Search PubMed⌕ Search

Biomedical subjects

U Pietsch

Publications and source records attributed to U Pietsch.

8 recordsLinked to original sources
PubMed1999

Experimental determination of electric-field-induced differences in structure-factor phases of the order of 2%

In order to understand the induced electron-density response of covalently bonded materials to an externally applied electric field, the change of structure-factor phases of several weak reflections of GaAs has been measured by three-beam interferences. Using a modulation technique, phase variations of the order of 1 degrees for a field strength of 1 kV mm(-1) were determined. Although the statistics of these first experiments are rather poor, the experiment verifies qualitatively the predictions of a semi-empirical bond-charge model. The measured phase variation is the smallest value determined up to now.

Journal Article↗
PubMed1991

Migration of Trichobilharzia ocellata schistosomula in the duck and in the abnormal murine host.

The migration of Trichobilharzia ocellata schistosomula in the duck host and the accidental mouse host was studied by the detection of [75Se]-methionine in radiolabelled cercariae using autoradiography of compressed host tissues and by the recovery of schistosomula following the mincing and incubation of host tissues. Exposure via duck feet (30 min) and mouse tails (60 min) resulted in low infection rates: 3.9% in the duck and 3.1% in the mouse. However, when mice were infected via the abdominal skin using the ring method, 25% of the cercariae were recovered in the skin. In the duck, schistosomula left the skin within 3 days post-infection (p.i.) and were detected in the lungs between days 2 and 4 p.i. Thereafter, only few radioactive foci were found in the liver, kidney and intestine. In the mouse, schistosomula were detected in the lungs within 10 h and for up to 6 days p.i., and some foci were detected in the liver and intestine on days 2-5 p.i. On days 3-4 p.i., 36% of the detectable parasites in the mouse (91 foci in 10 mice) had migrated from the skin to other organs. Living schistosomula could be extracted from mouse skin and lungs only until day 4 p.i. The schistosomula of T. ocellata migrate faster within their vertebrate hosts than do those of Schistosoma mansoni, indicating that the former may use other transformation and immune-evasion mechanisms.

Animals↗
PubMed1975

[The rate of healthy carriers of Listeria monocytogenes].

The feces of 318 healthy adults were examined for L. monocytogenes by means of the cold enrichment and of two different selective media (nalidixic acid-trypaflavin-serum agar; Braveny medium). 15 persons (4.7 percent) proved to be carriers. Three of the 15 strains only caused hemolysis on sheep blood agar and belonged to serotypes 1/2b, 1/2c and 3c. The nonhemolytic strains without exception belonged to serotypes 4f and 4g. The Braveny medium proved to be superior to the nalidixic acid-trypaflavin-serum agar for isolating L. monocytogenes from feces.

Adolescent↗