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Biomedical subjects

M Andersen

Publications and source records attributed to M Andersen.

At least 55 records · Page 3Linked to original sources
PubMed1985

Bilateral orbital floor fractures.

Nineteen patients operated on suspicion of bilateral orbital floor fractures are described. All of the patients had severe comminute midfacial fractures. Orbital floor deficiency requiring transplantation was found in 68% of the cases, demonstrating homolateral maxillary and zygomatic fractures. On the basis of their findings, the authors recommend acute reposition of the fractures and routine exploration of the orbital floor in the case of deficiencies requiring transplantation and in cases of homolateral combined maxillary and zygomatic fractures.

Adolescent↗
PubMed1985

Unilateral orbital floor fractures.

Ninety patients operated on, on suspicion of unilateral orbital floor fractures are described. Age, sex, and etiology are given. Operative indication is examined and related to the operative findings. Fifty-six of the patients had fractures requiring transplantation, 24 had fractures which did not. Ten patients had no fractures. Only autogenous bone graft was used. The patients were examined three months and one to 11 years postoperatively (questionnaire). Of 82 operated patients who answered the questionnaire diplopia was found in eight, enophthalmos in two, hypesthesia in 18, reduced mobility in four and sinuitis in four. Preoperative X-ray: Three patients showed false positive X-ray findings. In 19 patients with false negative X-ray findings 12 required transplantation. Twenty-five tomographed patients showed fractures, two of which proved to be false positives. In eight patients with negative tomographical findings, fractures were found, seven of which required transplantation. The frequency of complications assessed in relation to the time of operation shows no significant difference, if surgery takes place within seven days of injury. Surgery performed later than this seems to produce more cases of chronic sinuitis.

Adolescent↗
PubMed1979

Thyroid replacement therapy in Down's syndrome with hypothyroidism.

Three elderly subjects with Down's syndrome and biochemical evidence of hypothyroidism were investigated before and after four months of thyroid replacement treatment. The patients' appearance was demonstrated by photographs and the biochemical thyroid values and the intellectual performance were assessed. The appearance before treatment varied from a florid myxoedematous appearance to a state without features indicating myxoedema. Thyroid replacement therapy was given in usual dose and the biochemical response was similar to that seen in normal subjects. The intellectual performance improved little or not at all. The characteristic discomfort usually associated with hypothyroidism was very pronounced in one case and disappeared totally during treatment. It is concluded that the diagnosis of hypothyroidism in elderly subjects with Down's syndrome can be very difficult when based on appearance and history alone and biochemical thyroid tests are often necessary. The patients should be treated with replacement therapy just as other patients suffering from hypothyroidism.

Down Syndrome↗
PubMed1979

Can postoperative pulmonary conditions be improved by treatment with the Bartlett-Edwards incentive spirometer after upper abdominal surgery?

During the immediate postoperative course after upper abdominal surgery, pulmonary complications often occur, caused, inter alia, by reduced regional ventilation and by atelectases as a result of: (1) narrowing of the small peripheral bronchi, and (2) impaired respiratory function. Based on these pathophysiological mechanisms, an instrument (Bartlett-Edwards Incentive Spirometer) has been devised, which aims at giving the patient an opportunity of sustained maximal inspiration under standardized and controlled conditions. The use of this instrument has been followed by reports of a considerable reduction in postoperative pulmonary complications. In a controlled clinical investigation of the pre- and postoperative condition of the lungs, we were unable to show any beneficial effect of the instrument. In general, we have a low frequency of severe postoperative pulmonary complications, as compared with the results reported in the literature. We ascribe this to our very effective pre- and postoperative respiratory therapy.

Abdomen↗
PubMed1978

Mutagenicity of fume particles from metal arc welding on stainless steel in the Salmonella/microsome test.

Mutagenic activity of fume particles produced by metal arc welding on stainless steel (ss) is demonstrated by using the Salmonella/microsome mutagenicity test described by Ames et al., with strain TA100 (base-pair substitution) and TA98 (frame-shift reversion). Results of a representative but limited selection of processes and materials show that mutagenic activity is a function of process and process parameters. Welding on stainless steel produces particles that are mutagenic, whereas welding on mild steel (ms) produces particles that are not. Manual metal arc (MMA) welding on stainless steel produces particles of higher mutagenic activity than does metal inert gas (MIG) welding, and fume particles produced by MIG welding under short-arc transfer. Further studies of welding fumes (both particles and gases) must be performed to determine process parameters of significance for the mutagenic activity.

Gases↗
PubMed1977

Van der Waals interactions between cell surfaces.

Van der Waals energies of interaction between model cell surfaces are calculated for various distances of separation, layer thicknesses and compositions of cell surfaces and intercellular media. In these calculations the cell peripheries are considered to consist of two layers: (1) A phospholipid-cholesterol-protein plasma membrane and (2) a surface coat, which consists of protein, sugar and water. The required Van der Waals parameters of sugars, phospholipids and cholesterol are derived from refractive indices of their solutions in the visible and ultraviolet regions. Polarizabilities and Van der Waals parameters of these substances are determined and shown to be almost independent of concentration of solutions. Resulting isotropic polarizabilities differ by less than five percent from values obtained by the addition of bond polarizabilities. The magnitude of Van der Walls interactions between cell surfaces has been found to vary with composition according to the following sequence: water less than phospholipid less than cholesterol, protein less than sugar. A decrease in the concentration of a given substance in the cell surface at the expense of a corresponding increase in the concentration of a substance preceding it in this sequence lowers the magnitude of attractive interactions, whereas a similar change in the extracellular medium would have an opposite effect. A consideration of experimentally found variations in composition of cell surfaces results in calculated values of Hamaker's coefficients between 8 X 10(-15) ergs and 6 X 10(-14) ergs at 50 A distance of separation, which corresponds to free energies per unit area of 210-1600 kT/mu2.

Carbohydrates↗