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Biomedical subjects

C Reiners

Publications and source records attributed to C Reiners.

At least 181 records · Page 10Linked to original sources

[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↗

[Direct and indirect parameters of free thyroxine. I. Method, quality control and in vitro experiments on storage of samples and effect of drugs].

The clinical applicability of direct FT4 determinations by the radioimmunoassays ImmoPhase, GammaCoat, Liquisol, Amerlex and LisoPhase is tested in comparison to the FT4 index and the T4/TBG ratio. Part I of this study deals with technical aspects concerning quality control as well as with in-vitro experiments concerning storage of samples and interference of drugs. The precision of FT4-RIAs is satisfactory; inter-assay coefficients of variation are generally lower than 10% for medium hormone concentrations. Because of a change of the standard curve calibration by the manufacturer of the Liquisol kit, the inter-assay variability (17%) of this assay is unacceptably high. The comparison of working ranges shows that the sensitivity of all FT4 assays is sufficient. However, the upper limits of working ranges of the Liquisol and LisoPhase kits are too low. Storing the samples in form of serum yields lower values for any FT4 parameter than storing as whole blood. This unexpected observation is true for room temperature as well as for refrigeration at 4 degrees C. To be sure, the values of indirect FT4 parameters from serum and whole blood coincide somewhat better especially when the samples are stored in the refrigerator. Repeated thawing and refreezing does not influence the results of FT4-RIAs significantly. In vitro testing of drug interferences by addition of therapeutic doses of primidone, phenobarbital, phenytoin and acetylsalicylic acid yields significant effects only for the last quoted pharmaceutical. While the FT4 levels of the Liquisol and LisoPhase assays rise with the acetylsalicylic acid dose according to expectations, the values of the Amerlex and GammaCoat assays decrease. With regard to handling of the tests, there are no special technical problems for all FT4-RIAs tested.

Aspirin↗

[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↗

[Bone density and thyroid gland function in adolescents in relation to fluoride content of drinking water].

In 26 adolescents between 13--15 years of age living in a region with increased fluoride concentration in drinking water (3 ppm = 3 mg NaF/l) bone density-measurements by an I-125 profile scanner as well as measurements of thyroid function by means of numerous in vitro tests (T3U, T4, FT4-Index, RIA-T3, rT3, hTg, TSH, thyroglobulin and microsomal thyroid antibodies) have been done. Comparing 19 adolescents of same age from a region with low fluoride concentration in the drinking water (0,1--0,2 ppm) the study showed no influence of fluoride content of drinking water on skeleton mineralization and on thyroid function. There was found only--not depending on fluoride concentration--an increased bone density in females that was interpreted as a physiological difference between males and females.

Adolescent↗

Thyroid hormone changes in obese subjects during fasting and a very-low-calorie diet.

Total fasting was compared with VLCD (1.28 MJ, 300 kcal/day; 56 g protein, 12 g CHO) in 14 euthyroid obese patients, selected as matched pairs, over a period of 28 days. The weight loss was significantly greater during fasting than during the VLCD (16.5 kg vs. 12.7 kg). The basal metabolic rate of (BMR) showed a significant decrease (25 per cent) during total fasting, but was unchanged with the VLCD. With both diets there was a transient increase in T4, FT4 and FT4I, and a tendency for TSH to decrease. There was a decrease in T3 and a transient increase in rT3. Nitrogen balance was attained in five of seven patients on the VLCD after four weeks.

Adult↗

[Evaluation of functional scintigraphy of gastric emptying by the principal component method (author's transl)].

Gastric emptying of a standard semifluid test-meal, labeled with 99mTc-DTPA, was studied by functional scintigraphy in 88 subjects (normals, patients with duodenal and gastric ulcer before and after selective proximal vagotomy with and without pyloroplasty). Gastric emptying curves were analysed by the method of principal components. Patients after selective proximal vagotomy with pyloroplasty showed an rapid initial emptying, whereas this was a rare finding in patients after selective proximal vagotomy without pyloroplasty. The method of principal components is well suited for mathematical analysis of gastric emptying; nevertheless the results are difficult to interpret. The method has advantages when looking at larger collectives and allows a separation into groups with different gastric emptying.

Evaluation Studies as Topic↗

The use of recombinant human TSH in a patient with metastatic follicular carcinoma and insufficient endogenous TSH production.

We present a case of a patient suffering from metastatic differentiated thyroid carcinoma (DTC) and insufficient endogenous TSH production suspicious of secondary hypothyroidism. The use of recombinant human TSH (rhTSH) enabled us to administer a therapeutic activity of radioactive iodine (RAI) under maximal TSH-stimulation, achieving a marked decrease in thyroglobulin accompanied by a clinical improvement.

Adenocarcinoma, Follicular↗

[Bone density in children and adolescents with rheumatic diseases. Preliminary results of selective measurement of trabecular and cortical bone using peripheral computerized tomography].

UNLABELLED: Selective measurements of bone mineral density (BMD) of trabecular and cortical bone at the ultradistal radius were made in 27 children with rheumatic diseases and in age- and sex-matched healthy controls using peripheral quantitative computed tomography (pQCT). RESULTS: Mineral density of trabecular bone (-34,5%) and total bone mineral density (-18,9%) differed significantly between patients and controls (p < 0.01). BMD of the cortical bone (-13,6%) did not differ significantly between the groups. There was no difference in BMD in patients with systemic or non-systemic diseases. BMD did not correlate with duration of disease or steroid medication. CONCLUSIONS: Total bone mineral density and trabecular bone density are decreased in children and adolescents with sytemic and non-systemic rheumatic diseases. Age of onset of disease and steroid medication did not correlate with bone mineral density. PQCT has the advantages of low local and no total body radiation, high sensitivity, high reproducibility and selective measurement of different bone compartements. Because selective measurement can be made in metabolically active trabecular bone changes of BMD can be detected at an early stage before the whole bone is affected. With this method therapy for chronic diseases affecting bone density can be initiated and the course of the disease can be followed.

Adolescent↗

Confronting actual practice with practice guidelines in oncology.

Improving health care quality requires the availability of data to identify and eliminate unnecessary variations in the care process. Variations can be caused by an ineffective implementation of research findings or by obstacles to the translation of research into clinical practice. The analysis of current patterns of care by the use of routine data from electronic patient records or clinical registries may help highlight these deficiencies in actual care. The growing infrastructure of information technologies and the knowledge about clinically relevant variations of routine practice may help us understand the mechanisms that are impeding the translation of research into practice. There is a need to scrutinize these variations of practice and the barriers to guideline implementation. We think that an understanding and open discussion of such reasons may help, to continuously improve the quality of patient care. This process facilitates efforts and strategies to implement evidence-based medicine in the daily routine.

Data Collection↗