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Biomedical subjects

K Grossgebauer

Publications and source records attributed to K Grossgebauer.

At least 37 records · Page 2Linked to original sources
PubMed1981

Interactions between DNA-binding fluorochromes and mucopolysaccharides in agarose-diffusion test.

Interactions between the two DNA-binding fluorochromes DAPI (4',6-diamidino-2-phenylindole) und Hoechst 33258 (2[2-(4-hydroxy-phenyl)-6-benzimidazolyl]-6-(1-methyl-4-piperazyl)-benzimidazole. 3 HCl) and certain mucopolysaccharides (heparin, sodium dextran sulphate 500, chondroitin sulphate and hyaluronic acid) were demonstrated when applying the agarose diffusion test. The resulting reactions were observed with the naked eye and appeared as precipitation lines. Saponin, a glycoside, was included in these experiments because it led to intensive fluorescent nuclear envelopes when subsequently stained with DAPI. Comparing the two fluorochromes, DAPI achieved stronger reactions with heparin and dextran sulphate 500 whereas the Hoechst fluorochrome led to broader precipitation lines with hyaluronic acid, chondroitin sulphate and saponin. Preliminary experiments also confirmed these interactions at the cellular level.

Amidines↗
PubMed1980

Fluorescent staining of nuclear envelope coated with heparin.

Naturally and artificially devitalized cells of various origin can be loaded with heparin and subsequently stained with DAPI, a newer fluorochrome (4',6-diamidino-2-phenylindole), leading to a bright yellow fluorescence of the nuclear envelope. Depending on the cell type it is also possible to coat the outer cell membrane with heparin or other sulphated mucopolysaccharides and to achieve similar staining phenomena with DAPI.

Amidines↗
PubMed1979

[New fluorescence microscopic technic for the identification of Trichomonas vaginalis].

A new fluorescent dye for the identification of trichomonas vaginalis is described. Specimens under investigation were mixed with 4',6-diamidino-2-phenylindol (Dapi) and examined using white light and UV-light. The combined use of the two techniques allows to recognize the mobile non fluorescing and the dead intensive yellow fluorescing trichomonads. Devitalized epithelial cells, bacteria and leucocytes in contrast to living trichomonas are stained yellow in a few minutes. This is of diagnostic help.

Amidines↗
PubMed1979

[Experimental protection with tyrothrizin against herpes simplex virus infections in mice].

Using 12-day old baby mice, strain NMRI, the LD50 of a Herpes simplex virus type 1 was calculated. Intragastric inoculation of the mice was carried out applying a stomach tube. Lethality of the mice was reduced from 67% to 23% by pre-incubation of the virus suspension for 30 min at 37 degrees C in the presence of 0.2 mg tyrothricin/ml. The effect was statistically significant and could be produced only after direct contact between tyrothricin and virus. Under the same conditions there was no effect of lysozyme against virus infectivity.

Animals↗
PubMed1979

Staining of acid mucopolysaccharides appearing on and in various cell types by DAPI.

It could be shown that DAPI, a newer fluorochrome (4',6-diamidino-2-phenylindole), is able to stain various types of acid mucopolysaccharides, e.g. heparin and agar mucopolysaccharides. Due to their content of heparin, mast cells and basophil cells could be stained rapidly. Other cells e.g. mononuclear phagocytes and malignant epithelial cells, could be loaded with these acid mucopolysaccharides and subsequently stained by DAPI.

Amidines↗
PubMed1978

[Antiviral activity of tyrothricin against Sendai virus in suspension tests (author's transl)].

In suspension tests it could be found, that tyrothricin, isolated from bacteria, possesses an anti-infectious activity against Sendai virus. Concentrations of 10(2) to 10(3) ID50-units of Sendai virus were incubated with 0.5 and/or 1.0 mg tyrothricin per 5 ml for 30 minutes at 37 degrees C (pH 7.5). These mixtures were tested in embryonated eggs and showed a marked decrease of viral infectivity. Tween 80 added after the incubation period leads to an incomplete reactivation of the virus infectivity. According to these results and further preliminary studies on herpes simplex virus we suppose a virustatic effect of tyrothricin also in the case of other lipophilic viruses.

Antiviral Agents↗
PubMed1977

[Fluorescent test of mycoplasma colonies by agar diffusion technique (author's transl)].

An agar diffusion test to directly stain mycoplasma colonies using a new fluorochrome 4,6-diamidino-2-phenyl-indol (DAPI) is described. Next to a colony in question a well is punched into the agar and filled with DAPI. 30 min later the colonies in the diffusion zone show a light yellow - light green fluorescence. Due to the high affinity of DAPI to DNA it is easily possible to distinguish between granular mycoplasma colonies and unspecific substances e.g. proteins and lipids from clinical material.

Humans↗
PubMed1977

[Experiments on disinfection of vaccinia virus embedded in scabs and/or at the hand].

Vaccinia viruses embedded in rabbit dermal scabs were subjected to physical and chemical disinfection procedures. Scabs were suspended in vitro without saline or in physiological saline, and left for 1 hour at 70 to 90 degrees C. A complete inactivation was achived only in those scab samples which had been incubated at 90 degrees C for 1 hour and suspended in physiological saline. Scabs which had been placed in a disinfecting apparatus (Vacudes 4000) filled with mattrasses consistently proved to be free of infectious vaccinia viruses in each of the chosen programs. In addition scabs were subjected to disinfection by means of chemical disinfecting agents. The scabs had been placed in a chemical disinfecting suspension and left there for 90 minutes. Complete disinfection was obtained with glutaraldehyde 2%, formaldehyde 2%, Lysoformin 2% or 3%, phenol 5% and chloramine T 2%. Complete disinfection was likewise achieved after 3 hours treatment with some alchohols (ethylalcohol 80%, isopropylalcohol 7%, n-propylalcohol 60%), Amocid 5% and formaldehyde 1%.0.5% formaldehyde caused complete disinfection when applied for 6 hours. The only exception was a Quat which did not disinfect fully even after 18 hours application. Concerning the tests to disinfect the hands complete disinfection occurs when using chloramine T (1.5%) or isopropylalcohol (70%) in 2 to 5 minutes. Further tests were performed with scabs which were placed in sick rooms that were terminally disinfected with formaline vapor. It could be confirmed that the usual terminal disinfection with formaldehyde vapor was unable to completely disinfect the scabs. It is necessary to double the amount of formaldehyde (10 g formaldehyde per cubic metre of space) and prolong the period of treatment to 24 hours to achieve a greater degree of disinfection rate.

Animals↗
PubMed1977

[Mycoplasma induced damage to sperm head in infertile men].

The heavy contamination of T-mycoplasmas in ejaculates of infertile men can be found in coiled forms as well as in swollen necks of the spermatozoa. The analysis of the sperma of one infertile man shows significant changes of the head of numerous spermatozoa possible caused by mycoplasmas. Our findings support the assumption of a correlation between T-mycoplasmas in ejaculates and the infertility of men.

Adult↗
PubMed1976

[Clinical significance of sperm pathogens in fertility disorders].

The reasons for systematic microbial examinations of human ejaculates are discussed. The exact establishment of an association between bacteria isolated from human ejaculates and infertility is very difficult. There are several hints for such an association in the case of different micoplasmas though there is no clear-cut evidence. A physical association between these microorganisms and spermatozoa, which was recently observed, possibly could help to facilitate the diagnosis.

Bacteria↗
PubMed1976

[New fluorescent microscopical technique in diagnostic microbiology (author's transl)].

The practicability of 4',6-diamidino-2-phenylindole (DAPI) in the fluorescent microscopical demonstration of bacterial and other cellular structures for medical diagnostic purposes was investigated. Polar bodies in diphtheria bacilli and spores of spore-forming bacteria showed up well. The demonstration of phagocytosed bacteria in urinary sediment and the morphology of human spermatozoa are particularly impressive. Noteworthy advantages of DAPI are its stability (no bleaching of stained preparations), its use in minute quantities, rapid staining (within minutes), and simplicity of use.

Bacteriological Techniques↗