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Biomedical subjects

K Horn

Publications and source records attributed to K Horn.

At least 145 records · Page 8Linked to original sources

Effects of obesity, total fasting and re-alimentation on L-thyroxine (T4), 3,5,3'-L-triiodothyronine (T3), 3,3',5'-L-triiodothyronine (rT3), thyroxine binding globulin (TBG), cortisol, thyrotrophin, cortisol binding globulin (CBG), transferrin, alpha 2-haptoglobin and complement C'3 in serum.

UNLABELLED: The effects of total fasting for 31 +/- 10 days followed by re-alimentation with an 800 calorie diet on thyroid function, i.e. T4,T3,rT3,RT3U (resin T3 uptake), and TSH, and on TBG levels in serum were studied sequentially in obese hospitalized patients (N=18). Additionally, cortisol, growth hormone, prolactin, parathyrin and free fatty acids were followed as hormonal and metabolic parameters, respectively. Further, CBG, transferrin, alpha 2-haptoglobin and complement C'3 were measured as representatives of other serum proteins. Results before fasting: T4, T3, TBG, cortisol, CBG, alpha 2-haptoglobin and complement C'3 of the obese patients were elevated when compared with healthy normal weight controls, whereas rT3, T4/TBG ratio, T3/TBG ratio, TSH, coritsol/cbg ratio, growth hormone, prolactin, parathyrin and transferrin of the obese group were normal. RT3U and fT4 index were decreased in the obese patients. Results during fasting: Significant decreases were observed during fasting for the following parameters -- T3, TBG, T3/TBG ratio, transferrin, alpha 2-haptoglobin complement C'3. rT3, T4/TBG ratio, RT3U, fT4 index and FFA increased. T4, tsh response to TRH stimulation, cortisol, CBG, cortisol/cbg ratio, parathyrin, growth hormone and prolactin did not change. Results during re-alimentation: T3, TBG, T3/TBG ratio, TSH response to TRH, transferrin, alpha 2-haptoglobin and complement C'3 increased. Conversely, fT3, RT3U, FFA, cortisol and cortisol/cbg ratio decreased whereas the other parameters did not change. CONCLUSIONS: 1) There is no evidence for primary hypothyroidism in obese patients during prolonged fasting and re-alimentation. 2) The rapid decrease of T3 and increase of RT3U after initiation of fasting are not fully explained by the observed slower decreases in TBG. 3) The alterations of T3, rT3 and RT3U resemble in their kinetics the changes in FFA levels. 4) Fasting reduced the levels of only certain serum proteins, interestingly TBG, transferrin, alpha 2-haptoglobin and complement C'3, all of which, except transferrin, are elevated in obesity. 5) The magnitude of the observed decreases does not suggest any clinically relevant deficiencies in serum proteins. 6) Re-alimentation reverses rapidly all observed changes.

Adult↗

Isolation, characterization and radioimmunoassay of corticosteroid-binding globulin (CBG) in human serum -- clinical significance and comparison to thyroxine-binding globulin (TBG).

Isolation of the corticosteroid-binding globulin CBG was achieved by 5 chromatographical steps on cortisol Sepharose, QAE-Sephadex A-50, Con A-Sepharose and hydroxylapatite. The purity of the isolated CBG was demonstrated in polyacrylamide gel electrophoresis, SDS electrophoresis, immunodiffusion and ultracentrifugation. Microheterogeneity was shown in isoelectric focusing by 5 bands in the pH range of 3.7--4.2, which could be reduced to one major band after neuraminidase treatment. The equimolar binding of cortisol to CBG was demonstrated by binding studies. The association constant for cortisol was 2.8 x 10(8)M-1, for progesterone 1.7 x 10(6)M-1. From analytical ultracentrifugation, the molecular weight was calculated on 50 700; the sedimentation coefficient was 3.6 S, the partial specific volume 0.690 ml/g, the Stokes radius 38 A and the frictional coefficient ratio 1.5. A specific radioimmunoassay for CBG was established using the purified CBG for immunization, radioiodination and for calibration standards. The normal range of CBG levels in human serum was 2.4--4.4 mg/100 ml (mean +/- 2 SD). Studies were performed to compare the levels of CBG and thyroxine-binding globulin (TBG). No sex differences but a significant biphasic age dependence were observed for both proteins. In pregnancy and under oestrogen treatment of women and men, CBG was demonstrated to be the more distinct indicator of oestrogenic activity as compared with TBG, whereas the sensitivity of TBG was more pronounced to supposedly antioestrogenic substances like Danazol, and in severe disease. No coincidence of genetic CBG and TBG deficiencies have been found so far.

Amino Acids↗

[Catamnestic study about the fertility of the man (author's transl)].

Collective investigations of fertility in childless married couples were carried out in 9 andrological health centres of the GDR. Analysis of 1937 spermatograms in comparison to fertility after 1 to 2 years shows: (1) Fertility decreases significantly at sperm density nearly 10 million per ml. (2) Motility below 60 per cent caused reduced fertility. Normal motility is more important than normal density of spermatozoa. (3) Fructose level doesn't correlate to motility or fertility of man.

Cell Count↗

[Successful treatment of thyroid storm by continuous plasmapheresis with a blood-cell separator (author's transl)].

Continuous plasmapheresis with the IBM blood cell separator showed to be a successful therapy in a 26 year old patient with thyroid storm. The patient regained consciousness already during plasmapheresis whereby 5 liters of plasma were exchanged within 3.5 h. Although 633 mug thyroxine (T4) and 13.6 mug triiodothyronine (T3) were removed with the 51 plasma, no fall occurred in total serum T4 and T3 levels, probably due to the rapid reflux of thyroid hormones from the tissue into the intravascular space. Though total T4 and T3 did not change, there was a significant fall in free thyroid hormone levels documented by reduction of T3-uptake test and particularily of urine T4 and T3 excretion. These findings show that the elevation of thyroid hormone binding sites with donor plasma is even more important than the removal of thyroid hormones.

Adult↗