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Biomedical subjects

E Eriksen

Publications and source records attributed to E Eriksen.

7 recordsLinked to original sources

Linearity of cephalometric digitizers.

The present study aimed to develop a test procedure to diagnose and visualize errors in linearity of digitizing tablets. Errors of linearity are caused by the distortion of the x- and y-co-ordinates of the digitizing tablet. This results in a given object apparently having different dimensions when recorded on different locations of the digitizing surface. The test is performed by systematic recording of n equally spaced points from a calibrated test foil. Algorithms were developed to calculate the difference matrices DXji and DYji between expected and observed values of the co-ordinates. Three-dimensional mapping of the non-linearity of the x- and y-co-ordinates was performed by the UNIRAS-geopak, a 3-D surface representative system. The tested digitizers showed varying degrees of scaling errors, fields of non-linearity, and random noise. Most digitizers allow for correction of scaling by setting of switches in the control unit. A method is suggested for correction of non-linearities by use of the DXji and DYji matrices in the digitizing programme.

Algorithms

Influence of skin graft pathology on residual ridge reduction after mandibular vestibuloplasty. A 5-year clinical and radiological follow-up study.

The present study is a 5-year clinical and radiographic follow-up of 51 patients who had undergone a combined vestibuloplasty with a split skin graft and lowering of the floor of the mouth. Our purpose was to examine the effect of clinically evident graft pathology on the residual ridge reduction. The clinical records of the graft condition were classified into: healthy graft, partial loss of keratinization, and total loss of keratinization. The residual ridge reduction was monitored by ridge height measurements at different locations, and by the symphyseal and mandibular body areas. Patients with clinical signs of graft pathology (reddening, loss of keratinization) suffered a significantly more severe residual ridge reduction than those with a healthy skin graft (p less than 0.01). Subsequent findings including smear tests showing Candida albicans hyphae, and improvement of graft condition after antimycotic therapy, indicated that the graft pathology observed is a candidiasis.

Adult

Thyroid function tests in patients undergoing bone marrow transplantation.

Thyroid function was studied prospectively in 27 patients receiving bone marrow transplants to determine the effect of this procedure and its sequelae on serum thyroid hormone levels and thyrotropin secretion. Serum triiodothyronine and free triiodothyronine concentrations declined to subnormal levels in nearly all of the patients; free thyroxine concentration became subnormal in 15 patients. At the time of the nadir of the serum T3 concentration, serum thyrotropin concentration, measured by a sensitive immunoradiometric assay, declined significantly and became subnormal in nine patients. The data suggest that the reduction of serum thyroxine levels after transplantation is attributable, at least in part, to inhibition of thyrotropin secretion.

Adult

Reduction of mandibular residual ridge after vestibuloplasty. A two-year follow-up study comparing the Edlan flap, mucosal and skin graft operations.

Mandibular residual ridge reduction (RRR) after Edlan flap vestibuloplasty, buccal mucosal graft, and split skin graft vestibuloplasty was measured on lateral cephalometric radiographs obtained 1, 3, 6, 12 and 24 months postsurgery in 50 patients. The ridge reduction was most severe during the immediate postoperative period. The different operation methods did not give rise to significant variations in the reduction pattern, neither did the sex of the patient appear to be an important factor. The temporary increase of mandibular resorption after vestibuloplasty surgery is of a magnitude comparable to the average RRR during 1 year in full denture wearers with a long denture experience.

Aged

Evidence of steroid receptors in human osteoblast-like cells.

A nuclear binding assay was used to demonstrate steroid receptors in normal human osteoblast-like cells. Nuclear binding of [3H]estradiol was found in 27 of 30 (90%) cell strains and nuclear binding of [3H]androgen was identified in 21 of 25 (84%) separate osteoblast cell strains. The nuclear binding was saturable and steroid-specific. Estrogen and androgen receptor gene expression was confirmed by RNA blot analysis. These data suggest that circulating sex steroids may act directly on normal human osteoblasts through receptor-mediated mechanisms.

Androgens

An outbreak of meningo-encephalitis in fallow deer caused by Listeria monocytogenes.

An outbreak of listeric meningo-encephalitis occurred in a population of 1800 fallow deer (Dama dama) in a park during the winter and early spring of 1985 to 1986. Listeriosis was diagnosed in 41 of 42 fallow deer that showed the typical central nervous system signs of circling disease or were found dead. The diagnosis was verified by bacteriological examination of the brains of 35 animals. In five of the seven remaining cases listeriosis was diagnosed by histological examination, and in one animal by clinical signs alone. Listeria monocytogenes was isolated in three of 23 soil samples taken from the park. In addition, L monocytogenes was isolated from the intestinal contents of apparently normal fallow deer. Fifty isolates from animals and soil were serotyped and all of them belonged to serovar 4b except one from brain (serovar 1/2b) and three from intestinal contents (serovar 1/2a). In phage typing of 54 isolates, the 35 isolates from the brain and spleen of diseased animals belonged to the same lysovar, as did most isolates from other sources, but strains from intestinal contents belonged to three other phage types. No external source of L monocytogenes was demonstrated in the outbreak and stress due to the poor beech-mast crop, an increased stocking rate and a sudden change in the weather are suspected as predisposing factors.

Animals