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Biomedical subjects

T Lucas

Publications and source records attributed to T Lucas.

At least 55 records · Page 3Linked to original sources
PubMed1994

Recovery of visual and endocrine function following transsphenoidal surgery of large nonfunctioning pituitary adenomas.

A series of 35 patients with non-functioning pituitary adenomas undergoing transsphenoidal surgery is presented. In most cases, the presenting symptoms were related to the mass effect of the tumor. There was no operative mortality. Before surgery, visual field defects were documented in 21 patients (60%). After surgery, excluding 3 patients with preoperative blindness, 28% regained normal vision and 67% showed variable improvement. Preoperatively, 24 patients (69%) had abnormal pituitary function, 24 (69%) had hypogonadism, 7 (20%) adrenal insufficiency, 8 (23%) hypothyroidism and 2 (6%) panhypopituitarism. After pituitary surgery, all but one patient with normal preoperative function retained it. Of the patients with hypopituitarism, 11 (46%) had variable improvement and 13 (54%) had persistent deficits. After surgery, 4 patients (57%) with adrenal insufficiency recovered normal adrenal function, 7 patients (29%) with hypogonadism recovered gonadal function and 1 patient (13%) with hypothyroidism recovered thyroid function. Prior to surgery, the presence of a normal or slightly elevated PRL and a rise in TSH after TRH and in LH after GnRH stimulation were of value in predicting possible recovery of pituitary function after surgery. These observations suggest the presence of viable pituitary tissue in these cases and point out that, in some instances, the mechanism of hypopituitarism may be compression of the portal circulation, rather than destruction of the normal pituitary gland.

Adenoma↗
PubMed1994

Lymphocytic hypophysitis causing hypopituitarism and diabetes insipidus, and associated with autoimmune thyroiditis, in a non-pregnant woman.

A 25 year old non-pregnant woman presented with a one-year history of amenorrhoea and polyuria. Three months before her admission, she had suffered lymphocytic meningitis. Hormonal studies revealed hypopituitarism and central diabetes insipidus, with associated primary autoimmune hypothyroidism. Computed tomographic scan and magnetic resonance imaging showed a pituitary mass with suprasellar extension and thickened stalk. Transsphenoidal surgery was performed and the histological study revealed fibrosis and diffuse lymphocytic infiltration with predominance of CD4 lymphocytes. This further case of lymphocytic hypophysitis was not related to pregnancy and produced diabetes insipidus, two uncommon associations. We discuss the features that can lead to a preoperative suspicion of this rare disorder.

Adult↗
PubMed1994

Dexamethasone-suppressible feminizing adrenal adenoma.

A 39 year old man presented with gynaecomastia, loss of libido and high blood pressure. Hormone studies revealed elevated plasma levels of oestradiol and its precursors, which increased in response to adrenocorticotrophic hormone and were reduced to normal levels with dexamethasone. Computed tomography disclosed a left adrenal mass and surgery was performed. The removed tumour weighed 84 g and the histological diagnosis was of adenoma. Nine years after surgery, he is asymptomatic, without hypertension, and radiological and or hormonal evidence of recurrence. We discuss the hormone profile in this case and the dynamics of steroid production by the tumour which, in contrast to the classical concept of tumour autonomy, showed dependence of oestradiol secretion on endogenous adrenocorticotrophic hormone.

Adenoma↗
PubMed1993

Serum bone Gla protein as a marker of bone turnover in acromegaly.

Serum bone Gla protein, a sensitive and specific marker of bone turnover, was measured in 35 acromegalic patients (14 untreated, 8 clinically active, and 13 cured) and 21 controls. We also examined 10 acromegalic patients before and after transsphenoidal surgery. Untreated and clinically active acromegalic patients had significantly higher serum bone Gla protein concentrations than the control subjects. Other nonspecific biochemical markers of bone metabolism, such as urinary hydroxyproline and urinary calcium, were also present in significantly greater amounts in active acromegalic patients. After treatment, a significant decrease in levels was observed, with return to control levels. In acromegalic patients, positive correlations were found among serum bone Gla protein and serum growth hormone and serum insulin-like growth factor I levels, as well as among levels of insulin-like growth factor I and serum phosphorus, serum alkaline phosphatase, and urinary hydroxyproline. These results suggest that serum bone Gla protein is a sensitive marker of the action of growth hormone in bone metabolism in acromegaly, a role that is probably mediated by insulin-like growth factor I.

Acromegaly↗
PubMed1993

Anterior pituitary function after adrenalectomy in patients with Cushing's syndrome.

We assessed anterior pituitary function in five patients with Cushing's syndrome before and after the removal of cortisol-secreting adrenal adenomas. Before surgery, all patients lacked response of growth hormone to hypoglycaemia, four had low responses of thyrotrophin to thyrotrophin releasing hormone, three had hypogonadism and two had low prolactin reserve. After successful removal of the adrenal adenoma, all patients developed postoperative hypoadrenocorticism and recovered all impaired anterior pituitary hormones within a period of 3 months. Our results point to a direct inhibiting action of glucocorticoids at the pituitary level as the explanation for the impaired anterior pituitary function. Moreover, direct gonadal suppression by glucocorticoids may be an additional mechanism of hypogonadism in some patients.

Adrenalectomy↗
PubMed1993

[A malignant extra-adrenal pheochromocytoma. Apropos 2 cases].

We present the case of two patients with extra-adrenal pheochromocytoma (left and right para-aorta abdominal) in which the pre-surgery search with metaiodobenzylguanidine-I-123 (MIBG-I-123) showed the existence of bone metastasis in skullcap, not previously suspected. In both patients a total resection of tumor was performed together with the bone lesions. These two cases confirm the great usefulness of MIBG-I-123 in the localization of metastasis in patients with malignant pheochromocytoma. At the same time we think that the resection of whole tumoral tissue through surgery is an adequate treatment when dealing with pheochromocytoma with isolated metastasis.

3-Iodobenzylguanidine↗
PubMed1991

[Treatment of solitary toxic thyroid nodule with 131I: results in 43 patients].

BACKGROUND: Evaluation of the therapy with high-dose 131I in solitary toxic thyroid adenoma, with particular attention to the effects on thyroid function and on the nodular size. METHODS: A retrospective study of 43 patients with solitary thyroid nodule treated with radioactive iodine (mean dose 26.6 mCi, range 10-35) and followed up for 49.7 +/- 36.6 months (range 6-186) with periodical clinical, laboratory and echographic evaluations. RESULTS: Thirty-two patients (74.4%) had a normal thyroid function during follow-up. Five (11.6%) remained with hyperthyroidism and in 6 (13.9%) hypothyroidism developed 6-30 months after the administration of radioactive iodine. Three of these 6 had subclinical hypothyroidism, with mild increases in serum thyrotropin (TSH). Neither the development of hypothyroidism nor its persistence were significantly correlated with the initial thyroxin (T4) or triiodothyronine (T3) levels, the nodular size, the 131I dose, the incomplete inhibition of the extranodular thyroid parenchyma or the previous therapy with antithyroid drugs. The nodule diminished in size in 15 cases (38.4%), it disappeared in 9 (23%), it remained unchanged in 12 (30.7%) and it increased in 3 (7.7%). CONCLUSIONS: The treatment of the solitary toxic thyroid nodule with relatively high 131I doses is a safe and effective procedure, with a prevalence of residual hypothyroidism which is lower than previously reported. The disappearance of the nodule was only achieved in a minority of cases.

Adenoma↗
PubMed1991

Results of external pituitary irradiation after unsuccessful transsphenoidal surgery in Cushing's disease.

Fourteen adult patients (10 females and 4 males; age range 20-60 years) with persistent Cushing's disease after transsphenoidal microsurgery were treated with pituitary irradiation. Supervoltage multiportal administration was employed at a total dose of 50 Gy (+/- 0.65 SD). The interval between microsurgery and pituitary irradiation was less than 6 months in 6 patients and more than 6 months in 8. The pituitary-adrenal axis was evaluated postsurgically, before irradiation and every 6 months thereafter. The remaining anterior pituitary function was simultaneously tested. Remission rates at 12 months and 24 months after radiotherapy were 61 and 70%, respectively. Two patients developed TSH deficiency and another gonadotropin deficiency during the follow-up after radiation. We conclude that pituitary irradiation is the treatment of choice for persistent Cushing's disease after unsuccessful surgery because of its high efficiency and low incidence of adverse reactions when compared with other forms of treatment.

Adrenocorticotropic Hormone↗
PubMed1989

[Chronic dysplasia of the respiratory ciliary epithelium].

We report on a 14-year-old Turkish boy who suffered for more than seven years from recurrent pneumonia and bronchiectases. This led to the surgical removal of the left lower lobe. Brush biopsies taken from the bronchus and nose revealed severe dysmorphy of the ciliary epithelium with an altered cell-distribution of the normal surface pattern.

Bronchi↗