Anatomical classification of the shape and topography of the stomach

The aim of the study was to present the classification of anatomical variations of the stomach, based on the radiological and historical data. In years 2006–2010, 2,034 examinations of the upper digestive tract were performed. Normal stomach anatomy or different variations of the organ shape and/or topography without any organic radiologically detectable gastric lesions were revealed in 568 and 821 cases, respectively. Five primary groups were established: abnormal position along longitudinal (I) and horizontal axis (II), as well as abnormal shape (III) and stomach connections (IV) or mixed forms (V). The first group contains abnormalities most commonly observed among examined patients such as stomach rotation and translocation to the chest cavity, including sliding, paraesophageal, mixed-form and upside-down hiatal diaphragmatic hernias, as well as short esophagus, and the other diaphragmatic hernias, that were not found in the evaluated population. The second group includes the stomach cascade. The third and fourth groups comprise developmental variations and organ malformations that were not observed in evaluated patients. The last group (V) encloses mixed forms that connect two or more previous variations

The RNA Helicase Rm62 Cooperates with SU(VAR)3-9 to Re-Silence Active Transcription in Drosophila melanogaster

Gene expression is highly dynamic and many genes show a wide range in expression over several orders of magnitude. This regulation is often mediated by sequence specific transcription factors. In addition, the tight packaging of DNA into chromatin can provide an additional layer of control resulting in a dynamic range of gene expression covering several orders of magnitude. During transcriptional activation, chromatin barriers have to be eliminated to allow an efficient progression of the RNA polymerase. This repressive chromatin structure has to be re-established quickly after it has been activated in order to tightly regulate gene activity. We show that the DExD/H box containing RNA helicase Rm62 is targeted to a site of rapid induction of transcription where it is responsible for an increased degree of methylation at H3K9 at the heat shock locus after removal of the heat shock stimulus. The RNA helicase interacts with the well-characterized histone methyltransferase SU(VAR)3-9 via its N-terminus, which provides a potential mechanism for the targeting of H3K9 methylation to highly regulated genes. The recruitment of SU(VAR)3-9 through interaction with a RNA helicase to a site of active transcription might be a general mechanism that allows an efficient silencing of highly regulated genes thereby enabling a cell to fine tune its gene activity over a wide range

Effects of early starvation periods on zoeal development of brachyuran crabs

Larvae of the crabs Menippe mercenaria Say (Menippidae), Panopeus herbstii Milne-Edwards, Neopanope sayi Smith (Xanthidae), Sesarma cinereum Bosc (Grapsidae), and Libinia emerginata Leach (Majidae) were reared in the laboratory. Starvation periods different in length and timing within the first zoeal stage were studied as to their effects on later development and survival rate. After 1-3 days of initial feeding, most larvae had accumulated enough reserves to reach the second stage, independently of further food availability. The development of the survivors was delayed in the following stages, and their later mortality rate was higher than the fed controls. Starvation periods commencing directly after hatching of the larvae exert far stronger negative effects than those beginning later. All observations suggest a particularly sensitive phase in the beginning of larval life in brachyurans. When initial starvation periods exceed the point-of-no-return (PNR), the larvae will die later, even if feeding begins long before the energy reserves are depleted. Temporary lack of suitable prey may be an ecological factor controlling the survival of crab larvae as effectively as physical factors