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Biomedical subjects

R Rudolph

Publications and source records attributed to R Rudolph.

At least 253 records · Page 14Linked to original sources
PubMed1976

Kinetics of reassociation and reactivation of pig-muscle lactic dehydrogenase after acid dissociation.

Lactic dehydrogenase from pig skeletal muscle (M4) can be reversibly dissociated to the monomer at pH 4-5 depending on the anion applied. Using identical experimental conditions the pH-depending profiles of dissociation, denaturation, and deactivation coincide with each other. Deviations in the pH-dependence of protein fluorescence reflect changes in the microenvironment of specific chromophores rather than significant differences in the structure-function relationship as pH is changed. The dissociation state is characterized by the homogeneous inactive monomer of 35000. The reassociated material consists of up to 85% fully active tetramers, indistinguishable from the initial native enzymes, as shown by hydrodynamic, spectroscopic and enzymic properties. The rest represents a mixture of irreversibly denatured high aggregates. Under optimum conditions of reactivation both recovery of enzymic activity and native fluorescence obey strict second order kinetics with an activation energy of 44 kcal/mol (184 kJ/mol). NAD+ and NADH do not show any significant influence on the yield and kinetics of the refolding process and the recovery of enzymic activity. The kinetic results suggest the reassociation of inactive monomers to be rate-limiting in the refolding and reactivation processes being considered.

Animals↗
PubMed1976

Skin ulcers due to adriamycin.

Local skin necrosis at the site of intravenous or intra-arterial adriamycin infusion is an infrequent, but serious complication. Ulcers secondary to adriamycin have insidious beginnings, but progress to a much deeper extent than would be expected from their initial appearance. Deep structures, such as tendon or bone, may become exposed. The ulcers are indolent and do not develop a granulation tissue response or epithelialization, as might be expected from their early appearance. Injections of adriamycin in the dorsum of the hand should be avoided when possible, since tendons have little skin cover and the area is difficult to cover with local tissue if there is skin loss. While prevention is important, early surgical treatment may prevent progressive deep involvement and seems warranted when the patient has a life expectancy of months or years. Wide excision of all inflamed tissue is the treatment of choice, with split-thickness skin grafting or flap coverage.

Aged↗
PubMed1976

Species differences in the trypsin separation of epidermis and dermis.

Trypsin incubation was performed on split-skin grafts from rats, pigs, and humans. The separation of dermis and epidermis was best achieved when incubating in 0.5% crude trypsin in Hank's balanced salt solution. Separation occurred at 37 degrees C in 1 1/2 hours for all species. At 4 degrees C, the separation took 2 1/2 hours for pigskin, 3 1/2 to 4 1/2 hours for human skin, and 5 to 6 hours for rat skin. Histological examination showed a cleaner separation of both rat skin and pigskin was obtained at 4 degrees C than at 37 degrees C. Large areas of skin (1600 mm2) could be separated easily as long as adequate amounts of solution were used.

Animals↗
PubMed1976

The nasal application of beclomethasone diproprionate (Beconase) in allergic rhinitis.

The therapeutic effect of nasally applied Beconase (beclomethasone diproprionate) was investigated by a double blind trial of 32 patients with clinically manifest grass pollen rhinitis. A daily protocol showed a considerable improvement of the nasal symptoms and the general condition of the patient. The requirement of supplementary antihistamines decreased considerably whereas the conjunctival symptoms remained unaffected. In the course of the 2 week treatment period there was no certain evidence of local side effects.

Administration, Intranasal↗
PubMed1976

[The symptomatic treatment of seasonal allergic rhinitis (author's transl)].

The aetiology, pathophysiology and symptomatology of seasonal rhinitis are briefly presented. Symptomatic therapy with antihistamines, nasal decongestants and local and systemic corticosteroids is critically discussed. The results of a trial with Disodium cromoglycate are reported. This is shown to be a valuable drug in the symptomatic management of seasonal rhinitis. It should be tried before resorting to steroid therapy.

Adrenal Cortex Hormones↗
PubMed1976

The effect of skin graft preparation on wound contraction.

Both clinically and experimentally, full thickness skin grafts inhibit wound contraction better than do split thickness grafts. This occurs even if full thickness grafts are thinner than split grafts. Since inhibition of wound contraction does not depend on graft thickness alone, other differences should be sought between full and split grafts to explain this inhibition. One such difference is method of preparation. While full thickness grafts are cut with sharp dissection, split grafts are cut with mineral oil or with dermatome glue which is then stripped off. Both mineral oil and surface stripping in intact skin cause epidermal hyperplasia, more prominent in split grafts than in full thickness grafts. In this study, the effect of skin graft preparation on wound contraction and epidermal hyperplasia was tested. Seventy-four split thickness skin grafts were cut from Fischer rats with lubrication using mineral oil, Lubafax, normal saline solution or glue and a Padgett dermatome. Six full thickness grafts were treated with mineral oil. All grafts were placed on syngeneic rats; the area was measured with a planimeter, and biopsies were taken at zero, one, two, four, eight, 14 and 20 weeks. Mineral oil prepared split grafts lost 17.8 +/- 2.2 per cent area by one week, with a maximal loss of 38.8 +/- 4.8 per cent by four weeks. Split grafts cut with Lubafax, saline solution or glue plus drum dermatome lost similar area. Split grafts later enlarged as the rats grew, but in no group did split grafts surpass their original area. Full thickness grafts, even though treated with mineral oil, grew 3.9 +/- 4.3 per cent beyond their original area by four weeks and enlarged through 20 weeks. Histologic examination showed that all split skin grafts, regardless of surface preparation, had considerable epidermal hyperplasia and scarring in graft dermis and bed between one and four weeks. Thus, both skin graft contraction and epidermal hyperplasia occur independently of how grafts are prepared. The explantation of why full and split thickness grafts inhibit wound contraction differently must lie intrinsic rather than extrinsic to the skin.

Animals↗
PubMed1975

["Keratoacanthomas" in mastomys natalensis (author's transl)].

54 Tumors of Mastomys natalensis (GRA Giessen), described in the literature as "Keratoacanthomas" were investigated by light and electron microscopy. They are induced by a virus of the Papova group. Their histogenesis and their course are very different from human keratoacanthoma. The results reveal problems related to experimental animal tumour models and the similarities of different malignancies in the nomenclatures of several disciplines.

Animals↗
PubMed1975

[Allergies to animal hair in diseases of the upper respiratory tract (author's transl)].

Among 214 patients diagnosed in 1972 as being allergic to animal hair, 79 (48 women) were re-examined later. In almost all cases with a positive personal (33) or family history (26) of allergy there was a particularly rapid sensitization. The largest proportion of pathogenic allergens was from guinea pigs (39), cats (17), golden hamsters (11), rabbits (6), horses, dogs and budgerigars (2 each). 14 patients reacted to the main antigen alone in prick or intracutaneous tests, while in all other cases there were cross-reactions, most frequently to epithelium of sheep, cattle or horse. In interpreting intranasal provocation tests with the chief antigen, the degress of rhinorrhoea was particulary reliable (59 subjects). The most effective treatment was complete withdrawal of allergens: of 65 persons who removed their domestic pet or avoided contact with it, 32 were cured at once and a further 19 within about eight weeks. 14 subjects continued to have symptoms, but in half of these there was also house dust allergy, while others had resumed contact with domestic animals.

Adolescent↗
PubMed1975

Fournier's syndrome: synergistic gangrene of the scrotum.

Progressive spread of necrosis in the skin and subcutaneous tissues of the scrotum is the key feature of idiopathic scrotal gangrene. The disease may present initially as an acute abdomen, but laparotomy should be avoided. Usually an anaerobic Streptococcus is found, acting in synergism with aerobic, frequently gram-negative, bacilli. As in other synergistic gangrenes, wide dibridement with drainage of all sinus tracts is required. Although the testicles are frequently bared, they are usually not necrotic and should not be amputated. Once the infection has resolved, a surprising amount of skin coverage, including coverage of the testicles, can often be obtained from the scrotal remnants.

Abdomen, Acute↗
PubMed1975

Fluorescence and stopped-flow studies on the N in equilibrium F transition of serumalbumin.

In order to characterize the isomerization of serumalbumin in the acidic pH-range equilibrium and kinetic measurements of the intrinsic fluorescence of bovine serumalbumin and human serumalbumin were performed. Additional experiments with modified bovine serumalbumin made use of substituted 1.9 benzoxanthene dyes as SH-specific extrinsic fluorophores. The intrinsic fluorescence (lambda exc = 275 nm) shows a pH-dependent shift of the maximum of fluorescence emissions which correlates with the N in equilibrium F isomerization. This and the acid expansion at pH less than 3.5 is indicated by the pH-dependence of the fluorescence intensity at 350 nm. While tyrosine fluorescence is increased in all steps of the transition, tryptophane fluorescence is decreased in a different way for BSA (2 trp/molecule) and HSA (1 trp/molecule), the latter showing the N in equilibrium F transition only. Combining the tryptophan fluorescence data with the results from the SH-specific modification of BSA the conclusion may be drawn that the tryptophan residues in BSA and the SH-group belong to different domains of the molecule. Stopped-flow experiments prove the N in equilibrium F' and the F' in equilibrium F transitions to be separable along the time axis, the relaxation times being in the range between 40-50 and 300-600 msec respectively. For the "expansion" the kinetic constants critically depend on the initial pH conditions of the solutions. The backward reaction F leads to N seems to be a multistep isomerization process which is characterized by relaxation times greater than 1 sec.

Animals↗