Biomedical subjects

Luciana A Naves

Publications and source records attributed to Luciana A Naves.

4 recordsLinked to original sources

PubMed2006

Persistence of hyperprolactinemia after treatment of primary hypothyroidism and withdrawal of long term use of estrogen: are the tuberoinfundibular dopaminergic neurons permanently lesioned?

Long term use of high doses of estrogen and the presence of chronic hyperprolactinemia may, at least in the rat, provoke lesions in the tuberoinfundibular dopaminergic (TIDA) neurons responsible for the control of prolactin (Prl) secretion. This occurrence, which is not yet well documented in humans, may have taken place in a patient on chronic oral hormonal contraceptive (OC) treatment who was seen for primary hypothyroidism, hyperprolactinemia and a pituitary mass. After thyroid hormone replacement, OC withdrawn and bromocriptine treatment, this patient could not maintain normal Prl levels, unless continuously treated with a dopaminergic agonist even when MRI was indicative of a normal situation. Function of TIDA neurons was investigated by TRH test (200 microg IV) performed before and after treatment with 25 mg carbidopa plus 250 mg L-dopa every 4 hours for one day. Basal TSH was normal (3.9 microU/mL) whereas basal Prl was high (67.5 ng/mL); both TSH and Prl levels appropriately increased after TRH: peaks 31.8 microU/mL and 157.8 ng/mL, respectively. After treatment with carbidopa/L-dopa, basal TSH (1.6 microU/mL) and Prl (34 ng/mL) decreased and the response to TRH was partially blocked (10.3 microU/mL and 61 ng/mL, respectively). In spite of a normal response, we discuss the possibility that the persistence of hyperprolactinemia is due to lesion of the TIDA neurons produced by the long term use of high doses of estrogens and by the presence of chronic hyperprolactinemia.

Adult↗

PubMed2006

[Pituitary incidentalomas].

Clinically unsuspected pituitary lesions are demonstrated by magnetic resonance imaging in approximately 10% of the general adult population, characterizing the so-called pituitary incidentalomas. Their natural history is not yet completely established. Despite being typically small (<10 mm in the greatest diameter) and clinically silent, some pituitary incidentalomas may be hormonally active or cause mass effects by compressing neighboring structures. Furthermore, a minority of these lesions, particularly those greater than 10 mm (macroincidentalomas) may grow over time; hence, longterm follow-up is necessary. Therapeutic interventions are indicated for lesions that are hormonally active (use of dopamine agonists or transsphenoidal resection) or for those that cause mass effects or increase in size during the follow-up (transsphenoidal resection). Significant suprasellar extension or hypopituitarism may be additional indications for surgical treatment even in the absence of chiasm compression.

Disease Progression↗

PubMed2004

Nelson's syndrome: complete remission with cabergoline but not with bromocriptine or cyproheptadine treatment.

A woman affected by Cushing's disease underwent bilateral adrenalectomy followed by radiotherapy of the hypothalamic-pituitary area when she was 18 years old. Thereafter, she used hydrocortisone acetate replacement therapy (35.5 mg divided into two daily doses). At the age of 26 years, the patient exhibited the clinical signs of the Nelson's syndrome, i.e. skin and gingival hyperpigmentation accompanied by amenorrhea, and elevated ACTH plasma levels (2,850 pg/ml, normal range 15-80 pg/ml). The magnetic resonance imaging (MRI) analysis of the sellar region evidenced a pituitary macroadenoma, measuring 14 x 13 mm. The patient was initially treated with cyproheptadine hydrochloride (12 mg/day) for 18 months. There was a partial improvement of the symptoms, with a reduction of the ACTH plasma levels to 112 pg/ml, but without any modification of the tumor mass. Due to sleepiness and weight gain, the cyproheptadine treatment was interrupted and substituted by a cabergoline (0.5 mg twice a week) therapy. Soon after cabergoline was applied an improvement of the clinical symptoms and signs was observed such as a regression of the tumor mass and the normalization of the ACTH plasma titers (38 pg/ml). Later, cabergoline was substituted by bromocriptine (7.5 mg/day) and the plasma levels of ACTH increased again (247 pg/ml), and headache and cutaneous hyperpigmentation were recorded. When cabergoline was reintroduced there was a clinical improvement and normalization of ACTH plasma levels (64 pg/ml). The MRI analysis of the sella region demonstrated a complete remission of the pituitary adenoma. The results obtained show for the first time that a long-term treatment with cabergoline also brings about a complete remission of Nelson's syndrome in the presence of a pituitary macroadenoma.

Adenoma↗

PubMed2004

Nonthyroidal illness syndrome in patients with subarachnoid hemorrhage due to intracranial aneurysm.

We have previously reported that subarachnoid hemorrhage due to ruptured intracranial aneurysm (SH) is associated with changes in the hormonal profile in the first 24 hours after the event. We proposed that the hormonal changes observed are due to the intense stress to which the patients are exposed. However, the thyroidal hormonal profile is indicative of the presence of a nonthyroidal illness syndrome (NTIS). In this paper, we examined whether the change in the thyroid hormone profile is compatible with a NTIS. Two groups of patients were included in the study: A) 30 patients with SH (21 females and 9 males; 41.7+/-11.4 years) and B) a control group including 25 patients with benign diseases of the spine (BDS) (lumbar disc hernia or stable spinal trauma) (8 females and 17 males; 41.3+/-14.2 years). In a subgroup of eight patients of each group serum triiodothyronine (T3) and reverse T3 levels were measured. The blood samples were obtained between 8:00 and 9:00 AM. The following results were obtained: The SH group had smaller serum T3 and free T4 levels than the BDS group (p<0.05): T3 (ng/mL): SH = 58.7+/-1.1 and BDS = 74.5+/-13.9; free T4 (ng/dL): SH = 0.9+/-0.2 and BDS = 1.1+/-0.3. There was no significant difference in the serum levels of total thyroxine (T4) and thyroid-stimulating hormone (TSH) between the two groups: T4 ( microg/dL): SH = 6.9+/-1.1 and BDS = 7.4+/-2.1; TSH ( microUI/mL): SH = 1.5+/-0.8 and BDS = 1.8+/-1,0. In the sample of eight patients of each group we had the following results: T3 (ng/mL): SH = 66.8+/-3.8 and BDS = 77.2+/-1.1 (p <0.05); reverse T3 (ng/dL): SH = 32.8+/-8 and BDS = 24.7+/-2.2 (NS); T3/ reverse T3 ratio: SH = 2.6+/-0.3 and BDS = 3.3+/-0.4 (NS). Thyreoglobulin and microsomal antibodies were not detectable, except in one patient in the SH group. In conclusion, the SH patients present serum levels of T3 and free T4 significantly lower than that of BDS patients; the thyroidal hormone profile suggests that SH patients have developed the nonthyroidal illness syndrome.

Adult↗