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R Wahl

Publications and source records attributed to R Wahl.

At least 109 records · Page 6Linked to original sources
PubMed1984

Dot-based ELISA and RIA: two rapid assays that screen hybridoma supernatants against whole live cells.

Two assays are described that are suitable for the screening of large numbers of hybridoma supernatants as well as for the screening of a wide range of tissues for the distribution of a given cell surface antigen. These assays use whole live cells as targets, avoiding fixation or extraction, which could alter the antigenic structural profile. The assays are rapid, simple and inexpensive. Their advantages and applications are discussed.

Antibodies, Monoclonal↗
PubMed1984

Comparison of histamine release assay and RAST inhibition as tools for allergen extract standardization.

We compared allergen-induced histamine release (HRA) from actively sensitized human leukocytes and RAST inhibition (RI) for their capacity to measure the activity of allergen extracts. Four different grass pollen preparations were investigated for their allergenic activities by employing leukocytes and sera from 13 patients sensitive to grass pollen allergens. We could demonstrate that both test systems detect differences in allergenic activities of the preparations with similar accuracy and reproducibility. HRA is more sensitive than RI but shows greater variability of the results. Pooling of sera from individual patients diminishes individual sensitivities in RI. By this means the precision of RI is further increased. As reagents for RI can be standardized and stored under stable conditions, RI can be performed at different times and different laboratories under identical conditions. For these reasons, RI seems to be more suitable for routine standardization of allergen extracts than HRA.

Adolescent↗
PubMed1983

Comparison of three variations of the radioallergosorbent test-inhibition assay for measuring allergenic activity of grass pollen extracts.

Three variations of the radioallergosorbent (RAST)-inhibition assay (RI) have been compared for measuring the allergenic activity of grass pollen extracts. The main difference between the three assays consisted in the solid supports to which the allergens were coupled. These supports were paper disks, microcrystalline cellulose, and Matrex. It could be demonstrated that all three variations of RI yielded almost identical results as expressed by their F value (F0). Correlations between the three methods were highly significant (P less than 0.001). Three independent valid assays showed an excellent reproducibility of each test system (P less than 0.01). Three different preparations of each of the supports yielded highly reproducible F0 (0.76 +/- 3% SD). Evaluation of the 50% inhibition values achieved with the different assays based on protein showed differences between the three supports. Provided the same allergen extract is coupled to the different solid supports and the results are related to a reference preparation, different laboratories using different forms of RI will be able to compare their results.

Allergens↗
PubMed1983

Surgery for hyperthyroidism: indications, pretreatment, operative strategy and results.

In an endemic area nodular toxic goitre is the dominating type of hyperthyroidism, while Graves' or Basedow's disease with diffuse toxic goitre accounts for only 25 to 30% of the patients. Since antithyroid drug therapy has poor permanent effect and recurrence rates of about 50 to 60% and radioiodine in turn requires higher doses and often repeated application, surgery is to be recommended as the primary treatment of choice for the nodular hyperthyroid goitre. -For Graves' disease the method of therapy is not as clear cut. Operation is indicated mainly when the disease is severe with a larger goitre or in younger age groups (below 40 years) where radioiodine may not be advisable. For preoperative treatment the use of antithyroid drugs in preferred, although iodine perhaps in combination with beta blockers may be used safely as well at least for moderate cases. In the presence of alternative means of treatment surgery should not exceed an operative risk of 0.5-1.5% with virtually no mortality. Our own experiences are based on a retrospective analysis of 702 patients from three hospitals.

Adolescent↗
PubMed1982

Mathematical modelling of intravascular thyroid hormone stimulation by carrier proteins.

A simple mathematical model for the thyroid hormone stimulation in plasma after intravenous administration of pharmacological doses of thyroid hormone binding carrier proteins is described. The model concept is based on the observation of the time course of both radioactive labelled and unlabelled thyroid hormones before and after protein loading in rabbits. All model parameters are derived from experimental measurements in order to guarantee the identifiability with physiological data. The presented initial study could be a theoretical basis for a more effective therapy of thyroid storm by dialysis or plasma exchange methods.

Animals↗
PubMed1981

[Echographic localisation diagnosis of adenomas and hyperplasias of the parathyroid in primary hyperparathyroidism (author's transl)].

The results of echographic localization of adenomas and hyperplasia of the parathyroid glands in seven patients with primary hyperparathyroidism are reported. In four patients there was complete, and in three patients partial, agreement between the echographic diagnosis and the findings at surgery and histology. On the basis of this experience and the findings of other authors, echography must be regarded at present as the best method for pre-operative localization of adenomas and hyperplasia of the parathyroid gland.

Adenoma↗
PubMed1981

Micromethod of human thyrocyte cultures for detection of thyroid-stimulating antibodies and thyrotrophin.

The activation of adenylate cyclase of human thyrocytes in primary cell cultures and the release of cAMP into the medium are used to detect thyrotropin (TSH) and thyroid-stimulating antibodies (TSAb) in sera of patients with Graves' disease. Tissue digestion and cell dispersion are performed using a neutral protease of Bacillus polymyxa (Dipase II), which harvests more vital thyrocytes than does trypsin. The cells show an enhanced response to stimulation. The efficiency of the cell preparation and cultivation is increased by using microtest plates instead of culture flasks. By this minimization only 0.6-1.8 X 10(6) cells are needed to evaluate a single sample. Cyclic AMP concentrations are measured directly in the supernatant culture medium by a competitive protein binding assay with charcoal separation. The minimal detectable dose of bTSH is about 10 microU/ml. With increasing doses of bTSH cAMP concentrations rise to a peak at about 50 to 100 mU/ml, beyond which there is a gradual decrease of cAMP indicating negative cooperativity in the activating mechanisms. The 'long-acting thyroid stimulator' effect of TSAb is reflected by a protracted increase of cAMP to its maximal value. All 41 sera of hyperthyroid patients with Graves' disease were TSAb-positive, whereas sera of patients with toxic nodular goitre and euthyroid controls were TSAb-negative.

Autoantibodies↗
PubMed1980

[Thyreotrophic hypophysial function after surgery for euthyroid goiter or autonomous adenoma].

44 euthyroid patients with nodular goiter and 23 patients with autonomous adenomas were treated by hemithyrectomy or subtotal thyrectomy. Thyroid function was followed over 6 weeks post-operation by TRH tests, which were performed before and at the 5th, 14th, 28th and 42nd day after operation. Bilateral subtotal thyrectomized patients with euthyroid goiter showed a continous increase of basal and TRH stimulated TSH level into the hypothyroid range. 19 of 25 patients were hypothyroid 6 weeks after operation. In contrast, 14 of 19 hemithyrectomized patients with euthyroid goiters remained euthyroid during the time investigated; 5 patients showed a transient TSH increase into the hypothyroid range but were euthyroid again after 6 weeks. TSH levels obtained from patients operated for autonomous adenoma may not yet reflect thyroid function during the time interval investigated here. We conclude that all patients with euthyroid goiter after bilateral subtotal thyrectomy should receive hormone substitution because they are at high risk to develop recurrency. However, we propose that in patients hemithyrectomized for euthyroid goiters the decision of long term hormone substitution should be cased on the result of a TRH-test 3--4 month after operation. Substitution with thyroid hormone should be preferred to iodide because it is unclear yet how far a failure in iodide organification and hormone synthesis is the reason for goiter recurrency.

Adenoma↗
PubMed1979

Identification of phosphatidyl-1-aminopropane-2-ol in rat liver after administration of 1-aminopropane-2-ol.

Phosphatidyl-1-aminopropane-2-ol has been detected in rat liver after intraperitoneal administration of 1-aminopropane-2-ol hydrochloride. The new glycerophospholipid was chromatographically identified by comparison with chemically and enzymatically synthesized phosphatidyl-1-aminopropane-2-ol and by gas-liquid chromatography of the polar group as trifluoroacetyl derivative.

Animals↗
PubMed1978

[Familial coincidence of hypertrophic cardiomyopathies and thyroxine-binding globulin deficiency (athyropexinemia) (author's transl)].

A twenty-five year old man was found to have simultaneous total deficiency of thyroxine-binding globulin ("thyropexin") and hereditary hypertrophic obstructive cardiomyopathy (HOCM). The thyroxine-binding capacity (RT3U), thyroid hormone levels, PB127I, PB131I and TBG (RIA) in serum were very low and TBG cap was zero. Trapping of radioiodine in the thyroid was enhanced. Clinically, the patient appeared euthyroid. The case seems to be similar to another one described earlier by Ingbar. An investigation of the family showed that in one uncle and two nephews of the patient thyropexin was absent whilst the mother, one sister and one female cousin had partial thyropexin deficiencies. One of these nephews also suffers from asymmetric septal hypertrophy (ASH), the mother of the propositus has a non-obstructive hypertrophic cardiomyopathy (HCM).

Adult↗
PubMed1978

[Vitamin D deficiency in femoral neck fractures (author's transl)].

In a therapeutic trial 20 patients with femoral neck fractures (FNF) were treated alternatively without supplemental vitamin D, calcium and phosphate or with 15 000 I.U. vitamin D2, 500 mg Ca++ and 560 mg of phosphate daily. Within two weeks, 25-OH-D in serum increased in patients with supplementary therapy. It is concluded that in the German Federal Republic, vitamin D deficiency is frequently found in the elderly during the winter months and that vitamin D deficiency could be important for the development of FNF.

Aged↗
PubMed1978

[Thromboplastin activity of extracts of human thyroid glands (author's transl)].

Aqueous extracts of thyroid glands were prepared from 25 surgical specimens of 19 patients. The average prothrombin time of sixteen 3:4 diluted extracts of thyroids from 13 euthyroid patients was 16.8 +/- 2.3 sec as measured with 100% human plasma. Under similar conditions the average prothrombin time of extracts obtained from the grey matter of three human brains was 18.4 +/- 0.3 sec. The thyroid may thus be considered as an organ containing one of the highest concentrations of tissue thromboplastin.

Humans↗
PubMed1978

Properties of solubilized nuclear triiodothyronine binding proteins.

Rat liver nuclear proteins bind 3,5,3'-triiodo-L-thyronine (T3) to essentially one class of sites (Ka approximately 1 X 10(10) M-1). Gel filtration and sucrose gradient centrifugation studies show a main T3 binding component with a Stokes radius of 33 A and a sedimentation coefficient of 3.5S, and variable amounts of high molecular weight binding components, most of them being reversible aggregates of the main component formed during storage. But the uniqueness of the nuclean T3 binding proteins (NTBP) cannot be ascertained from polyacrylamide gel electrophoresis data. During storage in the absence of reducing agents, NTBP aggregate and rapidly lose their ability to bind T3; T3--NTBP complexes also aggregate and progressively dissociate. This can be reversed by dithiothreitol. Bound T3 could temporarily stabilize the binding site but cannot protect NTBP against general conformational changes which follow the oxidation of their essential --SH group(s). NTBP are DNA binding proteins with probably a relative independence of their DNA and T3 binding sites: they bind T3 to the same class of high affinity sites whether complexed or not with DNA; bound T3 is not a prerequisite for DNA binding.

Animals↗