The kinetics of relaxin oxidation by hydrogen peroxide

In this study, hydrogen peroxide was used to study the oxidation of rhRlx under various conditions. Oxidation of rhRlx occurred at both of the two methionines on the B chain, Met B(4) and Met B(25), as expected from the three-dimensional structure of the molecule, which shows that these two residues are located on the surface of the molecule and exposed to solvent. The reaction produced three different oxidized forms of rhRlx containing either Met B(4) sulfoxide, Met B(25) sulfoxide, or both residues oxidized. The corresponding sulfone was not formed under these conditions. The oxidation at the two methionines proceeded independently from each other but Met B(25) was oxidized at a significantly faster rate than Met B(4). The fact that the rate of oxidation at Met B(25) was identical to the rate of oxidation of free methionine and that of two model peptides mimicking the residues around Met B(4) and Met B(25) suggests that the lower reactivity at Met B(4) was due to steric hindrance, and at least in this case, neighboring groups do not influence the oxidation kinetics of methionine residues. The reaction was independent of pH, ionic strength, and buffer concentration in the range studied. The enthalpy of activation for the reaction was approximately 10-14 kcal mol-1, with an entropy of activation of the order of -30 cal K-1 mol-1. These data are consistent with previously published mechanisms for organic sulfide oxidation by alkyl hydroperoxides.

[Experimental and epidemiological studies on the interrelationship of thiocyanate and thyroid function]

The testing of a SCN- dose (32 mg NaSCN/kg oral 21 d long) which is about 100 fold above the alimentary SCN(-)-uptake on guinea pig has shown neither histologic/morphometrical nor clinical clue to thyrostatic effect. In 6 regions of the GDR (1,349 persons) has not been secured epidemiologically any relationship between SCN- serum level as well as SCN- urine level and goiter. The partly in the tendency low increase of SCN- level by patients with bland goiter was always under the levels of smokers without goiter, exceeded indeed the threshold of significance in the area of Werdau. In the industrial agglomeration areas the I(-)-SCN(-)-quotient at the most unfavourable cases ran to 3.5 (Halle, smoker, struma), was consequently close to the critical level of the goiter risk.

[Bone alkaline phosphatase as an activity parameter of acromegaly]

Serum levels of growth hormone (GH: arithmetic mean of three measurements eight hours apart), somatomedin C (SmC), alkaline phosphatase activity and the bone isoenzyme of alkaline phosphatase (as the liver/bone isoenzyme ratio) were measured in 26 patients with acromegaly (11 men and 15 women; mean age 45.5 [24-66] years), 18 in the active and eight in the nonactive phase of the disease. Activity was characterized by a raised (660 [330-1149] ng/ml), inactivity by a normal (186 [40-300] ng/ml) SmC concentration. All 18 patients with active acromegaly had an abnormally low liver/bone isoenzyme ratio (mean of 0.66 [0.01-1.28]). In seven of the eight patients with inactive acromegaly it was within normal limits. Thus measurement of bone alkaline phosphatase, which is significantly cheaper than that of SmC, is suitable for assessing activity.

Interdisciplinary aspects of iodine prophylaxis in German Democratic Republic

Endemic goiter still occurs in several European countries. Alimentary iodine deficiency could be proved as the main cause of endemic prevalence. Extensive epidemiologic surveys showed the great medical and economical impact of this matter for the GDR. Over 200 million Marks might be spent for diagnosis and treatment of thyroid patients per year. Also in the field of veterinary medicine and animal production iodine deficiency plays an important role. Under the conditions of iodine deficiency the fodder containing nitrate and glucosinolates (e.g. bruised rape extraction) results in additional goitrogenic effects (so-called indirect or relative iodine deficiency). Due to iodine deficiency disorders considerable losses of yields in cattle, pigs and sheep occurred. The content of iodine in animal products used for human nutrition was subsequently low. Considering the ecological implication of these problems an Interdisciplinary Iodine Commission within the Society for Endocrinology and Diseases of Metabolism of the GDR was established. Together with the governement authorities it worked out corresponding recommendations for the prophylaxis and control of its efficiency. In 1986 the iodination of most of the packed salt (32 mg KIO3/kg = = 19 mg I/kg) and the administration of iodinated mineral mixtures for the animal production were started for pigs in the whole territory of GDR and for cattle in the southern counties of the GDR only. These activities have been accompanied by information of TV as well as in the newspapers and medical journals. Thus, an improved supply of iodine to the population through iodinated table salt and animal products can be taken into account. The efficiency of these prophylactic measures is controlled interdisciplinarily.(ABSTRACT TRUNCATED AT 250 WORDS)

[TSH receptor antibody determination using the TSH radioreceptor antibody assay in clinical practice]

We tested the clinical valency of the TSH-receptor antibody (TBIAb) determination (TRAK assay, Fa. Henning) for the differential diagnostics of various diseases of the thyroid gland (n = 259), particularly of the hyperthyroidism. In 110 out of 114 basedowians TBAIAb could be proved (sensitivity 96%). The specifity to healthy persons (n = 20) was 100%, to the disseminated autonomy (n = 61) 92%. In 43 bland strumas and 22 cases of primary hypothyroidisms no circulating TBIAb were found. Of 40 cases of Basedow's hyperthyroidism the TBIAb titres were pursued during a 12-month methimazol therapy. In these cases was shown that negative antibody titres at the end of the treatment were connected with an essentially lower rate of early relapses than positive ones. Moreover, a highly dosed application of methimazol revealed a more favourable tendency than a low dosed one. From this we conclude that the TBIAb measurement with a commercial kit is a sensitive, sufficiently specific and practicable method for the differential diagnostics of hyperthyroidism and that to a certain degree it allows conclusions on the course of Basedow's disease after thyrostatic long-term therapy.

N-acetylator phenotypes in hyperthyroidism

Acetylator phenotypes were determined with sulfamethazine in 114 healthy volunteers, 87 patients with immunogenic hyperthyroidism (Graves' disease) and 38 patients with disseminated thyroid autonomies. About 90% of the patients were females. No significant differences of acetylator phenotypes were observed between female volunteers and hyperthyreotic patients younger than 50 years. The proportion of slow acetylators was higher in older patients. Early and late relapses did not depend on acetylator status.

[Therapy of hyperthyroidism]

The symptoms called hyperthyroidosis are caused by a thyroid hormone intoxication, which may have various causes. More than 95% of the hyperthyroidosis are caused by an autoimmune thyropathy (Basedow's disease) or autonomy (autonomous adenoma, disseminated autonomy). Other causes are rare. The therapy has 2 aims: the normalisation of the supply of the thyroid hormone and the removal or influence of the cause. Thus apart from an exact functional diagnostics the etiopathogenetic coordination must be done which has an essential influence on the differential-therapeutic decision. Beside the general therapeutic measures the thyrostatic long-term therapy, the subtotal thyroid resection and the radioiodine therapy are at our disposal. Diagnosis, performance, advantages and disadvantages are demonstrated.

[Development and effectiveness of struma prevention in East Germany]

For the control of iodine deficiency disorders in man and animal since 1985/1986 measures have been introduced which were interdisciplinary attuned: 84% of the paketed salt are iodized (32 mg KIO3/kg) and iodized mixtures of mineral substances are used in the animal production of agricultural useful animals. The effectiveness of the iodine prevention becomes visible by an increase of the renal iodine excretion, regression of the frequency of connatal goitre and iodine deficiency disorders in the animal production. Increased manifestations of cases of hyperthyroidism as sequelae are of transient importance.

[Status of goiter prevention in East Germany from an interdisciplinary viewpoint]

The endemic goiter occurs still in many countries of Europe. Alimentary iodine deficiency could be proved as essential cause of the increased prevalence. Comprehensive epidemiological investigations refer to the medical importance of this appearance for the GDR. 200 million marks might have to be spent annually for diagnostics and therapy. Also in the production of animals sequelae of iodine deficiency play a great part. Nitrate containing and glucosinolate containing feeding stuffs (e. g. rape extraction groats) here under the conditions of the iodine deficiency additionally develop goitrogenous effects (so-called indirect or relative iodine deficiency), which lead to decrease in vitality and clinical symptoms in the agricultural useful animals cattle, pig and sheep. The iodine content of animal products was frequently low. In view of the ecological connection of these problems an interdisciplinary iodine commission was founded which in accordance with the responsible state organs elaborates adequate recommendations for the prophylaxis and control of efficiency. From 1986 was begun with the iodisation of the largest part of packet salt (32 mg KJO3/kg) und the delivery of iodized mineral mixtures for the production of animals. Thus is to be reckoned with an improved direct supply of iodine for the population by iodized table salt or an indirect one over animal product. The iodisation of the entire common salt with modified iodine concentration is striven for. Measures for the control of efficiency are introduced.

[Prolactinoma in the male]

In a retrospective study the medical records of 13 male patients with macroprolactinomas were evaluated concerning anamnestic data, clinical, endocrinological and localisation-diagnostic findings as well as therapeutic measures. The main symptoms were disturbances of vision and impaired potency and impaired libido, respectively. The ophthalmological complaints nearly exclusively caused the patients to see the doctor. Clinically the signs of hypogonadism were found. The diagnosis was ascertained by increased serum prolactin levels, ophthalmological findings, X-ray of the sella, cranial computed tomography as well as angiography of the carotid. The operative treatment did not show any normalization of the serum prolactin levels. The rate of recidivations after exclusive operative treatment was high. An additional medicamentous therapy with dopamine agonists is nearly always necessary after operation. Whether or not bromocriptine shall be used as primary therapy, must be decided on in the individual case.

Thyroid status during pregnancy and post partum in regions of iodine deficiency and endemic goiter

During pregnancy the thyroid is subjected to increased demands which is associated with a tendency to endogenous iodine deficiency. Under the conditions of insufficient iodine supply in the GDR the pathophysiological changes result in: 1. prevalence of goiter in about 60% of pregnant women; 2. enlargement of the extent of neck in more than 50% of all pregnant women examined only returning to the prepregnant status in 25%-40%; 3. prevalence of goiter in newborn with 5%; 12.8% of 1948 stilborn had macroscopically an enlarged thyroid gland, the highest weight being 45 g. More than 53% of the stilborn examined by autopsy had a thyroid weight of over 3 g; 4. in contrast to the regions with sufficient iodine supply renal iodine excretion was steadily decreasing during pregnancy and post partum, changing the iodine deficiency from grade II to grade III; 5. low iodine excretion in newborn: 1.3 +/- 0.2 microgram I/day in goitrous (1.2 +/- 0.2 nmol I/mmol creatinine) 2.2 +/- 0.4 micrograms I/day in non-goitrous (2.0 +/- 0.4 nmol I/mmol creatinine); 6. according to ETR more than 50% of the pregnant examined showed a hypothyroid tendency. The pathophysiological changes during pregnancy caused by insufficient iodine supply can be met efficiently by careful thyroid hormone treatment or by the administration of 150 micrograms I daily. A mandatory iodine salt prophylaxis is demanded.

[Effect of thyroid hormones on noradrenaline-stimulated lipolysis in obesity]

11 extremely adipose patients were over 4 days loaded with a noradrenalin infusion of 0.1 microgram/kg body weight/minute over 60 minutes before and after a daily application of 200 micrograms tri-iodothyronine. The determination of the free fatty acids and of glycerin resulted in a significant elevation basally as well as after stimulation with noradrenalin. Thus the lipolytic influence of the thyroid hormones is confirmed under in-vivo-conditions. The possible mechanisms of lipolysis in the fatty tissue are discussed on the basis of literature.

[Intestinal flora under conditions of stress]

In healthy probands influenced by endocrinic stress (application of ACTH, growth hormone, and triiodothyronine) the microflora of the content of the duodenum and of the feces is examined. After three weeks, only, rising numbers of bacteria could be detected in the duodenal content. The number of the aerobic bacteria, mainly of the coliforms in the feces, decreased whereas the number of the anaerobic germs increased. This stress model seems to be suitable for such researches.

[Maternal and infant thyroid gland during pregnancy and in the postpartum period]

A survey is given of the clinically relevant changes in the thyroid hormone balance of the maternal organism. The total concentrations of thyroid hormone may on account of the increased carrier protein level be incorrectly interpreted in the sense of a hyperthyroidism. The latent hormone binding capacity, however, may by mistake indicate a hypothyroidism. For the determination of the functional position, therefore, a statement about the free hormone fraction is necessary. The TRH-test is evident in pregnancy. Beginning with the 12th week of pregnancy the fetal thyroid gland produces thyroid hormones, from the 16th to the 20th week of pregnancy the fetus is autonomous; and the pituitary gland-thyroid gland-axis is able to function nearly from the 20th week of pregnancy. The consequences resulting from this for the therapy of a disease of the thyroid gland of the mother are explained. Due to a massive TSH-flow with the birth typical changes of the hormone levels develop which may be used for the early recognition of the congenital hypothyroidism (TSH-screening). Possibilities of the diagnosis of the prenatal function of the thyroid gland as well as of the therapy of hypothyroidism are discussed.

[The behavior of the thyrotropin-releasing hormone test in fasting with and without triiodothyronine administration]

It is reported on the performance of the 400 microgram TRH/TSH test in adipose persons in the course of a zero diet and on the effects of an application of 50 micrograms tri-iodothyronine during 7 days on the TRH/TSH test on the same conditions. During total fasting the basic and TRH-stimulating TSH-level shows a slight tendency of decrease, but scarcely significant changes. After application of 50 micrograms tri-iodothyronine an unequivocal suppression of the TSH-concentration in the serum is to be recognized. By these results and with the help of literary data by means of the most sensitive test of the diagnostics of hypothyroidism a general hypofunction of the pancreas could be excluded, as it was supposed in the low T3 syndrome. But tri-iodothyronine deficiency in some tissues is still discussed at present.

[Results of thyroid hormone therapy in bland struma]

2,191 patients with bland struma were treated with tri-iodothyronine and a mixed preparation (thyreotom) for at least 2 years. Several clinical criteria were used for judgement. A good result could be obtained in 78.3 to 51.2% depending on the size of the struma (I-III). While in diffuse strumata good results were obtained in 87.8 to 69.0%, in nodular goitres we were successful only in 52.0-32.9%. The therapy may be successful at every age. Since with growing age the nodular goitres prevail, the chances of success become smaller. For the same reason there is a close correlation between age of the goitre and the therapeutic effect. The rate of success continuously decreases with growing age of the goitre. From this results that the therapy in goitre must begin early, before nodular and regressive changes, respectively, render the treatment difficult or render an acceptable result difficult.

[Alkaline phosphatase isoenzymes and hyperthyroidism]

We determined the serum total alkaline phosphatase as well as the alkaline phosphatase isoenzyme pattern in untreated and treated hyperthyreoses in the condition of euthyreosis and compared them with those of a healthy control group. The isoenzyme patterns, expressed as L/K quotient, ranged between 1.3 and 2.5 in the normal group and between 0.3 and 1.3 in the group with hyperthyreosis. The increase of the total alkaline phosphatase in hyperthyreosis was nearly exclusively conditioned by the increase of the activity of the osseous isoenzyme. The latter was increased already also then, when the total alkaline phosphatase had not transgressed the upper border of the normal. Depending on the functional condition of the thyroid gland the liver isoenzyme did not show any significant changes. In the course up to one year under thyrostatic therapy the increased activity of the osseous alkaline phosphatase decreased into the normal region as an expression of the very slowly repairing hyperthyreosis-conditioned disturbances of the osseous metabolism. An increase of the activity of the total alkaline phosphatase or of the osseous isoenzyme in the initial phase of a thyreostatic therapy of the sequel of an increase of the reactive activity of osteoblasts and must not lead to diagnostic and therapeutic uncertainties. By reason of the high sensitivity of the L/K quotient in hyperthyreoses (L/K at 95.5 % below 1.3) with a simultaneously high specifity of 89.5% the alkaline osseous phosphatase is to be discussed by all means as a helpful parameter of the peripheral function of the thyroid gland.

[Enlargement of the sella in primary hypothyroidism]

Length of the sella, depth of the sella and surface of the sella profile of 37 primary hypothyroids were compared with a normal group. All the three parameters were significantly different, though situated in the normal area. The results are discussed on the basis of literature. The reactive formation of hypophyseal tumours at adult age in primary myxoedema is relatively rare. However, in every enlargement of the sella also a primary hypothyreosis should be regraded differential-diagnostically. A therapeutic experiment with thyroid hormones should always be made.

[Problems of treatment with thyroid hormones. Thyroxin monotherapy or a T3/T4 combination preparation?]

At the instance of T3- and T4-measurements of the daily profile in the serum after the application of triiodothyronine and the usual T3/T4-combination preparations is referred to the unphysiologically high T3-peaks 2 to 4 hours after the application depending on the proportion of triiodothyronine. The three distributed all over the day doses of e.g. thyreotom do not sufficiently smooth such undulations. The lacking triiodothyronine serum peaks after application of pure thyroxin as a bolus confirm the demand of a thyroxin monotherapy. Nevertheless, for answering the question of the "physiologic thyroid hormone therapy" some problems remain open which are discussed. Taking into consideration these facts (particularly conversation and extrathyroid influence of the thyroid hormone metabolism) a combination of T3 to T4 in the ratio 1:10 is recommended.

[The lactate-pyruvate quotient in the framework of modern thyroid diagnosis]

In literature a big number of central and peripheral parameters for the diagnosis and control of therapeutical measures in diseases of human thyroid gland is described. That means, that none of the methods used has a sufficient weight. The enzymatic estimation of pyruvate and lactate reflect the peripheral effect of the hormones of thyroid gland. The pyruvate and lactate levels differ in the several groups of patients with euthyreosis, hypothyreosis, hyperthyreosis and euthyreotic goitre. Between these all groups the lactate/pyruvate ratio showed highly significant differences. The comparison of the lactate/pyruvate ratio and the T3-values showed highly significant correlation between both parameters. This good conformity is underlined by the behaviour of the parameters in courses of therapy, with additional support by farther functional tests--ETR-, T3- and T4-test. Our results confirmed the suggestion, also in agreement with literature, that the lactate/pyruvate ratio represent a possible enrichment in the laboratory programme for diagnosis and control of therapy in patients with thyroid diseases.

[Gynecomastia]

Gynaecomasty is no disease sui generis, but a symptom which may underlie different causes. Steroidal substances, above all oestrogens play a dominating role in these cases. Diagnostic and therapeutic measures must comply with the known causal factors. The gynaecomasty during puberty exhibits a high spontaneous retrogression rate. Only seldom an operative correction becomes necessary.

[Possibilities of ultrasonic diagnosis of thyroid and gastrointestinal diseases]

Issuing from the physical principles of the ultrasound technique and the explanation of the different investigation methods, the possibilities of the ultrasonic diagnosis are demonstrated on own results in 1,166 cases of struma nodosa and 154 palpatorically and radiologically, respectively, localised enlargements of the organs or demands of space in the abdominal region. The establishment of 46 cysts in 357 scintigraphically warm nodes of the thyroid gland allows the conclusion that a relatively high percentage of the warm nodes contains solid cold regions. In several cases the ultrasonic diagnosis makes a clear diagnosis, in other cases it is an important supplementation to the other diagnostic possibilities. The A-picture-apparatuses produced in the GDR are suitable for the differential diagnosis of palpatorically or radiologically localised enlargements of the organs or space demands. In diffuse diseases of the organs and for the search of disturbances in extended regions B-picture-apparatuses with improved resolving power are necessary.

[Behavior of the erythrocyte glucose-6-phosphate dehydrogenase in patients with functional thyroid disorders and in hyperthyroxinemic rats]

This paper deals with the activity of glucose-6-phosphate dehydrogenase in patients with hyper- and hypothyroidism as well as in hyperthyroxinaemic rats. The activity of glucose-6-phosphate dehydrogenase is enhanced in red blood cells of hyperthyreotic patients and hyperthyroxinaemic animals. The activity will be decreased to normal range in patients by administration of antithyreotic drugs, such as thiamazole. Patients with hypothyroidism exhibit decreased enzymatic activity. It is suggested that thyroid hormones stimulate the HMP-shunt in red blood cells as a defence mechanism against additional oxidative stress.

[The behavior of free fatty acids and free glycerin in functional thyroid gland disorders]

It is reported on the behaviour of the fasting serum levels of the free fatty acids and the free glycerol in patients with hyper- and hypothyroidism. The two parameters were significantly increased in hyperfunction of the thyroid gland, whereas a decrease was found in hypofunction. The possible causes are discussed with the help of literature.

[Thyroid gland function in obesity]

It is reported on in vitro tests of the thyroid gland in 7 males with normal weight and 9 adipose ones. No clear difference was found in the two groups. The TSH level, too, after TRH stimulation is not significantly different so that a latent primary hypothyroidism cannot be ascertained.

[Therapy of thyroid diseases]

A survey is given on the therapy of hyperthyroidism, hypothyroidism and the bland struma including the thyrogenic crises. Indications and contraindications of the therapeutic measures available are described. During the therapy of hyperthyroidism the suppression test for the control of the course is recommended. Furthermore it is shown that the thyroxine is more favourable for the long-term treatment than triiodine thyronine or the combination preparations offered at present. But the rules described for the treatment of diseases of the thyroid gland must always be adapted to the individual case.

[Nephrotic syndrome after treatment with penicillamine in Wilson's disease]

In a 33-year-old man with Wilson's disease a nephrotic syndrome appeared as a severe complication under penicillamine therapy. Under strong observation and exact controls of protein in the urine, leucocytes, differential blood picture and thrombocytes after interruption of the medication and retrogression of the side-effects a retarding new stabilisation of penicillamine can take place. Other side-effects of penicillamine observed as well as control measures under a long-term treatment with penicillamine are briefly discussed.

[Behavior of lactate and pyruvate as well as lactate/pyruvate quotient in blood in human thyroid gland disorders]

The pyruvate and lactate levels in blood of patients with thyroid diseases were investigated and also the lactate/pyruvate ratio. The levels of pyruvate were significantly elevated in hyperthyreotic patients in comparison with the euthyreotic control group; in hypothyreotic patients the levels were lowered. Only in hypothyreotic patients the lactate level was slightly increased. In all the three groups the lactate/pyruvate ratio showed highly significant differences, in hyperthyreosis decreased, in hypothyreosis increased in comparison with normal subjects. In patients suffering from hyperthyreosis as well as in cases with euthyreotic goitre we found similar pyruvate levels and lactate/pyruvate ratios as in the hyperthyreotic cases. It seems likely to be an inexpected effect of the treatment with pure triiodothyronine or triiodothyronine/thyroxine in combination.

Bioptical liver changes in florid hyperthyreosis

In 42 non-selected patients with a clinically, biochemically and radio-iodine proved hyperthyreosis, previously untreated, a Menghini liver needle biopsy was carried out for evaluation of histomorphologic changes of the liver. As a result, "reactive hepatitis" was found in 8 patients. Moreover, in about 40% of the cases vacuolated nuclei of hepatocytes were observed in such a great number, as has been found so far only in diabetes mellitus. The microscopic findings, however, are in general unspecific and without particular pathologic value, showing no positive correlation to the biochemical findings.