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G von Sengbusch

Publications and source records attributed to G von Sengbusch.

11 recordsLinked to original sources
PubMed1984

Hollow-fiber dialyzers and their pyrogenicity testing by Limulus amebocyte lysate.

Aqueous extracts of cellulose hollow fibers (CHF) exhibit positive reactions in some Limulus amebocyte lysate (LAL) tests. However, in spite of LAL activity, the extracts produce no fever reaction in rabbits. A comparison of lysates from different suppliers shows pronounced activity differences when extracts of cuprammonium-derived CHF are tested. One of the lysates, which is fully reactive against standard endotoxin, shows no reaction with such extracts, nor do CHF extracts diminish its sensitivity to standard endotoxin. Investigations of the cuprammonium process have shown that endotoxins introduced by the linters are degraded and washed out. Other endotoxin introduction, particularly by the process water, has been excluded. Oxidative or acidic degradation of cellulose does not result in the formation of LAL-reactive material (LAL-RM). On the other hand, sterile cotton wool shows LAL reactivity, and cellulose acetate regains LAL reactivity when it is saponified. Thus, it appears likely that the LAL-RM found in CHF is of purely cellulosic origin and crossreacts with a number of commercially available lysates.

Animals↗
PubMed1984

Residual ethylene oxide in hollow-fiber dialyzers.

The deaeration and extraction kinetics of ethylene oxide (ETO) in hollow-fiber dialyzers were examined. The investigations showed that both deaeration and extraction can be described by two additive first-order kinetic expressions. The ETO content of membranes decreased rapidly at first, followed by a second slower decrease. Even after prolonged storage time, residual ETO was still detectable in the milligram range. These residuals cannot be eliminated by the usual rinsing of the dialyzer prior to use.

Ethylene Oxide↗
PubMed1979

Signal analysis of slit-scan contour data.

As a method for the preselection of alarms in gynecological cell samples, the Battelle Cytophotometry Research Group uses the slit-scan technique to obtain various cell parameters, such as the N/C ratio and the relative DNA content, from fluorescently stained cells, which are aligned one-dimensionally in the tape system designed at Battelle. The system developed at Battelle Institute analyzes all signals that exceed the background noise. As the first step in processing the slit-scan data, several threshold levels permit the separation of various artifacts. In subsequent steps, the nuclear peak is recognized, the nuclear boundaries are calculated, and seven cell parameters are determined. For the alarm detection at present only one parameter, DNA fluorescence, is used for these determinations. Visual assignment of these data to definite objects on the tape makes it possible to obtain frequency distributions of: (a) all recorded objects within the sample on the tape; (b) all signals that are classified as cells; and (c) all types of objects that preferentially cause alarms.

Cell Nucleus↗
PubMed1979

Preselection of alarms in a hybrid system for screening of cervical cancer.

In this report, a preselection of alarms in a system for automated screening of cervical cancer based on depositing the cell sample linearly as a "cell trace" on a tape and analyzing it at different decision levels with increasing complexity, and preliminary results on analyzing cervical material with this system are discussed. The "cell trace" is analyzed with the slit-scan technique. Six parameters are computed: 1) cellular diameter; 2) nuclear diameter; 3) nuclear fluorescence (acriflavin-Feulgen) as nuclear DNA; 4) cellular fluorescence; 5) nuclear to cytoplasm ratio (N/C ratio); and 6) nuclear density. At present, only nuclear fluorescence is used to define a decision boundary between normal and potentially atypical cells. Under this criteria the slit-scan analysis leaves 5% of the events in a sample that must be rechecked at a second decision level in normal cell samples. A further reduction is expected when several slit-scan parameters are used at the first decision step. All events declared suspicious will be investigated in more detail by a two dimensional image analyzing system where the fluorescence image is generated by a laser scanning system. Results obtained in preliminary experiments are discussed in this paper.

Computers↗