Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
  • 1
    ISSN: 1432-2307
    Keywords: Transgenic mice ; Glucagon ; Colon carcinoma ; Pancreatic endocrine carcinoma ; Morphology
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract We report the histological, immunohistochemical and ultrastructural changes in mice containing a chimeric glucagon-simian virus 40 T antigen (SV40Tag) gene. Transgene expression was detected in endocrine cells of pancreas, small and large intestine. Hyperplasia of glucagon-containing cells developed in pancreas and large bowel by gestational day 19. In large bowel, hyperplastic cells increased in number postnatally and invasive carcinomas were identified at 4 weeks; several animals had lymph node metastases. In contrast, no pathology was detected in the small bowel in any of the transgenic mice. Colonic tumours expressed SV40Tag, proglucagon-derived peptides and peptide YY (PYY); scattered cells contained cholecystokinin or glycoprotein hormone α-subunit. Somatostatin or serotonin was also detected in some tumours. By electron microscopy, the colonic tumours retained features of endocrine differentiation, but secretory granules were smaller than those of non-tumorous intestinal glucagon-producing L cells. In postnatal pancreas, atypical cells containing SV40Tag and glucagon were initially clustered at the periphery of islets; this atypical hyperplasia progressed to neoplasia by 11–12 weeks. Some neoplastic pancreatic cells contained glucagon, PYY or vasoactive intestinal peptide immunopositivity, but most were negative for all peptides; they contained immunoreactivity for tyrosine hydroxylase and by electron microscopy, pancreatic tumour cells had neuronal features. Pancreatic polypeptide was not detected in the non-tumorous islets of transgenic animals. This line of transgenic mice provides a model for the analysis of endocrine tumour progression in the gut and pancreas.
    Type of Medium: Electronic Resource
    Signatur Availability
    BibTip Others were also interested in ...
  • 2
    ISSN: 1432-0509
    Keywords: Key words: Hemoptysis—Lung tumor—Cholangiocarcinoma.
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract A case of peripheral cholangiocarcinoma with the presentation of chronic hemoptysis and lung mass without evident jaundice is reported. Exophytic spread of hepatobiliary disease through the diaphragm through perihepatic ligaments is described as the possible route of invasion of the tumor.
    Type of Medium: Electronic Resource
    Signatur Availability
    BibTip Others were also interested in ...
  • 3
    ISSN: 1432-0614
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Abstract  The DNA sequence encoding Thermus protease aqualysin I was inserted downstream from a bacteriophage T7 promoter in an expression vector. In the T7 expression system, using a strain lacking an F′ episome, aqualysin I was produced in soluble form without chemical induction. The deletions of part (30 amino acid residues) or all (105 residues) of the C-terminal pro-sequence from the C terminus significantly affected both cellular growth and the production of the enzyme. Complete deletion adversely affected both. In contrast, the 30-residue deletion markedly improved productivity by approximately four times compared to non-deletion, and shortened the time needed for the activation of a precursor to active enzyme. The concentration of inducer isopropyl β-D-thiogalactopyrano-side (IPTG) was varied to examine its effects, and it was found that a low concentration of IPTG improved aqualysin I production. To avoid the inhibitory effects of acetic acid accumulation in the culture medium, the use of other carbon sources besides glucose was examined. When cells were cultivated with glycerol, the acetic acid level remained relatively low, and both good cellular growth and a high level of production were attained. The aqualysin I productivity for a fed-batch culture using two carbon sources, glucose and glycerol, reached more than 150 kU/ml enzymatically active aqualysin I.
    Type of Medium: Electronic Resource
    Signatur Availability
    BibTip Others were also interested in ...
  • 4
    Electronic Resource
    Electronic Resource
    s.l. : American Chemical Society
    Accounts of chemical research 28 (1995), S. 321-327 
    ISSN: 1520-4898
    Source: ACS Legacy Archives
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    Signatur Availability
    BibTip Others were also interested in ...
  • 5
    ISSN: 1365-2044
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: In order to improve arterial oxygenation and venous admixture during one lung ventilation, the effect of selective infusion of prostaglandin Ei into the pulmonary artery of the ventilated lung was investigated in 12 adult patients undergoing thoracotomy. Patients’bronchi were intubated with a Mallinckrodt bronchial tube and ventilated with 66% oxygen in air. Cardiopulmonary factors such as systemic and pulmonary arterial pressures, pulmonary vascular resistance, blood gas analyses, cardiac output and airway pressure were measured before and during one-lung ventilation; venous admixture (Qs/Qt) was calculated. Serial blood samples were taken from the pulmonary artery of the ventilated lung for endothelin-1 estimation. One lung ventilation reduced the mean Pao2 from 42.1 (2.3)kPa to 11.8 (1.4)kPa (p 〈 0.001) and increased Qs/Qt from 10.8 (3.2)% to 39.2(4.7)% (p 〈 0.001). Pulmonary vascular resistance also increased from 167 (24) dyne.s.cm-5 to 262 (38) dyne.s.cm-5 (p 〈 0.05) with a corresponding increase of plasma endothelin-1 (p 〈 0.05). After 30min of one lung ventilation, PGE, was infused continuously into the pulmonary artery of the ventilated lung at a rate which increased incrementally from 0.04–0.10 μg.kg-1.min-1. Pao2 increased to 20.7 (2.6) kPa (p 〈 0.01) and Qs/Qt decreased to 30.6 (3.5)% (p 〈 0.05). During the infusion, pulmonary vascular resistance reduced to 173 (30) dyne.s.cm-5 (p 〈 0.01). The plasma endothelin-1 concentration reached a plateau between the end of one lung ventilation (before closing the thorax) and 6h postoperatively. This correlated inversely with the pre-operative forced expiratory volume in one second (r =— 0.68, p 〈 0.005), declining to normal values 72 h after operation. The selective infusion of PGEi into the pulmonary artery of the ventilated lung corrected pulmonary vasoconstriction and improved both arterial oxygenation and venous admixture during one lung ventilation for thoracotomy.
    Type of Medium: Electronic Resource
    Signatur Availability
    BibTip Others were also interested in ...
  • 6
    Electronic Resource
    Electronic Resource
    Woodbury, NY : American Institute of Physics (AIP)
    Applied Physics Letters 75 (1999), S. 2038-2040 
    ISSN: 1077-3118
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Device-quality Ga2O3(Gd2O3) thin films have been grown on GaAs using molecular-beam epitaxy. Photoluminescence measurements have been performed within a temperature range of 4.2–300 K. Detailed analysis on the peak position, peak width, and peak intensity has been compared with those of a conventional Al0.45Ga0.55As/GaAs sample, which is known to be the state-of-the-art structure of dielectrics/GaAs. Both the peak intensity and the peak width are very similar between the two. The results show an almost indistinguishable excellent quality between the Ga2O3(Gd2O3)/GaAs and the Al0.45Ga0.55As/GaAs samples. This demonstrates the superiority of the Ga2O3(Gd2O3)/GaAs structure and supports further the reported successfully manufactured GaAs metal-oxide-semiconductor field-effect transistors using this Ga2O3(Gd2O3) as the gate oxide. © 1999 American Institute of Physics.
    Type of Medium: Electronic Resource
    Signatur Availability
    BibTip Others were also interested in ...
  • 7
    Electronic Resource
    Electronic Resource
    Woodbury, NY : American Institute of Physics (AIP)
    Applied Physics Letters 73 (1998), S. 2802-2804 
    ISSN: 1077-3118
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Depth profiling measurements of photoluminescence on GaN epitaxial films grown on c-plane sapphire with metalorganic chemical vapor deposition have been performed. Dry etching technique of reactive ion etching is used with reactive gas of CCl2F2/H2/Ar under an operation power of 200 W. Before and after each etching, reflectivity and photoluminescence spectra are measured. Film thickness is determined from both the scanning electron microscopy and the interference oscillations of the reflectivity spectra. An excellent steady etching rate of 19.2 nm/min is established. The photoluminescence measurements show that both the near-band-edge and the yellow luminescence remain fairly constant until the film thickness of about 700 nm, and a large drop is obtained in the ratio of near-band-edge to yellow emission intensity under about 300 nm. Analysis shows that the yellow luminescence emitters are mostly confined within the near interface region, and supports the origin of yellow luminescence to be due to native defects instead of impurities. © 1998 American Institute of Physics.
    Type of Medium: Electronic Resource
    Signatur Availability
    BibTip Others were also interested in ...
  • 8
    ISSN: 1573-4943
    Keywords: Lectin ; tryptophan ; fluorescence ; lifetime ; glycopeptide
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract The plant lectin Tetracarbidium conophorum agglutinin II binds to glycoproteins and glycopeptides in a structurally specific manner [Animashaun et al., (1994) Glycoconjugate J. 11, 299–303]. We have characterized the steady-state and time-resolved fluorescence of the tryptophan residues of this lectin. The fluorescence (λex = 295 nm, λem = 350 nm) decay is complex and can be described by four decay times with the following values: τ1 = 7.4nsec, α1 = 0.22; τ2 = 2.9 nsec, α2 = 0.25; τ3 = l.0 nsec, α3 = 0.34; τ4 = 0.2 nsec, α4 = 0.18. The addition of a biantennary glycopeptide $$\begin{array}{*{20}c} {Gal\beta (1 \to 4)GlcNAc\beta (1 \to 2)Man\alpha (1 \to 6)\neg } \\ {Man\beta (1 \to 4)GlcNAC\beta (1 \to 4)GlcAc\beta (1 \to )\begin{array}{*{20}c} {Glu - Nh_2 } \\ | \\ {Asn} \\ | \\ {COOH} \\ \end{array} } \\ {Gal\beta (1 \to 4)GlcNAc\beta (1 \to 2)Man\alpha (1 \to 3)} \\ \end{array} $$ to the lectin results in a quench and an 8 nm blue shift of the emission spectrum. The effect is saturable, and is described by an association constant of 1.8×105 M−1. The tryptophan fluorescence of Tetracarbidium conophorum agglutinin II may therefore be utilized to characterize thermodynamically the binding interactions between this lectin and complex glycoprotein.
    Type of Medium: Electronic Resource
    Signatur Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...