[Dyspnea and skin rash in a 49-year-old male patient]. / Dyspnoe und Hautausschlag bei einem 49-jährigen Patienten.

We report on the case of a 49-year-old man who presented with increasing dyspnea and a skin rash. The community-acquired pneumonia was initially treated with broad spectrum antibiotics. The patient's respiratory condition rapidly worsened and the clinical picture of Waterhouse-Friderichsen syndrome developed with disseminated intravasal coagulopathy and necrosis of the toes. An infection with Capnocytophaga canimorsus, which had been caused by an initially unmentioned dog bite was confirmed. In view of the fulminant course and the high risk of operative treatment of the ubiquitous necroses in all limbs, a joint decision for deescalation of therapy was made together with relatives. The patient died 14 days after admission to hospital.

Novel p62dok family members, dok-4 and dok-5, are substrates of the c-Ret receptor tyrosine kinase and mediate neuronal differentiation.

Docking proteins are substrates of tyrosine kinases and function in the recruitment and assembly of specific signal transduction molecules. Here we found that p62dok family members act as substrates for the c-Ret receptor tyrosine kinase. In addition to dok-1, dok-2, and dok-3, we identified two new family members, dok-4 and dok-5, that can directly associate with Y1062 of c-Ret. Dok-4 and dok-5 constitute a subgroup of dok family members that is coexpressed with c-Ret in various neuronal tissues. Activated c-Ret promotes neurite outgrowth of PC12 cells; for this activity, Y1062 in c-Ret is essential. c-Ret/dok fusion proteins, in which Y1062 of c-Ret is deleted and replaced by the sequences of dok-4 or dok-5, induce ligand-dependent axonal outgrowth of PC12 cells, whereas a c-Ret fusion containing dok-2 sequences does not elicit this response. Dok-4 and dok-5 do not associate with rasGAP or Nck, in contrast to p62dok and dok-2. Moreover, dok-4 and dok-5 enhance c-Ret-dependent activation of mitogen-activated protein kinase. Thus, we have identified a subclass of p62dok proteins that are putative links with downstream effectors of c-Ret in neuronal differentiation.

Detection of invasive pulmonary aspergillosis in critically ill patients by combined use of conventional culture, galactomannan, 1-3-beta-D-glucan and Aspergillus specific nested polymerase chain reaction in a prospective pilot study.

Invasive pulmonary aspergillosis (IPA) is an emerging and life-threatening infectious disease in patients admitted to the intensive care unit (ICU). Most diagnostic studies are conducted in hematological patients and results cannot readily be transferred to ICU patients lacking classical host factors. In a multicenter, prospective clinical trial including 44 ICU patients, hematological (n = 14) and non-hematological patients (n = 30), concurrent serum and bronchoalveolar lavage (BAL) samples were analyzed by conventional culture, galactomannan (GM), 1-3-beta-D-glucan (BDG) as well as an Aspergillus specific nested polymerase chain reaction (PCR). Nine patients (20%) had putative IPA according to AspICU classification. GM and PCR showed superior performance in BAL with sensitivity/specificity of 56%/94% and 44%/94% compared to 33%/97% and 11%/94% in serum. Despite better sensitivity of 89%, BDG showed poor specificity of only 31% (BAL) and 26% (serum). Combination of GM and PCR (BAL) with BDG (serum) resulted in 100% sensitivity, but also reduced specificity to 23%. Whereas mean GM levels were significantly higher in hematological patients BDG and PCR did not differ between hematological and non-hematological patients. Under present clinical conditions test combinations integrating both BAL and blood samples are advantageous. BDG might best serve as possible indicator for ruling out IPA. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT01695499. First posted: September 28, 2012, last update posted: May 8, 2017.

A role of the cryptic gene in the correct establishment of the left-right axis.

During vertebrate embryogenesis, a left-right axis is established. The heart, associated vessels and inner organs adopt asymmetric spatial arrangements and morphologies. Secreted growth factors of the TGF-beta family, including nodal, lefty-1 and lefty-2, play crucial roles in establishing left-right asymmetries [1] [2] [3]. In zebrafish, nodal signalling requires the presence of one-eyed pinhead (oep), a member of the EGF-CFC family of membrane-associated proteins [4]. We have generated a mutant allele of cryptic, a mouse EGF-CFC gene [5]. Homozygous cryptic mutants developed to birth, but the majority died during the first week of life because of complex cardiac malformations such as malpositioning of the great arteries, and atrial-ventricular septal defects. Moreover, laterality defects, including right isomerism of the lungs, right or left positioning of the stomach and splenic hypoplasia were observed. Nodal gene expression in the node was initiated in cryptic mutant mice, but neither nodal, lefty-2 nor Pitx2 were expressed in the left lateral plate mesoderm. The laterality defects observed in cryptic(-/-) mice resemble those of mice lacking the type IIB activin receptor or the homeobox-containing factor Pitx2 [6] [7] [8] [9], and are reminiscent of the human asplenic syndrome [10]. Our results provide genetic evidence for a role of cryptic in the signalling cascade that determines left-right asymmetry.

[Acute pulmonary embolism and contraindication of anticoagulation : Bedside implantation of a new temporary vena cava inferior filter]. / Akute Lungenembolie und Kontraindikation für eine Antikoagulation : Bettseitige Implantation eines neuen passageren V.-cava-inferior-Filters.

Pulmonary embolism (PE), mostly caused by deep vein thrombosis, is a life-threatening complication in critically ill patients in the intensive care unit. A potential strategy to prevent PE in patients with contraindication for anticoagulant therapy is the implantation of a vena cava filter (VCF), to provide fast and safe PE protection against ascending thrombi. We report the case of a 56-year-old woman with an intracranial hemorrhage, who developed a PE. Because of acute contraindications for anticoagulant therapy, bedside implantation of a new VCF was performed to overcome the period of absolute contraindications for anticoagulation. After explanation, several thrombi were found on the filter.

Structure-function integrity of the adult hippocampus depends on the transcription factor Bcl11b/Ctip2.

The dentate gyrus is one of the only two brain regions where adult neurogenesis occurs. Throughout life, cells of the neuronal stem cell niche undergo proliferation, differentiation and integration into the hippocampal neural circuitry. Ongoing adult neurogenesis is a prerequisite for the maintenance of adult hippocampal functionality. Bcl11b, a zinc finger transcription factor, is expressed by postmitotic granule cells in the developing as well as adult dentate gyrus. We previously showed a critical role of Bcl11b for hippocampal development. Whether Bcl11b is also required for adult hippocampal functions has not been investigated. Using a tetracycline-dependent inducible mouse model under the control of the forebrain-specific CaMKIIα promoter, we show here that the adult expression of Bcl11b is essential for survival, differentiation and functional integration of adult-born granule cell neurons. In addition, Bcl11b is required for survival of pre-existing mature neurons. Consequently, loss of Bcl11b expression selectively in the adult hippocampus results in impaired spatial working memory. Together, our data uncover for the first time a specific role of Bcl11b in adult hippocampal neurogenesis and function.

Gene expression profiling of fibroblasts resistant toward oncogene-mediated transformation reveals preferential transcription of negative growth regulators.

The signal-transducing Ras proteins are important driving forces of diverse cellular processes such as proliferation, neoplastic transformation, differentiation and growth inhibition. As a step toward understanding the complex mechanisms underlying cellular responses, gene expression patterns were examined in two phenotypically normal fibroblast lines which differ in their sensitivity toward oncogene-mediated transformation. Suppression subtractive hybridization (SSH) was used to establish a subtracted cDNA library specific for the REF52 cell line which, like normal diploid fibroblasts, is refractory toward neoplastic transformation induced by mutated HRAS oncogenes. In contrast, rat 208F control cells can be efficiently transformed by HRAS. The nucleotide sequence of 549 subtracted cDNA clones ('REF52 minus 208F') was determined. We identified 93 preferentially expressed gene fragments in resistant REF52 cells as compared to 208F cells. Seventeen of the 52 known genes (32.6%) are capable of inhibiting cell proliferation or of adversely affecting oncogenic signal transduction pathways. These results suggest that the anti-oncogenic properties of resistant REF52 cells are determined by multiple negative growth regulators. The preneoplastic state expressed in 208F cells is characterized by impairment of unexpectedly redundant control mechanisms. Our results also demonstrate that SSH is a powerful method for identifying specific transcriptional patterns in closely related cell types.

Ion channels involved in insulin release are activated by osmotic swelling of pancreatic B-cells.

Measurements of the membrane potential showed that osmotic swelling (-80 mosmol/l) of pancreatic B-cells led to a transient hyperpolarization followed by a more sustained depolarization of the cell membrane. Cell swelling triggers a transient activation of the K+ATP current and of an inward current, carried by Cl-. This current was inhibited by DIDS, D600, and by omission of extracellular Ca2+. The depolarization opens voltage dependent L-type Ca2+ channels, thereby increasing the intracellular Ca2+ activity ([Ca2+]i). This effect was blunted by D600 or abolished by omission of Ca2+. Moreover, osmotic swelling transiently increased the amplitude of the Ca2+ currents. Replacement of NaCl by d-mannitol proved that the observed effects are due to an increase in cell volume and not to a reduction of extracellular Na+ or Cl-. Our results suggest that regulatory volume decrease is achieved by activation of K+ and Cl- currents. The Cl- current is responsible for the previously described depolarization and increase in insulin release induced by osmotic cell swelling.

The influence of cell-matrix interactions on the development of quail chorioallantoic vascular system.

The extracellular matrix-component fibronectin (FN) was detected in close localisation to the vascular system (VS) of the quail chorioallantoic membrane (CAM). We have examined the role of cell-fibronectin interactions within the developing CAM. In two series of experiments the CAM was directly exposed to (1) an antibody against the cell-binding fragment of FN, and to (2) RGD-containing synthetic peptides which are recognized by the FN receptor. For controls an antibody against tubulin and a SHLVE-pentapeptide that does not interfere with the FN-receptor were applied. In the presence of anti-FN antibodies and RGD-sequences the CAM could not establish a normal vascular system. We observed hypo- and partially avascular regions; the resulting vascular pattern was atypically lacunar. None of the control substances affected the regular development of the chorioallantoic vascular system. These results demonstrate the essential role of FN in CAM angiogenesis.

MyMiCROscope: intelligent virtual microscopy in a blended learning model at Ulm University.

The growing diversity among students and the rapid increase in new technologies entering the system of higher education, demand reconsideration of traditional learning methods. To improve the individual student's learning situation we developed and integrated a novel virtual microscope, MyMiCROscope, into a face-to-face approach for teaching microscopic anatomy. The intelligent virtual microscope has not only enabled self-directed learning of the students at their individual learning speed independent of time and place but also offered new possibilities to interact with the user because it implements systematic annotations accessible from different operational levels. Furthermore the alteration of a sole instructor-led course into a blended learning model resulted in a change of the learning behaviour of the students: group work and social interactions were facilitated. The results of this study show the advantages that intelligent virtual microscopy incorporates for self-directed learning and that blended learning in undergraduate medical education is able to fulfil the individual needs of the students and support social interactions without disregarding practical skills.

Functional BOLD MRI: comparison of different field strengths in a motor task.

The purpose was to evaluate the benefit of an increased field strength for functional magnetic resonance imaging in a motor task. Six right-handed volunteers were scanned at 1.5 T and 3.0 T using a motor task. Each experiment consisted of two runs with four activation blocks, each with right- and left-hand tapping. Analysis was done using BrainVoyagerQX. Differences between both field strengths concerning signal to noise (SNR), blood oxygen level-dependent (BOLD) signal change, functional sensitivity and BOLD contrast to noise (CNR) were tested using a paired t test. Delineation of activations and artifacts were graded by two independent readers. Results were further validated by means of a phantom study. The sensorimotor and premotor cortex, the supplementary motor area, subcortical and cerebellar structures were activated at each field strength. Additional activations of the right premotor cortex and right superior temporal gyrus were found at 3.0 T. Signal-to-noise, percentage of BOLD signal change, BOLD CNR and functional sensitivity improved at 3.0 T by a factor of up to 2.4. Functional imaging at 3.0 T results in detection of additional activated areas, increased SNR, BOLD signal change, functional sensitivity and BOLD CNR.

Age-dependent differences in human brain activity using a face- and location-matching task: an FMRI study.

PURPOSE: To evaluate the differences of cortical activation patterns in young and elderly healthy subjects for object and spatial visual processing using a face- and location-matching task. MATERIALS AND METHODS: We performed a face- and a location-matching task in 15 young (mean age: 28 +/- 9 years) and 19 elderly (mean age: 71 +/- 6 years) subjects. Each experiment consisted of 7 blocks alternating between activation and control condition. For face matching, the subjects had to indicate whether two displayed faces were identical or different. For location matching, the subjects had to press a button whenever two objects had an identical position. For control condition, we used a perception task with abstract images. Functional imaging was performed on a 1.5-tesla scanner using an EPI sequence. RESULTS: In the face-matching task, the young subjects showed bilateral (right > left) activation in the occipito-temporal pathway (occipital gyrus, inferior and middle temporal gyrus). Predominantly right hemispheric activations were found in the fusiform gyrus, the right dorsolateral prefrontal cortex (inferior and middle frontal gyrus) and the superior parietal gyrus. In the elderly subjects, the activated areas in the right fronto-lateral cortex increased. An additional activated area could be found in the medial frontal gyrus (right > left). In the location-matching task, young subjects presented increased bilateral (right > left) activation in the superior parietal lobe and precuneus compared with face matching. The activations in the occipito-temporal pathway, in the right fronto-lateral cortex and the fusiform gyrus were similar to the activations found in the face-matching task. In the elderly subjects, we detected similar activation patterns compared to the young subjects with additional activations in the medial frontal gyrus. CONCLUSION: Activation patterns for object-based and spatial visual processing were established in the young and elderly healthy subjects. Differences between the elderly and young subjects could be evaluated, especially by using a face-matching task.

[O-twist marker for post-interventional marking in imaging of suspected breast lesions]. / O-Twist-Marker zur postinterventionellen Markierung in der Bildgebung suspekter Mammaläsionen.

AIM: The aim of this study was to develop a marker clip for use in minimally invasive diagnostics of breast cancer that can be placed and visualized during ultrasonography, mammography, and magnetic resonance imaging. METHODS: The newly developed O-twist marker consists of three 0.15-mm biocompatible nitinol wires twisted together to form rings with a diameter of 2.5 mm. These are inserted elongated into a 20G cannula. The marker is ejected into the tissue through a mandrin and reverts to its predetermined ring form. RESULTS: The multiple curves of the surface render the marker highly visible. Its geometry permits secure anchorage even in larger biopsy cavities and additionally prevents migration within the tissue. CONCLUSION: The O-twist marker is applicable for all examination modalities and biopsy needles or biopsy systems and represents an important development for breast cancer diagnostics.

[Sonographically guided, minimally invasive biopsy of uncertain mammary lesions. Clinical experience with a new biopsy system]. / Sonographisch gesteuerte minimalinvasive Biopsie unklarer Mammaläsionen Klinische Erfahrungen mit einem neuartigen Biopsiesystem.

METHODS: We performed Vacora biopsy on 53 patients for minimally invasive breast diagnostics. Each histologically malignant lesion underwent surgery. The histopathology of the Vacora biopsy was then compared to the surgical report. When there was a discrepancy between Vacora histopathology and the report, the patient underwent open biopsy. In all patients with benign histopathology results, sonography was performed 5-7 days after biopsy and after 3 months. RESULTS: We performed biopsies on two lesions in eight patients, and on three lesions in one patient. Mean age of the patients was 52.1+/-12.8 years. A total of 62 lesions were examined. Mean size of the lesions was 13.3+/-9.6 mm. Fourteen (26.4%) were malignant (n=2 DCIS, n=12 invasive carcinoma). Histological grading was identical for Vacora biopsy and the surgical specimens. One case showed ADH by Vacora biopsy, which was confirmed by open biopsy. Vacora biopsy generated one false negative. There were a total of 36 benign lesions. CONCLUSION: Vacora biopsy under sonographic guidance is a method which is easy to handle, diagnostically accurate and without severe complications. Due to higher costs in comparison to high speed core biopsy, Vacora biopsy should be performed only in cases in which high speed core biopsy is not expected to result in a valid result.

[The quality of digital mammograms. Development and use of phantoms for optimal safety]. / Qualität digitaler Mammogramme. Entwicklung und Einsatz eines Phantoms zur optimierten Sicherung.

Digital imaging in mammography is becoming more and more accepted using both computed (CR) and direct radiography (DR). These techniques will soon be used in screening programs. Therefore, quality assurance for this technique is indispensable. The relevance of the current regulations, such as EPOC and the German QS-RL was investigated. For the investigation, a breast phantom and appropriate software were developed. Both were tested using digital mammography systems from six manufactures. Quality assurance parameters (such as contrast to noise ratio and contrast resolution) were calculated from these data sets. The results should be considered in future standards for mammography (IEC respectively DIN). In addition, this type of test procedure is time saving and enables a reduction in test devices, i. e. in costs.

Neuregulin, a factor with many functions in the life of a schwann cell.

The signalling system comprising the ligand Neuregulin-1, and its receptors, ErbB2 and ErbB3, plays multiple and important roles in glial development. These include functions in early development of neural crest cells, in expansion of the Schwann cell precursor pool and in myelination. Neuregulin is one of the crucial axon-derived signals that influence development of Schwann cells. These are specialized cells that ensheath peripheral axons and provide electrical insulation. Schwann cells have also long been implicated in providing more than a simple ensheathing function. Compelling evidence for this has emerged from the analysis of mice lacking these cells, resulting from a non-functional or compromised Neuregulin signalling system. They serve as a model to study glia-nerve interactions in vivo and indicate that Schwann cells provide important neurotrophic signals, and also cues that regulate perineurium development and nerve fasciculation.

Effects of SH-group reagents on Ca2+ and K+ channel currents of pancreatic B-cells.

The whole-cell patch-clamp technique has been applied to elucidate the effects of H2O2 and the SH-group reagent 2,2'-dithio-bis(5-nitropyridine) (DTBNP) on Ca2+ currents of mouse pancreatic B-cells. We also tested the effect of DTBNP on the whole-cell K+ ATP current. DTBNP (20 and 100 mumol/l) blocked both the current through Ca2+ channels (with Ba2+ as the charge carrier) and the K+ATP current in a concentration-dependent manner. The results suggest that the channels themselves or regulating proteins possess free SH-groups which may be of functional relevance. However, H2O2 did not influence the Ca2+ channel currents under standard whole-cell conditions as well as when recorded with the perforated patch technique. These results indicate that the two agents act differently on ion channel currents in B-cells although both are known to oxidize SH-groups.

Glucagon-like peptide-1 modulates Ca2+ current but not K+ATP current in intact mouse pancreatic B-cells.

The influence of GLP-1 on electrical activity and ion currents of mouse pancreatic B-cells was studied with intracellular microelectrodes and the whole-cell configuration of the patch-clamp technique. In the presence of 15 mmol/l glucose 5, 50 and 100 nmol/l GLP-1 slightly increased electrical activity. This effect may be caused by the slowing of Ca2+ channel inactivation observed with GLP-1. Thus, changes in Ca2+ channel kinetics are suggested to contribute to the insulinotropic action of the hormone. The most prominent effect of GLP-1 on the membrane potential was the conversion of irregular electrical activity into regular oscillations of the membrane potential. At the threshold concentration for insulin secretion (7 mmol/l glucose) GLP-1 did not alter the membrane potential. Accordingly, in patch-clamp experiments GLP-1 had no effect on the whole-cell K+ATP current.

Effects of osmotic changes in extracellular solution on electrical activity of mouse pancreatic B-cells.

The influence of changes in the osmolarity of the extracellular solution on electrical activity of mouse pancreatic B-cells was studied with intracellular microelectrodes. In the presence of 15 mmol/l glucose the membrane potential of B-cells oscillates. A reduction of the osmolarity by 40 mosmol/l caused a small temporary hyperpolarization in six out of eight cells. After 2 to 3 min electrical activity was increased in all cells. However, this effect was also transient. 5 to 8 min after onset of exposure to hypotonic solution the cells repolarized again and electrical activity decreased. Increasing the osmolarity of the extracellular solution by 40 mosmol/l led to a sustained and reversible depolarization of the membrane potential. However, the electrical activity was transiently suppressed. The changes in electrical activity observed in hypotonic solution might explain the previously described transient rise in insulin secretion provoked by osmotic cell swelling.