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Biomedical subjects

J Köbberling

Publications and source records attributed to J Köbberling.

At least 55 records · Page 3Linked to original sources
PubMed1990

Evaluation of a new enzyme immunoassay system for free thyroxine (Enzymun-Test FT4).

Free thyroxine (FT4) represents the metabolically active fraction of the circulating thyroid hormone thyroxine (T4). In this paper the results of the evaluation of a newly developed FT4 assay are reported. This assay system is based on an enzyme-labelled one-step immunoassay. The within-run imprecision, checked using serum pools and several commercial reference materials, showed a coefficient of variation (CV) of between 0.8 and 9.8%, depending on the reference material used. The between-run imprecision showed a CV of between 1.0 and 13.2%. Accuracy experiments yielded values between 80 and 116%. When the new FT4 was compared with the calculation of an index for free thyroxine (FT4I; derived from either the ratio of T4/thyroxine binding coefficient of from T4/thyroxine binding globulin) in a number of samples in the hypo-, eu- and hyperthyroid range, a good correlation was obtained. The same was true when the new FT4 assay was compared with a widely used two-step radioimmunoassay (y = -0.146 + 0.943 x). In euthyroid subjects the measured FT4 concentration was 10.3-25.8 pmol/l. No effect was evident when the influence of EDTA and citrate was investigated, whereas addition of heparin led to an increase in FT4 concentration of about 12 to 15%. Investigation of the possible influence of a large number of drugs showed that probenezid, carbamazepine and furosemide led to an increase in the measured FT4 concentration. Dialysis increased the FT4 concentration, as measured in patients before and after haemodialysis. No effect of alteration in protein concentration and/or protein distribution of FT4 concentration could be detected. In pregnancy, FT4 values were within the normal range.(ABSTRACT TRUNCATED AT 250 WORDS)

Evaluation Studies as Topic↗
PubMed1989

Treatment of endemic goitre due to iodine deficiency with iodine, levothyroxine or both: results of a multicentre trial.

Preliminary clinical studies and recent in vitro investigations suggest that iodine administration may be an effective alternative in the treatment of the diffuse euthyroid goitre of iodine deficiency. Therefore a 12-month multicentre study was initiated in which 166 patients were randomly assigned to take either 150 micrograms levothyroxine day-1 (group A, n = 61), 400 micrograms iodine day-1 (group B, n = 50), or a combination of 75 micrograms levothyroxine and 200 micrograms iodine day-1 (group C, n = 55) for 8 months with follow-up examinations at 4 and 8 months as well as 4 months after cessation of treatment. Initially, thyroid volume, as determined by ultrasound, was not significantly different in the three groups. In all three groups, during treatment a significant and comparable mean decrease in goitre size was documented (-32.1% in group A, -37.3% in group B, -38.7% in group C). After cessation of treatment in group A mean thyroid volume again increased to near the baseline value (-12.0% compared to the initial investigation), while the therapeutic effect was sustained in group B (-32.5%). In group C, only a slight rebound effect was observed (-26.3% vs baseline volume). Total thyroxine (T4) increased sharply and significantly in group A from 7.8 +/- 1.9 to 10.9 +/- 2.8 micrograms dl-1 after 8 months (P less than 0.001), but only slightly, although significantly in group B (from 7.8 +/- 1.5 micrograms dl-1 to 8.9 +/- 1.6 micrograms dl-1; P less than 0.02).(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1988

[Description and evaluation of diagnostic measures in German-language clinical journals].

A literature study was performed in four German-language medical journals of 1985 and 1986 on the methodology of published diagnostic studies. A total of 93 papers was investigated. The results showed that fundamental requirements for the evaluation of diagnostic tests, such as blindness of judgement, were met only in 5% of the papers. In more than half of the publications the use of test parameters (sensitivity, specificity) was insufficient and the relationship between pretest and posttest probability was considered only in isolated cases. It is concluded that the methodologic criteria for the evaluation of diagnostic tests do not seem to be widely known and that a significant improvement is desirable.

Austria↗
PubMed1988

[Principles for evaluating simple, diagnostic tests].

The fundamental terms in the evaluation of diagnostic tests are described and the differences to corresponding test parameters in clinical chemistry are emphasized. The derivation of a two-by two contingency table is explained in detail and basic characteristics of diagnostic tests, i.e. sensitivity and specificity as well as their independence of the prevalence (in the sense of a-priori-probability) is pointed out. The importance of the so-called predictive values is shown graphically, also the problem of selecting a cut-off-level (discrimination value) for the evaluation of quantitative data. The various attempts to find a single value for the description of a diagnostic test are discussed and it is stressed that there is no principal necessity to use other terms than those mentioned above. Nevertheless it is possible to give a prevalence-independent measure which has some additional advantages in rating and comparing simple diagnostic tests.

Diagnostic Tests, Routine↗
PubMed1988

[Alcoholic ketoacidosis. An important differential diagnosis from diabetic ketoacidosis].

Ketoacidosis developed in two patients, a woman aged 36 and a man aged 55 years, 48 and 36 hours, respectively, after a bout of drinking alcohol to excess. Both were dehydrated with hyperventilation and signs of cachexia. Other findings were polydipsia, polyuria, loss of weight and (in the woman) abdominal pain. Biochemical tests revealed a marked metabolic acidosis (pH 7.00 and 7.09, respectively), base deficit of -25 and -20 mmol/l, hyperglycaemia (210 and 297 mg/dl) and hyperkalaemia (6.3 and 6.0 mmol/l). Treatment with insulin and fluids, as well as normalization of the electrolytes, brought about rapid regression of the metabolic disorder and restoration of the carbohydrate metabolism. Both patients were discharged without medication or dietary prescription, other than abstinence from alcohol.

Acidosis↗
PubMed1988

[Cold agglutinin disease].

Cold agglutinin disease is a normo- or macrocytic anemia due to antibodies, active under body temperature, mostly belonging to the immunoglobulin class M. Initially the agglutination of erythrocytes with acrocyanosis is reversible at body temperature. High antibody activity or long lasting period of coldness lead to intravascular or intrahepatic hemolysis, but high risk anemia is rare. Beside the idiopathic form, infection induced (especially infectious mononucleosis, cytomegalovirus, Mycoplasma pneumoniae, Klebsiella), and drug induced (especially quinidine, alpha methyldopa, penicillin, para-aminosalicylic acid, various analgetics, sulfonylurea), tumor associated (especially malignant lymphomas), and autoimmune disease associated (especially systemic lupus erythematosus) cold agglutinin anemias are discribed. "Cross reacting antigenity" to the hemolysing agent and the membrane of erythrocyte, exogenous induced changing of erythrocytic antigenity, and diversification concerning the production of antibodies are discussed as pathophysiological explanations.

Agglutinins↗
PubMed1988

[Cold agglutinin disease--initial description in erythroblastosis and polycythemia vera].

The cold agglutinin disease is a hemolytic anemia induced by antibodies. Beside other etiological factors the disease is associated with tumors. In this paper cold agglutinin disease combined with erythroblastosis and combined with polycythemia vera is presented at the first time. In one case malignant proliferation followed the appearance of cold agglutinin antibodies. Blood transfusion, plasmapheresis, corticosteroids and chlorambucil were not successful. In the other case antibodies were temporarily expressed after a long time of malignant proliferation. Blood transfusion and corticoids were sufficient. Production of antibodies as a kind of tumor defence is discussed as reason for hemolysis. "Cross reacting antigenity" between normal and malignant erythrocytes is postulated.

Aged↗
PubMed1988

Effect of voluntary intake of iodinated salt on prevalence of goitre in children.

The availability of iodinated salt containing 20 mg of iodine as iodate/kg salt consumed on a voluntary basis enabled us to investigate its effect on goitre prevalence and iodine excretion in urine in a longitudinal, prospective, randomized study over 4 years. With this salt, under the assumption of a consumption of 5 g salt per day and person, an additional intake of 100 micrograms of iodine can be achieved. The study was performed on initially 334 children (168 boys, 166 girls) at the age of 10 years living in an area of iodine deficiency. After 4 years, 286 children still participated in the study. Initially, goitre prevalence as assessed by palpation was found to be 30.5% (37.4% in girls and 23.8% in boys). Neck circumference was found to be significantly higher in children with goitre compared with those without (30.2 +/- 1.4 vs 29.4 +/- 1.4 cm; P less than 0.001). Iodine excretion in the urine was significantly lower in children with goitre compared with those without (40.4 +/- 16.7 micrograms/g creatinine vs 46.1 +/- 24.9 micrograms/g creatinine; x +/- SD; P less than 0.05). The children were randomly assigned to two different groups: group A (N = 146) was asked to use iodinated salt, group B (N = 188) non-iodinated salt. Over the 4 years, a continuous increase in iodine excretion in urine could be demonstrated in group A.(ABSTRACT TRUNCATED AT 250 WORDS)

Child↗
PubMed1987

Iodine vs thyroxine. A changing concept of therapy in endemic goiter?

The hypothesis that goitrogenesis in iodine deficiency can be attributed to the stimulatory effect of thyrotropin (TSH) on the thyroid gland and has long been held to be valid. The task of this review is to describe the reasons why this concept is being challenged. In addition, we report on the autoregulation of the thyroid gland and on in vitro investigations dealing with TSH as a growth factor, which have yielded conflicting results. Finally, we summarize preliminary studies comparing the therapeutic effect of thyroxine and iodine on goiter size. In comparison to thyroxine, iodine application in doses of 300-500 micrograms/day may represent an equally effective way of treatment in areas of endemic goiter, especially in younger patients. In this age group, the risk of side-effects, e.g., iodine-induced thyrotoxicosis, should be low.

Diiodotyrosine↗
PubMed1987

Colorectal carcinoma and Haemoccult. A study of its value in mass screening using meta-analysis.

Meta-analysis has been performed on the world literature relating to Haemoccult screening for colorectal cancer. The analysis indicated a sensitivity of about 50%, specificity of about 97%, positive predictive value of 4.3% and negative predictive value of 99.85%. These figures assume a prevalence of colorectal cancer in the population of 0.3%. A model calculation using these figures together with some additional realistic assumptions suggests no reduction in mortality compared to an unscreened population. It is concluded that many questions about faecal occult blood screening remain and that uncontrolled mass population screening is not justified at this stage.

Adenoma↗
PubMed1987

Age-corrected empirical genetic risk estimates for first-degree relatives of IDDM patients.

The families of 554 type I (insulin-dependent) diabetics were genetically analyzed according to probands' sex and age at onset applying a modification of Strömgren's method of age correction. Lifetime recurrence risk of type I diabetes (risk up to age 80 yr) for first-degree relatives in three consecutive generations was calculated. The overall risk (+/- 1 SE) for siblings was 6.6 +/- 1.1% and for children was 4.9 +/- 1.7%. The similar risks among siblings and children argue against a simple autosomal recessive trait. The results do not permit a conclusion about a distinct mode of inheritance. Regardless of age at onset, offspring of male probands always had a higher risk than offspring of female probands. Among all probands, fathers were significantly more often affected with type I diabetes (about twice) than mothers (4.1 +/- 0.9 vs. 1.7 +/- 0.6%, respectively). The risk for further siblings of the proband was significantly increased in the presence of a type I diabetic parent (25.2 +/- 10.3 vs. 5.8 +/- 1.0% for remaining probands), indicating a nonrandom clustering type I diabetes in families. Younger age at onset (less than 25 yr) was not associated with an increased risk to siblings. Type II diabetes was not more frequent among parents and siblings of type I diabetics than in the general population. The calculated risk estimates are of practical value in genetic counseling and are important for genetic models concerning type I diabetes.

Adult↗