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Biomedical subjects

W Gehring

Publications and source records attributed to W Gehring.

65 records · Page 4Linked to original sources
PubMed1971

Imaginal disc abnormalities in lethal mutants of Drosophila.

Late lethal mutants of Drosophila melanogaster, dying after the larval stage of development, were isolated. The homozygous mutant larvae were examined for abnormal imaginal disc morphology, and the discs were injected into normal larval hosts to test their capacities to differentiate into adult structures. In about half of the mutants analyzed, disc abnormalities were found. Included among the abnormalities were missing discs, small discs incapable of differentiating, morphologically normal discs with limited capacities for differentiation, and discs with homeotic transformations. In some mutants all discs were affected, and in others only certain discs. The most extreme abnormal phenotype is a class of "discless" mutants. The viability of these mutant larvae indicates that the discs are essential only for the development of an adult and not of a larva. The late lethals are therefore a major source of mutants for studying the genetic control of disc formation.

Abnormalities, Drug-Induced↗
PubMed1971

Determination of blastoderm cells in Drosophila melanogaster.

A method for culturing blastoderm cells of Drosophila in vivo has been developed that allows these cells to differentiate into larval or adult structures. By intermixture of genetically marked cells from bisected and whole embryos, it was shown that blastoderm cells are restricted in their potential for forming adult epidermal structures. Cells isolated from anterior-half embryos are determined for forming head and thoracic structures, whereas cells from posterior-half embryos are determined for forming thoracic and abdominal structures. The specificity of determination and the localization of determinative factors is discussed.

Animals↗
PubMedDate not supplied

Do urea/ammonium lactate combinations achieve better skin protection and hydration than either component alone?

Twenty subjects with healthy skin were treated with the following formulations for two weeks: drug-free W/O vehicle, 5% ammonium lactate (CAS 52003-58-4) in W/O vehicle, 5% urea (CAS 57-13-6) in W/O vehicle, 3% ammonium lactate + 3% urea in W/O vehicle, 5% ammonium lactate + 5% urea in W/O vehicle. These formulations were applied in randomized order to 6 test areas on the forearms; one area was left untreated. Repetitive washings were additionally performed in the second treatment week. TEWL, stratum corneum water content (corneometry-determined electrical capacitance), and cutaneous blood flow (laser Doppler) were measured at baseline, day 7, and day 14. 5% urea and both ammonium lactate/urea combinations produced significant stratum corneum hydration and improved stratum corneum barrier function; there were no significant differences between these three treatments.

Adult↗
PubMedDate not supplied

Do shake lotions, zinc oil and polyethylene glycol gels produce dehydration or moisturization?

We carried out three studies to evaluate the effects of white zinc shake lotion (Zinkschüttelmixtur DAC), zinc oil ( Zinköl NRF 11.20), Lotio Cordes, PEG ointment (Polyethylenglykolsalbe DAB) and PEG paste on nonmoisturized and moisturized skin. The aim of the study was a clear indication for these vehicles in the clinical practice. Studies 1 and 2 were performed on 20 healthy volunteers. Study 1 was carried out on nonmoisturized skin, while test areas in study 2 were treated with the study products after 1-hour moisturization with hydrophilic aqueous ointment (hydrophile wasserhaltige Salbe DAB), covered with a semiocclusive film dressing. Study 3, carried out on 10 subjects, differed from study 2 by a longer follow-up period. The water content of the horny layer before and after application of the different vehicles was estimated by the capacitance measurement (Corneometer CM 820) and the conductance measurement (Skikon). The glycerol-containing zinc shake lotion and both PEG gels (with or without zinc oxide) produced hydration under the conditions of study 1 and 2. Zinc oil and moisturizer-free Lotio Cordes had little impact on stratum corneum hydration under the conditions of studies 1-3. Therefore, zinc shake lotion and the two PEG ointments can be used in the treatment of dry atopic skin, but not in overhydrated skin, e.g. in intertriginous regions. Zinc oil and Lotio Cordes can be used in overhydrated skin but not in dry skin, for the missing water-binding capacity in the horny layer. On the other hand an effective dehydrating effect cannot be expected.

Adult↗
PubMedDate not supplied

[Occupationally-induced formaldehyde allergy of the immediate type].

An autopsy assistant developed respiratory distress at his job after four years of work on post-mortems. His symptoms commenced immediately upon entering the work rooms. Diagnosis was confirmed by positive medical history, skin tests and RAST investigations, all of which taken together gave proof of occupationally induced asthma of anaphylactic origin (Type I reaction).

Adult↗