Loss of R-spondin1 and Foxl2 amplifies female-to-male sex reversal in XX mice.

In vertebrates, 2 main genetic pathways have been shown to regulate ovarian development. Indeed, a loss of function mutations in Rspo1 and Foxl2 promote partial female-to-male sex reversal. In mice, it has been shown that the secreted protein RSPO1 is involved in ovarian differentiation and the transcription factor FOXL2 is required for follicular formation. Here, we analysed the potential interactions between these 2 genetic pathways and have shown that while Rspo1 expression seems to be independent of Foxl2 up-regulation, Foxl2 expression partly depends of Rspo1 signalisation. This suggests that different Foxl2-positive somatic cell lineages exist within the ovaries. In addition, a combination of both mutated genes in XX Foxl2(-/-)/Rspo1(-/-) gonads promotes sex reversal, detectable at earlier stages than in XX Rspo1(-/-) mutants. Ectopic development of the steroidogenic lineage is more pronounced in XX Foxl2(-/-)/Rspo1(-/-) gonads than in XX Rspo1(-/-) embryos, suggesting that Foxl2 is involved in preventing ectopic steroidogenesis in foetal ovaries.

Mechanical thrombectomy with the Penumbra recanalization device in acute ischemic stroke.

BACKGROUND AND PURPOSE: The aim of this study was to assess the clinical outcome of patients treated with the Penumbra system (PS) for acute ischemic stroke. A retrospective, monocentric matched-pair analysis in comparison with patients treated by intraarterial thrombolysis (IAT) with alteplase was designed for this purpose. METHODS: Twenty-two consecutive patients, (mean age 62), with acute ischemic stroke and National Institutes of Health Stroke Scale (NIHSS) scores ≥ 7 were treated with the PS. Twenty corresponding patients could be identified, treated with IAT. Matches were sought for initial NIHSS score and target vessels. Thrombolysis in myocardial infarction (TIMI) grades, mortality rates, NIHSS upon discharge, and modified Rankin scores (mRs) at 90 days were compared. RESULTS: A total of 32 vessels in 20 patients were treated in either arm of the study. Recanalization to TIMI 2/3 was successful in 25/32 (78%) of target vessels with the PS, and 17/32 (53%) of target vessels in the IAT group. Upon discharge, 2/20 patients treated with PS and 7/20 patients treated with IAT had a NIHSS score of 0 to 1 or an improvement greater or equal to 10-point on the NIHSS scale. All cause mortality at 90 days was 3/20 patients treated with PS, and 2/20 patients treated with IAT. Three out of twenty patients treated with PS and 7/20 patients treated with IAT had a mRS of ≤ 2 at 90 days. CONCLUSION: The Penumbra system is effective in re-opening occluded major arteries. Our data seems to indicate that not all patients benefit clinically from improved revascularization of occluded major arteries.

High resolution in situ magneto-optic Kerr effect and scanning tunneling microscopy setup with all optical components in UHV.

A surface magneto-optic Kerr effect (MOKE) setup fully integrated in an ultrahigh vacuum chamber is presented. The system has been designed to combine in situ MOKE and scanning tunneling microscopy. Magnetic fields up to 0.3 T can be applied at any angle in the transverse plane allowing the study of in-plane and out-of-plane magnetization. The setup performance is demonstrated for a continuous film of 0.9 monolayers (ML) Co/Rh(111) with in-plane easy axis and for a superlattice of nanometric double layer Co islands on Au(11,12,12) with out-of-plane easy axis. For Co/Au(11,12,12) we demonstrate that the magnetic anisotropy energies deduced from thermally induced magnetization reversal and from applying a torque onto the magnetization by turning the field are the same. For the presented setup we establish a coverage detection limit of 0.5 ML for transverse and 0.1 ML for polar MOKE. For island superlattices with the density of Co/Au(11,12,12), the latter limit corresponds to islands composed of about 50 atoms. The detection limit can be further reduced when optimizing the MOKE setup for either one of the two Kerr configurations.

Chromosomal microarray mapping suggests a role for BSX and Neurogranin in neurocognitive and behavioral defects in the 11q terminal deletion disorder (Jacobsen syndrome).

We performed a prospective analysis on 14 11q- patients to determine the relationship between the degree of cognitive impairment and relative deletion size. Seventeen measures of cognitive function were assessed. All nine patients with a deletion of at least 12.1 Mb had severe global cognitive impairment, with full-scale IQ <50, whereas all five patients with smaller deletions,

Effect of shortening the barrel in contact shots from rifles and shotguns.

In a suicidal gunshot fired to the chest from a carbine, the barrel of which had been shortened to half its original length, an unexpectedly large degree of destruction of the anterior thoracic wall with extensive undermining of the subcutis was found. This phenomenon was investigated for reconstructive purposes by firing test shots from two different long guns (caliber 7.92 x 57 repeating rifle with full-jacketed pointed bullet and caliber 12/70 single-barreled shotgun with shotgun slug) into blocks of soap (38 x 25 x 25 cm). The contact shots were fired before and after shortening the barrels (repeating rifle from 60 to 30 cm and single-barreled shotgun from 72 to 36 cm). The volume of the cavities in the simulant was visualized three-dimensionally with the help of a multislice computed tomography (CT) scanner and calculated sectionally. With the repeating rifle and the single-barreled shotgun, the shots from the sawed-off barrels produced significantly larger cavity diameters in the first section of the bullet track. This effect is attributable to the fact that, with a shortened barrel, the gas pressure at the muzzle is higher, thus, leading to increased expansion in the initial part of the wound track in contact shots.

[Von Hippel-Lindau disease. Interdisciplinary patient care]. / Von-Hippel-Lindau-Erkrankung. Interdisziplinäre Patientenversorgung.

Von Hippel-Lindau disease is an important hereditary tumor syndrome with a clear option for effective treatment if diagnosed in time. Interdisciplinary cooperation is the key to successful management. Major components of the disease are retinal capillary hemangioblastomas, hemangioblastomas of cerebellum, brain stem and spine, renal clear cell carcinomas, pheochromocytomas, multiple pancreatic cysts and islet cell carcinomas, tumors of the endolymphatic sac of the inner ear, and cystadenomas of the epididymis and broad ligament. A well structured screening program should be performed at yearly intervals.

[Diagnostic imaging of inflammatory and tumorous diseases of the colon]. / Diagnostik entzündlicher und tumoröser Erkrankungen des Kolons.

The detection of inflammatory and tumorous conditions of the colon is one of the main topics in current abdominal radiology. The barium enema was introduced first in 1923 by Fischer, and has represented the workhorse of intestinal diagnostics for decades. The widespread use of endoscopy and the ongoing technical improvements in CT and MRI, however, have led to an inevitable displacement of this technique. Nevertheless, radiographs and enema are frequently employed in the initial work-up of patients with suspected colonic disease. This article provides an overview of the most important entities of inflammatory and tumorous changes of the colon.

Hedgehog signaling is required for pituitary gland development.

Pituitary gland development serves as an excellent model system in which to study the emergence of distinct cell types from a common primordium in mammalian organogenesis. We have investigated the role of the morphogen Sonic hedgehog (SHH) in outgrowth and differentiation of the pituitary gland using loss- and gain-of-function studies in transgenic mice. Shh is expressed throughout the ventral diencephalon and the oral ectoderm, but its expression is subsequently absent from the nascent Rathke's pouch as soon as it becomes morphologically visible, creating a Shh boundary within the oral epithelium. We used oral ectoderm/Rathke's pouch-specific 5' regulatory sequences (Pitx1(HS)) from the bicoid related pituitary homeobox gene (Pitx1) to target overexpression of the Hedgehog inhibitor Hip (Huntingtin interacting protein) to block Hedgehog signaling, finding that SHH is required for proliferation of the pituitary gland. In addition, we provide evidence that Hedgehog signaling, acting at the Shh boundary within the oral ectoderm, may exert a role in differentiation of ventral cell types (gonadotropes and thyrotropes) by inducing Bmp2 expression in Rathke's pouch, which subsequently regulates expression of ventral transcription factors, particularly Gata2. Furthermore, our data suggest that Hedgehog signaling, together with FGF8/10 signaling, synergizes to regulate expression of the LIM homeobox gene Lhx3, which has been proved to be essential for initial pituitary gland formation. Thus, SHH appears to exert effects on both proliferation and cell-type determination in pituitary gland development.

Multistep signaling and transcriptional requirements for pituitary organogenesis in vivo.

During development of the mammalian pituitary gland, specific hormone-producing cell types, critical in maintaining homeostasis, emerge in a spatially and temporally specific fashion from an ectodermal primordium. We have investigated the molecular basis of generating diverse cell phenotypes from a common precursor, providing in vivo and in vitro evidence that development of these cell types involves at least four sequential phases of signaling events and the action of a gradient at an ectodermal boundary. In the first phase, we hypothesize that this notochord induces invagination of Rathke's pouch from the oral ectoderm. This is followed by appearance of an ectodermal boundary, formed with exclusion of Shh from the nascent pouch. Next, signals from the ventral diencephalon--expressing BMP4, Wnt5a, FGF10, and FGF8--in concert with Shh represent critical in vivo signals for pituitary determination. Subsequently, a dorsal-ventral BMP2 signal gradient emanates from a ventral pituitary organizing center, forming at the boundary to oral ectoderm region from which Shh expression is selectively excluded. In concert with a dorsal FGF8 signal, this creates opposing gradients that generate overlapping patterns of specific transcription factors that underlie cell lineage specification events. The mechanisms by which these transient gradients of signaling molecules lead to the appearance of four ventral pituitary cell types appear to involve the reciprocal interactions of two transcription factors, Pit-1 and GATA-2, which are epistatic to the remainder of the cell type-specific transcription programs and serve as a molecular memory of the transient signaling events. Unexpectedly, this program includes a DNA-binding-independent function of Pit-1, suppressing the ventral GATA-2-dependent gonadotrope program by inhibiting GATA-2 binding to gonadotrope- but not thyrotrope-specific genes. This indicates that both DNA-binding-dependent and-independent actions of abundant determining factors contribute to generate distinct cell phenotypes. In the fourth phase, temporally specific loss of the BMP2 signal is required to allow terminal differentiation. The consequence of these sequential organ and cellular determination events is that each of the pituitary cell types--gonadotropes, thyrotropes, somatotropes, lactotropes, corticotropes, and melanotropes appears to be determined, in a ventral to dorsal gradient, respectively, apparently based on a combinatorial code of transcription factors induced by the gradient of specific signaling molecules.

Pax6 is essential for establishing ventral-dorsal cell boundaries in pituitary gland development.

Pax6, a highly conserved member of the paired homeodomain transcription factor family that plays essential roles in ocular, neural, and pancreatic development and effects asymmetric transient dorsal expression during pituitary development, with its expression extinguished before the ventral --> dorsal appearance of specific cell types. Analysis of pituitary development in the Small eye and Pax6 -/- mouse mutants reveals that the dorsoventral axis of the pituitary gland becomes ventralized, with dorsal extension of the transcriptional determinants of ventral cell types, particularly PFrk. This ventralization is followed by a marked decrease in terminally differentiated dorsal somatotrope and lactotrope cell types and a marked increase in the expression of markers of the ventral thyrotrope cells and SF-1-expressing cells of gonadotrope lineage. We suggest that the transient dorsal expression of Pax6 is essential for establishing a sharp boundary between dorsal and ventral cell types, based on the inhibition of Shh ventral signals.

Reciprocal interactions of Pit1 and GATA2 mediate signaling gradient-induced determination of pituitary cell types.

The mechanisms by which transient gradients of signaling molecules lead to emergence of specific cell types remain a central question in mammalian organogenesis. Here, we demonstrate that the appearance of four ventral pituitary cell types is mediated via the reciprocal interactions of two transcription factors, Pit1 and GATA2, which are epistatic to the remainder of the cell type-specific transcription programs and serve as the molecular memory of the transient signaling events. Unexpectedly, this program includes a DNA binding-independent function of Pit1, suppressing the ventral GATA2-dependent gonadotrope program by inhibiting GATA2 binding to gonadotrope- but not thyrotrope-specific genes, indicating that both DNA binding-dependent and -independent actions of abundant determining factors contribute to generate distinct cell phenotypes.

Multistep signaling requirements for pituitary organogenesis in vivo.

During development of the mammalian pituitary gland specific hormone-producing cell types, critical in maintaining homeostasis, emerge in a spatially and temporally specific fashion from an ectodermal primordium. We have investigated the molecular basis of generating diverse pituitary cell phenotypes from a common precursor, providing in vivo and in vitro evidence that their development involves three sequential phases of signaling events and the action of a gradient at an ectodermal boundary. In the first phase, the BMP4 signal from the ventral diencephalon, expressing BMP4, Wnt5a, and FGF8, represents a critical dorsal neuroepithelial signal for pituitary organ commitment in vivo. Subsequently, a BMP2 signal emanates from a ventral pituitary organizing center that forms at the boundary of a region of oral ectoderm in which Shh expression is selectively excluded. This BMP2 signal together with a dorsal FGF8 signal, appears to create opposing activity gradients that are suggested to generate overlapping patterns of specific transcription factors underlying cell lineage specification events, whereas Wnt4 is needed for the expansion of ventral pituitary cell phenotypes. In the third phase, temporally specific loss of the BMP2 signal is required to allow terminal differentiation. The consequence of these sequential organ and cellular determination events is that each of the hormone-producing pituitary cell types-gonadotropes, thyrotropes, somatotropes, lactotropes, corticotropes, and melanotropes-appear to be determined, in a ventral-to-dorsal gradient, respectively.

Reduced ubiquitin-dependent degradation of c-Jun after phosphorylation by MAP kinases.

The proto-oncogene-encoded transcription factor c-Jun activates genes in response to a number of inducers that act through mitogen-activated protein kinase (MAPK) signal transduction pathways. The activation of c-Jun after phosphorylation by MAPK is accompanied by a reduction in c-Jun ubiquitination and consequent stabilization of the protein. These results illustrate the relevance of regulated protein degradation in the signal-dependent control of gene expression.

The hypothalamic-pituitary axis: co-development of two organs.

Development of the anterior pituitary gland ultimately leads to the appearance of five distinct cell types that are defined by the trophic hormones which they produce, providing an instructive model system for elucidating the molecular mechanisms that underlie the determination of distinct cell phenotypes within an organ from a common precursor lineage. The recent identification of several homeodomain transcription factors expressed specifically in the anterior pituitary gland has revealed a transcriptional cascade orchestrating a developmental program that leads to the determination of the five mature cell types. Recent data from gene-targeting experiments in mice further imply that the execution of this program is dependent on inductive signals originating in the floor of the diencephalon.

Differential regulation of c-Jun and JunD by ubiquitin-dependent protein degradation.

c-Jun and JunD are two closely related members of the Jun family of transcription factors which markedly differ in their biological functions. Whereas c-Jun behaves as a positive regulator of cell growth and may cause cell transformation when overexpressed, JunD antagonizes both of these effects. To better understand how the activities of c-Jun and JunD are controlled, we investigated how their stabilities within the cell are determined. We show that, in contrast to c-Jun which is degraded following multi ubiquitination, JunD is not efficiently ubiquitinated and exhibits a correspondingly longer half-life. Mutational analysis reveals that the determinant for the difference in ubiquitination resides in the NH2-terminal regions of the proteins which in c-Jun contains the delta-domain.

Identification of a novel family of ubiquitin-conjugating enzymes with distinct amino-terminal extensions.

The ubiquitin/proteasome system is the main eukaryotic nonlysosomal protein degradation system. Substrate selectivity of this pathway is thought to be mediated in part by members of a large family of ubiquitin-conjugating (E2) enzymes, which catalyze the covalent attachment of ubiquitin to proteolytic substrates. E2 enzymes have a conserved approximately 150-residue so-called UBC domain, which harbors the cysteine residue required for enzyme-ubiquitin thioester formation. Some E2 enzymes possess additional carboxyl-terminal extensions that are involved in substrate specificity and intracellular localization of the enzyme. Here we describe a novel family of E2 enzymes from higher eukaryotes (Drosophila, mouse, and man) that have amino-terminal extensions but lack carboxyl-terminal extensions. We have identified four different variants of these enzymes that have virtually identical UBC domains (94% identity) but differ in their amino-terminal extensions. In yeast, these enzymes can partially complement mutants deficient in the UBC4 E2 enzyme. This indicates that members of this novel E2 family may operate in UBC4-related proteolytic pathways.

JUN cooperates with the ETS domain protein pointed to induce photoreceptor R7 fate in the Drosophila eye.

R7 photoreceptor fate in the Drosophila eye induced by the activation of the Sevenless receptor tyrosine kinase and the RAS/MAP kinase signal transduction pathway. We show that expression of a constitutively activated JUN isoform in ommatidial precursor cells is sufficient to induce R7 fate independent of upstream signals normally required for photoreceptor determination. We present evidence that JUN interacts with the ETS domain protein Pointed to promote R7 formation. This interaction is cooperative when both proteins are targeted to the same promoter and is antagonized by another ETS domain protein, YAN, a negative regulator of R7 development. Furthermore, phyllopod, a putative transcriptional target of RAS pathway activation during R7 induction, behaves as a suppressor of activated JUN. Taken together, these data suggest that JUN and Pointed act on common target genes to promote neuronal differentiation in the Drosophila eye, and that phyllopod might be such a common target.