PubMed Health⌕ Search

Biomedical subjects

W Wiedemann

Publications and source records attributed to W Wiedemann.

At least 37 records · Page 2Linked to original sources

[Differential diagnosis of thyroid nodules. Sonography as a complement to scintigraphy and puncture cytology].

The place of ultrasound in the diagnosis of thyroid nodules was assessed in 384 patients by comparing its findings with those obtained on palpation, scintigraphy, fine-needle cytology and (in 45 cases) histology. Further diagnosis of scintigraphically "cold" nodules is the main indication for ultrasound examination in goitre-endemic areas. In 13 of 69 cases of a cold nodule with complex or echo-poor echo image proved it to be malignant, while in 74 with cold nodules but with a normal or increased echo pattern there was no malignant tumour. Thus, if the echo pattern is "complex" or "echo-poor" urgency of surgical intervention is strengthened, while with echo-normal or echo-rich nodules or cysts indications for operation are relative. In future, a combination of scintigraphy, ultrasound and cytology (ultrasound-guided small-needle biopsy) will give the highest rate of diagnostic accuracy in the differentiation of malignant from benign thyroid lesions.

Biopsy, Needle↗

[Direct and indirect parameters for free thyroxine. II. Diagnostic accuracy in disorders of thyroid function and binding protein anomalies].

Part II of the study concerning the clinical applicability of direct and indirect parameters for free thyroxine evaluates the diagnostic accuracy of the FT4-RIAs ImmoPhase, GammaCoat, Liquisol, Amerlex and LisoPhase in relation to FT4 index and T4/TBG ratio. This comparison of methods is done on a thoroughly classified collection (n = 640) of patients with normal and impaired thyroid function including patients with binding protein anomalies (pregnancy, estrogen-medication, phenytoin therapy, renal protein loss). FT4 normal ranges of a given kit harmonize well with data of the manufacturers and of the literature. On the other hand, the normal ranges of the various kits are not comparable. The differentiation of euthyroidism from hyper- or hypothyroidism can be made without problems using any of these methods, with the exception of the FT4-RIA GammaCoat. As expected, patients with euthyroid goiter show, on the average, slightly lower parameters for FT4. In pregnancy all direct and indirect parameters for FT4 have a tendency to lower values after the first trimester. This trend is most distinct for the T4/TBG ratio. A weak negative correlation of FT4 parameters with basal TSH, which does not exceed the upper normal range, however, can be interpreted in the sense of a relative hypothyroxinemia. Under contraceptive estrogen medication FT4 parameters do not fall outside the normal range, with the exception of the FT4-RIA ImmoPhase assay which yields a significantly increased frequency of high FT4 levels. On therapy with phenytoin FT4 values are generally lower than in controls. FT4 parameters in patients with renal protein loss of more than 2 g daily do not behave uniformly. While three of the FT4-RIAs tested (ImmoPhase, GammaCoat, Amerlex) show a tendency to lower values, the results of the remaining FT4 parameters do not differ significantly from the distribution of normals. The study leads to the conclusion that indirect FT4 parameters are still useful in the diagnosis of thyroid function; currently available FT4 radioimmunoassays may yield comparable results. With regard to the varying quality of the various commercial test kits, the choice between FT4-RIAs and indirect FT4 parameters does not depend primarily on clinical but on technical viewpoints.

Adult↗

[Combined disease picture of an autonomous thyroid adenoma with acute and chronic thyroiditis].

This is a case report of a 20 year old woman suffering from a single toxic hot nodule of the thyroid gland. Following inflammation of the neck a cystic nodule with a thick fibrotic capsule was resected. Histology revealed a follicular adenoma with central necrosis surrounded by chronic fibrosing thyroiditis with intima proliferation of the blood vessels similar to Riedels thyroiditis.

Adenoma↗

[Possibilities and limits of thyroid sonography in the diagnosis of thyroid cancer].

The echographic appearance of 19 histologically confirmed malignant thyroid tumours has been analyzed. The value of information by ultrasonography is compared to scintigraphy and fine-needle aspiration biopsy. All patients demonstrated a sonographic pattern of relatively low amplitude, sparse and disordered echoes. Extended thyroid tumours (T2-3) exhibited a serrated marginal border as a sign of the infiltration to the surrounding thyroid tissue. The clinically important separation of solid and cystic nodules can always be made with certainty. Provided that a subtile examination technique is used, ultrasonography can be of great value in choosing the adequate therapy in scintigraphic cold nodules. Diagnostic ultrasound also yields information concerning the reliable and reproducible classification and accurate location of circumscribed thyroid lesions. In all cases, however, the ultrasound pattern did not provide reliable clues as to their histology. A successful differentiation between benign and malignant solid nodules can be obtained only by cytology and histology. Ultrasonography, scintigraphy and aspiration biopsy, therefore, are complementary methods.

Adenocarcinoma↗

[Mechanical properties and acid solubility of the dental surface. I. Microhardness].

The present paper deals with the relationship between microhardness, and the circumferential as well as radial location of the test points on the tooth surface. The measurements did not indicate a significant correlation between the average hardness of the tooth sections, and their location on the circumference. The average hardness of the sections on one probe, however, showed a large variation. Hardness was also correlated with the distance from the enamel surface. There was a steep hardness gradient in the outermost 50 micrometer thick enamel layer: hardness increased in the direction to the dentino-enamel junction. The investigated enamel layer seems to be layer of less mineralized enamel which might have its origin in de-, and remineralization processes on the enamel surfaces.

Bicuspid↗

[Comparative phorogrammetric studies on a periodontal index].

Reproducibile results are difficult to obtain with subjectively recorded periodontal indexes. The information acquired via such indexes therefore may be called into question. Inflammation of the gingiva was induced in 15 subjects. The degree of gingival swelling was determined via monophotogrammetry; the degree of inflammation, with the PMA index which emphasizes the symptom "swelling". The results were compared and discussed. It is highly probable that the PMA index is subjectively overrated.

Female↗

[Comparative clinical and photogrammetric studies on the marginal periodontium after the use of dentifrices].

A suggestion was made for testing the therapeutic effect of certain substances on gingival inflammation. Gingivitis was induced in 60 subjects by discontinuing of all forms of oral hygiene. Three tooth pastes, one of which was a placebo, were used for the study. Regression of the inflammation was determined with the periodontal indexes and photogrammetry. Photogrammetry appears to be well suited for objective evaluation of the therapeutic value of certain substances.

Dental Plaque↗

[The effect of periodontal resistance on experimental gingivitis].

The distribution and degree of severity of periodontal diseases depends on many different factors. One of the factors, periodontal resistance, was studied in 62 subjects. The test with experimental gingivitis showed that the dividing the subjects into periodontal-resistant and periodontal-insufficient groups led to more differentiated results.

Adult↗