We report on the combination of a scanning near-field optical microscope and a modified Sagnac interferometer for magnetic-domain imaging in the reflection mode. The Sagnac interferometer is used for detection of the magneto-optical Kerr effect. Since the interferometer is inherently insensitive to polarization changes caused by topography effects, magnetic-domain imaging is not limited to samples with flat surfaces. In this way, it is possible to image magnetic bits written on the tracks of a magneto-optical disc that has a rather pronounced surface profile.

Journal Article↗

PubMedDate not supplied

[Coxitis fugax--the beginning of Perthes' disease?].

We present the clinical case of a decennial boy with acute leftsided hip pain without appropriate trauma. The initial diagnosis of coxitis fugax was verified in this case with inconspicuous blood parameters and X-ray by a sonographically proven intraarticular effusion. An immediate magnet resonance imaging (MRI) study of the affected hip joint was done. Here, a complete "necrosis" of the proximal femur epiphysis was verified. With knowledge of these results, an immediate operation of the hip joint with a ventral capsule incision and consecutive intraarticular decompression was performed. A complete reperfusion of the femur head was evident in the MRI scan seven days postoperatively. In accordance with this clinical case report, we would like to point out the necessity for the immediate diagnosis of indifferent hip pain by means of MRI, especially for patients in the atypical "critical age" (> or = 8 years) for coxitis fugax. This is discussed under consideration of the possible aetiopathogenesis and the current literature.

Arthralgia↗

PubMedDate not supplied

Positron emission tomography in a case of intracranial hemangiopericytoma.

Due to the low prevalence of hemangiopericytomas (HPCs), data on the biophysiological characteristics of this tumor are rare. Positron emission tomography (PET) demonstrated a sixfold increased uptake of [11C]methionine and hyperperfusion in the HPC, whereas glucose utilization was decreased in this area. This low glucose utilization is in contrast to the high [11C]methionine uptake and the malignancy of these tumors. The characteristics of HPCs in PET described herein for the first time offer additional diagnostic criteria and may help especially to differentiate these tumors from meningiomas.

Adult↗

PubMedDate not supplied

Transepidermal water loss dynamics of human vulvar and thigh skin.

Refinement in procedures to assess skin surface water loss (SSWL) dynamics of the vulvar skin on a large sample of subjects (60) is described and compared to another semi-occluded skin site, the inner thigh. Vulvar SSWL significantly decreased over a 30-min period from 46.2 +/- 2.6 (SE) to 24.7 +/- 1.6 g m(-2) h (p < 0.001). The inner thigh, another semi-occluded region, showed no similar pattern for SSWL (6.2 +/- 0.3 to 6.6 +/- 0.5 g m(-2) h), and the values were significantly less than those for vulvar skin. There was no significant effect of age, body mass index or atopic status on vulvar SSWL.

Adolescent↗

PubMedDate not supplied

Molecular genetic analysis of glucocorticoid signaling using the Cre/loxP system.

Glucocorticoids (GC) are involved in a plethora of physiological processes that range from the regulation of the stress response and the control of the immune system to modulation of behavior. Most GC effects are mediated by the glucocorticoid receptor (GR) via activation and repression of gene expression. Whereas in most cases activation requires DNA binding of the receptor, repression is usually mediated by protein-protein interaction with other transcription factors. To decipher the molecular mode of action of GR, mice were generated by gene targeting carrying a point mutation in one of the dimerization domains, thus abrogating DNA binding by GR. Analysis of these mice demonstrated that thymocyte apoptosis and stress erythropoiesis require the DNA binding-dependent function of GR, whereas lung development and the anti-inflammatory activity of GR are mediated by protein-protein interaction. Furthermore, to study the role of GC in the brain, mice were generated specifically lacking GR function in the nervous system. Using these mice we demonstrated that GR is essential for the regulation of the HPA-axis and the stress response, as well as for the control of emotional behavior. Taken together, gene targeting using the Cre/loxP system proved to be highly valuable for the analysis of both molecular mechanism and tissue-specific functions of the GR.

Animals↗

PubMedDate not supplied

Mutation analysis of the cationic trypsinogen gene in patients with pancreatic cancer.

Recently, an Arg to His mutation at residue 117 of the cationic trypsinogen gene (Arg117His) has been shown to be associated with hereditary pancreatitis (hp). A serious complication of hp is development of pancreatic cancer. Patients suffering from hp have been reported to have a 53-fold increased risk to die from pancreatic cancer. However, the quantitative contribution of mutations in the cationic trypsinogen gene to all pancreatic cancer cases is unknown. A relevant contribution of the Arg117His-mutation to pathogenesis of pancreatic cancer might be possible, since also asymptomatic individuals have been reported to carry this mutation and individuals with only mild symptoms may be undiagnosed as hp. In the present study we analyzed genomic DNA obtained from pancreatic cancer tissue from 34 patients and corresponding normal tissue from 28 of these individuals. The third exon of the cationic trypsinogen gene was amplified by nested PCR and digested with AflIII, since the Arg117His mutation creates an AflIII-restriction site. None of the examined samples carried the Arg117His mutation, whereas the amplification product obtained from a patient with known hp was clearly positive. Sequencing of the complete third exon of the cationic trypsinogen gene in 10 of the pancreatic cancer patients resulted exclusively in the wild-type sequence. In addition DNA obtained from venous blood of 116 further patients with pancreatic cancer did not carry the Arg117His mutation. Our results show that the Arg117His mutation does not contribute to pathogenesis of a substantial fraction of all pancreatic adenocarcinomas. In contrast to most oncogenes or tumor suppressor genes the cationic trypsinogen gene (3rd exon) does not contain mutational hot spots.

Adenocarcinoma↗