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Biomedical subjects

E F Eriksen

Publications and source records attributed to E F Eriksen.

143 records · Page 8Linked to original sources
PubMed1985

Prostaglandin E2 receptors on human peripheral blood monocytes.

The prostaglandin E2 (PGE2) receptor on human peripheral blood monocytes is characterized. The receptor binding at physiological temperature and pH was saturable, specific, and reversible. Scatchard analysis of binding data revealed a linear plot giving a Kd = 1.1 X 10(-9) mol/l and Bmax = 4.1 fmol/10(7) cells, equal to 240 binding sites per cell. PGE2 increased intracellular cyclic adenosine 5'-monophosphate by a maximal factor of 3. PGF2 alpha and arachidonic acid had no stimulatory effects on adenyl cyclase, in accordance with their low binding to the cells. The characterization of the PGE2 receptor on human monocytes creates a basis for the study of the clinical significance of changes in PGE2-receptor binding in disease states involving PGE2-monocyte interactions such as various immunological disorders and bone resorption.

Arachidonic Acid↗
PubMed1984

Solid-phase radioimmunoassay of immunoglobulins G, A and M: applicability in analysis of sucrose gradients.

A simple and sensitive solid-phase radioimmunoassay for the detection of immunoglobulins G, A and M in sucrose gradients is described. The solid-phase consisted of immunoglobulins adsorbed to polystyrene tubes. Using buffers without detergent and 125I-labeled sheep anti-rabbit IgG as radioligand, the assay was able to detect 0.8 ng per tube in the IgG assay and 1.6 ng per tube in the IgA and IgM assays. Standard curves with antigen dissolved in 10% and 32% sucrose were superimposable and did not deviate from standard curves with antigen dissolved in buffer without sucrose. Using these techniques on ultracentrifugation samples from patients with systemic lupus erythematosus, Schönlein-Henoch nephritis and IgA glorulonephritis it was possible to detect both immunoglobulin fragments and immunoglobulin aggregates at the same time without prior dialysis of the samples.

Animals↗
PubMed1984

Treatment of cervical disc disease using Cloward's technique. III. Evaluation of cervical spondylotic myelopathy in 138 cases.

Among 1,106 patients with cervical disc disease treated with Cloward's operation over a fifteen-year period, 138 patients had symptoms and signs of spinal cord involvement. The median symptom duration was one year. Nearly all had gait disturbances, 63% had spasticity of the lower extremities and 11% had various degrees of tetraplegia. Three months after surgery 78% of the patients were found to have some symptoms, but only 5% had no symptoms at all. At the time of the questionnaire (average 7.7 years postoperatively) 46% of the patients stated they were still affected by the operation. The duration of preoperative symptoms was of significance to the outcome, but age, sex, and severity of myelopathy were not. It was demonstrated that patients with medullary involvement had a higher annual mortality rate than patients with radicular symptoms, and that this rate depended on the severity of the spinal cord symptoms.

Cervical Vertebrae↗
PubMed1984

Treatment of cervical disc disease using Cloward's technique. I. General results, effect of different operative methods and complications in 1,106 patients.

During the period from April, 1965, to October, 1979, 1,106 patients with symptoms or signs of cervical disc disease were operated on using Cloward's technique. 94% of the patients alive filled in a questionnaire forwarded on October, 1980. The study revealed that 81% experienced an immediate effect of the operation, and 63% were in a better condition than preoperatively at the time of the questionnaire. It appeared that the effect of the operation 1 year postoperatively was independent of age and observation time, but the functional result and postoperative working capacity were very significantly better in young patients, but still independent of observation time. The result was independent of the number of primarily inserted grafts, cutting of the posterior spinal ligament or the finding of a free herniated disc. Use of calf bone grafts resulted in more reoperations. Primary complications were registered in 13% of the patients, reduced to 5% after 3 months. 3 patients developed a severe tetraplegia, and 6 patients died within 3 months of the operation.

Adolescent↗
PubMed1984

Treatment of cervical disc disease using Cloward's technique. The prognostic value of clinical preoperative data in 1,106 patients.

During a fifteen-year period 1,106 patients underwent Cloward's operation due to cervical disc disease. An analysis of the clinical features showed that the diseases had a very complex pattern of symptoms and signs. In young patients a syndrome of herniated disc predominated whereas a clinical picture of "cervical spondylosis" was found more often in the elderly. It was demonstrated that best results were obtained in young patients, patients with slight symptoms and patients with monoradicular symptoms. A short duration of symptoms is essential for a good outcome, and, on the basis of the data presented, operation is recommended 3 months after the onset of symptoms of cervical disc disease, if previous conservative treatment has failed.

Adolescent↗
PubMed1984

Reconstruction of the resorptive site in iliac trabecular bone: a kinetic model for bone resorption in 20 normal individuals.

The variations with time in function and morphology at the resorptive site in normal iliac crest trabecular bone were reconstructed from tetracycline double-labeled iliac crest bone biopsies from 20 normal individuals. Resorption depths below osteoclasts, mononuclear cells, and preosteoblast-like cells were measured by counting the number of lamellae of known thickness eroded. Mean resorption depth below osteoclasts was 19.0 (+/- 4.9) micron. Lacunae containing mononuclear cells were deeper (P less than less than 0.0001), with a mean resorption depth of 49.1 (+/- 10.2) micron. The deepest lacunae were lacunae containing preosteoblast-like cells, with a mean resorption depth of 62.6 (+/- 12.5) micron. This depth was significantly deeper (P less than 0.001) than the resorption depth found below mononuclear cells. Median total resorption period was 48 days (31-68; 95% confidence interval). Median osteoclastic function period was 8 days (6-12), median mononuclear cell function period was 34 days (24-48), and median period where preosteoblast-like cells were present in lacunae before matrix synthesis started was 9 days (6-13). Distribution curves describing the occurrence of the three cell types in relation to resorption depth showed that osteoclasts occupied the more superior parts of the resorption lacunae, with mononuclear cells and preosteoblast-like cells situated in the deeper parts. The distribution curves support the hypothesis that osteoclasts precede mononuclear cells, which again precede preosteoblast-like cells. Based on this hypothesis, curves showing the variation in resorption depth with time were constructed in duplicate. Resorption rates were calculated for three periods.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1984

Reconstruction of the formative site in iliac trabecular bone in 20 normal individuals employing a kinetic model for matrix and mineral apposition.

A stereologic procedure for the reconstruction of matrix and mineralized bone growth curves at formative sites in trabecular bone is presented. Iliac crest bone biopsies obtained from twenty normal individuals after tetracycline double-labeling were investigated histomorphometrically. Corresponding values for osteoid width and apparent distance between bone markers and width of mineralized bone walls were classified using a sector plotting system. Observed structure widths were converted to three-dimensional structure thicknesses by a stereologic unfolding procedure. Osteoid thickness, calcification rate, and fractional labeling of osteoid varied characteristically with increasing wall thickness and permitted the construction of curves describing the time-dependent variations in matrix and wall thicknesses. The mean thickness of completed walls was 61.9 +/- 1.5 micron (SE), and the mean bone formation period (Sigma f) was 145 days (124-168; 95% confidence interval.). The initial appositional rates for bone matrix (2.1 microns3/microns2/day) (1.4-2.9) and bone mineral (1.1 micron3/micron2/day) (0.4-1.9) declined gradually toward zero at the end of Sigma f. The initial mineralization lag time was 15 days (12-24) and increased to a maximum of 27 days during the first 45% of Sigma f. Thereafter, it decreased gradually toward zero. The height of the osteoblast nuclei gradually declined from 6.7 +/- 0.5 micron at the start of bone formation to 1.2 +/- 0.1 micron at the end. The study demonstrates that it is possible to reconstruct growth curves for trabecular bone walls based on three-dimensional values for structure thicknesses using different sections for light and fluorescence microscopy and avoiding classification according to osteoblastic nuclear morphology.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1984

Serum immunoglobulin sedimentation patterns and circulating immune complexes in IgA glomerulonephritis and Schönlein-Henoch nephritis.

Sera from 8 patients with IgA glomerulonephritis and from 6 patients with Schönlein-Henoch nephritis were investigated by the C1q-binding assay (C1q-BA) test and by sucrose gradient centrifugation followed by sensitive solid phase radioimmunoassay determinations of IgA, IgG and IgM in each fraction obtained. Abnormal sedimentation profiles were found in sera from 3 of 8 patients with IgA nephritis and in 3 of 6 patients with Schönlein-Henoch nephritis. The abnormal fraction consisted of low molecular weight IgA in 2 patients, IgG in 1 patient and IgM in 4 patients. The absolute level of polymeric IgA was increased in 3 of 8 patients with IgA nephritis, but the relative distribution was normal. An abnormal sedimentation pattern of immunoglobulins was correlated to a positive C1q-BA test (p less than 0.001).

Adolescent↗
PubMed1984

Prostaglandin E2 receptor binding and action in human fat cells.

The prostaglandin E2 (PGE2) receptor in human adipocytes was identified by the use of [3H]PGE2. The receptor binding at physiological temperature and pH was specific, saturable, and slowly reversible. Half-maximal displacement for [3H]PGE2 binding occurred with 2.5 nmol/liter. Half-maximal inhibition of isoproterenol-induced lipolysis was achieved at a concentration of PGE2 of 3.8 nmol/liter and half-maximal inhibition of basal lipolysis was achieved at a concentration of PGE2 of 0.9 nmol/liter. The order of potency for prostaglandin inhibition of receptor binding and antilipolytic effect was the same, with PGE2 greater than PGF2 alpha much greater than arachidonic acid. Scatchard analysis of the binding data revealed a nonlinear plot indicating the existence of two or more binding sites with different affinities. The binding sites of high affinity had an equilibrium constant (Kd) of 2 nmol/liter and a total binding capacity of 58 fmol/10(6) adipocytes which corresponds to about 33,000 binding sites per adipocyte. The binding sites of low affinity had a Kd of 56 nmol/liter and a total binding capacity of 700 fmol/10(6) adipocytes. We conclude that [3H]PGE2 binds to receptors in isolated human adipocytes and that their antilipolytic effects are mediated by this binding.

Adipose Tissue↗
PubMed1981

Bilirubin-liposome interaction. Binding of bilirubin dianion, protonization, and aggregation of bilirubin acid.

Interaction of bilirubin with phospholipid liposomes was studied at varying pH. Liposomes were prepared from egg-phosphatidylcholine, dipalmitoyl-phosphatidylcholine, phosphatidylethanolamine, egg-phosphatidylcholine, and phosphatidylethanolamine with 5% (w/w) cholesterol, phosphatidylserine, sphingomyelin, and a lipid preparation from cat brain. Experiments were also conducted with erythrocyte ghosts. Interaction with bilirubin was studied by observing quenching of fluorescence from 1,6-diphenyl-1,3,5-hexatriene, incorporated in the lipid bilayers, by gradient centrifugation of the product, by measuring light scattering during the process, and by studying the solubility and infrared spectra of the final aggregates. At pH values above 8.2, the findings are consistent with formation of a bilirubin dianion-phospholipid complex. At pH 6-8, protonization of bilirubin in the complex is indicated and is followed by self-aggregation of bilirubin acid with formation of large bilirubin particles containing a small amount of phospholipid. Results were qualitatively similar with all lipids studied; marked quantitative differences in degree of fluorescence quenching and aggregation rates were observed with liposomes from different phospholipids. Reflections on affinities and available concentrations indicate that this train of processes may be part of the toxic mechanism of bilirubin.

Animals↗
PubMed1981

Neuropeptides in the retina: evidence for differential topographical localization.

The retina has been examined for the presence of vasoactive intestinal polypeptide (VIP), substance P, somatostatin, and gastrin/cholecystokinin immunoreactive structures by immunocytochemistry. The results indicate that all four peptides reside in neuron-like processes of the inner plexiform layer. Interestingly, the immunoreactive processes display distinctive distributional patterns in different strata of this layer, suggesting that they may serve distinct functions, possibly related to integration and modification of visual input. This supposition is strengthened by the observation that the immunoreactivity of the VIP cell bodies and processes varies extensively with the amount of light entering the eye.

Animals↗
PubMedDate not supplied

Age- and sex-related changes in iliac cortical bone mass and remodeling.

Iliac crest bone biopsies were obtained from 64 normal individuals (41 women and 23 men) aged 19-90 (mean 48.2) years. Thirty-four were double-labeled with tetracycline before biopsy. The following variables were measured in all biopsies: biopsy core width (C.Wi), absolute (A.Ct.Wi) and fractional (F.Ct.Wi) cortical width, absolute (A.Cn.Wi) and fractional (F.Cn.Wi) cancellous width, cortical porosity (Ct.Po), osteon diameter (On.Dm), Haversian canal diameter (Ha.Ca.Dm), and wall thickness (W.Th). In the tetracycline-labeled biopsies the typical cortical remodeling cycle was reconstructed and the activation frequency was estimated. A negative cortical bone balance with aging was found in both sexes. In females F.Ct.Wi decreased (p < 0.02) with aging because of marrow expansion (p < 0.05). Furthermore, Ct.Po increased (p < 0.001) because of a decrease in W.Th (p < 0.01) and an increase in H.Ca.Dm (p < 0.001). In males the negative cortical bone balance with aging was exclusively caused by an increase in Ct.Po (p < 0.001) partially explained by an expanding H.Ca.Dm (p < 0.01). The On.Dm increased with aging (p < 0.01), but surprisingly, no fall in W.Th was observed. Reconstruction of the remodeling cycle did not reveal any significant difference between younger women and men. However, the activation frequency rose from 0.5 per year in premenopausal to 1.0 per year in postmenopausal women (p < 0.001), giving rise to a high turnover state, an increase in the remodeling space, and thereby the porosity in the cortical bone immediately after menopause. The present study has shown a reduction in cortical bone mass in elderly people, compared with younger, which may be explained by an age-related remodeling imbalance. This reduction is further increased in women in the postmenopausal state because of a postmenopausal accelerated bone turnover.

Adult↗
PubMedDate not supplied

Rates of cancellous bone remodeling and turnover in osteopenia associated with primary biliary cirrhosis.

Osteoporosis and fracturing are well-recognized manifestations of primary biliary cirrhosis (PBC), but the abnormalities of bone remodeling and turnover that result in bone loss are poorly understood. We used dynamic histomorphometric techniques to measure tissue level rates of cancellous bone resorption, formation, and turnover in 12 premenopausal women with PBC and in 12 normal premenopausal women. We compared these values with estimates of bone resorption and formation obtained concurrently in the same subjects by radiocalcium kinetics and biochemical markers. Rates of bone turnover were analyzed as a function of a risk score that reflects the severity of hepatic disease and cholestasis (Mayo proportional-hazards model). Positive correlations were observed between tissue level and whole skeletal estimates of bone remodeling. At the remodeling site (bone multicellular unit [BMU]), the depth of eroded lacunae was unaltered by PBC, but wall thickness was decreased. At the level of bone tissues, mean bone turnover was increased in PBC patients but varied widely and increased as hepatic disease and cholestasis worsened. We conclude that PBC causes a reduction in the volume of bone formed at the remodeling site and that the overall level of bone remodeling and turnover in PBC is strongly influenced by the severity of hepatic disease and cholestasis. We hypothesize that the rate of bone loss in PBC may be decreased by therapeutic agents that slow bone turnover, and that further bone loss may be halted by liver transplantation.

Adult↗
PubMedDate not supplied

Growth hormone (GH) and adult bone remodeling: the potential use of GH in treatment of osteoporosis.

Decreased osteoblastic activity seems to be of major importance in the pathogenesis of postmenopausal and senile osteoporosis and several lines of evidence suggest that GH may become useful in treatment of osteoporosis. GH stimulates osteoblastic proliferation and differentiation in vitro and increases production of Insulin-like Growth Factor-I and II (IGF-I and IGF-II) which both have profound stimulatory effects on osteoblasts and are important local regulators of bone remodeling. GH affects several other osteotropic hormones in vivo and increases bone turnover while the effect on bone mass is less pronounced and depends on the skeletal compartment. The few published clinical studies on the use of GH in treatment of osteoporosis have been inconclusive and well controlled studies of adequate size are greatly needed. Future research should focus on intermittent use of GH in combination with other hormones stimulating IGF production or antiresorptive agents.

Bone Remodeling↗