Biomedical subjects

A Colao

Publications and source records attributed to A Colao.

At least 181 records · Page 10Linked to original sources

PubMed1996

Vasopressin levels in Cushing's disease: inferior petrosal sinus assay, response to corticotrophin-releasing hormone and comparison with patients without Cushing's disease.

BACKGROUND: Higher vasopressin (AVP) levels have been found in the inferior petrosal sinus ipsilateral to the ACTH-secreting adenoma than in the contralateral one, suggesting a potential pathogenetic role of AVP in Cushing's disease. DESIGN: In order to investigate AVP release, plasma ACTH and AVP concentrations were assayed in the inferior petrosal sinuses and in the peripheral blood before and after CRH stimulation. PATIENTS: Twenty patients with Cushing's disease and 12 with other pituitary diseases were subjected to simultaneous and bilateral inferior petrosal sinus sampling for diagnostic purposes. Ten healthy sex and age-matched subjects served as control for peripheral AVP values. MEASUREMENTS: Plasma ACTH concentrations were measured by RIA using commercial kits. Plasma AVP concentrations were assayed by RIA in acetone extracts of 1-2 ml plasma. RESULTS: Plasma AVP levels in the inferior petrosal sinuses were significantly higher in Cushing's disease than in patients with other pituitary diseases (P < 0.05) and in both groups AVP levels were higher in the inferior petrosal sinuses than in the peripheral blood (P < 0.01). In Cushing's disease, ACTH, but not AVP levels, were higher in the inferior petrosal sinus ipsilateral to the adenoma than in the contralateral one (P < 0.01). Seven patients showed a significant ACTH and AVP increase (greater than 50% of baseline) after CRH stimulation in the inferior petrosal sinus ipsilateral to the adenoma. Conversely, no change was found in AVP levels in the remaining 13 patients. When AVP values were analyzed in relation to surgical cure, higher inferior petrosal sinus levels (P < 0.05) were found in 6 patients with poor outcome: 4 of these patients had significantly decreased plasma AVP concentrations (by 32-43% of baseline) after CRH bolus. Peripheral AVP levels were similar in healthy subjects and patients with Cushing's disease whereas they were significantly reduced in patients with other pituitary diseases (P < 0.002). CONCLUSIONS: The results of this study show that patients with Cushing's disease and poor surgical outcome had the highest AVP levels in our series. CRH administration caused different effects on AVP levels: it increased them in 35% of patients whereas there was no response in the remaining patients. On the basis of these findings, it is hypothesized that AVP might be involved in the persistence of ACTH hypersecretion in a subset of patients poorly responsive to surgery.

Adenoma↗

PubMed1996

Tumor necrosis factor-alpha increases after corticotropin-releasing hormone administration in Cushing's disease. In vivo and in vitro studies.

The aim of this study was to evaluate the effect of acute human corticotropin (ACTH)-releasing hormone (CRH) administration (100 micrograms, as i.v. bolus) on tumor necrosis factor-alpha (TNF alpha) levels in the inferior petrosal sinuses and in the peripheral blood of 7 patients with Cushing's disease subjected to diagnostic inferior petrosal sinus sampling. Blood samples for ACTH, beta-endorphin (beta-EPH) and TNF alpha were collected from inferior petrosal sinuses and periphery simultaneously. In addition, TNF alpha concentrations were measured after CRH administration (10 nmol/l, 100 nmol/l and 1 mumol/l) in culture medium from primary cultures obtained in 3 of 7 patients. At baseline, plasma ACTH and beta-EPH levels were significantly higher in the inferior petrosal sinus ipsilateral to the ACTH-secreting adenoma than in the contralateral one and in the periphery (p < 0.001) whereas no significant difference was found as far as serum TNF alpha levels were concerned. CRH administration caused a significant increase of ACTH (p < 0.001), beta-EPH (p < 0.01) and TNF alpha (p < 0.01) levels greater in the ipsilateral inferior petrosal sinus than in the contralateral one and in the periphery. In addition, CRH increased ACTH, beta-EPH and TNF alpha levels in the culture medium of three ACTH-secreting tumors at the doses of 100 nmol/l and 1 mumol/l (greater than 300, 200 and 110% of baseline pretreatment incubation levels, respectively). These data suggest that CRH may increase TNF alpha concentrations in the inferior petrosal sinus ipsilateral to the ACTH-secreting adenoma and in the peripheral blood as well. In addition, it stimulated TNF alpha release both in vivo and in vitro. These findings suggest the possibility that an imbalanced intrapituitary TNF alpha production can be detected in ACTH-secreting adenomas.

Adenoma↗

PubMed1996

Corticotropin-releasing hormone administration increases alpha-melanocyte-stimulating hormone levels in the inferior petrosal sinuses in a subset of patients with Cushing's disease.

The effect of corticotropin (ACTH)-releasing hormone (CRH) administration on alpha-melanocyte-stimulating hormone (alpha-MSH), ACTH and beta-endorphin (beta-EPH) was evaluated in the inferior petrosal sinuses and in the periphery of 30 patients affected with Cushing's disease subjected to simultaneous and bilateral inferior petrosal sinus sampling for diagnostic purposes. Baseline PRL levels, sensitivity to dexamethasone and surgery outcome were compared to alpha-MSH response. CRH bolus did not modify alpha-MSH concentrations either in the inferior petrosal sinuses or in the periphery in the 30 patients considered as a whole. In 7 of 30 patients, however, a greater than 50% increase over baseline alpha-MSH levels (from 50 to 115.5%) was recorded in the inferior petrosal sinus ipsilateral to the adenoma (from 42.9 +/- 1.7 to 76.4 +/- 4.6 ng/l; p < 0.001), whereas no change was found in the contralateral inferior petrosal sinus or in the periphery. Conversely, as expected, ACTH and beta-ELI significantly increased in all the patients after CRH both in the inferior petrosal sinuses and in the periphery (particularly in the inferior petrosal sinus ipsilateral to the adenoma). No difference in sensitivity to dexamethasone (urinary cortisol percent decrease: 66.4 +/- 4.9 vs. 67.8 +/- 3.4) and surgery outcome (chi 2 test: p = 0.7) was found between patients with alpha-MSH response to CRH and patients without such a response. By contrast, baseline PRL levels, although being normal in both groups, were significantly higher in patients with alpha-MSH response to CRH (18.1 +/- 1.6 vs. 10.1 +/- 0.7 micrograms/l; p < 0.001). In conclusion, the results of the present study suggest that in a subset of patients with Cushing's disease (23.3% of our series) alpha-MSH may be released after the administration of CRH together with ACTH and beta-EPH by adenomatous corticotrophs. In this subset of patients, PRL levels may be in the upper normal range.

Adolescent↗

PubMed1996

Reevaluation of growth hormone (GH) secretion in 69 adults diagnosed as GH-deficient patients during childhood.

At present, the most appropriate method for diagnosing GH deficiency (GHD) in adults remains unclear. Recently, it has been demonstrated that GHD in adults can be identified by insulin tolerance test (ITT). Moreover, it has been described that the GHRH plus pyridostigmine (GHRH+PD) test is more accurate than an arginine, glucagon, levodopa, or GHRH test to diagnose GHD in adults. In the current study, firstly we reevaluated GH secretion by the GHRH+PD test in adults previously diagnosed as GH deficient in childhood. The study included 69 patients and 38 healthy subjects. After the GHRH+PD test, the patients and the healthy subjects had peak GH levels of 10.6 +/- 11.2 and 56.7 +/- 28.1 micrograms/L, respectively (P < 0.001). The patients were divided into two groups, responder patients and nonresponder patients, considering an arbitrary cut-off of 10 micrograms/L as the GH peak after the GHRH+PD test. Thirty-nine patients had GH peak below 10 micrograms/L (1.9 +/- 1.7 micrograms/L), whereas the remaining 30 patients above 10 micrograms/L (21.6 +/- 8.] micrograms/L; P < 0.001). Secondly, we compared the GHRH+PD test and the ITT in diagnosing GHD. Twenty-one of the 39 patients with a GH peak below 10 micrograms/L and 29 of the 30 patients with a GH peak above 10 micrograms/L after the GHRH+PD test underwent an ITT. The GH peak after insulin administration was 2.1 +/- 1.7 micrograms/L in nonresponder patients and 21.1 +/- 9.3 micrograms/L in responder patients after the GHRH+PD test (P < 0.001). Three of the responder patients to the GHRH+PD test were identified as GH deficient by the ITT. The relative diagnostic accuracies of the two tests to discriminate GH-deficient patients from healthy subjects were similar (ITT vs. GHRH test: sensitivity, 100%, specificity, 90%; GHRH+PD vs. ITT; sensitivity, 88%; specificity, 100%). In conclusion, in adults previously diagnosed as GH deficient, it is mandatory to reevaluate GH secretion. GHRH+PD and/or ITT are able to diagnose GHD in adults with similar accuracies. Taking into account the potential side-effects of the ITT, however, the GHRH+PD test is the most reliable and safe test to accurately diagnose GHD status in adults.

Adult↗

PubMed1996

Prediction of efficacy of octreotide therapy in patients with acromegaly.

Octreotide (OCT) administration provides a biochemical cure in most acromegalic patients. This drug, however, causes several side effects and is very expensive. Acute testing has been reported to predict chronic responsiveness to OCT administration. The aim of this retrospective study was to evaluate which test, if any, among acute testing, short-term (1 month) administration, and 111In-pentetreotide (111In-DTPA-Phe-D-OCT) scintigraphy, is best in predicting response to long-term OCT treatment. Sixty-eight patients with active acromegaly were studied. An acute test (100 micrograms sc OCT) was performed as usual: a GH decrease greater than or equal to 50% of baseline was considered a positive response. GH and insulin-like growth factor I (IGF-I) were then assayed after 1 month (300 micrograms daily) and 3 months (150-600 micrograms daily) of OCT administration. GH was considered normalized when decreased less than or equal to 5 micrograms/L. Twenty-six of 68 patients were subjected to 111In-pentetreotide scintigraphy. Linear correlation analysis of the results was performed. Sensitivity, specificity, and positive and negative predictive values of the three tests were also calculated. Thirty-eight of 68 patients (56%) responded to the acute test. Among these 38 patients, 20 experienced normalization of GH and IGF-I levels during long-term therapy, as did 8 patients who did not respond to the acute test. No significant correlation was found between GH percent decrease during acute testing and long-term therapy (r = 0.11). Seven patients who responded to the acute test and 2 who did not respond had adenoma shrinkage during therapy. Conversely, GH and IGF-I decrease after short-term treatment significantly correlated with long-term treatment (r = 0.76 and 0.64, P < 0.01). Of the 26 patients subjected to 111In-pentetreotide scintigraphy, 13 had significant tracer uptake: normalization of GH and IGF-I was obtained in 8 patients. A significant correlation was found between tracer uptake and GH/IGF-I inhibition after 3 months of therapy (r = 0.6; P < 0.05). In the whole population, the positive predictive value of acute testing, short-term OCT administration, and 111In-penetreotide scintigraphy was 53%, 70%, and 73%, respectively, when the GH normalization (< 5 micrograms/L) after 3 months of therapy was considered. Moreover, 111-In-pentetreotide scintigraphy had the highest specificity (100% in patients with baseline GH values below 50 micrograms/L) compared with that of acute testing and short-term OCT administration. The acute test cannot be considered as a valuable index to identify patients' responsiveness to long-term OCT therapy, but it can be useful to test tolerability. By contrast, 1 month of OCT administration or the in vivo imaging of somatostatin receptors by 111-In-pentetreotide might better indicate the patients who might effectively benefit from this treatment.

Acromegaly↗

PubMed1996

Chronic treatment with CV 205-502 restores the gonadal function in hyperprolactinemic males.

The aim of this study was to evaluate the effects of a chronic treatment with the non-ergot-derived dopamine agonist quinagolide (CV 205-502) on sexual and gonadal function in hyperprolactinemic males. Thirteen males with macroprolactinoma and one with microprolactinoma were treated with CV 205-502 at the dose of 0.15-0.6 mg/day for 6-24 months. Baseline prolactin (PRL) was 464 +/- 75.7 microg/l. All the patients suffered from libido impairment, five of reduced sexual potency, six had infertility and in four bilateral induced galactorrhea was shown. The semen analysis revealed a severe oligoasthenospermia with reduced sperm count, motility and forward progression, with an abnormal morphology and decreased viability. A significant reduction of serum PRL levels (nadir PRL = 12.3 +/- 5.4 microg/l) was obtained during the treatment. Normalization of prolactinemia was reached in 13 of the 14 patients after 3 months. After 1 year, a significant improvement of sperm parameters, in terms of increase of number (from 5600 +/- 111 to 20,564 +/- 587 mm3), motility at 1 h (from 24.8 +/- 0.1 to 52.6 +/- 0.5%), forward progression (from 24 +/- 1.4 to 62.3 +/- 2.9%) and normal morphology (from 53.8 +/- 2.5 to 62.2 +/- 2.4%), was recorded. In addition, a significant increase of serum follicle-stimulating hormone (from 5.3 +/- 0.6 to 7.8 +/- 0.4 U/l), luteinizing hormone (from 4.4 +/- 0.5 to 7.7 +/- 0.4 U/l) and testosterone (from 3.4 +/- 0.4 to 4.7 +/- 0.2 microg/l) was recorded. A significant increase of luteinizing hormone (9.4 +/- 0.7 U/l) and testosterone (5.2 +/- 0.4 microg/l), as well as a further improvement of sperm parameters, was found after 2 years of therapy. Sellar computed tomography and/or magnetic resonance showed a considerable shrinkage (> or = 30%) of tumoral mass in 8 out of 13 patients with macroprolacinoma. Side effects were recorded in only one patient. In conclusion, the treatment with CV 205-502 normalizing PRL levels improves gonadal and sexual function and fertility in males with prolactinoma, providing good tolerability and excellent patient compliance to medical treatment. This result demonstrates that the impairment of gonadal function in hyperprolactinemic patients is a functional modification.

Aminoquinolines↗

PubMed1996

Lung volumes and respiratory muscle strength in adult patients with childhood- or adult-onset growth hormone deficiency: effect of 12 months' growth hormone replacement therapy.

We have described impairment of the respiratory function in adult patients with childhood-onset growth hormone (GH) deficiency. The aim of the present study was to evaluate lung volumes and respiratory muscle strength in patients diagnosed as GH deficient before and after 6 and 12 months of recombinant GH treatment. Ten adults diagnosed as GH deficient in childhood, ten adults diagnosed as GH deficient in adulthood and ten healthy subjects entered the study. For each subject, evaluation of respiratory function followed the same standard approach, consisting of respiratory muscle strength assessment, record of flow-volume curves, measurement of static lung volumes and lung diffusing capacity. Childhood-onset GH-deficient patients had a significant reduction of maximal inspiratory (p < 0.01) and maximal expiratory (p < 0.05) mouth pressures. Total lung capacity, vital capacity and functional residual capacity were significantly reduced compared to healthy subjects (p < 0.05). Conversely, residual volume and diffusing lung capacity did not show any significant change. No significant change of the ratio between the percentage forced expiratory volume in 1 s and the forced vital capacity was observed. The decrease of respiratory mouth pressures was not correlated to the decrease of lung volumes. Adult-onset GH-deficient patients had only a significant reduction of maximal expiratory pressure compared to healthy subjects (p < 0.05). After 6 months of treatment no significant differences in any of the evaluated parameters were found. After 12 months of treatment patients with childhood-onset GH deficiency show a significant improvement of lung volumes (p < 0.01) and maximal respiratory mouth pressures (p < 0.005), whereas adult-onset GH-deficient patients show a significant improvement of maximal expiratory pressure (p < 0.05). In conclusion, the results of this study showed that adult patients affected with childhood-onset GH deficiency suffer from an impairment of the ventilatory function due to a reduction of lung volumes and a decrease of respiratory pressures probably due to a reduction of respiratory muscle strength. This impairment was reversed after 12 months of treatment with recombinant GH. Conversely, adult-onset GH-deficient patients had only an impairment of the maximal expiratory pressure, probably due to respiratory muscle weakness re-established after 12 months of GH therapy.

Adult↗

PubMed1996

[Usefulness of color echo Doppler with power Doppler in the diagnosis of hypoechoic thyroid nodules: work in progress].

The aim of this study was twofold: first, to improve the predictive value of ultrasonography (US) in differentiating benign from malignant thyroid nodules and, second, to investigate whether color Doppler and power Doppler can distinguish different morpho-hemodynamic patterns of hypoechoic thyroid nodules according to their vascularity. Twenty-nine patients with hypoechoic thyroid nodule(s) were entered into this work in progress. Three typical power Doppler patterns were recorded and compared with color Doppler patterns and with cytologic and/or histologic findings. Power Doppler patterns were classified as follows: type A, a perilesional vascular halo; type B, a peri- and intralesional vascular halo, subdivided into: 1) with moderate intralesional vascularization, homogeneous structure and regular vessel caliber and 2) with rich intralesional vascularization, anarchical structure and winding vessel caliber and flow; type C, a perilesional vascular halo with a characteristic peripheral large afferent vessel characterized by winding caliber and flow. Of 29 patients, 21 had type A power Doppler (benign nodular goiter at cytology, in 4 of them with regressive phenomena); seven patients had type B power Doppler patterns-4 had a subtype 1 pattern (3 with nodular hyperplasias and 1 with a papillary adenoma), 3 had a subtype 2 (two had a follicular adenoma and one had a final diagnosis of angioinvasive follicular carcinoma). The patient with undifferentiated carcinoma had a type C power Doppler pattern. In conclusion, according to our early results, PD seems to be more sensitive and reliable than CD in the screening of thyroid nodules, and to yield better vascular information.

Adult↗

PubMed1995

Growth rate and growth hormone response to growth hormone-releasing hormone challenge in slowly growing children during chronic administration of clonidine.

In this study the effects of chronic administration of clonidine, an alpha-2-adrenergic agonist, on the growth rate and GH response to GHRH in 12 "slowly growing" children were reported. Clonidine was administered at the dose of 0.04 mg/m2 body surface twice daily along 12 months. The protocol of the study consisted in five periods of growth rate, insulin-like growth factor-1, basal and GHRH-stimulated GH level evaluation: 1) 6-month pretreatment (P1); 2) 6-month placebo administration (PO); 3) after 4 months of therapy (P1); 4) after 4 months of clonidine withdrawal (P2); 5) after 4 months of therapy reinstatement (P3). No difference was observed between P-1 and P0 when all the parameters were considered. During P1 a significant increase of linear growth (p < 0.05 vs P0 and P-1) was observed while standard deviation of height was not modified. At the end of P2, the growth rate and standard deviation of height were similar to those recorded in P0 and P-1. After reinstatement of clonidine therapy a new but less pronounced rise of the growth rate was found (p < 0.05 vs P1, p < 0.01 vs P0 and P-1). GH, insulin-like growth factor-1, GHRH-stimulated GH levels had significantly increased during P1 than P0 and P-1 (p < 0.05), while during P2 they were similar to P0 and P-1. During P3 a new increase of insulin-like growth factor-I baseline and GHRH-stimulated GH levels were observed. However, these were significantly lower than those observed during P1.(ABSTRACT TRUNCATED AT 250 WORDS)

Age Determination by Skeleton↗

PubMed1995

Comparison among different dopamine-agonists of new formulation in the clinical management of macroprolactinomas.

BACKGROUND: In the last decade, the treatment of macroprolactinomas has been significantly improved by the introduction in the clinical practice of new drugs with dopamine-agonist properties. In particular, the availability of different forms of bromocriptine (BRC) with long duration of action and slow absorption, suitable for injectable (BRC-LAR) or oral (BRC-SRO) administration, has allowed one to obtain a more constant bromocriptinemia than with standard BRC, thus reducing adverse reactions. Moreover, a selective action on dopamine D2 receptors has been achieved using a new non-ergot derivative: the quinagolide (CV 205-502). The aim of this study was to evaluate the effects of BRC-LAR, BRC-SRO and CV 205-502 in 34 patients with macroprolactinoma. PROTOCOL OF THE STUDY: BRC-LAR was given at the monthly dose of 50-100 mg for 6-24 months to 8 patients whose PRL levels were 150-700 micrograms/l. BRC-SRO was given at the daily dose of 5-20 mg for 1-24 months to 10 patients whose PRL levels were 120-900 micrograms/l. CV 205-502 was given at the daily dose of 0.075-0.6 mg for 6-12 months to 16 patients whose PRL levels were 250-2,050 micrograms/l. CT and/or MRI scans were performed before and during treatment to evaluate tumor shrinkage. Data are presented as Mean +/- SD. RESULTS: Serum PRL levels normalized in 8/8 with BRC-LAR, 7/10 with BRC-SRO and 12/16 patients with CV 205-502. A significant shrinkage of tumor mass was obtained in 7/8 with BRC-LAR, 9/10 with BRC-SRO and 16/16 patients with CV 205-502, with consequent improvement of visual-field defects. Overall, the drugs were rather well tolerated: no patient stopped BRC-LAR or BRC-SRO and only 2 stopped CV 205-502. In particular, nausea, vomiting, headache, hypotension that disappeared spontaneously were observed in 5/8 with BRC-LAR, 4/10 with BRC-SRO and 4/16 with CV 205-502. CONCLUSIONS: The medical approach with long-acting BRC preparations and CV 205-502 which selectively binds D2 receptors allows one to obtain rapid normalization of PRL levels and shrinkage of macroprolactinomas in a large series of patients. These drugs are rather well tolerated also by patients proven to be untolerant to standard BRC.

Administration, Oral↗

PubMed1995

Acute and chronic effects of human recombinant GH (hrGH) on adrenal steroidogenesis in children affected with isolated GH deficiency (IGHD).

In a previous study we demonstrated that, in children affected with isolated GH deficiency, an acute high-dose human recombinant GH (hrGH) treatment increases the 11-deoxycortisol and induces an IGF-I responsiveness to ACTH. The aim of the present study was to reevaluate, in the same children, the adrenal and IGF-I responsiveness to ACTH after a chronic replacement-dose GH therapy. Ten children (seven males and three females, mean age 7 years) affected with isolated GH deficiency underwent a synthetic ACTH 1-17 test before and after sc administration of human recombinant GH at a dose of 0.6 UI/kg/week for 3 months. After therapy, the 11-deoxycortisol responsiveness to ACTH significantly decreased compared with that observed after acute treatment (P < 0.001), and so it returned to baseline. No differences were detected in the responsiveness to ACTH of cortisol, dehydroepiandrosterone-sulphate, D4-androstenedione, and 17-hydroxyprogesterone. On the other hand, the chronic treatment induced an IGF-I responsiveness to ACTH (P < 0.001). In conclusion, our study demonstrates that, in isolated GH deficiency, replacement doses of hrGH do not modify the adrenal steroid basal levels or its responsiveness to ACTH, whereas both replacement and high doses of hrGH induce an IGF-I responsiveness to ACTH.

17-Ketosteroids↗

PubMed1995

The effect of hexarelin on growth hormone (GH) secretion in patients with GH deficiency.

Hexarelin (Hex) is a new synthetic hexapeptide with potent GH-releasing activity in both animals and men. We evaluated the GH response to maximal doses of Hex (2 micrograms/kg, iv) and GHRH-(1-29) (1 microgram/kg, iv) in 15 children (11 boys and 4 girls, aged 6.0-17.3 yr) and 4 adults (3 men and 1 woman, aged 20.2-30 yr) with GH deficiency (GHD). GHD was idiopathic in 8 patients and associated with pituitary stalk interruption syndrome in 8, with a pituitary cyst in 2, and with empty sella syndrome in 1. In 11 patients, GHD was isolated, whereas in 8, it was associated with other pituitary hormone deficiencies. Forty-five short normal children (24 boys and 21 girls, aged 5.9-14 yr) served as controls. In patients with idiopathic GHD, the GH response to Hex was similar to that observed in short normal children, and it was significantly higher than the response to GHRH. In the patients with GHD associated with anatomical abnormalities, the GH responses to GHRH varied from normal to absent. Among these subjects, only 1 patient with a pituitary cyst had a sizable GH response to Hex, whereas in all others, the GH response to Hex was absent or blunted compared with those in the short normal children and the patients with idiopathic GHD. In all patients except those with associated ACTH deficiency, Hex administration caused a slight, but significant, increase in cortisol concentrations. This study shows that Hex stimulates GH secretion in patients with idiopathic GHD. The inability of Hex to stimulate GH secretion in patients with hypothalamic-pituitary disconnection strongly supports the concept that in humans, the GH-releasing effect of GH-releasing peptides is mediated by the hypothalamus.

Adolescent↗

PubMed1995

CV 205-502 treatment in therapy-resistant acromegalic patients.

The growth hormone (GH) inhibitory effect of CV 205-502 was evaluated during acute and 3-month administration, alone or in combination with octreotide, in 12 therapy-resistant acromegalic patients. Although these patients previously had undergone surgery and received chronic therapy with octreotide at 0.3-0.6 mg/day, they still had high GH and insulin-like growth factor I (IGF-I) levels. CV 205-502 (0.15 mg), octreotide (0.1 mg) and placebo were tested acutely. CV 205-502 at the dose of 0.15 mg caused a decrease of GH level (from 34.9 +/- 15.1 to 2.7 +/- 0.3 micrograms/l) in 4/12 (33.3%) and completely inhibited prolactin (PRL) secretion in all the patients. Octreotide caused a decrease of GH level (from 37 +/- 6.7 to 15.9 +/- 3.0 micrograms/l) without any change of PRL level. The GH and PRL levels were not changed during placebo administration. CV 205-502 at the dose of 0.3 mg/day (chronic test) normalized GH and IGF-I levels in five patients (41.6%: the four responders to the acute test and an additional patient who was a poor responder to acute CV 205-502 administration). The remaining seven patients were subjected to CV 205-502 (0.6 mg/day) and octreotide (0.6 mg/day) in combination for 3 months. In 2/7 patients the combined therapy induced a greater inhibition of GH and IGF-I levels than did each drug when administered alone. The drug was well-tolerated by the 12 patients. In conclusion, CV 205-502 is able to normalize GH and IGF-I levels and to improve clinical symptoms in certain acromegalic patients resistant to other therapeutic approaches.(ABSTRACT TRUNCATED AT 250 WORDS)

Acromegaly↗

PubMed1995

Technetium-99m pentavalent dimercaptosuccinic acid imaging in patients with pituitary adenomas.

We studied the tumor-seeking agent technetium-99m-labeled pentavalent dimercaptosuccinic acid ([99mTc](V)DMSA) to visualize 21 growth hormone (GH)-, nine prolactin (PRL)-, two mixed GH/PRL-, six adrenocorticotrophin (ACTH)-secreting and 15 clinically non-functioning pituitary adenomas, three craniopharyngiomas and one dysgerminoma of the sella. All non-adenomas and 31 out of 53 adenomas were studied before treatment: 22 after surgery and/or radiotherapy. Eight cases of acromegaly were studied before and after chronic treatment with octreotide, whereas three cases of acromegaly, one of prolactinoma and two of non-functioning adenoma were imaged before and after adenomectomy. As a control group, 27 patients without any clinical evidence of pituitary adenoma were studied: 10 of them were operated on previously and treated with iodine-131 for metastatic thyroid carcinoma, 10 had brain tumors and the remaining seven patients had functional pituitary hypersecretion (four Klinefelter's syndrome, two primary hypothyroidism and one Addison's disease). The scintigraphy was repeated after testosterone in Klinefelter's syndrome, L-thyroxine in primary hypothyroidism and cortisone administration in Addison's disease. Seventeen GH-secreting (81%), seven PRL-secreting (78%), three ACTH-secreting (50%), 15 non-functioning (100%) and one (50%) mixed adenoma significantly concentrated [99mTc](V)DMSA, showing elevated tumor-to-background (T/B) ratios. The T/B ratios were similar in untreated and surgically treated adenomas (11.2 +/- 5.6 vs 11.8 +/- 6.2). Radiotherapy significantly lowered the [99mTc](V)DMSA uptake to 5.1 +/- 2.8 (p < 0.1 vs untreated patients). Non-adenomatous lesions of the sella turcica did not concentrate [99mTc](V)DMSA in the pituitary as well as brain tumors and 8 out of 10 metastatic thyroid cancers. The treatment with octreotide normalized GH and insulin-like growth factor I levels and reduced [99mTc](V)DMSA from 15.7 +/- 4.8 to 13.5 +/- 3.9 (p < 0.05). Conversely, adequate substitutive therapy completely inhibited the uptake of the radiotracer in Klinefelter's syndrome, in primary hypothyroidism and in Addison's disease. The [99mTc](V)DMSA scintigraphy showed an overall sensitivity of 81% (43/53) in detecting pituitary adenomas, which was increased to 95% for lesions greater than 10 mm in size. High-quality images with minimal total body radiation were obtained, enabling a good in vivo characterization of viable adenomatous tissue as well as an accurate monitoring of the effects of different therapeutic regimens.

Addison Disease↗

PubMed1995

Acute and chronic effects of octreotide on thyroid axis in growth hormone-secreting and clinically non-functioning pituitary adenomas.

The effect of somatostatin on thyroid function was studied in 12 patients with growth hormone (GH)-secreting and eight patients with clinically non-functioning adenomas (NFA) and normal pituitary/ thyroid axis; the patients were subjected to the administration of octreotide (OCT), which is a long-acting somatostatin analog. All the patients received an acute test with 100 micrograms of OCT, both short term (1 month) and long term (6 months), with doses ranging from 300 to 600 micrograms/day. Serum thyroxine (T4), triiodothyronine (T3), free T4, free T3, thyroglobulin and basal and thyrotropin (TSH)-releasing hormone (TRH)-stimulated TSH were evaluated before and after 1 and 6 months of therapy. Circulating GH and insulin-like growth-factor I (IGF-I) in acromegalics and GH, IGF-I and alpha-subunit in NFA were assessed at baseline and every month. The acute administration of 100 micrograms of OCT significantly reduced the TSH response to TRH (p < 0.01) in both acromegalics and NFA. In all the patients OCT administration caused a significant decrease of GH, IGF-I and alpha-subunit levels (p < 0.01). In addition, after 1 month of therapy both baseline and TRH-induced TSH secretion were decreased significantly in acromegalics and NFA. After 6 months of therapy, baseline and TRH-induced TSH was still reduced in NFA. Conversely, in acromegalics, baseline TSH levels were increased while TSH response to TRH was inhibited. No change of T4, T3, free T4 and free T3 was observed in NFA, whereas a slight but significant increase of T4 and decrease of T3 was recorded in acromegalics.(ABSTRACT TRUNCATED AT 250 WORDS)

Adenoma↗

PubMed1995

Impairment of lung volumes and respiratory muscle strength in adult patients with growth hormone deficiency.

Little is known of the respiratory function in patients with growth hormone (GH) deficiency. The aim of the present study was to evaluate lung volumes and respiratory muscle strength in patients diagnosed as GH deficient in childhood. Ten patients diagnosed as GH deficient in childhood and ten healthy subjects entered the study. For each subject the evaluation of respiratory function followed the same standard approach, consisting of respiratory muscle strength assessment, recording of flow-volume curves, measurement of static lung volumes and lung diffusing capacity. Both maximal inspiratory and expiratory mouth pressures were decreased in GH deficiency. Vital capacity, N2 functional residual capacity and total lung capacity were significantly reduced when compared to healthy subjects. Conversely, the residual volume and diffusing lung capacity to CO did not show any significant change. No significant change of percentage forced expiratory volume in 1 s/forced vital capacity ratio was observed. The decrease of respiratory mouth pressures was not correlated to the decrease of lung volumes. In conclusion, the results of this study show that adult patients affected with childhood onset GH deficiency suffer from impairment of ventilatory function and a decrease of respiratory muscle pressures, probably due to reduction of respiratory muscle strength.

Adult↗

PubMed1995

Impaired luteinizing hormone responsiveness to gonadotropin-releasing hormone in the inferior petrosal sinuses of hyperprolactinemic patients.

The aim of this study was to evaluate serum baseline and gonadotropin-releasing hormone (GnRH)-stimulated follicle-stimulating hormone (FSH) and luteinizing hormone (LH) concentrations in the inferior petrosal sinuses and in peripheral blood in nine normoprolactinemic and eight hyperprolactinemic patients who were being subjected to perihypophyseal phlebography for diagnostic purposes or neurosurgical indications. Serum FSH and LH concentrations were significantly higher in both inferior petrosal sinuses than in peripheral blood (p < 0.001 and p < 0.05, respectively) in normoprolactinemic but not in hyperprolactinemic patients. Additionally, in normoprolactinemic patients, the LH response to intravenous bolus GnRH in the inferior petrosal sinuses (evaluated as peak/basal) was significantly greater than in hyperprolactinemic patients (p < 0.01). No difference was found as far as FSH response to GnRH was concerned. In conclusion, these findings suggest that the hypogonadism of hyperprolactinemic patients may depend on the impaired release of LH at the pituitary level.

Adult↗

PubMed1995

Technetium-99m-tetrofosmin imaging of differentiated mixed thyroid cancer.

This report describes the accurate localization of metastatic lesions in a patient with differentiated mixed thyroid cancer using 99mTc-tetrofosmin imaging. A 66-yr-old women with a cytological diagnosis of follicular thyroid cancer associated with a large amount of goiter changes was studied by 99mTc-tetrofosmin total-body scintigraphy. No significant tetrofosmin uptake was observed in the thyroid nodules, which mainly showed goiter abnormalities. Abnormal increased tetrofosmin uptake, however, was found in metastatic tumor lesions located in the cervical and dorsal spine as well as in the left lower chest wall and lungs. In conclusion, 99mTc-tetrofosmin, a new radiopharmaceutical proposed for myocardial perfusion imaging, may be useful in patients with thyroid cancer.

Aged↗