An upper mass limit for the progenitor of the Type II-P supernova SN 1999gi

Masses and progenitor evolutionary states of Type II supernovae remain almost unconstrained by direct observations. Only one robust observation of a progenitor (SN 1987A) and one plausible observation (SN 1993J) are available. Neither matched theoretical predictions, and in this Letter we report limits on a third progenitor (SN 1999gi). The Hubble Space Telescope (HST) has imaged the site of the Type II-P supernova SN 1999gi with the Wide Field Planetary Camera 2 (WFPC2) in two filters (F606W and F300W) prior to explosion. The distance to the host galaxy (NGC 3184) of 7.9 Mpc means that the most luminous, massive stars are resolved as single objects in the archive images. The supernova occurred in a resolved, young OB association 2.3 kpc from the center of NGC 3184 with an association age of about 4 Myr. Follow-up images of SN 1999gi with WFPC2 taken 14 months after discovery determine the precise position of the supernova on the preexplosion frames. An upper limit of the absolute magnitude of the progenitor is estimated (M-v greater than or equal to -5.1). By comparison with stellar evolutionary tracks, this can be interpreted as a stellar mass, and we determine an upper mass limit of 9(-2)(+3) M.. We discuss the possibility of determining the masses or mass limits for numerous nearby core-collapse supernovae using the HST archive enhanced by our current SNAP program.

Urotensin II in the central nervous system of the frog Rana ridibunda: Immunohistochemical localization and biochemical characterization

Urotensin II (UII) is traditionally regarded as a product of the neurosecretory cells in the caudal portion of the spinal cord of jawed fishes. A peptide related to UII has been recently isolated from the frog brain, thereby providing the first evidence that UII is also present in the central nervous system of a tetrapod. In the present study, we have investigated the distribution of UII-immunoreactive elements in the brain and spinal cord of the frog Rana ridibunda by immunofluorescence using an antiserum directed against the conserved cyclic region of the peptide. Two distinct populations of UII-immunoreactive perikarya were visualized. The first group of positive neurons was found in the nucleus hypoglossus of the medulla oblongata, which controls two striated muscles of the tongue. The second population of immunoreactive cell bodies was represented by a subset of motoneurons that were particularly abundant in the caudal region of the cord (34% of the motoneuron population). The telencephalon, diencephalon, mesencephalon, and metencephalon were totally devoid of UII-containing cell bodies but displayed dense networks of UII-immunoreactive fibers, notably in the thalamus, the tectum, the tegmentum, and the granular layer of the cerebellum. In addition, a dense bundle of long varicose processes projecting rostrocaudally was observed coursing along the ventral surface of the brain from the midtelencephalon to the medulla oblongata. Reversed-phase high-performance liquid chromatography analysis of frog brain, medulla oblongata, and spinal cord extracts revealed that, in all three regions, UII-immunoreactive material eluted as a single peak which exhibited the same retention time as synthetic frog UII. Taken together, these data indicate that UII, in addition to its neuroendocrine functions in fish, is a potential regulatory peptide in the central nervous system of amphibians. (C) 1996 Wiley-Liss, Inc.

Dynamics of the Indonesian seas circulation. Part II – The role of pressure head

The aim of this paper is to analyze the role of the pressure head, i.e., the difference of total pressure forces acting on the Indonesian seas waters from the western Pacific and the eastern Indian Ocean, in driving the Indonesian Throughflow (ITF) and in determining the total transport of the ITF. These questions have been discussed in the literature but no consensus has been reached. A regional model of the Indonesian seas circulation has been developed that properly resolves all major topographic features in the region. The results of model runs have been used to calculate all components of the overall momentum balance. The estimates disclose that the dynamical balance is primarily between the volume integrated Coriolis acceleration, pressure gradient and the area integral of local wind stress. It is shown that consideration of components of momentum balance in the direction of the outflow through the Indian Ocean port leads to the formulation of a diagnostic relation between total inflow transports due to the Mindanao and New Guinea Coastal Currents and the external pressure head, internal pressure head, bottom form stress, and area integrated wind stress. Based on this relation, it is concluded that the external pressure head is not the major driving force of the ITF, which is why there is no unique relation between the total transport of the ITF and the external pressure head. However, Wyrtki's suggestion to monitor the variability of the total transport of the ITF by measurement of the sea-surface-height difference between the western Pacific and the eastern Indian Ocean is validated.

Recurrence of Urothelial Carcinoma of the Bladder: A Role for Insulin-Like Growth Factor-II Loss of Imprinting and Cytoplasmic E-Cadherin Immunolocalization

Purpose:This study documents the frequency of insulin-like growth factor-II (IGF-II) loss of imprinting (LOI) in a series of 87 bladder tissues. E-cadherin (CDH1) immunolocalization was also investigated due to the known redistribution of this adherence protein to the cytoplasm following exogenous exposure to IGF-II.
Experimental Design: Informative IGF-II cases were identified following DNA-PCR amplification and subsequent sequencing of the transcribable ApaI RFLP in exon 9 of IGF-II. Similar approaches using primer-specific cDNA templates identified the imprinting status of IGF-II in these informative cases. CDH1cellular localization was assessed on a tissue microarray platform of 114 urothelial carcinoma of the bladder (UCB) cases (70 pTanoninvasive and 44 pT1laminapropria invasive) using the commercially available Novocastra antibody.
Results: IGF-IILOI was evident in 7 of17 (41%) UCB tumors and 4 of11 (36%) tumor-associated normal urothelial samples.Two of four pT1grade 3 tumors, the subject of much debate concerning their suitability for radical cystectomy, showed LOI at the IGF-II locus. In those tumors showing IGF-II LOI, 4 of 7 (57%) displayed concomitant CDH1cytoplasmic staining. In contrast, only 3 of 10 (30%) IGF-IImaintenance ofimprinting tumorshad concomitant CDH1cytoplasmiclocalization. UCB cell lines displaying cytoplasmic CDH1immunolocalization expressed significantly higher levels of IGF-II (CAL29, HT1376, and RT112) compared with RT4, a cell line displaying crisp membranous CDH1staining. Finally, cytoplasmic CDH1staining was an independent predictor of a shorter time to recurrence independent of tumor grade and stage.
Conclusions: We suggest that CDH1 cytoplasmic immunolocalization as a result of increased IGF-II levels identifies those nonmuscle invasive presentations most likely to recur and therefore might benefit from more radical nonconserving bladder surgery

Mutations within subdomain II of the extracellular region of epidermal growth factor receptor selectively alter TGF alpha binding

The interactions of epidermal growth factor (EGF) and transforming growth factor alpha (TGF alpha) with the epidermal growth factor receptor (EGFR) were examined by insertion mutagenesis of the receptor. Seventeen insertions were made throughout a construct containing only the extracellular domain. This truncated receptor (sEGFR) was secreted and had a dissociation constant similar to that of the full-length solubilized receptor. Receptors with insertions within subdomain III were not secreted. Two receptors with insertions at positions 291 and 474, which border subdomain III, have significantly decreased binding to both EGF and TGF alpha relative to wild type. This confirms previous work demonstrating that subdomain III forms the primary binding site for EGF and TGF alpha. Four of the mutants within subdomain II had a decreased binding to TGF alpha relative to wild type, but had wild type binding to EGF. These results suggest that a region within subdomain II may selectively regulate the binding of TGF alpha. Two receptors which contained insertions within subdomains II and IV, approximately equidistant from the center of subdomain III, bound twofold more ligand molecules than wild type receptor, with an affinity similar to that of wild type receptor. These findings suggest that insertion at these positions allows the access of more than one ligand molecule to the binding site.

Moving beyond the rhetoric of provocation: the French and World War II in the novels of the Hussards (1949-1954)

In the immediate aftermath of the Second World War, only those who had opposed the Germans or were perceived to have done so could freely express themselves. Soon, however, three young writers clearly leaning to the right of the political spectrum – Antoine Blondin, Roger Nimier and Jacques Laurent – dared to challenge their narratives in a series of provocative novels published between 1949 and 1954. Quickly referred to as the Hussards after the publication in 1952 of a famous essay by Bernard Frank, these writers momentarily occupied the literary space left vacant by their older peers. Without denying the provocative, political and subversive dimensions of the Hussards’ war novels, this article will argue that their success was mainly due to the fact that they were largely in line – and not in contradiction – with the ‘horizon of expectations’ of their time (Jauss, 1982).

Molecular Medicine and Molecular Pathology for Hematologists:II. Lets go Techno; Principles of the Molecular Technologies and their Applications in Haematology

Molecular techniques have a key role to play in laboratory and clinical haematology. Restriction enzymes allow nucleic acids to be reduced in size for subsequent analysis. In addition they allow selection of specific DNA or RNA sequences for cloning into bacterial plasmids. These plasmids are naturally occuring DNA molecules which reside in bacterial cells. They can be manipulated to act as vehicles or carriers for biologically and medically important genes, allowing the production of large amounts of cloned material for research purposes or to aid in the production of medically important recombinant molecules such as insulin. As acquired or inherited genetic changes are implicated in a wide range of haematological diseases, it is necessary to have highly specific and sensitive assays to detect these mutations. Most of these techniques rely on nucleic acid hybridisation, benefitting from the ability of DNA or RNA to bind tighly to complimentary bases in the nucleic acid structure. Production of artificial DNA molecules called probes permits nucleic acid hybridiation assays to be performed, using the techniques of southern blotting or dot blot analysis. In addition the base composition of any gene or region of DNA can be determined using DNA sequencing technology. The advent of the polymerase chain reaction (PCR) has revolutionised all aspects of medicine, but has particular relevance in haematology where easy access to biopsy material provides a wealth of material for analysis. PCR permits quick and reliable manipulation of sample material and its ability to be automated makes it an ideal tool for use in the haematology laboratory.