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Biomedical subjects

D Knorr

Publications and source records attributed to D Knorr.

At least 91 records · Page 5Linked to original sources
PubMed1980

[Thyroid carcinoma in children (author's transl)].

In about 50% the thyroid carcinoma in childhood presents regional lymphnode metastases as leading symptom. The "cold nodule" is the typical scintigrafic equivalent of thyroid cancer in infants. Papillary carcinoma is the predominating histologic type (80%) with a good prognosis. Radical removal of the thyroid lobe with the primary lesion and subtotal resection of the opposite lobe, combined with selective neck dissection if necessary seems to improve the results. Scintigrafic control postoperatively detects malignant remnant tissue for 131-iodine-treatment, finally TSH-suppressive hormone administration is followed. In our own cases the survical rate in 25 children was at least more than 90%.

Carcinoma, Papillary↗
PubMed1980

Antibodies against testosterone: valuable tools for the investigation of the hypothalamo-pituitary-gonadal system in the rabbit fetus.

16 female rabbits were actively immunized against testosterone (T). 9 of them conceived and gave birth to 89 neonates. In all neonatal plasma samples antibodies against T were detected. In the males the plasma T levels were elevated 1,000-fold. The testes of these animals were examined by means of morphometrical and biochemical methods. The results indicate increased stimulation of Leydig cells in fetuses exposed to antibodies against T, and suggest that even in the fetus a negative feedback is acting between testes and hypothalamo-pituitary system, which is interrupted by the antibodies which bind and inactivate T.

Animals↗
PubMed1980

Plasma levels of aldosterone, corticosterone, 11-deoxycorticosterone, progesterone, 17-hydroxyprogesterone, cortisol, and cortisone during infancy and childhood.

Plasma aldosterone (A), corticosterone (B), deoxycorticosterone (DOC), progesterone (P), 17-hydroxyprogesterone (17-OHP), cortisol (F), and cortisone (E) were measured simultaneously by specific radioimmunoassays in small plasma samples obtained from 174 normal infants and children between 2 hr and 15 yr of age. The significantly elevated neonatal mean levels (ng/ml) of 2.5 (A), 4.1 (DOC), 53.0 (P), and 6.6 (17-OHP) dropped significantly during infancy reaching prepubertal levels between 3 months and 3 yr of age, with a transient, significant DOC increase between 1--7 yr. The glucocorticoids F andB declined significantly from means of 68 and 4.4 to 11.4 and 0.28 ng/ml, respectively, during the first weeks of life, then increased significantly reaching adult levels between 1--3 yr of age. Mean E fell progressively from 74 ng/ml after birth to 10 ng/ml during 1--5 yr (P less than 0.0001), then slightly increased to adult levels. After age 7 yr, P and 17-OHP, in contrast to the other steroids, rose significantly in both boys and girls relative to pubertal development. The observed changes are thought to be due to (1) adaptation of the adrenal neocortex to extrauterine life after disruption of the fetoplacental unit, (2) a physiologic lack of corticosteroid binding globulin (CBG) during infancy due to maturation of hepatic CBG biosynthesis, (3) the functional immaturity of the infant kidney compensated by an increased activity of the renin-angiotensin-aldosterone system, and (4) gradually increasing gonadal secretion of progestins during puberty.

Adolescent↗
PubMed1980

17-ketosteroid reductase deficiency -- plasma steroids and incubation studies with testicular tissue.

The patient, diagnosed as a case of testicular feminisation in infancy, was examined at the age of 15 years because of severe symptoms of virilising puberty with poor breast development. Plasma steroid analyses revealed a 10-fold elevated androstenedione concentration (A: 1562 ng/100 ml). Testosterone (T: 266 ng/100 ml) was in the male pubertal range. Thus the A/T-ratio was far above normal. The oestrone/oestradiol ratio was also elevated (Oe1/Oe2: 10.2/2.2 ng/100 ml). A, T, Oe1 and Oe2 could not be suppressed by dexamethasone, but reacted promptly to fluoxymesterone (A: 781 ng/100 ml). hCG caused a further increase of the A/T-radio (2220/246 ng/100 ml); ACTH did not alter the A-concentration. These findings together with simular investigations after gonadectomy suggest that the failure to convert A to T and Oe1 to Oe2 is essentially located in the testes. In vitro incubations of testicular tissue showed reduced 17-ketosteroid reductase activity in tissue slices and in the subcellular fractions microsomes and cytosole. This form of male pseudohermaphroditism can easily be detected already in infancy, if steroid analyses and stimulation tests are performed. In case of female sex assignment patients should be submitted to early orchidectomy in order to avoid virilisation in puberty.

17-Hydroxysteroid Dehydrogenases↗
PubMed1980

Treatment of anorchia with oral testosterone undecanoate: pharmacodynamics and clinical effectiveness.

The pharmacodynamics of plasma testosterone (T) and androstenedione (A) levels were studied in ten hypogonadal boys after oral administration of testosterone undecanoate (TU). Plasma T and A levels were measured by specific radioimmunoassays. Six hours after a single dose of 120 mg TU, there was a significant increase (P < 0.005) in plasma T and A with a median T peak level of 940 ng/100 ml. Furthermore, twelve agonadal boys treated with a mean dose of 60 mg TU/day were examined over a period of 18-24 months. During this therapy, plasma T and A levels were significantly higher than before (P < 0.005), whereas plasma levels of LH and FSH did not decrease significantly. With the exception of one anorchic boy, all patients showed signs of sexual maturation, such as growth of pubic and axillary hair, and steady development of bone age during oral TU treatment.

Administration, Oral↗
PubMed1980

Precocious puberty in a boy with HcG-producing hepatoma. Case report.

This paper deals with a three-year-old male patient with sexual precocity due to a gonadotropin-producing hepatoma. Maximum levels of serum-gonadotropins were 340 muULH/ml, 430 muUHCG/ml, but only 1.4 muUFSH/ml. The level of plasma testosterone was 985 ng/dl, and of plasma delta 4-androstenedione 109 ng/dl. Gonadotropin in serum reacted like choriongonadotropin but unlike pituitary luteinizing hormone when compared in dilution tests by radioimmunoassay. Gonadotropin and androgen levels returned to normal after removal of the tumour. Histopathology showed a carcinomatous hepatoblastoma of the epithelial type with immunohistological evidence of beta-HCG production.

Carcinoma, Hepatocellular↗
PubMed1979

[Maldescensus testis, therapy and prognosis].

Since histologic changes are found in undescended testes after the second year of life, treatment is necessary. Often therapy with human choriongonadotrophin is successful, otherwise operative treamtnet is indicated. Infertility at a high rate is found in boys treated for maldescence of the testicles in later childhood. Therapy before the age of two years improves the prognosis.

Child↗
PubMed1979

Comparison of two tests for heterozygosity in congenital adrenal hyperplasia (CAH).

The increase of plasma cortisol (F), androstenedione (A), 17 alpha-hydroxy-progesterone (17-OH-P) and testosterone (T) was measured after iv administration of ACTH in heterozygotes for CAH and in controls under two different conditions: Test 1: ACTH stimulation was performed without any particular preparation. Test 2: 1.5 mg of dexamethasone (dex.) was given the evening before the ACTH stimulation. Plasma F, A, 17-OH-P and T were measured by specific radioimmunoassays (RIA). Following ACTH stimulation, the increase of 17-OH-P was significantly higher in CAH-heterozygotes than in controls in both tests (P less than 0.0005). Heterozygotes were characterized by a 17-OH-P increase after ACTH stimulation exceeding the + 2 SD limit of the 17-OH-P increase found in controls. The detection of female heterozygotes was considerably improved by the administration of dex. before testing (test 2). In males, however, a better identification of heterozygotes was obtained without previous administration of dex. (test 1). By these tests, 100% of female (test 2) and 79% of male (test 1) CAH heterozygotes could be correctly identified. There were no significant differences in the levels of F, A and T between heterozygotes and controls except for decreased T levels in test 1 (2P less than 0.01) in most male heterozygotes after ACTH stimulation.

Adrenal Cortex Function Tests↗
PubMed1979

Plasma testosterone in male puberty. II. hCG stimulation test in boys with hypospadia.

Plasma testosterone was determined by radioimmunoassay in 36 prepubertal boys with hypospadia prior to and 3 days after stimulation with 5000 IU of human chorionic gonadotrophin (hCG). As a control group, 30 boys of comparable age, predominantly with unilateral cryptorchidism, were studied. The increase in plasma testosterone levels after hCG was (median and range) 204 (83-393) ng/100 ml in the control group, whereas in the hypospadiac group a median increase of only 90 (33-272) ng/100 ml was found. The difference between the median testosterone levels after hCG stimulation in the two groups investigated is statistically highly significant (P less than 0.0001). After hCG stimulation, 13 out of the 36 boys with hypospadia did not reach the lowest stimulated testosterone level (87 ng/100 ml) found in the control group. It is concluded that a substantial portion of the aetiologically obscure cases of hypospadia are caused by an endocrine testicular insufficiency.

Child↗
PubMed1978

Longitudinal studies of plasma aldosterone, corticosterone, deoxycorticosterone, progesterone, 17-hydroxyprogesterone, cortisol, and cortisone determined simultaneously in mother and child at birth and during the early neonatal period. I. Spontaneous delivery.

In order to obtain the still lacking reference data of individual plasma steroids in the immediate postnatal period needed for the assessment of adrenocortical function in various neonatal maladaptation syndromes, aldosterone (A), corticosterone, deoxycorticosterone (DOC), progesterone (P), 17-hydroxyprogesterone (17-OHP), cortisol, and cortisone were simultaneously followed in the same human newborn in a single 250-500 microliters peripheral plasma sample obtained at constant times during the first week of life using a mechanized Sephadex LH-20 multicolumn chromatography and standardized RIAs. Mean concentrations in 12 spontaneously delivered full term newborns of either sex and in paired umbilical (UV) and peripheral maternal (MV) venous plasma are given in the table. Besides significant maternoumbilical gradients in each steroid, DOC, P, 17-OHP, and cortisone, originating predominantly from the fetoplacental unit, disappear rapidly with steadily increasing half-lives. A, corticosterone, and cortisol, however, remain elevated in comparison with later infancy, with the exception of a marked "glucocorticoid dip" in cortisol and corticosterone levels between 2 and 12 h after birth.

17-alpha-Hydroxyprogesterone↗
PubMed1978

[Normal values of LH and FSH excretion in the urine of children and juveniles by the luteonosticon and FSH-nosticon test (author's transl)].

The normal values of the LH and FSH excretion in 12-h-overnight-urine-samples were measured by the commercial technique for the estimation of LH (Luteonosticon) and FSH (FSH-nosticon). These methods were used to determine the hormone excretion of these hormones in healthy individuals, 94 boys (0-18 years) and 48 girls (0-16 years). Only one urine sample was assayed for each subject. There was a highly significant correlation between the plasma LH and FSH concentrations and the urinary content of the same hormones: for FSH, r = 0.8 and for LH, r = 0.6. The plasma concentrations were measured radioimmunologically immediately before the period of urine collection. Five girls with Turner's syndrome aged 12 to 17 years showed LH values (5.0-14.5 IU/12 h) at the upper end of or slightly above the normal range and pathologically high values (22.2-43.5 IU/12 h) for FSH.

Adolescent↗
PubMed1977

Adult height of patients treated in childhood for undescended testes.

101 patients successfully treated for undescended testes with human chorionic gonadotrophin (HCG) or with HCG followed by surgery reached normal adult heights. Deviations from normal growth in individual patients did not appear to be related either to their earlier undescended testes or to the successful therapy, but rather to their genetic background. Therefore, apart from patients with chromosomal abnormalities and other primary causes for maldescent of the testes, boys with undescended testes show a normal distribution for height and do not represent a different population with regard to growth.

Adolescent↗