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Biomedical subjects

C Eil

Publications and source records attributed to C Eil.

At least 37 records · Page 2Linked to original sources
PubMed1985

The effects of triacetyloleandomycin and oleandomycin phosphate on the glucocorticoid receptor in cultured skin fibroblasts.

Triacetyloleandomycin (TAO) has been described as a "steroid-sparing" drug in that poorly controlled asthmatic patients can be stabilized or improved with the addition of TAO despite decreasing dosages of steroids, specifically methylprednisolone (MP). It is not clear whether the beneficial effects of TAO are due to decreased MP clearance or are due to enhanced glucocorticoid effect peripherally. We tested the latter possibility by studying the interaction of TAO and oleandomycin phosphate (OLEO), the active metabolite of TAO in vivo, with glucocorticoid receptors in dispersed, intact cultured human skin fibroblasts. With the use of cells incubated with [3H]dexamethasone at 22 degrees C, we examined the competitive binding properties of TAO and OLEO (at varying concentrations) with and without MP as compared with several other steroids and MP alone. We also studied the effects on cellular glucocorticoid receptor number and affinity when TAO at a concentration of 4 X 10(-5) alone, at 10(-5) M in combination with a receptor saturating concentration of MP (5 X 10(-8) M), with MP alone, or with OLEO (10(-5) M) combined with MP was added to fibroblasts in the growth phase 1 wk before assay. TAO and OLEO did not compete for the binding of [3H]dexamethasone to the fibroblast glucocorticoid receptor, nor did they alter the binding properties of MP. With prolonged cellular exposure, TAO alone did not alter the number of glucocorticoid receptors (per cell) or their affinity for [3H]dexamethasone. Interestingly, prolonged exposure to saturating concentrations of MP alone decreased glucocorticoid receptor density; this effect was not altered by the presence of TAO or OLEO.(ABSTRACT TRUNCATED AT 250 WORDS)

Cell Count↗
PubMed1985

Androgen receptor characteristics in skin fibroblasts from hirsute women.

Hormonal measurements in some women with hirsutism often reveal little or no elevation in androgen levels to explain the disorder. Thus, it has been postulated that increased sensitivity of the hair follicle to androgen may contribute to the development of hirsutism in such patients. We, therefore, sought androgen receptor abnormalities in skin fibroblasts cultured from 10 hirsute women (ages 17-43) and normal or mildly elevated plasma testosterone levels (28-82 ng/dl). Androgen receptor content (Ro) and binding affinity (Kd) in cultured pubic skin fibroblasts were measured using a dispersed, whole cell assay. Ten such cell lines from these women were compared with 19 pubic skin cell lines from 9 normal volunteers (6 males and 3 females) and from 10 other subjects (males with gynecomastia or hypospadias). There was no statistically significant difference in the mean androgen receptor content (11,600 +/- 2700 (SE) sites/cell fibroblasts vs 7900 +/- 700 sites/cell or binding affinity (2.0 +/- 0.3 (SE) X 10(-9) M vs 1.5 +/- 0.2 X 10(-9) M, respectively) between the patients' fibroblasts and those of the controls. We conclude that hirsutism cannot be explained by abnormalities in fibroblast androgen receptor number or affinity. These observations do not exclude the possibility that other mechanisms might lead to increased peripheral androgen sensitivity in such patients.

Adolescent↗
PubMed1985

Vitamin D-dependent rickets type II. Defective induction of 25-hydroxyvitamin D3-24-hydroxylase by 1,25-dihydroxyvitamin D3 in cultured skin fibroblasts.

UNLABELLED: 1,25(OH)2D3 induces 25(OH)D3-24-hydroxylase (24-OHase) in cultured skin fibroblasts from normal subjects. We evaluated 24-OHase induction by 1,25(OH)2D3 in skin fibroblasts from 10 normal subjects and from four unrelated patients with hereditary resistance to 1,25(OH)2D or vitamin D-dependent rickets type II (DD II). Fibroblasts were preincubated with varying concentrations of 1,25(OH)2D3 for 15 h and were then incubated with 0.5 microM [3H]25(OH)D3 at 37 degrees C for 30 min; lipid extracts of the cells were analyzed for [3H]24,25(OH)2D3 by high performance liquid chromatography and periodate oxidation. Apparent maximal [3H]24,25(OH)2D3 production in normal cell lines was 9 pmol/10(6) cells per 30 min and occurred after induction with 10(-8) M 1,25(OH)2D3. 24-OHase induction was detectable in normal fibroblasts at approximately 3 X 10(-10) M 1,25(OH)2D3. [3H]24,25(OH)2D3 formation after exposure to 1,25(OH)2D3 was abnormal in fibroblasts from all four patients with DD II. In fibroblasts from two patients with DD II, [3H]24,25(OH)2D3 formation was unmeasurable (below 0.2 pmol/10(6) cells per 30 min) at 1,25(OH)2D3 concentrations up to 10(-6) M. Fibroblasts from the other two patients with DD II required far higher than normal concentrations of 1,25(OH)2D3 for detectable [3H]24,25(OH)2D3 induction. In one, [3H]24,25(OH)2D3 production reached 2.9 pmol/10(6) cells per 30 min at 10(-6) M 1,25(OH)2D3 (30% normal maximum at 10(-6) M 1,25(OH)2D3). In the other, [3H]24,25(OH)2D3 production achieved normal levels, 7.3 pmol/10(6) cells per 30 min after 10(-6) M 1,25(OH)2D3. The two patients whose cells had a detectable 24-OHase induction by 1,25(OH)2D3 showed a calcemic response to high doses of calciferols in vivo. Our current observations correlate with these two patients' responsiveness to calciferols in vivo and suggest that their target organ defects can be partially or completely overcome with extremely high concentrations of 1,25(OH)2D3. The two patients whose cells showed no detectable 24-OHase induction in vitro failed to show a calcemic response to high doses of calciferols in vivo. IN CONCLUSION: (a) the measurement of 24-OHase induction by 1,25(OH)2D3 in cultured skin fibroblasts is a sensitive in vitro test for defective genes in the 1,25(OH)2D effector pathway. (b) This assay provides a useful tool for characterizing the target tissue defects in DD II and predicting response to calciferol therapy.

Alopecia↗
PubMed1985

The effects of radiographic contrast agents and other compounds on the nuclear binding of L-[125I]triiodothyronine in dispersed human skin fibroblasts.

Using a dispersed intact cell assay system, we screened a number of compounds for their ability to compete for nuclear binding of L-[125I]T3 in cultured human skin fibroblasts incubated for 90 min at 37 degrees C. T3 inhibited nuclear [125I]T3 binding by 50% at a concentration of 3.4 +/- 0.3 (+/- SE) X 10(-10) M. 3,5-Dimethyl-3'-isopropyl-thyronine, a nonhalogenated thyroid hormone agonist, had an affinity for the nuclear thyroid hormone receptor (4.4 X 10(-9) M, as judged by 50% inhibition of nuclear [125I]T3 binding) that correlates well with its thyromimetic potency. Of several radiographic contrast agents and other compounds tested (iodipamide, iopanoic acid, sodium ipodate, sodium diatrizoate, sodium tyropanoate, diphenylhydantoin, carbamazepine, amiodarone hydrochloride, propylthiouracil, propranolol, and potassium iodide), only sodium ipodate (Oragrafin) and iopanoic acid (Telepaque) interfered with nuclear [125I]T3 binding, with 50% inhibition at 5 X 10(-5) and 1.8 X 10(-4) M, respectively. Interestingly, diphenylhydantoin and amiodarone, two compounds previously thought to interact with thyroid hormone receptors, did not impair fibroblast nuclear [125I]T3 binding at concentrations up to 10(-3) M. We conclude that this in vitro assay system with intact human cells is useful in evaluating the nuclear T3 receptor affinity of compounds that affect thyroid hormone action or metabolism. These studies more closely approximate in vivo conditions and, therefore, provide information not obtainable by studies with isolated nuclei or nuclear extracts.

Binding, Competitive↗
PubMed1985

Evidence of extraocular muscle restriction in autoimmune thyroid disease.

Patients with Graves' disease lacking eye symptoms frequently have abnormal intraocular pressure (IOP) increases on upward gaze (greater than or equal to 3 mm Hg) indicative of apparent subclinical ophthalmopathy. Because of the close relationship between Graves' disease (GD) and Hashimoto's thyroiditis (HT), we examined 30 patients with a history of HT as well as 26 patients with a history of GD, 4 patients with a history of subacute thyroiditis, 1 patient with a history of silent thyroiditis, and 25 normal subjects for the presence of IOP abnormalities at 15 degrees and 25 degrees upgaze. While all of the patients were asymptomatic, had no exophthalmos, and were euthyroid at the time of the exam, Hertel exophthalmometer readings (mean +/- SD) for the patients with GD were significantly higher (P less than 0.005) than those for either the HT patients or normal subjects (17.1 +/- 2.4 vs. 14.5 +/- 2.3 vs. 14.4 +/- 4.2 mm, respectively). At 15 degrees upgaze, IOP abnormalities occurred in 25% and 13% of patients with GD and HT, respectively. At 25 degrees upgaze, these figures rose to 54% for the GD patients and 37% in HT patients. Only 1 of 25 normal subjects had elevated IOP changes on upgaze, as did the 1 patient with silent thyroiditis, but the patients with subacute thyroiditis did not. These data suggest the frequent presence of extraocular muscle restriction in patients with a history of HT as well as in patients with a history of GD. Maximal detection of these IOP abnormalities requires that patients be examined at 25 degrees upgaze. These data support the belief that the autoimmune bases of both GD and HT are closely linked, at least as manifested by eye muscle involvement.

Adult↗
PubMed1985

Simulation of a prolactin-secreting adenoma by an intrasellar craniopharyngioma.

We report here an unusual case of a 21-year-old woman who presented with amenorrhea, galactorrhea, and hyperprolactinemia (66 to 81 ng/ml) secondary to an unsuspected intrasellar craniopharyngioma. The results of preoperative endocrine testing were compatible with the presence of a prolactin-secreting adenoma. Moreover, high resolution computed tomographic scanning revealed an uncalcified hypodense sellar mass that did not enhance after contrast administration, a feature shared by many prolactinomas. This report illustrates that amenorrhea, galactorrhea, mild to moderate hyperprolactinemia, and a sellar mass should not automatically be attributed to the presence of a prolactin-secreting adenoma.

Adenoma↗
PubMed1985

Hypercalcemia and disseminated cytomegalovirus infection in the acquired immunodeficiency syndrome.

Two patients with the acquired immunodeficiency syndrome and disseminated cytomegalovirus infection developed hypercalcemia associated with suppressed parathyroid gland activity. Neither patient had evidence of a malignant, endocrinologic, granulomatous, or drug-related cause for hypercalcemia. Increased osteoblastic bone resorption induced by cytomegalovirus infection may have been the cause for the hypercalcemia. Physicians should be alert for the occurrence of endocrinologic and metabolic problems in immunosuppressed patients.

Acquired Immunodeficiency Syndrome↗
PubMed1984

Vitamin D3--resistant fibroblasts have immunoassayable 1,25-dihydroxyvitamin D3 receptors.

Cultured fibroblasts obtained from patients with tissue resistance to 1,25-dihydroxyvitamin D3 (vitamin D3--dependent rickets, type II) contain normal, low, or undetectable concentrations of this hormone's receptor protein as measured by a ligand-binding assay. Extracts from these cells were evaluated for receptors by immunoassay with a recently developed monoclonal antibody to the chick receptor. The results show that a protein sedimenting at 3.7S and recognizable by the antibody exists in comparable concentrations in cells from both normal and resistant patients, irrespective of the hormone-binding abnormalities of the cells. This implies that deficiencies in hormone binding associated with inherited tissue resistance to 1,25-dihydroxyvitamin D3 probably arise from structural variations in the receptor molecule and not from defective receptor synthesis.

Antibodies, Monoclonal↗
PubMed1984

Androgen receptor abnormalities in identical twins with oligospermia. Clinical and biochemical studies.

Identical twin brothers presented with oligospermia, small testes, normal male phenotypes, elevated serum luteinizing hormone levels, and normal or elevated serum testosterone levels. Both men had low to low-normal cytosol androgen receptor binding capacity in cultured fibroblasts from pubic skin biopsy specimens. Qualitative abnormalities of cellular androgen receptors were suggested by low-normal or low nuclear androgen uptake in fibroblasts from both brothers as well as abnormal thermolability and subnormal molybdate stabilization of androgen receptors from one brother. In vivo androgen sensitivity was assessed in one twin following administration of testosterone or the non-aromatizable androgen fluoxymesterone. Fluoxymesterone suppressed serum luteinizing hormone and serum testosterone/estradiol-binding globulin, and although testosterone suppressed both serum luteinizing hormone and serum follicle-stimulating hormone, the suppression of serum luteinizing hormone by testosterone was subnormal. Both subjects showed marked exaggeration of the serum 17-hydroxyprogesterone increase after administration of human chorionic gonadotropin, despite normal serum testosterone increases, suggesting a block in testicular 17,20-desmolase, which converts 17-hydroxyprogesterone to testosterone. These studies suggest that oligospermia and block of the enzyme 17,20-desmolase may be the earliest manifestations of androgen resistance, and the finding of the syndrome of oligospermia, normal male phenotype, and androgen receptor abnormalities in identical twins indicates a genetic etiology of this disorder.

17-alpha-Hydroxyprogesterone↗
PubMed1984

Reversible hypocalciuric hypercalcemia associated with hypothyroidism.

Hypothyroidism is known to affect calcium homeostasis by decreasing bone turnover and serum calcium level, and by increasing parathyroid hormone and 1,25-dihydroxyvitamin D concentrations. A 52-year-old hypothyroid woman is described who had hypercalcemia associated with elevated parathyroid hormone and 1,25-dihydroxyvitamin D levels, but decreased 24-hour urinary calcium excretion and ratio of calcium to creatinine clearance. These parameters normalized following thyroid hormone replacement therapy. Hypercalcemia appeared to result from a combination of reduced renal calcium excretion and a change in the "set point" for calcium feedback inhibition of the parathyroid glands. These data suggest that thyroid hormone has a direct effect on the parathyroid glands, regulating parathyroid hormone secretion, and on the kidney's ability to excrete calcium. It is recommended that parathyroid hormone, 1,25-dihydroxyvitamin D, and urinary calcium excretion values be interpreted in light of thyroid hormone status.

Calcitriol↗
PubMed1984

Concurrent renal hypomagnesemia and hypoparathyroidism with normal parathormone responsiveness.

A 24-year-old woman presented with clinical features suggesting hypoparathyroidism: tetany, basal ganglia calcification, and a history of a seizure disorder. Hypocalcemia was present on admission despite therapy with calcium and vitamin D. Hormonal evaluation revealed undetectable parathormone levels and a normal cyclic AMP and phosphaturic response to parathormone infusion, suggesting the diagnosis of idiopathic hypoparathyroidism. Additional testing, however, revealed hypomagnesemia and elevated urinary magnesium levels. Normomagnesemia could not be consistently achieved despite oral magnesium administration. When the serum magnesium level was temporarily normalized via intravenous magnesium supplementation, parathormone levels rose into the normal range. These data indicate that the patient's hypomagnesemia was most likely due to renal magnesium loss. The normalization of her parathormone level during magnesium replenishment, along with the parathormone infusion data, suggests that this patient's hypomagnesemia was responsible for decreased parathormone synthesis and/or secretion, while target tissue responsiveness to parathormone was maintained.

Adult↗
PubMed1984

Carbamazepine does not interact with thyroid hormone receptors in human fibroblasts.

Treatment with carbamazepine is associated with decreases in the serum levels of thyroxine, free thyroxine and triiodothyronine without alteration in the thyrotropin. Therefore, the mechanism of action of carbamazepine on the hypothalamo-pituitary thyroid axis may involve interference in the feedback regulation of secretion of thyroid hormone by interacting with the pituitary thyroid hormone receptors. The present authors investigated the ability of carbamazepine to compete with the nuclear uptake of [125I]triiodothyronine in dispersed intact cultured fibroblasts of human skin. Carbamazepine did not inhibit the specific binding of [125I]triiodothyronine into the nuclei of intact fibroblasts, suggesting that it does not interact with thyroid hormone receptors in this system and is unlikely to do so in vivo.

Carbamazepine↗
PubMed1984

A unique case of Sertoli cell only syndrome with normal gonadotropins.

A 23-year-old male presented with primary infertility, normal male phenotype, and azoospermia. He had normal basal T, FSH, and LH levels and responded normally to clomiphene citrate stimulation. He also had normal androgen receptors in cultured pubic skin fibroblasts. A testis biopsy showed only Sertoli cells and no evidence of seminiferous tubule damage, lacking the fibrosis or Leydig cell hyperplasia usually seen in SCOS. This case of SCOS, combined with those previously reported, suggests that the etiology of SCOS is heterogeneous, with a single common end point, or that it is a single process that has been studied at different developmental stages by different investigators.

Adult↗
PubMed1984

Leydig cell hypoplasia causing male pseudohermaphroditism: diagnosis 13 years after prepubertal castration.

An 11-yr-old patient with male pseudohermaphroditism who was castrated at nine days of age and raised thereafter as a female was evaluated to determine the cause of abnormal sexual differentiation. Stimulation with ACTH for 8 h revealed no abnormality in the biosynthesis of cortisol or adrenal androgens. The administration of fluoxymesterone (10 mg, orally, daily) for 5 weeks at age 13 yr led to significant decrements in serum levels of sex steroid-binding globulin and T4-binding globulin to a degree similar to that found in 2 normal men, but no change in the basally elevated levels of FSH and LH. LH bioactivity was normal in the rat Leydig cell bioassay. Skin fibroblasts cultured from a labial skin biopsy revealed normal 5 alpha-reductase activity and normal androgen receptors. Reexamination of the original testis specimens by light microscopy failed to reveal Leydig cells. Furthermore, when immunoperoxidase staining for testosterone was performed on the tissue sections, only 30-35 positive cells/10 high power fields were seen. In contrast, examination of testis sections from 4 male infants who died of other causes revealed 94-836 cells/10 high power fields that stained positively for testosterone. Although hCG stimulation testing to confirm Leydig cell hypoplasia could not be done in this patient because of previous castration, this patient demonstrates that the diagnosis can be made without it by the use of immunohistochemical stains and in vivo and in vitro tests to exclude other disorders of androgen biosynthesis or androgen action.

Adrenocorticotropic Hormone↗
PubMed1984

The use of human skin fibroblasts to obtain potency estimates of drug binding to androgen receptors.

Although several drugs with antiandrogenic properties have been used to treat such conditions as prostatic carcinoma, precocious puberty, acne, and hirsutism, their relative strengths in human tissues are not known. Most of the compounds that are effective clinically in opposing androgen action interact with the androgen receptor in various assay systems. To determine in human cells the relative potencies of these agents as well as others with androgenic properties, we measured the abilities of various compounds to compete with [3H]dihydrotestosterone [( 3H]DHT) for androgen-binding sites in dispersed human genital skin fibroblasts at 22 degrees C. The concentrations of unlabeled DHT, methyltrienolone (a synthetic non- metabolizeable androgen), and testosterone required for 50% inhibition of [3H]DHT binding were similar, approximately 1 nM [0.87 +/- 0.12 (+/- SE), 1.18 +/- 0.18, and 1.01 +/- 0.20 nM, respectively]. The relative binding activities, defined by the ratio of the concentration of methyltrienolone to the concentration of competitor required for 50% displacement of [3H]DHT, were as follows: spironolactone greater than R2956 (a synthetic antiandrogen) greater than megestrol acetate greater than cyproterone acetate greater than estradiol greater than flutamide much greater than testolactone greater than cimetidine. Danazol, an androgen agonist that causes hirsutism, was nearly as effective as spironolactone in its ability to compete for the fibroblast androgen receptor, 50% inhibition of fibroblast [3H]DHT binding was achieved by 1.76 +/- 0.31 nM spironolactone and 2.85 +/- 0.50 nM danazol. Two other compounds that induce hirsutism, diphenylhydantoin and diazoxide, did not displace [3H]DHT. We conclude that 1) of the compounds tested, spironolactone, which is rapidly metabolized in vivo to a much less potent competitor, is the most potent antiandrogen in its ability to interact in vitro with human skin fibroblast androgen receptors; 2) estradiol is a relatively potent androgen receptor binder; and 3) this receptor assay, combined with metabolic clearance and pharmacokinetic considerations, should be useful in selecting drugs for androgen and antiandrogen therapy.

Binding, Competitive↗
PubMed1984

Decreased nuclear uptake of [125I]triiodo-L-thyronine in fibroblasts from patients with peripheral thyroid hormone resistance.

The cellular mechanisms that cause the syndrome of generalized, peripheral, and pituitary resistance to thyroid hormones are unclear. In order to investigate the possibility of a defect at the nuclear receptor for T3, we examined: 1) equilibrium binding of [125I]T3 (64 analyses) to the nuclei of intact cultured fibroblasts from 12 patients with both sporadic and familial generalized or selective pituitary resistance, 17 normal subjects, and two apparently normal siblings from affected families; and 2) kinetics of [125I]T3 nuclear uptake (22 analyses) in intact fibroblasts from 4 generalized resistant patients from two different kindreds, compared to one apparently normal sister of one affected patient and 6 normal subjects. Statistical analysis of the equilibrium binding parameters showed no differences in nuclear binding capacity for T3 among all groups. The equilibrium dissociation constants (Kd) also were not significantly different in fibroblasts from the selective pituitary resistant patients, the normal siblings, and the normal subjects. In contrast, the KdS from the general resistant patients were significantly increased (median = 1.94 X 10(-10) M, 5-95% confidence interval = 1.18-2.93 X 10(-10) M 1.11, 0.77-1.25 X 10(-10) M; P less than 0.008). Since there was considerable overlap of the equilibrium binding values among groups, we studied the kinetics of [125I]T3 nuclear uptake in selected cell lines from normal subjects and familial generalized resistant patients. Kinetic analysis of the association curve revealed that, compared to the normal subjects, maximum binding at 10(-10) M [125I]T3 was significantly reduced to 50% in two resistant patients, to 10% in another two patients, and to 65% in one apparently-normal sibling. The empiric parameter lambda that corresponds to the slope at the origin of the curve was not significantly different in any patient compared to normal. The calculated apparent association constant, derived from lambda, and the binding capacity obtained at equilibrium, showed differences that were significant for only one of the patients. We conclude that cultured fibroblasts from patients with familial generalized resistance to thyroid hormone display abnormal kinetics of T3 nuclear uptake which provide a convenient in vitro method for the recognition of thyroid hormone resistance at the cell level. Furthermore, because cultured fibroblasts can be grown under controlled experimental conditions, they are a suitable tissue for further study of the molecular basis of these disorders.

Adolescent↗
PubMed1983

Prevalence of increased intraocular pressure in Graves' disease--evidence of frequent subclinical ophthalmopathy.

Graves' exophthalmos is frequently associated with elevated intraocular pressure on upgaze. Eighty patients with Graves' disease were evaluated prospectively by applanation tonometry to assess the prevalence of ophthalmopathy in this disorder. Whereas 21 (26 per cent) of the 80 patients had exophthalmos, 61 (76 per cent) had abnormal intraocular pressure (delta greater than or equal to 3 mm Hg). All patients with exophthalmos had elevated intraocular pressure on upgaze; 40 (68 per cent) of 59 patients without proptosis had abnormal pressure readings. The mean interval between the onset of Graves' disease and this study was 6.3 +/- 1.0 years (S.E.M.) for those patients who had exaggerated positional changes in intraocular pressure, as compared with 3.0 +/- 1.0 years for those with normal intraocular pressure (P less than 0.005). All but 1 of 15 patients in whom the diagnosis of Graves' disease had been documented 10 or more years earlier had increased intraocular pressure on upgaze. We conclude that Graves' ophthalmopathy is more common than is recognized clinically and that eye involvement is an inevitable complication of the disease.

Adult↗