Embedded macrophages induce intravascular coagulation in 3D blood vessel-on-chip.

Macrophages are innate immune cells that prevent infections and help in wound healing and vascular inflammation. While these cells are natural helper cells, they also contribute to chronic diseases, e.g., by infiltrating the endothelial layer in early atherosclerosis and by promoting vascular inflammation. There is a crosstalk between inflammatory pathways and key players in thrombosis, such as platelets and endothelial cells - a phenomenon known as 'thromboinflammation'. The role of the embedded macrophages in thromboinflammation in the context of vascular disease is incompletely understood. Blood vessels-on-chips, which are microfluidic vascular cell culture models, have been used extensively to study aspects of vascular disease, like permeability, immune cell adhesion and thrombosis. Blood perfusion assays in blood vessel-on-chip models benefit from multiple unique aspects of the models, such as control of microvessel structure and well-defined flow patterns, as well as the ability to perform live imaging. However, due to their simplified nature, blood vessels-on-chip models have not yet been used to capture the complex cellular crosstalk that is important in thromboinflammation. Using induced pluripotent stem cell-derived endothelial cells and polarized THP-1 monocytes, we have developed and systematically set up a 3D blood vessel-on-chip with embedded (lipid-laden) macrophages, which is created using sequential cell seeding in viscous finger patterned collagen hydrogels. We have set up a human whole blood perfusion assay for these 3D blood vessels-on-chip. An increased deposition of fibrin in the blood vessel-on-chip models containing lipid-laden macrophages was observed. We anticipate the future use of this advanced vascular in vitro model in drug development for early atherosclerosis or aspects of other vascular diseases.

[Naevus flammeus: an alternative to surgical therapy?]. / Naevus flammeus: Alternative zur chirurgischen Therapie?

Solcoderm is a new medication which has been used for the treatment of port-wine stains. It has so far produced very promising results in the treatment of benign, pre-cancerous and malignant skin lesions. The disadvantages of alternative treatment for the port-wine stain are listed.

[Functionally stable fixation in severe midface fractures using an external cranial fixator]. / Die funktionsstabile Fixation schwerer Mittelgesichtsfrakturen mit dem Craniofixateur externe.

With the external Cranial-fixator we can achieve a stable fixation of the severe maxillofacial injuries. In a period of 10 years (1973-1982) 61 patients were treated with a external cranial fixation, which is tolerated very well by the patients. The intermaxillary fixation is not necessary, the application is easy, the morbidity rate is low and the results are good (table 3 und 4).

[Functionally stable osteosynthesis and simulography in sagittal osteotomy of the ascending ramus. A comparative clinical study]. / Funktionsstabile Osteosynthese und Simulographie bei der sagittalen Osteotomie des aufsteigenden Astes Eine vergleichende klinische Untersuchung

Sagittal mandibular osteotomy is a well-founded means to correct various dysgnathias. The method is enhanced by the possibilities of fixation which osteosynthesis has offered to the treatment of bone fractures. The success of using osteosynthesis in osteotomy depends partly of preoperative planning combined with simulography which allows for orthograde adaptation of the proximal fragments and the proper localization of the traction screws. 75 sagittal osteotomies were checked. They had all been operated the same way, but the fixation was varied: without fixation, fixation by wiring, fixation by Kirschner wire, fixation by bilateral traction screws, 1 each, 2 each, 3 each. The evaluation was made by using many criteria. It was found that without functionally stable osteosynthesis, inspite of 2-3 months immobilization a recurrence occurred in most cases and that postoperative treatment by activator or by head-chin appliance was necessary. With 3 screws on each side and preoperative planning with simulography no recurrence was found in 30 cases. Also, the hospitalization could be shortened and with it the working incapacity. These patients could be left without intermaxillary fixation and late postoperative treatment.