfuchsin substrate. The binding of gold-labelled antibodies was visualized by silver enhancement. CK18+ cells co-expressing PSA were found in bone marrow aspirates from 5 out of 14 patients with carcinomas of the prostate. The specificity of CK18 for epithelial tumour cells in bone marrow was supported by negative staining of 12 control aspirates from patients with benign prostatic hyperplasia (BPH).
