Microwave-assisted derivatization: application to steroid profiling by gas chromatography/mass spectrometry.

Gas chromatography-mass spectrometry (GC-MS) remains as the gold-standard technique for the study of the steroid metabolome. A main limitation is the need of performing a derivatization step since incubation with strong silylations agents for long periods of time (usually 16 h) is required for the derivatization of hindered hydroxyls present in some steroids of interest. In the present work, a rapid, simple and reproducible microwave-assisted derivatization method was developed.

[Clinical usefulness of the determination of fibroblast growth factor 23 in the evaluation of patients with osteomalacia].

Background And Objective: The aim of the present study was to analyze the usefulness of the determination of fibroblast growth factor 23 (FGF23), a regulatory hormone of phosphate metabolism, in the evaluation of patients with osteomalacia of different causes.

Patients And Method: Seventeen patients with osteomalacia were included: 12 hypophosphatemic osteomalacia (by several causes), 4 vitamin D-deficiency osteomalacia and one with hypophosphatasia. Plasma C-terminal FGF23 was determined in all patients.

Earlier decrease of FGF-23 and less hypophosphatemia in preemptive kidney transplant recipients.

Background: Levels of fibroblast growth factor (FGF)-23, a phosphaturic hormone, increase from the early stages of CKD and are dramatically elevated in dialysis patients. Excessive FGF-23 may be involved in the hypophosphatemia and inappropriately low calcitriol levels observed after kidney transplantation (KT).This prospective observational cohort study was carried out to determine whether there are any differences in the changes in FGF-23 levels after surgery in KT recipients according to whether they were or not on dialysis before transplantation and to assess the influence of FGF-23 in the development of posttransplantation hypophosphatemia.

Effects of bilirubin and sera from jaundiced patients on osteoblasts: contribution to the development of osteoporosis in liver diseases.

Unlabelled: Low bone formation is considered to be the main feature in osteoporosis associated with cholestatic and end-stage liver diseases, although the consequences of retained substances in chronic cholestasis on bone cells have scarcely been studied. Therefore, we analyzed the effects of bilirubin and serum from jaundiced patients on viability, differentiation, mineralization, and gene expression in the cells involved in bone formation. The experiments were performed in human primary osteoblasts and SAOS-2 human osteosarcoma cells.

Osteomalacia revisited : a report on 28 cases.

The aim of this study was to analyse the clinical manifestations and the most frequent causes of osteomalacia (OM) in a group of 28 patients diagnosed with this disorder during a 20-year period. OM was diagnosed by bone biopsy and/or by Bingham and Fitzpatrick criteria (two of the following: low calcium, low phosphate, elevated total alkaline phosphatase [total AP] or suggestive radiographs). Of these patients, 13 had vitamin D deficiency OM (VD-OM), 14 hypophosphatemic OM (HypoP-OM) and one had OM-associated hypophosphatasia.

Interaction between serotonin 5-HT1A receptors and beta-endorphins modulates antidepressant response.

Unlabelled: Interactions between serotonergic and the endogenous opioid systems have been suggested to be involved in the etiopathogenesis of depression and in the mechanism of action of antidepressants. Activation of serotonin 5-HT1A receptors has been shown to increase plasma beta-endorphin (beta-END) levels in animal studies and in healthy humans.

Objectives: To assess interaction abnormalities between 5-HT1A receptors and the endogenous opioid system in patients with major depression and the possible modulating effect of citalopram.

Hormonal response to buspirone is not impaired in major depression.

It has been suggested that interactions between hypothalamic pituitary adrenal (HPA) axis and serotonin-1A (5-HT(1A)) receptor system are involved in the pathophysiology of major depression. Pharmacologic challenge test with 5-HT(1A) receptor agonists is a useful approach to study the sensitivity of 5-HT(1A) receptors in depressed patients and the interaction of these systems. A cross-sectional case-control study was designed to assess the effect of the 5-HT(1A) receptor agonist, buspirone, on 5-HT(1A) receptor function in 30 patients with major depression (DSM-IV) and in 30 age- and sex-matched healthy controls.

Effects of citalopram treatment on hypothermic and hormonal responses to the 5-HT1A receptor agonist buspirone in patients with major depression and therapeutic response.

Serotonin (5-HT) 5-HT1A receptor seems to play an important role in the pathophysiology of major depression and in the mechanism of action of antidepressants. In vivo function of 5-HT1A receptors can be monitored using specific pharmacological challenge tests. The present study aimed at exploring the adaptative 5-HT1A receptor changes in depressed patients before and after 8 week treatment with citalopram.

Use of gonadotropin-releasing hormone agonists in patients with Hodgkin's disease for preservation of ovarian function and reduction of gonadotoxicity related to chemotherapy.

In young women receiving chemotherapy for Hodgkin's disease, the combined use of triptorelin and tibolone cotreatment may be a useful tool for preserving ovarian function because all but three (10%) of the women in this treatment group returned to spontaneous ovulation and menses, in contrast to 23% of subjects in the control group (P<.05). No significant differences were observed in bone mineral density between groups.

Clinical, biochemical and morphologic diagnostic markers in an infant male pseudohermaphrodite patient with compound heterozygous mutations (G115D/R246W) in SRD5A2 gene.

A patient with male pseudohermaphroditism and clinical diagnosis of partial androgen insensitivity in the neonatal period was studied at pubertal age for a molecular diagnosis. Hormone studies were conducted at baseline and under hCG stimulation for testosterone and dihydrotestosterone determinations at 2 months of age. Gonadectomy was performed at 4 months.

Secreting ovarian tumors may protect women from osteoporosis.

Objective: It is well known that ovarian steroids modulate bone turnover. Conditions associated with low levels of these hormones, such as menopause, hypogonadism, and others, have been related to osteopenia or osteoporosis. On the other hand, hyperandrogenism in premenopausal women, mainly in polycystic ovarian syndrome, has been reported to have a protective effect on bone mass.