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Biomedical subjects

K P Wenzel

Publications and source records attributed to K P Wenzel.

At least 19 recordsLinked to original sources
PubMed1985

[Documentation in the polyclinic-internal medicine care process].

In five full-time and part-time specialists for internal medicine, respectively, of the district outpatient department the quality of the documentation of the ambulatory care has been tested. The documentations proved to be sufficient. Obviously this or that specialist sometimes keeps away from establishing a tentative diagnosis in the primary consultation. But the making of a preliminary diagnosis involves to do with a limited but sufficient examination programme.

Ambulatory Care↗
PubMed1982

[Mechanical stability of vascular grafts for chronic hemodialysis, preserved with methanal or peroxyethanic acid].

Vessels implants as possible vessel connections for chronic haemodialysis have to meet certain requirements concerning resistance to cutting and kinking and ability to be sewn under tolerable intraoperative damage risk. Preservation in peroxyethanic acid significant reduces the mechanical resistance of the biological primary material; by contrast, preservation in methanal clearly raises the mechanical stability of the preparations.

Arteries↗
PubMed1982

[Stability of acetate buffered methanal solutions].

The determination of the concentration in acetate puffered methanol solutions (formaldehyde solutions) with pH = 5.60 during 14 months disproved the opinion of the limited durability of these solutions. Neither a significant decrease of the methanal mass concentration nor a noticeable change of the pH value could be proved during the period of the examination under different influences of light and temperature. Methanal solutions can be applied farther in the practice of the preservation.

Acetates↗
PubMed1982

[Detoxication of methanal preserved bioprostheses].

The substitutes could be decontaminated by means of six to eight times soaking into sterile sodium chloride solution (154 mmol/l = 9 g/l) in each case half an hour if a short preparation time for the implantation of protein cross-linked and methanal storaged bioprotheses is existent. This procedure must be carried out under strict aseptic conditions. A microbial recontamination of the preparations threats moreover.

Animals↗
PubMed1982

[Mechanical resistance of methanal preserved bioprostheses].

Methanal (formaldehyde) preserved and ethane acid peroxide finally sterilised aortic segments showed in vitro and in vivo a significant decrease of the material characteristics in case of watering for 180 days. Intraperitoneal incorporation in a xenogeneous animal species during 60 days reduced the mechanical stability of the substitutes without long-term watering and also with long-term watering, but with an additionally greater negative effect.

Animals↗
PubMed1980

[Permeation of formaldehyde (methanal) through supravital and preserved tissue].

Allogenic and xenogenic tissues can be preserved with acetate buffered formaldehyde solution 1,332 mol/l and pH 5,60. The permeation of methanol molecules through the tissue was analysed with a double chamber research arrangement with a rotating set-up. The coefficient of diffusion of the formaldehyde (methanal) through the wall of the aorta descendens of pigs was calculated by means of the first Fick principle from the obtained measured particulars.

Absorption↗
PubMed1976

[Decontamination tests of heart valve grafts with cialit].

After exposure of contaminated xenogenous aortic valve grafts to 0.5 g% Cialit solution for 30 minutes, to 0.1 g% solution for 24 hours, or to 0.02 g% solution for 288 hours, growth of germs on the graft had stopped. Cialit has bacteriostatic and fungistatic effectiveness and fair stability of solubility; nevertheless it ought to be used with reservation. No safe destruction of microbes- spores and viruses in particular- can be guaranteed at acceptable Cialit concentrations of 0.1 g% and below.

Animals↗
PubMed1975

[Beta-propiolactone for cold sterilization of heart valve transplants].

Biologic cardiac valve substitutes were sterilized at room temperature using beta-propiolactone with a 0.5 vol.% solution within 120 minutes, with a 1.0 vol.% solution within 90 minutes, and with a 1.5 resp. 2.0 vol.% solution within 60 minutes. The physico-chemic properties of the graft can be influenced by appropriately chosen concentration and sterilizing period. Enlarged procedures for decontamination are not necessary because of the rapid dissolution of aqueous beta-propiolactone solutions.

Animals↗