Structure-specific amyloid precipitation in biofluids.

The composition of soluble toxic protein aggregates formed in vivo is currently unknown in neurodegenerative diseases, due to their ultra-low concentration in human biofluids and their high degree of heterogeneity. Here we report a method to capture amyloid-containing aggregates in human biofluids in an unbiased way, a process we name amyloid precipitation. We use a structure-specific chemical dimer, a Y-shaped, bio-inspired small molecule with two capture groups, for amyloid precipitation to increase affinity. Our capture molecule for amyloid precipitation (CAP-1) consists of a derivative of Pittsburgh Compound B (dimer) to target the cross ß-sheets of amyloids and a biotin moiety for surface immobilization. By coupling CAP-1 to magnetic beads, we demonstrate that we can target the amyloid structure of all protein aggregates present in human cerebrospinal fluid, isolate them for analysis and then characterize them using single-molecule fluorescence imaging and mass spectrometry. Amyloid precipitation enables unbiased determination of the molecular composition and structural features of the in vivo aggregates formed in neurodegenerative diseases.

Revascularized composite grafts with inserted implants for reconstructing the maxilla--improved flap design and flap prefabrication.

We present a new technique including prefabrication of a revascularized composite scapular flap that will fit a maxillary defect exactly. The method is based on careful preoperative planning using three-dimensional reconstructions of data obtained from computed tomograms and stereolithographic models. A pedicled scapular flap with a split skin graft envelope that has endosteal implants already inserted is prepared and covered by a polytetrafluoroethylene (PTFE, Goretex) membrane. After 3-4 months these prefabricated grafts are harvested, inserted into the maxillary defects, and reanastomosed to the facial vessels. Two to three weeks later, after mucosal healing, a prosthesis can be fitted on the endosteal implants. Histological evaluation of the flap shows vital bone reactions and attachment of the split skin graft.

[Tissue preparation in combined scapula flap for microsurgical reconstruction of defects of the oromaxillofacial area]. / Die Gewebevorbereitung kombinierter Skapulalappen zur mikrochirurgischen Rekonstruktion bei Defekten im Mund-Kiefer-Gesichtsbereich. Eine neue Methode.

Nowadays, in congenital or acquired large oro-maxillofacial defects microsurgical reconstruction is mainly performed by revascularized osseous, osteocutaneous, or osteomyocutaneous distant flaps. The aim of reconstruction includes not only restoration of stable continuity and esthetic contour, but also the restoration of a functioning "chewing organ". For reconstruction in maxillary and midface defects, we prefer the scapular flap for a single-step reconstruction. Tissue prefabrication results in osseointegrated implants and thin mucosal linings with stable soft tissue conditions at the time of microsurgical reconstruction. Following dental restoration, full oral function is given. This single-stage procedure improves the psychosocial situation of the patient considerably when compared with conventional multi-stage reconstruction.

The prefabricated combined scapula flap for bony and soft-tissue reconstruction in maxillofacial defects--a new method.

A concept for improving the precision of reconstruction of the maxilla in terms of form and function, including gnathologic, functional, and prosthetic aspects, is presented with a prefabricated combined scapula flap. In four cases, a bony flap from the lateral border of the scapula with osseointegrated titanium implants, covered with skin grafts and encapsulated with a Goretex sheet to create a stable soft-tissue coverage, was performed. Three months later, the prefabricated combined scapula flap was harvested and transferred to reconstruct a maxillary bony and soft-tissue defect in the face using microsurgical vascular anastomoses to the facial vessels. One flap was lost because of vascular thrombosis and was repeated successfully 1 year later. In each of the four cases, full dental rehabilitation and marked improvement of the facial contour was achieved in a single surgical intervention of the face. For this purpose, new radiodiagnostic methods for precise correlation between the maxillofacial defect and the donor area were use. With this new concept, an organ-specific reconstruction of soft-and bony-tissue defects of the alveolar ridge and the hard palate, with a pseudogingiva and teeth, is possible in an optimal way.

Prefabrication of combined scapula flaps for microsurgical reconstruction in oro-maxillofacial defects: a new method.

Nowadays, in congenital or acquired large oro-maxillofacial defects, microsurgical reconstruction is mainly performed by revascularized osseous, osteocutaneous, or osteomyocutaneous distant flaps. The aims of reconstruction include not only restoration of stability and aesthetic contour, but also the restoration of a functioning 'chewing organ'. In addition to bulkiness of the flaps, the stepwise surgical procedure (microvascular reconstruction, osseointegration of implants, secondary correction of flaps including preprosthetic surgery, etc.) prevents physiological oral function for a long time, and has some implications for creating an alternative method of microsurgical reconstruction with newly designed flaps. For reconstruction in maxillary and midface defects we prefer the use of the scapula flap. Since modern diagnostic methods allow comprehensive planning and defining of all relevant anatomical and functional factors in advance, the 'simultaneous' microvascular reconstruction by prefabricated scapula flaps has become possible and offers some advantages. The tissue prefabrication results in osseointegrated implants and thin mucosal linings with stable peri-implant soft tissue conditions at the time of microsurgical reconstruction. Postoperatively, after immediate dental restoration full oral function is attained. The 'simultaneous' reconstruction improves the psychosocial situation of the patient considerably.

Magnetic resonance imaging in the preoperative evaluation of suspected ovarian masses.

Meticulous pretreatment evaluation is basic to the successful management of suspected ovarian masses. Among currently available imaging techniques, sonography and computerized tomography are the most important diagnostic modalities. The purpose of our study was to determine whether magnetic resonance imaging provided additional information on masses in the true pelvis. 73 patients with masses in the true pelvis underwent preoperative magnetic resonance imaging. MRI was done with a 1.0 T supraconductive magnet (Magnetom Impact, Siemens). The results obtained were compared with sonographic (transabdominal and transvaginal), intraoperative and histopathologic findings. MR images were evaluated for their information on differentiation between benign and malignant neoplasm, tumor staging, lymph node involvement, peritoneal spread, local extension and organ relation. MRI correctly characterized malignant and benign tumors in 97% of cases versus 81% on ultrasound. The site of the primary tumor was correctly diagnosed in 94% of cases on MRI images versus 86% on ultrasound images. Invasion of adjacent intestinal segments as well as peritoneal carcinomatosis and omental metastases (metastasis > 1 cm) were also detected in the majority of cases. Based on our results MRI performs well at lesion detection and characterization in the evaluation of suspected ovarian masses. MRI should be considered in the investigation of patients with complicated findings on ultrasound.