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  • 1
    Electronic Resource
    Electronic Resource
    Kinetic study on oxygenation of Lingula unguis hemerythrin using the stopped-flow 02-jump method (1990)
    Springer
    European biophysics journal 18 (1990), S. 9-16 
    Details
    ISSN: 1432-1017
    Keywords: Hemerythrin ; Oxygenation ; Lingula unguis ; Stopped-flow
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Physics
    Notes: Abstract O2-jump experiments with an improved stopped-flow apparatus have been used to study oxygenation and deoxygenation processes in Lingula unguis hemerythrin. With an O2 electrode set in the observation cell, O2 concentration conld be obtained directly. The reliability of this method has been compared with other conventional methods. O2-jump (up and down) experiments were carried out with L. unguis hemerythrin at pH 6.8 (non-cooperative pH) and at pH 7.6 (cooperative pH). At pH 6.8, both O2-jump (up) and O2-jump (down) experiments showed single exponential processes which were consistent with the following scheme: $${\text{Hr + O}}_{\text{2}} \mathop \rightleftharpoons \limits_{{\text{k}}_{{\text{off}}} }^{{\text{k}}_{{\text{on}}} } {\text{HrO}}_{\text{2}} $$ . The value of k on was estimated to be (4.4 ± 0.5) × 105 M−1 s −1, and k off was (15 ± 5) s−1. These values are consistent with those obtained by the temperature-jump method (Zimmer et al. 1986). At pH 7.6, O2-jump (up) experiments showed two relaxation processes, whereas O2-jump (down) experiments showed a single exponential process. The faster process in the O2-jump (up) experiments could be attributed to the same process as that seen in the temperature-jump experiments (Zimmer et al. 1986). The slower process in the O2-jump (up) experiments corresponds to the process obtained in the O2-jump (down) experiments. The results are discussed in terms of a state with intermediate affinity in O2-binding and with the possible existence of a slow step in O2-binding.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00185415
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  • 2
    Electronic Resource
    Electronic Resource
    Analysis of tumor recurrence following anterior skull base surgery (1998)
    Springer
    European archives of oto-rhino-laryngology and head & neck 255 (1998), S. 155-162 
    Details
    ISSN: 1434-4726
    Keywords: Key words Skull base surgery ; Neoplasms ; Tumor ; recurrence ; Anterior cranial fossa ; Salvage surgery
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract In order to elucidate the predictive factors for tumor recurrence following skull base surgery and the significance of salvage surgery in cases of recurrence, we retrospectively surveyed the incidence, site, and time of local recurrences in 20 patients who underwent either anterior or anterolateral skull base surgery for malignant tumors invading the anterior cranial fossa between 1989 and 1995 at the University of Tokyo Hospital. Nineteen patients underwent total resections of malignancies, with recurrences and/or metastases occurring in 13. Local recurrences occurred at the skull base in 5 patients (group A), outside the skull base in 4 patients (group B), and in both locations in 2 patients (group C). The mean time interval between surgery and recurrence was 29 months in group A, and 4.2 months in groups B and C. The local recurrence-free rates were 51% at 1 year and 34% at 5 years. Both brain and/or dural invasion and a microscopic positive surgical margin were proven to be predictive factors for tumor recurrences. The 3-year local recurrence-free rate was 20% in patients with dural invasions and 83% in those without. The incidence of recurrence-free patients was 79% in cases with negative margins, with no patient being recurrence-free in positive cases. All recurrences found more than 6 months after the initial surgery resulted in patients being salvaged successfully by a second operation.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s004050050034
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    Paper (German National Licenses)
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