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Biomedical subjects

J Beumer

Publications and source records attributed to J Beumer.

At least 37 records · Page 2Linked to original sources

Dental management of the irradiated patient.

There is an increasing number of patients receiving radiation therapy for oral malignancies. In many malignant tumors, radiation is often the treatment of choice, while in others it may be used in conjunction with surgery or chemotherapy. There are inherent dental and oral problems associated with radiation therapy. It is the purpose of this paper to deal briefly with the physical principles and the biological basis of radiation therapy. In addition, the specific radiation effects on oral mucous membranes, taste buds, salivary glands, bone, the periodontium and teeth will be discussed. Radiation complications in edentulous patients, and in particular the problems of wearing dentures in such patients will be evaluated. An approach to the problem of dental extractions and other dental treatments in the pre- and post-irradiated patient is suggested.

Bone and Bones

Radiation complications in edentulous patients.

Complete dentures were fabricated for 88 patients following completion of cancericidal doses of radiation therapy to the head and neck regions. All were followed for at least 6 months after delivery. All patients received dentures resting within the radiation field. Three patients developed osteoradionecroses directly attributable to their dentures. These three had been dentulous prior to therapy and had either pre- or posttreatment extractions. Of the 58 patients who had been edentulous prior to therapy, none developed osteoradionecrosis. Five patients developed soft tissue necroses secondary to the use of dentures.

Denture, Complete

Prosthetic rehabilitation of large midfacial defects.

Advanced tumors of the midfacial region often require removal of the nose, upper lip, portions of the maxilla, and other adjacent structures. When the resultant defects do not lend themselves to surgical reconstruction, prosthetic appliances may be used successfully to restore the functions of speech and swallowing to near-normal levels. The degree of success depends upon the nature of the previous treatment, the existing surgical defect, and the adaptability of the patient. The most important anatomical consideration is the form and amount of the remaining maxilla. Recent advances in the development of the polyurethanes have resulted in lighter, more flexible, and, therefore, better tolerated prostheses. Close cooperation between the surgeon and the prosthodontist is necessary if successful rehabilitation of these patients is to be achieved.

Aged

[Chemotypes of "Shigella flexneri" R mutants and related phage receptors. II. -- Localization of phage receptors (author's transl)].

Receptor sites for phages FP3, V, P1kcvir, H+, C21, T4, T3, T7 and 6SR have been investigated, by comparing the lytic activity of these phages on R mutants of strain F6 (F6R) and of various serotypes (FH) of Shigella flexneri with their inhibition by the lipopolysaccharides isolated from these mutants. The results suggest the following localizations for the receptor sites: phage FP3: lipid A-KDO; phage V: heptose or glucose; phage C21: heptose-glucose; phages H+, P1kcvir, T4 and T3: glucose; phage T7: glucose-galactose; phage 6SR: complete core structure.

Bacteriophages

[Chemotypes of "Shigella flexneri" R mutants and related phage receptors. I. -- Chemical study of the lipopolysaccharides (author's transl)].

The F6R rough mutants isolated from Shigella flexneri F6S, serotype 5b, and the FH rough mutants, derived from other serotypes of S. flexneri, were chemotyped according to the chemical analysis of their lipopolysaccharides. Further, the following stages of lipopolysaccharide core biosynthesis in S. flexneri have been established: --(KDO)3--heptose--heptose--glucose--galactose; the last three stages are: either --glucose--glucosamine--glucose, or --glucosamine--glucose--glucose. The results of the chemical study of the R lipopolysaccharides are compatible with the assumption of the existence of a similar core in all considered S. flexneri serotypes.

Bacterial Proteins