Zementaugmentation bei Wirbelmetastasen (Vertebro- und Kyphoplastie)

Zusammenfassung: Pathologische Wirbelfrakturen bei Metastasen oder im Rahmen eines multiplen Myeloms können mittels einer Zementaugmentation (Vertebro- oder Kyphoplastie) effizient stabilisiert werden. Die Indikationsstellung beschränkt sich auf Läsionen im Wirbelkörper, sobald die posterioren Elemente involviert sind genügt eine Zementierung nicht mehr, ebenso wenn eine Spinalkanaleinengung/Neurokompression vorhanden ist. Technisch wird gleich verfahren wie bei der osteoporotischen Fraktur - das Extravasationsrisiko ist aber erheblich größer und die klinischen Ergebnisse sind nicht so uniform positiv wie bei Osteoporosefrakturen. Die Zementaugmentation per se ist keine Tumorbehandlung sondern eine Stabilisierung des Wirbels. Osteolysen ohne mechanische Kompromittierung brauchen keine Augmentation. Die Patientenbetreuung sollte interdisziplinär vernetzt erfolge

Time-resolved charge detection with cross-correlation techniques

We present time-resolved charge sensing measurements on a GaAs double quantum dot with two proximal quantum point contact (QPC) detectors. The QPC currents are analyzed with cross-correlation techniques, which enables us to measure dot charging and discharging rates for significantly smaller signal-to-noise ratios than required for charge detection with a single QPC. This allows to reduce the current level in the detector and therefore the invasiveness of the detection process and may help to increase the available measurement bandwidth in noise-limited setups.Comment: 6 pages, 4 figure

Zementaugmentation bei Wirbelmetastasen (Vertebro- und Kyphoplasie) [Cement injection for spinal metastases (vertebroplasty and kyphoplasty)]

Osteolytic lesions of the spine (metastasis, myeloma) can be treated extremely efficiently by percutaneous cement injection. The treatment should be restricted to osteolytic lesions of the vertebral body, and only if a relevant mechanical deterioration is present. If the pedicles and/or the lamina are involved and if there is compression of the spinal canal, the treatment is no longer appropriate. The surgical technique is similar to the treatment of osteoporotic fractures; however, there is definitely a higher risk for cement leakage and the clinical outcome is not as predictable as in osteoporotic fracture treatment. It is important to realize that cement injection per se has no impact on the tumor itself, but provides stability to the vertebral body. An osteolytic lesion without mechanical compromise does not need a vertebroplasty. Patients with tumorous lesions of the spine should be followed by an interdisciplinary team of spine surgeon, oncologist and radio-oncologist

[When eating becomes dangerous...]

We report the case of a 59-year-old women with idiopathic insulin auto-immune syndrome, a rare cause of endogenous hyperinsulinemic hypoglycemia. It is characterized by extremely high levels of insulin in the presence of high titers of insulin antibodies despite the absence of previous insulin injections. Early postprandial increase in glucose concentrations due to impaired insulin action resulting from the buffering effect of the antibodies and late postprandial hypoglycemia as a consequence of the dissociation of insulin from the antibodies was observed. A correct diagnosis is important to avoid unnecessary investigations and surgery in these patients who are best treated conservatively - with a good prognosis - by fractionating carbohydrate intake during the day

Structure of octreotide, a somatostatin analogue

Octreotide, a synthetic somatostatin analogue, is an octapeptide with one disulfide bridge. Crystals of octreotide are orthorhombic, space group P212121, a = 18.458 (5), b = 30.009 (7), c = 39.705 (27) Å, with three molecules of octapeptide, one ordered oxalate dianion and 52 water molecules in the asymmetric unit. Complete protonation of the NH2 groups (as assumed in the refinement) would require three oxalate dianions in the asymmetric unit for charge neutrality; a chemical analysis indicated that four are present. In either case they are so disordered that they cannot be distinguished from the water molecules. The 18 951 unique reflections (Rsym = 0.026) used for structure solution and refinement were recorded with the EMBL imaging-plate scanner using synchrotron radiation. The structure was solved by Patterson interpretation, locating the three disulfide bridges, followed by tangent phase expansion and E-Fourier recycling. The anisotropic refinement against all F2 data between 1.04 and 10.0 Å resolution by blocked restrained full-matrix least-squares techniques converged to a conventional R index based on F of 0.084 [I > 2a(I) and 10.0 > d > 1.04 Å] and wR2, the weighted R-index on F2, of 0.246 (for all data). One peptide molecule adopts a flat [beta]-sheet structure; the other two possess different irregular backbone conformations, but are similar to each other. All three molecules have a distorted type II' [beta]-turn around the D-Trp-Lys region, but exhibit different side-chain conformations. The crystal structure is stabilized by a network of inter- and intramolecular hydrogen bonds

Structure of Octreotide, a Somatostatin Analogue

Octreotide, a synthetic somatostatin analogue, is an octapeptide with one disulfide bridge. Crystals of octreotide are orthorhombic, space group P212121, a = 18.458 (5), b = 30.009 (7), c = 39.705 (27) Å, with three molecules of octapeptide, one ordered oxalate dianion and 52 water molecules in the asymmetric unit. Complete protonation of the NH2 groups (as assumed in the refinement) would require three oxalate dianions in the asymmetric unit for charge neutrality; a chemical analysis indicated that four are present. In either case they are so disordered that they cannot be distinguished from the water molecules. The 18 951 unique reflections (Rsym = 0.026) used for structure solution and refinement were recorded with the EMBL imaging-plate scanner using synchrotron radiation. The structure was solved by Patterson interpretation, locating the three disulfide bridges, followed by tangent phase expansion and E-Fourier recycling. The anisotropic refinement against all F2 data between 1.04 and 10.0 Å resolution by blocked restrained full-matrix least-squares techniques converged to a conventional R index based on F of 0.084 [I > 2a(I) and 10.0 > d > 1.04 Å] and wR2, the weighted R-index on F2, of 0.246 (for all data). One peptide molecule adopts a flat [beta]-sheet structure; the other two possess different irregular backbone conformations, but are similar to each other. All three molecules have a distorted type II' [beta]-turn around the D-Trp-Lys region, but exhibit different side-chain conformations. The crystal structure is stabilized by a network of inter- and intramolecular hydrogen bonds