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Biomedical subjects

L Audí

Publications and source records attributed to L Audí.

12 recordsLinked to original sources
PubMed1995

Androgen binding protein is tissue-specifically expressed and biologically active in transgenic mice.

In view of the inconclusive data concerning the role of androgen-binding protein (ABP) in male reproductive physiology, we thought it would be pertinent to make several transgenic mouse lines overexpressing the rat ABP gene to unravel its role in Sertoli cell and epididymal homeostasis. Heterozygote transgenic mouse lines carrying the 5.5 kb ABP rat genomic DNA were produced by pronuclear microinjection. Northern blot analysis showed overexpression of rat ABP (rABP) mRNA in the testis of transgenic mice compared to rat testis control. rABP was appropriately expressed in Sertoli cells as demonstrated by in situ hybridization analysis. Sertoli cell number is increased in the seminiferous tubules of mice overexpressing rABP compared to non-transgenic littermates and scattered Sertoli cells present vacuolated-like cytoplasms, PAS and osmium negative. Compared to the wild type, the transgenic mice exhibited reduced fertility and focal damage in seminiferous epithelium characterized by morphological features compatible with programmed cell death.

Androgen-Binding Protein↗
PubMed1992

Suppressive therapy with levothyroxine for solitary thyroid nodules.

OBJECTIVE: To evaluate the effect of treatment with TSH suppressive dose of levothyroxine in patients with benign thyroid nodules. DESIGN: Prospective randomized study. Group A (n = 20) patients received levothyroxine and group B (n = 20) patients did not. The dose of levothyroxine was adjusted to obtain an effective suppression of TSH. A clinical, analytical and morphological (with ultrasound) review was performed every 3 months. The mean +/- SD follow-up period was 10.6 +/- 2.2 months. PATIENTS: Forty euthyroid women with solitary thyroid nodule on palpation, cold on scintigraphy and cytologically benign without contraindication participated. MEASUREMENTS: At entry: biochemical and hormonal parameters, thyroid scintigraphy and thyroid ultrasonography. Every 3 months additional determinations of thyroid hormones and TSH levels were carried out, if necessary, to verify effective TSH suppression. Every 6 months thyroid ultrasound imaging was performed. RESULTS: Patients were euthyroid at entry into the study. The mean dose of levothyroxine necessary to obtain TSH suppression was 2.82 +/- 0.6 micrograms/kg/day. No significant modification in the thyroid nodule diameter (mean +/- SD 2.6 +/- 1.2 vs 2.5 +/- 1.2 cm) or in the thyroid nodule volume (10.3 +/- 11.9 vs 10.1 +/- 12.2 ml) were observed in group A. In group B the results were similar (2.8 +/- 0.9 vs 2.7 +/- 1.8 cm and 9.2 +/- 6.4 vs 9.2 +/- 9.5 ml, respectively). No differences were found in either group in the number of nodules that reduced significantly their volume (four and three, respectively). CONCLUSIONS: The suppressive therapy with levothyroxine was not effective in reducing nodule sizes in patients with solitary benign thyroid nodules.

Adult↗
PubMed1992

Clinical usefulness of urinary growth hormone measurements in normal and short children according to different expressions of urinary growth hormone data.

To assess the clinical usefulness of urinary growth hormone (UGH) measurements, a UGH determination technique, including dialysis, ultrafiltration, and measurement by polyclonal-coated tube RIA, was established. Sixty-three short children were studied: 56 idiopathic growth retarded (37 prepubertal and 19 pubertal) and seven prepubertal with classic GH (growth hormone) deficiency. Forty-two healthy children (32 prepubertal and 10 pubertal) served as controls. Two groups of adults were studied: eight with active acromegaly and 11 healthy controls. UGH was measured in 24-h urine samples from all patients and controls. Mean +/- SD UGH excretion expressed as ng/24 h was significantly lower in the GH-deficient group compared with prepubertal growth-retarded and control children (p less than 0.01). No differences were found between UGH excreted by controls and by the growth-retarded groups. Pubertal children excreted significantly higher amounts of GH when UGH was expressed as ng/24 h (p less than 0.02 and p less than 0.03, respectively), but this difference disappeared when UGH was expressed as ng/g creatinine. UGH was significantly higher in acromegalic patients compared with adult controls (p less than 0.001). Differences between day, night, and 24-h UGH were studied in 23 children. UGH in night urine was significantly lower whether expressed as the total amount or as ng/g creatinine. The effect of recombinant hGH administration on UGH was studied in 13 children after 6 and 12 mo of treatment. UGH increased significantly under recombinant hGH treatment.(ABSTRACT TRUNCATED AT 250 WORDS)

Acromegaly↗
PubMed1992

Somatostatin effects on cultured human fetal epiphyseal chondrocytes.

Somatostatin effects on cultured human fetal epiphyseal chondrocytes were evaluated by studying the effects of somatostatin on DNA synthesis. Cultured epiphyseal chondrocytes from human fetuses (12-40 wk old) were incubated for 48 h in Ham's F-12 serum-free medium. After this, the medium was replaced by MCDB-104 serum-free medium and the cells were incubated for an additional 48 h in the presence or absence of somatostatin 1 pM to 10 microM, with the addition of 3H-thymidine (5 microCi/mL) for the last 24 h of incubation. A significant (p < 0.02) inhibitory effect of somatostatin (1 nM to 10 microM) on 3H-thymidine DNA incorporation was observed in cultured chondrocytes from fetuses of all gestational ages studied (12-40 wk), with no significant differences among fetal ages. In conclusion, our results show that somatostatin exerts a biologic effect on cultured human fetal epiphyseal chondrocytes, as it does in its target cells. These results suggest that somatostatin could regulate human skeletal growth not only by growth hormone secretion regulation, but also by acting directly on chondrocyte metabolism. However, the physiologic significance of the latter remains to be elucidated.

Cells, Cultured↗
PubMed1991

Male pseudohermaphroditism due to Leydig cell agenesia and absence of testicular LH receptors.

OBJECTIVE: The aim of our study was to establish the definitive diagnosis in an adult patient with male pseudohermaphroditism in whom testicular feminization syndrome had been suspected at the age of 8, based on genetic, clinical and pathological studies. DESIGN: Hypothalamo-hypophysio-testicular function was assessed in vivo. Androgen mechanism of action and testicular gonadotrophin binding were studied in vitro. PATIENT: At the age of 33 the phenotype was almost completely feminine except for slight clitoral enlargement and posterior labial fusion. Internal genital duct derivatives were masculine except for a short vagina. Both testes were cryptorchid. MEASUREMENTS: LH and FSH were determined pre- and post-gonadectomy. Progesterone, 17-OH-progesterone, androstenedione, dehydroepiandrosterone testosterone (T) and oestradiol were determined basally in peripheral and spermatic blood post-hCG stimulation, and in peripheral blood after orchidectomy. Dihydrotestosterone (DHT) receptors and 5 alpha-reductase activity were determined in genital skin fibroblasts. Receptors for LH and FSH were determined in membrane preparations from both testes. RESULTS: LH was high (31 IU/l) and FSH (8 IU/ml) normal. T or steroid precursors were detected basally or after hCG stimulation in peripheral blood showing absence of testicular production. Spermatic venous blood steroid concentrations were consistent with slight T production, in accordance with testis histology which showed few Leydig-like cells among fibroblasts in the interstitial space. DHT specific binding capacity and affinity and 5 alpha-reductase activity were normal in genital skin fibroblasts. Gonadotrophin binding studies in testicular membranes confirmed the absence of LH specific binding, whereas FSH binding was higher than normal when expressed per mg of protein (27.0 vs 9.4 +/- 0.6 fmol/mg protein in controls), and lower than normal in both testes since patient's testicular weights were abnormally low. CONCLUSIONS: The patient was considered to have an almost complete form of Leydig cell agenesia/hypoplasia in which absence of specific LH binding correlated with total absence of differentiated Leydig cells and insensitivity of undifferentiated interstitial cells to LH stimulation.

Adult↗
PubMed1990

Assay-dependent results of immunoassayable spontaneous 24-hour growth hormone secretion in short children.

Forty-eight children, referred for evaluation of short stature, underwent 24-hour spontaneous growth hormone (GH) secretion studies. The GH level in pooled sera was assessed for each child, using up to 11 commercial immunoassays. In a group of 15 children, the mean GH values obtained by nine of the assays were compared with the mean value given by a polyclonal radioimmunoassay (RIA) from Sorin: four gave higher results (p less than 0.0001), three gave comparable results and two gave lower results (p less than 0.001). The assay yielding the highest results (Nichols: 5.9 +/- 2.3 ng/ml, mean +/- SD) gave values that were approximately triple those obtained by the assay yielding the lowest results (Hybritech: 1.8 +/- 0.8 ng/ml; p less than 0.0001); both of these are monoclonal immunoradiometric assays (IRMAs). The GH concentrations measured in 24-hour pools from 32 children using a monoclonal IRMA from Biomérieux were similar to those obtained using a polyclonal RIA from Farmos (2.8 +/- 1.1 ng/ml and 2.9 +/- 1.4 ng/ml, respectively) but significantly lower than those measured by another polyclonal RIA from Sorin (3.5 +/- 1.5 ng/ml). Two polyclonal assays (Biomérieux and Sorin) were then used to measure the GH levels in all of the 30-minute samples and in the day, night and 24-hour pools from the secretion studies of 22 children. The ratio of the results of the two assays remained fairly constant for a given child (although the GH levels in different 30-minute samples differed considerably). However, the ratios between different children showed quite wide variation (from 2.03 to 1.04).(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1985

Morphologic and metabolic development of human fetal epiphyseal chondrocytes in primary culture.

Primary chondrocyte culture was carried out after enzymatic digestion of femoral and tibial epiphyseal cartilage of human fetuses, collected with informed parental consent within 12 h postmortem. Chondrocytes were cultured in HAM F-12 medium with penicillin and 15% serum. Three types of serum were used: human placental cord serum (HPS), fetal calf serum, and human male adult serum. Chondrocytes cultured with HPS grew as monolayers, formed abundant colony groups with a highly metachromatic pericellular matrix, and floating round cells were observed in the culture medium. By the 10th day of culture the great majority of proteoglycans present in the culture medium were found as aggregates. Chondrocytes cultured with fetal calf serum or human male adult serum grew as monolayers, were polygonal in shape, and the pericellular matrix was far less developed than in HPS cultures. By the confluent phase of growth, only approximately a third of the proteoglycans present in the culture medium were found as aggregates. Chondrocytes cultured with HPS proliferated significantly more rapidly than those cultured with fetal calf serum or human male adult serum. The results suggest that certain, as yet unidentified, factors are present in sufficient amount in HPS to allow chondrocytes in culture to retain phenotypic morphological and biochemical characteristics. HPS also facilitates growth of human fetal epiphyseal chondrocytes in culture. Primary human fetal epiphyseal chondrocyte culture could be a suitable experimental tool for the in vitro study of biochemical characteristics of cartilage and factors involved in fetal cartilage metabolism.

Blood↗
PubMed1983

17-ketosteroid reductase deficiency in an adult patient without gynaecomastia but with female psychosexual orientation.

A 24 years old male with pseudohermaphroditism due to a deficiency in 17-ketosteroid reductase activity is described. Plasma delta 4 is 21 times higher than normal for an adult male, delta 4/T is greater than 6, both E1 and F2 are elevated and E1/E2 = 3. There is very slight modification of delta 4 on administration of ACTH, dexamethasone, hCG and fluoxymesterone. Steroid concentrations in the spermatic veins and arteries confirm the testicular origin of the increased secretion of delta 4 and E1 and show a lower secretion by the cryptorchidic testis. In vitro testicular tissue incubation and fibroblast studies confirm the 17-ketosteroid reductase deficiency and rule out any other anomaly as the cause of the ambiguous genitalia. Psychologically the patient seemed to be identified with a female social and sexual role in spite of her advanced degree of virilization.

17-Hydroxysteroid Dehydrogenases↗
PubMedDate not supplied

Human studies on the biological actions of IGF-1. Evidence suggesting that human fetal and postnatal epiphyseal cartilage is a target tissue for IGF-1 action.

Recent data show that in humans IGF-1 has insulin-like anabolic and growth promoting effects. However, the plasma levels at which IGF-1 exerts these effects differ. IGF-1 plasma levels similar to those in normal children and adults have a growth promoting effect, but higher levels are necessary for IGF-1 to exert insulin-like anabolic effects, and hypoglycemia is a potential risk. Longitudinal bone growth results from the proliferation and differentiation of chondrocytes in epiphyseal cartilage. We present our data from cultured human epiphyseal chondrocytes, which suggest that epiphyseal cartilage may be a target tissue for IGF-1 action during human fetal and postnatal development.

Adult↗